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Why do excited electrons fall to intermediate orbitals before falling to ground state? | When an electron in an atom is excited it jumps up in energy levels, and then falls back down to a lower energy level and emits a photon. For the Balmer series, the visible emission spectrum of hydrogen, the wavelengths of light are produced by electrons falling to the second energy level. What causes it to stop there, if its just going to then fall to ground state immediately anyway | Selection rules. Certain decays are suppressed relative to others because they involve drastic changes in the angular momentum of the atom.
Rather than undergoing a single decay from a highly excited state to the ground state, where the two states have little matrix element between each other, the atom will undergo a cascade of decays between “more similar” states in order to eventually reach the ground state. | 15 | 21 |
ELI5: when a huge skyscraper is built, how do they get the cranes and construction equipment down from the top when complete? | Each situation is different... but it's usually some version or combination of one of these basic methods:
1) The "big" crane is dismantled and brought to the ground by a smaller crane. Compared to the building parts they lift... cranes are relatively lightweight in small pieces... so they can be carried by smaller/mobile cranes.
2) Same concept but the big crane is disassembled and lowered using its own structure or the building as a support system.
3) (less common) The bulk of the crane support is designed into the guts of the building and is essentially abandoned... or there actually is no "tower" and the crane is simply lifted as the building goes up so there is very little to take down at the end of the job. | 60 | 96 |
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Is There a Limit To How Hot Something Can Get? | I know that there is and absolute zero, but is there an absolute hot? A point where something is so hot that it can't get any hotter? Also what is the hottest thing in the universe? | It depends on whether you are speaking of a small finite system or not. For a small finite system (like a handful of atoms), you can end up with negative temperatures which are hotter than any positive temperature, and so there is an 'absolute hot' which happens to be 0 (or arbitrarily close to it at least, just like absolute zero). This is because temperature is defined as the inverse ratio of the change in entropy of a system over the change in energy. If you end up in a situation where adding energy lowers entropy, as can happen in finite systems, then the system will have negative temperature and then be hotter than any positive temperature, in the sense that heat will naturally flow from the system to any other system with positive temperature.
Outside of 'small' finite systems, the question is a little more difficult to answer. There is a very high (positive) temperature called the Planck temperature, after which energies are so high that we need a theory of quantum gravity just to say what is happening. This isn't an 'absolute hot' though, it is just saying that we don't know what happens when you raise the temperature beyond it. It could be possible that you can still achieve negative temperatures in a large finite system, but we don't really know what that would mean anymore. | 20 | 21 |
ELI5:How do we calculate the world's population from 100s of years ago? | Countries have had Census programs since the Egyptian empire. Taking the averages of those, and applying it to other areas with assumed similar population density, allows for a fairly accurate prediction. | 12 | 15 |
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How SHOULD we determine a worker's worth? |
A lot of talk has been done about how much people should be paid. Specifically, I've seen TONS of news about Walmart and their pay, and I see lots of arguments from both sides. Some assert that Walmart should pay more to provide a wage that the employees are more likely to be able to live off of, while others point out that walmart is a still a private company and they should have the right to run their business as they see fit. One talking point that all of this swirls around is the question "How much is a walmart employee worth?"
That's when I started researching, and realized that we dont really HAVE a concrete number that can be stapled to a walmart cashier. I am not aware, really, of any method to determine how much added profit Cashier A of a random Walmart location X brings to the corporation of Walmart. When they hired Cashier A to their company, they end up making $Z more than they would be making if they didnt hire him. So for the transaction to not be one-sided in some way, and for neither side to be getting screwed over in some way, he should be compensated $Z for his labor, right? Is that even true, or are there other factors worth considering? What do we have to determine that number? How close can we get?
I feel like we can spend a lifetime drawing lines in the sand over what minimum wage would be hypothetically "best" for society, but I think we're entirely missing the point of the discussion, if it isn't focused on prioritizing an equal transaction of labor/compensation between employer and employee, and it's instead just focused on the emotional side of why a wage should increase
Tl;dr In need of a concrete/scientific way to determine a laborer's worth (any econ nerds have any models/equations/figures/info at all would be greatly appreciated)
Forgive me if this edges into the political, I know wage talks can devolve into bickering quickly. I also posted this in r/economics but got redirected here. (I already read this sub's faq on min wage) | There isn't a way, there are far too many variables that are too difficult to collect to judge such a thing externally, and what's more, value is almost entirely subjective That's the whole reason why market prices are so foundational, because they simplify and volunteer the information required to make such decisions. There really isn't a way to see how much a laborer is "actually" worth other than to see how much firms are willing to pay them.
A more politically charged answer to the question of "how SHOULD" would be by bidding. If more firms are looking to employ the same workers, or the government "competes" by offering generous welfare, then you will ultimately find the maximum amount that a firm is willing to pay for a worker.
If you're looking to justify minimum wages, the best you're going to be able to do is tracking down some of the empirical studies showing that a minimum wage of X% of the applicable median wage has beneficial/not harmful to the economy (this number is usually 35-50%). | 31 | 41 |
ELI5: How does high blood pressure work in the body and why is it genetic? | It helps to imagine the body's blood vessels like plumbing, water being pumped will exert a force on the pipes itself. In the body the heart has a few ways to increase this force, namely: increasing the rate the heart is pumping, or increasing the volume of blood. The body's blood vessels itself can also change its size (vasoconstriction or dilation) to further modulate blood pressure, with vasoconstriction being used to increase BP | 10 | 78 |
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If I move both my index fingers at once, am I sending one signal to both hands, or am I sending 2 individual signals? Is there a signal queue? | Lots of signals!
How are you moving your index finger? Just a quick movement and then stop? Sustained goal-tracking? Sustained proximal extension?
There is a swirl of signals operating between prefrontal cortex (probably both sides), supplementary motor cortex (probably both sides) and primary motor cortex (primarily contralateral to the moved finger); as well as between cortex, brainstem, cerebellum, thalamus, and back to cortex; and between cortex, basal ganglia, thalamus, and cortex. These are all for smoothing movements, planning movements, etc.
The final pathway is a series of pulses down the corticospinal tracts to alpha motoneurons in your spine, which send pulses directly to muscle fibers in your forearm and hand. Depending on how much effort you need, there may be more or fewer groups of muscle fibers contracting, and at different rates. The rates are governed by the spiking rate in the alpha motoneurons and the groups are governed by the activation pattern in the cortex and the spine.
With sustained effort, there will be a feedback loop set up with additional spike trains sent by intrafusal muscle cells and bag fibers both to the motoneurons and up the dorsal columns to the thalamus and the cortex to help regulate the muscle firing rate. If you're looking at your finger, that information can also be used as feedback. So now there's visual processing and flows from association visual cortex to prefrontal cortex.
There's no queue. Neurons send spikes, or *action potentials*, at varying rates. They code for responses by the rate of spiking or sometimes by the timing of spikes. Spikes propagate from neuron to neuron by the release of neurotransmitters across small fluid gaps (the synapses). Of course spike trains can also lead to inhibition, setting a gate to interrupt spike propagation from other cells (analogous to a transistor); or they can cause changes in gene expression altering the properties of the target neuron (analogous to resetting circuit props in an FPGA).
So if you're extending both index fingers, you have bilateral corticospinal tract signalling, bilateral dorsal column signalling, and bilateral intraspinal, cerebellar, basal ganglionic, thalamic, visual, and prefrontal signalling. | 21 | 26 |
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So How Do you Build a Desktop Application? | I see so many tutorials and guides for making websites that it's easy to see the process, but I'm at a loss for how to make desktop applications. What languages can be used? Are there frameworks for desktop apps? Are there guides online? Do you just use the same stuff for web app design now? I have no idea .... | For c# you can use old Windows Forms, or newer technology WPF.
Framework provides you with main form to which you can add controls (there are some predefined controls but for more complex requirements you can create your own).
It is actually very easy to start, you can create empty desktop app from project template, without writing single line of code. | 19 | 27 |
CMV: Social Conservatism is just a manifestation of the "End of History Illusion" | Qualifier 1: I am talking about social conservatism specifically, rather than conservatism as a whole, including economic policy. i.e. just the ethics and morality.
Qualifier 2: Although ["End of History Illusion"](https://en.wikipedia.org/wiki/End-of-history_illusion) is typically used for individuals, it can be used as a sociological perspective too (see: [Fukuyama](https://www.google.com/search?q=fukuyama+end+of+history&ie=utf-8&oe=utf-8&client=firefox-b-ab)). This is true because, just as people believe they are a finished article, the same idea can equate towards society.
As conservatism is about maintaining traditional values, it implies that all history has led to the values we hold today/recently and should be maintained as such. It is a mindset which assumes there is no more progress to be made, and that any change is movement backwards.
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> *This is a footnote from the CMV moderators. We'd like to remind you of a couple of things. Firstly, please* ***[read through our rules](http://www.reddit.com/r/changemyview/wiki/rules)***. *If you see a comment that has broken one, it is more effective to report it than downvote it. Speaking of which,* ***[downvotes don't change views](http://www.reddit.com/r/changemyview/wiki/guidelines#wiki_upvoting.2Fdownvoting)****! Any questions or concerns? Feel free to* ***[message us](http://www.reddit.com/message/compose?to=/r/changemyview)***. *Happy CMVing!* | First, what about an issue like abortion? While it does touch on "traditional values," to a degree, it's not really framed like resistance against undesired change (a la gay marriage.
Second, a lot of things are about not stopping or slowing change, but actually going back. That sounds like the end of history you are referring to actually occurred a while ago, in the conservatives' view. In that case, is it still the best description?
Third, much of the "tradition" and "past" conservatives evoke is fictional or grossly misrepresented. So, the illusion is not "culture has culminated in the present moment," but "culture culminated in an imaginary world decades ago, and has been in decline since" | 10 | 27 |
CMV: Internal monologue should be more normalized in films and television. | You ever see a scene in a film or a show that just makes you go, "uhhhhhhh, what were you thinking?"
I find that there are many scenes in film and television that are a little too open to interpretation. Often it would be helpful for the audience to know exactly what a character is thinking, and it's a massive insight that books and comics can give that film tends to avoid at any cost. For example, in the Amazon show The Boys (FIRST SEASON SPOILERS AHEAD), the main character Hughie >!kills Translucent with an explosive planted inside his body.!< Before the act itself, and earlier within that episode, Hughie is seen looking at a poster contemplatively. The scene implies that staring at the poster made Hughie reflective, but there's never a good explanation as to what exactly that poster did to change his mind. [The scene in question.](https://youtu.be/_W7hIHnYbc8) What was it about that spaghetti-covered baby that changed Hughie's mind? Was it the phrase, "Keep your hands clean"? Is it a rebellious streak? Did he actually just do it on a whim? We don't know, but I feel like that's a great opportunity to learn.
This is simply one example (I haven't finished the season, so if there's further explanation in the show, don't discount my point just on that). An example of what I'm talking about would be from David Lynch's Dune: [Gom Jobbar Scene](https://youtu.be/A54yfyi00dI). Throughout that film, several characters have an internal monologue, such as Paul's mother noticing someone else has something on their mind and is holding back information. As problematic as that film can be, I think that's the best feature. Knowing what someone feels is a huge reason why folks who see film adaptions often feel the book was better.
Also, I want to leave the caveat that this does not really include narration. Narration is a 4th-Wall break, as a character is speaking directly to the audience, and is often done in the past tense. This isn't to say narration is bad (I actually quite like narrators), but that it is functionally different from a character's internal thoughts. | “Show, don’t tell” is a common technique in storytelling for good reason. It makes scenes more vivid, dramatic, and full of action.
I would put it to you that if a character’s motivation is not clear, it is because the creators or the performers did a bad job at showing why they did that thing, not a reason to have an inner monologue tell the audience what they’re thinking. If you came away from watching The Boys and it was not clear why Hughie did that, it suggests to me that the writing or acting was at fault, not that they should have included a voiceover of Hughie mulling over the decision.
In other words, the actions taken by the character should demonstrate who they are, they should not be explaining that to the audience. | 49 | 56 |
[TNG] What if the Borg cube of Wolf 359 that went on to be destroyed in earth orbit... wasn't? | Following the battle of Wolf 359, the cube resumed course towards Earth, completely undamaged. The Enterprise, having finally completed repairs, raced to catch up to the Borg. In preparation for a Borg invasion of Earth, a state of emergency was declared on the planet. Brushing aside the last line of defense by easily destroying a flotilla of Mars Defense Perimeter sentry pods, the Borg cube took up position in Earth orbit. However, using the recaptured Locutus and his link to the collective mind of the Borg, Data manages to invoke a man-in-the-middle attack on the secure link between the local Collective aboard the Cube, and Locutus, injecting a global sleep command to all drones. The entire crew of the Cub simultaneously begins their regeneration cycles, entering a state of dormancy and leaving the cube entirely undefended.
Automated counter measures detect the anomaly and are unsuccessful in reversing the hack, and thus execute a self-destruct sequence to avoid contamination further up the network topology, in addition to preventing Borg technology -- ironically -- assimilated.
*However, Data detects this malware defense response, and is successful in disabling it, while spoofing a command acknowledgement along the Locutus link up the network. The subspace link is then disabled -- if necessary, on the hardware level -- and the Collective loses contact with the Cube, seemingly due to successful execution of self destruct command.*
*The Cube remains in orbit around Earth, disconnected from the Collective, and all drones offline, and completely at the mercy of Starfleet scientists.*
**How do events from this point unfold differently along the future timeline, including the Dominion war and the Voyager incident?** | Federation science is advanced by decades. By the time of the Dominion War, our weapons and regenerative tech make it a brief conflict. The DMZ probably never is established, because the Cardassian War goes much better, so no Maquis and no loss of Voyager in the Badlands.
The Federation learns how to hijack the Borg transwarp network, and eventually takes a more proactive stance against future Borg incursions, dismantling or locking out the Borg, hedging them out of near space one conduit at a time.
It still learns about Species 8472, the Voth, and the Hirogen. If we are lucky we just stay out of fluidic space. If not they may become a dire enemy defending against 'invasion' if first contact does not go well.
The Hirogen are naturally predatory and will see Federation explorers as new and interesting prey. They might be able to be bought off with holodeck tech from the start, if it's a Galaxy or Sovereign class crew instead of an Intrepid. Voyager's poor showing was due to simple inadequate defenses.
The Federation is not ready for the Voth and vice versa. It will probably devolve into a holy war against the human race.
The worst threat, however, are probably the time-meddling Krenim. Without Voyager's interference who knows how far they would have screwed up Delta-Quadrant chronology before their timeship was destroyed.
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Are modern medicines designed or discovered? What are the processes involved? | Modern medicines are extraordinarily diverse. These include, but are not limited to:
1. Analogues of existing medicines - Synthetic chemists are able to take existing compounds and modify them chemically to give them new potency, better half-life, less toxicity, or simply to extend patent law.
2. Rationally guided discovery - Gleevec (imatinib) is the most famous example of this. They used what they knew about the structure of BCR-ABL fusion kinase, and then rationally designed a scaffold and side chain modifications to selectively inhibit the protein. However, it still has off-target effects on other kinases.
3. Biological medicines - Antibody based therapy is becoming very popular. Scientists will raise inhibitory antibodies to protein targets, small molecules, etc, in mice, humanize them, and then use them directly as a source of treatment. Infliximab is an example that targets TNF to treat auto-immune diseases.
4. Natural sources - New classes of antibiotics are still being discovered in bacteria/fungi, although the rate of discovery is very slow nowadays.
5. Random screen, pray for luck - This is what a lot of people in academia and industry are doing right now. Chemists have created extensive chemical compound libraries. For example, a quinone group with every modification possible off of the carbon backbone. People will just screen these libraries (thousands and thousands of compounds) in an assay and look for the desired phenotype. Once they have a "hit" they will optimize it to improve solubility, toxicity, efficacy, etc. | 40 | 45 |
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ELI5: f-Stop and Aperture | Aperture is one of the things that determines how much light reaches the sensor on your camera.
Think of it as a hole in a box. Inside the box is a kid drawing with crayons. (Don't worry, he's being fed.) The bigger the hole (the larger the aperture), the more light that gets in, the more the kid can see his paper to draw what he sees through the hole. The size of the aperture is measured in f-stops. The smaller the f-stop, the larger the aperture, or the larger the hole in the box, or the more light that gets in.
Shutter speed is also important: how long does that hole in the box stay open to let the light in? The longer the shutter speed, the longer the hole stays open, the more light that gets in. That's one reason why some pictures are blurry: the subject moves while the hole in the box is still open.
Sports photographers use very quick shutter speeds (which requires smaller f-stops to let more light in) so they can capture motion without blur. If the aperture was not large enough, and the shutter speed too fast, the photo would be too dark because the settings did not let enough light in to accurately capture the image to the sensor. | 32 | 98 |
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ELI5: What were to happen if the Panama Canal's locks were all open at the same time? | The locks are in place because the canal climbs up a hill to Gatun Lake, and then back down the other side (this was done to minimize the amount of excavation work that needed to be done). If all the locks were open, the lake would drain into the ocean a bit more quickly is all. | 10 | 20 |
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Public Lectures: What are some basic dos and don'ts? | I'm giving my first public talk in a couple of months, but I'm nervous and want to start thinking about it now. Given my credentials (or lack, really, since I'm still in undergrad) I don't feel super confident about it all, and I want this to go really well. My supervisor/mentor is letting me have a very long rein on this one, so that I can get some practice in for organising/planning talks. How this is all received by the public matters a great deal to me, for various personal reasons that are not really relevant. The subject will be on radio astronomy in general, with a little bit on the work I have done in galaxy evolution and AGN jets. The location will be the town I grew up in (in Australia), where few people graduate high school and many more dropped out of primary school.
So far, I've gathered that I should avoid all equations unless they're exceptionally simple. Given the location of the talk, even (what appear to me as) simple equations could be too confusing. I'm also acutely aware that the audience will likely span all ages and levels of education though, and I want everyone to be able to get something out of it without feeling like I spoke down to them or simplified things too much. I want people to leave feeling as though they learnt some cool stuff; maybe the kind of things they might briefly mention to a mate at work the next day or something.
Do you have any other, perhaps blindingly obvious, tips for a public talk? I'm thinking that some general physics-y demonstrations could be useful as well, although I haven't made any decisions about what those would be.
Apologies for the really simple question, but I suppose I have to start somewhere. | >the audience will likely span all ages and levels of education
This is key. Keep it simple. Describe the history of how the discipline developed, where it is today, and how your work fits into it. Tell a human story... not just formulas, but who developed them, how they were developed, what they allow us to understand (in simple terms). Show pictures. Do not put too much text on a slide.
**Practice your talk in front of an audience that will be brutally honest with you.** It will help you pace your timing and curb bad public speaking habits. Have someone that knows nothing about what you're doing listen and ask questions, it will help you see your work from an outside perspective and anticipate the types of questions you might receive during the actual talk.
Good luck, you will do great. | 40 | 35 |
The Bayesian vs Frequentist debate | In which cases do you decide to go for one instead of the other and what are the reasons that lead you to choose a bayesian approach instead of a frequentist one? | practicaly speaking, there are IMHO three types of situations where Bayesian approach wins over the frequentist one:
1) When the idea of repeated sampling from the same population is not tenable. This happens for example in pre-elections survey. Since voting preferences are changing significantly from day to day, it’s practically impossible to sample from the same population more than once. In situations like this, the frequentist interpretation of probability is not particularly helpful.
2) When there is a need to add outside information to the model. This happens when the sample size is too small or the model too complex to get a useful result based just on the data at hand.
3) When you someone asks for a probability of a hypothesis being correct, e.g. "what is the probability that implementing this policy will reduce unemployment?". This kind of question is natural for Bayesians, but virtually unanswerable for frequentists. | 19 | 16 |
ELI5: Why is saline the default hydration method for IVs and not just regular water? | Fluid in your body has an average concentration of 0.9% NaCl so it is most effective to hydrate a person with this type of fluid. If regular water is used it will disrupt many cells in your system.
Basically it is easier for your body to take care of saline. | 73 | 32 |
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ELI5: How is Tesla worth more than Ford? | My question comes from this news article: [Tesla is worth more than Ford](http://money.cnn.com/2017/04/03/investing/tesla-ford-market-value-gm/index.html)
Ford sells more vehicles in 2 days than Tesla sells in a year. Ford sold 17.55 million vehicles in 2016 while Tesla sold 76,000.
The article even says that Tesla is losing money. How can Tesla be worth more than Ford? | Stock price and market cap are based on projection for growth. Ford is a mature auto maker fighting in saturated markets full of uninspiring vehicles, with 100 years of legacy costs and overhead -- older, less efficient plants, retiree pensions, etc.
Tesla has a new exciting product that's revolutionary because it runs on electricity, yet doesn't suffer from the negative perception other "green" cars did/do. And they are investing billions in building state of the art factories to build their cars and -- of great importance for electric cars -- batteries. Tesla has only sold small numbers of expensive vehicles since their launch... not only did they have to win people over to electric cars, but they also had to do so with people willing and able to pay $60-100k to buy one.
Once their upcoming Model 3 -- starting at $35k -- is released, and these plants are up and running to allow for greater capacity to produce cars, they will be selling many times the number of cars they do today, and their investment in building that capacity will have been made. So a company selling tens of thousands of cars could be selling a million in a few years, and the stock price anticipates that kind of growth for Tesla.
Meanwhile, Ford is selling millions of vehicles but where's the growth opportunity for them? Maybe their next ___ model is more popular than Toyota's similar model and they grow that one model by 20% vs. it's previous version? That's not a lot of growth relative to the whole company... | 31 | 40 |
ELI5:Why do members of an orchestra need to read music to perform a concert yet members of a band don't read music in concerts? | Does the length of the music make it difficult to remember the different nuances? I can't imagine that they practice less than a band. It seems more difficult as a band member because they would have to know many different songs.
*edit* Thank you all for your reply's. I've been teaching myself the guitar and wondered this while I was talking things over with my wife. I had the feeling that the simplicity of rock songs versus a classical piece was the core issue here. I appreciate all your input and time! :) | Orchestras can be anything from 30-100 strong. The pieces they play, instead of 3-5 minutes of pretty repetitive music (not to be rude on pop/rock/etc in any way, but there's a structure, and it's easy to learn) are usually around half an hour to an hour long, although this varies hugely. Orchestras are tricky to coordinate and it's a risk to ask that many musicians to memorise a huge piece.
On top of this, there are a lot of directions the conductor would have given the orchestra in the rehearsals that depend on performance practice as well - different time periods had different styles. All the sections have to play exactly the same, and this has to blend with all the other sections of the orchestra.
Band members have probably also written their own materials, and it comes more naturally to memorise this than an hour long symphony.
If it's an opera, you also have the singers to consider - they will have their own nuances that will most likely change each night and it's much easier to anticipate these if you have your music in front of you. | 22 | 19 |
ELI5:Can someone explain washing machine cycles? | Can someone explain the differences on my washing machine cycles? I know it seems silly to ask but I've been doing the wash since I was 15 and never really questioned what everything on the dial meant.
Specifically what does the machine do differently in the "permanent press cycle" versus Cotton? What happens in wool? or silk?
why have a delicate cycle when you have hand wash?
Why have a dark cycle when I can just click the water temp to "cold"?
Such cycles like sports gear (cold and long), hand wash (cold, gentle) make perfect sense but how do the others differ? Is there any material benefit? | Different fabrics tolerate different levels of physical stress and water temperature. If you wash something delicate on a very vigorous or hot cycle, it's more likely to come out wrinkled or with weakened seams. If something is very bulky, a fast spin cycle will probably lead to an unbalanced load. If something is very dirty, it needs harsher treatment than something that just has a little body odor. IIRC, a permanent press cycle is gentler and shorter than a cotton cycle, and it's designed to reduce wrinkling.
Part of it is also that people will choose to purchase a machine that has more options, even if those options don't have a significant performance difference. Similar to how a bike with 18 speeds will sell better than one with only three, even though you probably only need three.
Most of your laundry can be done in cold water. Always use a cold rinse cycle; warm or hot is completely useless (your clothes should already be clean by that point) and just wears out your clothes faster. | 258 | 906 |
CMV: Schools should place more emphasis on civics than any other core class |
Before I get to the bulk of my argument, I want to make it clear that I don't want to attack other classes. I think that a good education is a liberal arts education -with plenty of real world, practical education thrown in. As such, English/literature, history, the sciences, mathematics, economics, etc, are all important.
Still, I think Civics is probably the most important subject.
Why?
First, I think the most important thing that a school curriculum needs to achieve is to prepare the student to become a good citizen. Even though the 2020 US election had the highest turnout in the 21st century, the turnout was still only 66.8% of the total number of eligible voters.
[https://www.census.gov/newsroom/press-releases/2021/2020-presidential-election-voting-and-registration-tables-now-available.html](https://www.census.gov/newsroom/press-releases/2021/2020-presidential-election-voting-and-registration-tables-now-available.html)
For democracy to continue and not just die over time, we must have concerned, educated citizens who fully understand their rights, and more importantly how they can practically execute their rights.
Take my own high school experience for example, I attend one semester, half a year, course in the US government, one two semester course in US government, and one half semester course in economics. I left the US government class, which I took as a sixteen year old sophomore, with a vague understanding of the judiciary, legislative, and executive systems; the ability to, temporarily, recite the preamble; and maybe some understanding of the amendments. What I didn’t learn is the particulars for how supreme court judges are nominated, how and in what way supreme court cases have been decided, how foreign policy is implemented, how grassroots organizing, protesting, writing letters and other civic actions can allow citizens to be more active in their government, the specifics in regards to protest, why, how, and when it is legal, etc.
I think that every American citizen should have a deep understanding of all of these questions, and many more. Specifically, I’d love to see Civics treated just as importantly as English, math, and sciences, each of which, at least in my state, were four year long classes. Ideally, I’d like for Civics -history too, but that’s a different CMV- to be studied all throughout highschool. In freshmen year, students should take intro classes covering the origin of American government, the judiciary, legislative, and executive branch, how laws are passed, the job of the president, how voting works. All the basic stuff. Year 2 should cover all of this in more depth with some hands on material, i.e. writing mock campaign speeches. Year 3 should go even deeper by looking at government on the local and civil level. Practical applications are even more important. Students should be taught how to write letters to their representatives and be allowed to send them if they like -and the teacher allows it. Students should be taught about local issues and laws. Year 4 should return to the federal level focusing on the nitty gritty details of far reaching governmental decisions: foreign policy, climate change, relation to economics, civics. Specifics on protest should be taught so that students who have now become adults can go out and actually fight for their rights and believes.
So, what do you all think? And no, I’m not stupid enough to actually think any of this would happen. | There are tons of good ideas of things we could add to high school curriculum. Yours is a good idea too. Adding more classes in Personal Finance, or Sex Ed or Drivers Ed, or things like that are also good ideas.
But in education, it’s going to be a trade-off. What are you dropping to add this new class? Are we going to get less Math or English or Science? Are we going to extend the school day to add this class? | 12 | 15 |
ELI5: How do we know what colors are visible to other animals and why are the visual spectrums so diverse? | I have heard the old addage that dogs are colorblind, but what do people really mean when they say that? Because of science we know that dogs have a very limited visual range, yet butterflies can see more colors, and don't even get started on Mantis shrimp. As if they were not already the most badass creature on earth, they get to have godlike perception as well?
I know there must be a sciency way that people have used to figure out the visual perception of creatures... But for the life of me it does not make sense in my head. As humans we can use our imagination, technology and bad CGI to see the world as some of these creatures do... But how did we find out what they can see to begin with? I am especially interested in how we know what dogs see, and how the heck that was figured out... But I would also like to hear about other creatures eyesight capabilities and limitations and how we as humans came to those conclusions. | We can know because vision works in a similar way in all animals (including humans).
For humans, our eyes, have two kinds of vision cells. One kind is called 'cone cells'. Cone cells are in charge of detecting colour. Cones themselves are further divided into three types depending on what wavelength (colour) of light they absorb. One type absorbs red, one absorbs blue, and one green. (Technically all three absorb all colours, but peak in red, blue, and green). Every other colour we see comes from these three colours. Our eyes and brain work together to process and create the remaining colours. Since we have three colours we detect, humans are called trichromatic.
Dogs are dichromatic. Which means they do not have three different types of cones. They only have two. They have vision equivalent to red-green colour blindness in humans. This means for them red and green look the same. In general, most mammals are dichromats.
Cool fact: Some humans (mostly women) have four different types of cones which means they can distinguish and see colours normal humans can't.
| 11 | 17 |
ELI5: How to submit a tv show idea to a network and what prevents them from stealing it? | To submit ideas, you need representation, generally. You need an agent or someone who knows the legal layout of entertainment, and who has enough pull for the network to know that their time isn't being wasted.
The reason for this is that so many people in the past have been burned by studios/networks/publishers from idea stealing that rather than dealing with the repercussions, all pitches, ideas, whatever, MUST be solicited. This means a meeting, representation, and all the right players in the same room.
If you submit something unsolicited, they won't look at it at all. Trash/returned script that says "hey, we can't look at these. It's our policy. Don't send us these." Nothing guarantees that they can't just steal the idea and then send you the letter, but then again, you have postmarked correspondence that might be able to be used in court.
Plus - networks have so many people in their, well, network, that they're not short on good ideas. They're not in the business to steal from the little guy. Even if your idea is the best they would have ever seen, there are thousands of ideas that will work just fine for them. | 11 | 25 |
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ELI5: How exactly do brethalyzers work? | How realistic are breathalyzers in determining how impaired you are? For example, if I swished around some liquor in my mouth, spit it out, and then blew- would it register that I have alcohol in my system? | For the ones which count as evidence in a DUI, there are two mechanisms which measure the alcohol. One is infrared, the other is electrochemical.
One of them falls for the liquor-swishing, the other guards against it. Some of hand-held ones are electrochemical and will be duped by mouth alcohol. But those aren't valid for a DUI trial.
That's why DUIs wait 20 minutes before taking it just as an extra measure. All the alcohol will be gone by 15 minutes, unless you puke up fresh booze from the stomach.
It's also why the breath sample has to be almost impossibly long, so the infrared mechanism gets the air from the longs and not stuff from the mouth.
| 14 | 23 |
If I leave my postdoc for a non-academic position, would I be able to re-join academia later on? | I have a job offer for a science communication- outreach position. I am thinking of taking it because I want to see if that career path would make me happier. The position involves grant writing and fieldwork, but no opportunities for publishing. I am on my first postdoc. If I leave my postdoc for this position and then decide that I miss research, would I be able to get another postdoc and get back in the game? Or am I really shutting the door on the academic career track? I do have some trailing papers from my PhD so I will probably still have publications coming out for the next year or two. | The vast majority of postdocs in most fields have no realistic academic career prospects, so likely you can't actually decrease your chances very much. But yes, it will be difficult to get back into the game. When applying for jobs, you will likely be judged by people who have never known anything but the very linear career paths that academics are meant to follow and will look down on any deviation from that path. Many will think that you went into a non-academic position because you were not good enough to get a tenure track position, though many will think that if you do more than one or two postdocs anyway. Academia is very social status oriented and non-academic jobs are for many academics low-status. It is not impossible though. Ones chances are never zero. | 128 | 118 |
ELI5: Why do animal clones die prematurely but plants can be vegetatively propagated (essentially cloned) many times over with no ill effects? | I've read that for animals, say, a cloned mammal the DNA of the original host is the same used for the clone, so it's already aged and degraded from time. I grow many plants, and so I regularly make clones via cuttings and divisions. So I wonder why the new individuals can have the same vigor as it's parent plant? Does DNA not degrade in plants? I've also read that inbreeding can occur in plants. On a side note, about the super massive tree structure Pando, that Aspen forest from only like 1 tree I think. It's estimated to be 80,000 years old and is technically a single individual, as every stem (tree) comes from the same roots and has the same DNA. Meaning at some point a long time ago a single seed made 1 tree which eventually became a forest occupying over 100 acres. How does DNA replicate so many times over in plants with no issues? Is it because the differences between plant and animal cells? I don't know a lot about these things, just a random thought I had. Any explanation would be appreciated :) | Plants are in general evolutionarily closer to having duplication as a legitimate reproduction strategy. Some plants straight up reproduce by sending out suckers and growing new plants from them, and those plants can be easily and simply divided.
It's not impossible to fix damage caused to DNA by replication, it simply isn't done in animals, because dying off to make room for a new generation with new combinations of genes and mutations means that a species is more adaptible to changing environments and can therefore migrate faster and survive disasters better than a species that can't. Typically adaptability isn't a strong selector for species that don't move with simple environmental concerns, which means purposeful die off is a waste of resources.
Importantly telemere damage doesn't occur for some types of stem cells, otherwise all species would eventually die off. The same process just happens longer in an individuals life in plants. | 25 | 47 |
Why is it that light with short wavelengths (x-rays) can penetrate objects, but so can light with long wavelengths (radio waves) yes visible light can't? | Different materials are capable of absorbing only certain wavelengths of light. The visible spectrum is the range of the spectrum that tends to undergo a lot of interaction with common materials--this is why it was relatively easy to evolve sensitivity to it, and it is also particularly useful for perceiving the world around us.
Both higher and lower energy photons (shorter and longer wavelengths) lie outside of the typical energy ranges that electrons in atoms interact with. Therefore they tend to pass through materials without interacting as readily. | 54 | 44 |
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A question on Evolution | If a population of animal lives in an area where their food started to cause rapid tooth decay, would evolution sort it out in ways such as a different diet? Or maybe just generally make them stronger? Even a different means to chew and consume food?
If humans stopped brushing their teeth and continued to consume sugary foods, after a LONG period of time would their teeth undergo changes (other than being severely decayed). Or is it our ability to create tools to keep them clean keep them from evolving? Would we create superior tools? | Hypothetically, if the ecosystem changed in such a way as to cause serious enough tooth decay that many individuals in a species starved to death before living long enough to rear offspring, then one of two things would happen: Either the species would die off completely and become extinct, or some subpopulation would adapt in such a way to cope with the change in the environment.
It's very important to keep in mind that nature doesn't care whether the species goes extinct. Evolution isn't "looking" for an adaptation to cope with the change in environment. If such an adaptation is already in some members of the species when the environmental change is occurring, then those members are the individuals who live long enough to procreate, so the adaptation becomes more widespread.
| 25 | 16 |
ELI5: How do “take with a meal” pills get absorbed into our body properly if there is a large amount of food in our stomach? | Medicines, vitamins and other chemicals are generally either water soluble or fat soluble. Water soluble chemicals can be absorbed directly into your bloodstream and don't need to be taken with food. But fat-soluble chemicals won't dissolve in water, and thus need some fat in your stomach. Generally when a pill is suggested to take "with food" or "with a meal", it's because it's fat-soluble and almost all food has at least some fat/oil/lipids in it, so they don't bother to specify what kind of food. | 35 | 24 |
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ELI5: How are photos colourised? | Some modern cameras store images much like these pictures. They use two channels, color and intensity. The intensity channel would be like the grayscale image. Intensity ranges from 0% (white) to 100% (black). The color is painted over this intensity, resulting in different shades of that color.
To colorize old pictures like this, an artist takes a relatively small color palate and applies it to the image, using the greyscale as the intensity channel. This way, the artist doesn't have to create shades of a color, the intensity channel does it automatically.
As for how accurate it is to the original color, it's often not very close. The artist may make a few educated guesses as to what color things should be (grass is green, sky is blue, etc.), but unless there is some other documentation as to what color the clothes, eyes, hair, etc., were, it's all just guesses and whatever the artist thinks looks good. | 104 | 141 |
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ELI5: why are churches exempt from paying taxes? | Tax exempt status is allowed for nonprofit organizations that are operated exclusively for religious, educational, scientific or other charitable purpose. There are a few more rules, but those are the two big requirements: (1) nonprofit and (2) religious, education, scientific, or charitable.
As you can see, churches don't get special treatment over other nonprofits. However, you might still ask why "religious" organizations are included at all. One reason is that it helps maintain separation of church and state. As the Supreme Court noted in one of its earliest decisions regarding a national bank, the power to tax is the power to destroy. By not taxing churches, the state removes itself from interfering in church business and also makes sure the state doesn't start relying on church taxes for its operation.
Another reason is that historically churches were important charitable and social centers. That's still true for many churches today, but it was even more apparent when the tax laws were first being made. | 487 | 513 |
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Burnt out - want to quit research project | (somewhat venting - mainly asking advice on how to talk to PI about burnout)
\[Recent Graduate BS - 2020 - USA\]
I've been with this lab for 2 yrs as an undergrad and started a research project with them for my senior dissertation. They wanted to turn the project into something publishable and I agreed thinking I could do it. We had bumps along the way with figuring out how to do our project and it somewhat changed so now it's just taking longer to complete. I've since graduated in 2020 and am still working on this with them (2yrs on this project) but after I graduated, I really just wanted to move on and have the project passed on to another undergrad to finish, though I know I've made a commitment to create this paper with them. I honestly don't care about having my name first on the publication at this point - which was something that enticed me at first being an undergrad. I'll be starting graduate school in fall and really want to cut ties with this project. I just feel like it's being dragged out and I want to focus on a project that's more my own.
I'm not sure how to approach my PI about this - like it'll probably look bad since I'm going to do more research in grad school right? And if I drop out of this project it won't look good on my resume or something, or say something about me as a researcher? I'm not sure if it's a bad thing that I don't care about it would I look if I stop this project, I just want to be done with it. | In research, there is always going to be an ongoing project. You might be working on 5 at a time in various stages of publication. This is just the nature of the job. Just move on and make sure to discuss authorship and how to keep in the loop regarding publication before you leave, preferably in writing. PIs understand the nature of research and the revolving door for students. | 68 | 90 |
ELI5: What information does the doctor get out of hitting my knee with a tiny hammer? | That the L2, L3, and L4 segments of your spinal cord are working. If your leg doesn't kick out, or doesn't kick out well (absent mobility issues), something is wrong (Westphal's sign) and can mean motor neuron lesions (the neurons that control muscular contractions), cerebellar diseases, and even thyroid problems. So that little tap actually tells the doctor a lot about what's going on in your braincase.
There are many other reflexes that are used to measure brain function such as the plantar reflex (see Babinski's sign) which is a great way to determine if a comatose ER patient suffered damage to the central nervous system. | 17 | 19 |
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UPDATE to the previous question on tackling misogyny | My earlier question [Tackling misogyny as a female researcher](https://www.reddit.com/r/AskAcademia/comments/ry3g5u/tackling_misogyny_as_a_female_phd_researcher/) got some serious and very helpful responses. I wanted to update on it. 1 week before the official booking of the thesis defence, I was shouted at by my sup. in essence, saying that I have not performed my activities as a PhD and hence need to work more and \*postpone\* my defence. This came not as a surprise since (a) our work did not produce the results we wanted (b) other senior collaborators were handling personal issues which delayed my work, and they did not give way for me to get the work done on time either. So for my sup., accusing me seemed to be the easiest thing for their job/position.
I actually stood up for myself without losing my cool and mentioned the failures that provoked their actions. I also mentioned postponing won't solve our scientific challenge. In the end, I decided to postpone because I cannot work to get the thesis done in a month in such a toxic-unsupportive work environment.
I sought help from the dept rep. and it somehow helped to find a middle ground. The greatest help I got from is from another senior (female) researcher at the dept in my field. Her support is still available for me to bank on.
The entire incident broke me, I became depressed and found it hard to cope with (even now).
I have decided that if something like that happens again, I will take it up with the head of the department and quit my PhD, even though I have spent 5 years on this degree. | You are in Sweden, are you not? Don't you have a reference person? They should have helped you in this case - that is their role.
FYI your *Examinator/Examiner* (examinatorn) is the one handling the defense schedule; not your supervisor. You should talk to them. You can trigger the defense at any time.
You also count as staff. You should consider talking to HR and occupational healthcare (they do more than healthcare). Your university also has an ombudsman for PhD students (doktorandombudsman) and you should have also access to union representatives. Try to consult them too.
I know it is hard, but there is a large support network and procedures in place to help students. In many ways, in Sweden, students have more power than supervisors (you can even switch them *at any point of time*). COnsider getting mental health help and consulting external people before rushing to 'quitting' or anything else. | 44 | 62 |
CMV: George Carlin was primarily a philosopher, not a stand up comedian. | George Carlin is always touted as a great stand up comedian, but most of what he is known for are observations of human reality like time, stuff, losing things, government, children, how groups act. His routines go beyond saying things to get laughs, he gets people to think. He just happens to get people to think by point out certain realities in a way people find funny, but what he does and who is primarily is is a philosopher not a comedian.
His comedy was distinct from other stand up comics that usually all focused on the laughs and any thinking was secondary, where as his routines all center around getting people to think, not laugh, though they usually do, the laughing isn't the point.
If he were still alive to he would have had a ton of new material between 2015- now. He will truly be missed.
GEORGE CARLIN 1937-2008 | An essential element of philosophy is being able to give evidence as to why you are right. Simply pointing out inconsistencies isn't really philosophical. Being able to explain your thought process and at least give an attempt at a solution or resolution is key. | 24 | 41 |
[Marvel] Taskmaster can instantly and perfectly memorize and duplicate other people's fighting techniques. If he watched a few experts playing Halo or League of Legends for a bit, could he sit down and be a master of those games? | Taskmaster's skill is defined as:
>Taskmaster injected himself with SS-Hauptsturmführer Horst Gorscht’s primer, an elaborate modification of the adrenal steroid cortisol designed to unlock the mind’s procedural memory potential. The Taskmaster thus gained the ability to absorb knowledge instantaneously. This ability is linked to his muscle memory, allowing the Taskmaster to instantly replicate the physical movement of peak-level humans. Using these "photographic reflexes", the Taskmaster is highly skilled in various forms of combat, as an exceptional martial artist (mimicking Elektra, Iron Fist, Shang-Chi), a skilled swordsman (Black Knight, Silver Samurai, Swordsman), a deadly accurate marksman (Captain America with a shield, Hawkeye with a bow and arrow, Punisher with firearms, and Bullseye with various projectiles) as well as displaying a strenuously honed athletic ability (Black Panther, Daredevil).
Because he is able to use this person's skills as they would normally use the skill, in reaction to stimuli that trigger the response, it seems that Taskmaster could immediately become a master of any video game after watching an expert. | 84 | 107 |
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CMV: People with a PhD in an unrelated field shouldn't be allowed to introduce themselves as "Dr." when presenting medical facts | This comes directly from something I saw earlier about somebody complaining about COVID etc., I'm all for the vaccination so as you can imagine when I hear somebody introduced as "Dr. \[surname\]" with a different opinion to me, it could imply that he actually knows what he's talking about.
No. A tiny bit of research shows that he has a PhD in *theology*, this was never specified, yet I see the same video circulating quite a bit around the internet (between anti-vaxxers) because he was called "Dr.", anybody that doesn't do research would therefore assume that he has some sort of medical or at least scientific background which is not the case.
I don't disagree with people being *allowed* to introduce themselves as "Dr." because a PhD does take a long time and it is a big thing etc. but it's very immoral
EDIT: When I refer to a "doctor" in this post I mean a licensed physician/MD, I've said "person with a PhD" any other time, I'm aware that they're both considered "doctors" by definition. | There are synergy benefits for Dr. of biology to comment on medical issues or Dr of sociology commenting on social effects of medical issues etc. Lot of doctors (and their related scientific disciplines including theology) have lot import things to say about Covid. | 841 | 3,899 |
ELI5:How can dogs smell cancer? | The current theory is that cancer cells produce characteristic organic compounds which get into the bloodstream and are then also present in the patient's breath - only in tiny amounts, but enough to be detected by a dog's amazingly keen sense of smell.
Which compounds those are exactly is still being researched, in the hope of using the knowledge to produce test kits. | 20 | 41 |
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ELI5: why is it woman and children first during natural disasters | I really dont understand | For women:
Women are needed for reproduction and rebuilding of the human race. One male can impregnate a lot of females to ensure that life goes on. If there is only one female and hundreds of males, re-population isnt going anywhere fast.
For children:
They are the future of the human race and naturally have a longer life expectancy than older males. 10 year old will remain on earth much longer than a 50 year old on average, especially with care from all the women being saved.
Basically to make sure that the human race survives. | 44 | 16 |
I am defending my master's thesis on Friday. Any tips to make sure I don't get publicly humiliated? | I got my examiners' reports and they requested quite a few changes, like reorganizing the structure of my Previous Studies chapter, adding some theories, citing some articles, focusing more on one aspect that I had barely mentioned, giving more information about the experimental groups, etc.
With all these comments, I am EXTREMELY nervous. Not to mention all my colleagues from the program are planning to attend the defence.
Do you have any tips? And what happens if they ask a question and I have no idea how to answer?! This is the nightmare scenario for me. | It's common procedure to give a practice talk to an audience of friends or colleagues - potentially even your advisor, if that's appropriate in your field. Encourage those friendly audience members to ask tough questions, so you both (a) get some experience answering off the cuff, and (b) outsource the task of figuring out the "tough questions" beforehand. If they ask you something you don't know, then take a day to figure out the answer *before* your talk on Friday. | 16 | 16 |
ELI5: If microwaves are tuned to the resonant frequency of water, why is it that heating up a bowl of soup results in the bowl being so hot it burns my hand while the soup itself remains tepid? | Writing this as I'm nursing a sore hand and eating cold soup. | In physics there is a concept called specific heat. It is a measure of the amount of heat energy it takes to raise the temperature of a substance, specifically the amount of energy it takes to raise 1 gram 1 degree centigrade.
It happens that water has easily the highest specific heat of any common substance you are likely to find in your home, including anything a bowl is likely to be made out of. The water in food may actually absorb more energy from microwaves than the container, but still heat more slowly because the container takes far less energy per gram to increase in temperature. | 1,086 | 2,130 |
Professor wants to "see what I've done so far?" (x-post from /r/ApplyingToCollege) | Hey, I was told people here might be able to answer this better.
I'm a high schooler who did some research under a professor at a local University last summer, and when I emailed to see if I could come back to his lab this summer he arranged a meeting with me. What surprised me was that he told me to put together a short powerpoint so that he can "see what I have done." I haven't been able to achieve any progress further than where I was last summer because of my heavy school schedule and classes on weekends, and he knows this because he acknowledges it in some of his emails to me. Does he actually expect me to have done further work throughout the year or is this just a refresher to remind him what I was working on and what I was doing at the end of last summer? If it's the former, what should I do?
Thanks so much. | You should probably summarize what you did last summer and then highlight your ideas for where to go next (even if you're just parroting what the professor has suggested in the past, it will show that you remember and understood where the project is going) | 54 | 20 |
Given enough time could a crab, snail or anything really eventually evolve to become as intelligent as us? | EDIT: Ok wow lots of responses. Its going to take a while to read through them all but I think the top comments and most others describe it well.
It isn't just time, its environmental factors as well. | As long as increased intelligence was competitively advantageous from a fitness perspective, the rest of evolution is up to random mutation.
In a hypothetically infinite time scale, mutations that increase crustacean intelligence certainly could accumulate.
However, it's also important to keep in mind that "intelligence" is not some sort of evolutionarily apex quality. Most living things are quite well adapted to their environments already and face a cross-section of different selective pressures than early hominids. Optimizing energy balance, disease resistance, evasion of or defense against predators, ability to attract mates and beget fit progeny, exploiting new ecological niches, etc are all extremely powerful forces that *may* improve with increased intelligence, but are largely unrelated.
In addition, any intelligence needs to be utilizeable in order to be a benefit. If we consider "tool use" as a marker of intelligence... that would be incredibly challenging for a creature with the body pattern of a snail. Higher order brains are energetically very expensive, and they need to be worth it. | 806 | 850 |
What philosophers will be remembered in the future as we do now with Nietzsche, Bertrand Russell, etc ? | It seems there isn't that much in the way of influential thinkers( that's my opinion), or is it and I'm just looking at the wrong places? | I expect for currently living philosophers: John Searle, Daniel Denett, Noam Chompsky, Judith Butler, Slavoj Zizek, David Chalmers, Judith Thompson, Peter Singer, Thomas Nagel and Saul Kripke. These people all have potential to be remembered(and some already have really famous arguments, see: John Searle’s The Chinese Room). | 30 | 17 |
If planets were all formed from the same molecular clouds, why do some planets have different atmospheres and elemental make-ups? | Title says it all. | Broadly speaking, the planets of the solar system are divided into two major groups: the terrestrial planets (Mercury, Venus, Earth, and Mars), and the gas giants (Jupiter, Saturn, Uranus, and Neptune). The terrestrial planets formed closer to the sun where temperatures are too high for appreciable amounts of volatiles (like methane and water) to condense and accumulate. Therefore, the terrestrial planets are primarily composed of metals and materials with relatively high melting points (Ni, Fe, Al, and silicates).
Farther from the sun, beyond what's called the "frost line," temperatures are cool enough for solid methane and water to accumulate, providing the outer solar system with more raw material for planet formation. The outer planets were therefore able to grow much larger, causing them to gravitationally attract light gases, such as hydrogen and helium, which the smaller terrestrial planets were unable to capture.
The differences between the atmospheres of Venus, Earth, and Mars are further explained by their different distances from the sun, as well as their different masses. | 16 | 22 |
ELI5: Why is it that when you're in a "dark" room and you focus on a really dark spot everything around you (even light) starts to fade away? | I know I probably didn't make any sense since it's hard to explain but imagine being in a dark room with nothing but a little red LED light in the center of the room if you focus on a really dark corner, the light will start fading away into darkness. Why is that? | ELI5 Answer: Your eyes see things by seeing changes. When nothing changes, we can't see anymore.
Complicated answer: Image burn-in. Humans see light as an "excitement" of the cones and rods in our eyes. If we continue to stare at the same image without it changing, the excitement ends even though the image does not. If you stare at anything for a while, you will notice that your peripheral vision starts to fade and eventually your primary vision starts to fuck up as well. | 17 | 29 |
ELI5: My boss sends me PDF through company email about a vendor he's considering. Next day, said vendor's ads are showing up in my FB newsfeed. How did they know? | How can FB tell what PDF's I'm opening or email I'm reading? Our company uses Exchange and Outlook. I use Chrome and FF for browsers. | If you have your workplace listed in your Facebook profile they can target you with their ads. If they have a bid in with your company they could be trying to stealthily get their name in your subconscious by targeting employees of your company. | 91 | 230 |
CMV: It's selfish for a dead person (or their family) to not allow their body to be used for science or transplants. | Normal inheritance is fine; at least, it requires a big enough change to the systems in place that I can't think it through without undoubtedly spending way too long making a new method of shuffling the necessary types of property about and redistributing wealth and stuff.
However, unless in the rare case your family are going to use your body for some purpose themselves (which is a whole separate thing) then simply burying it is a waste, and dumb. The thing that started me thinking about this was an article about a family who had managed to get a grandson by harvesting sperm from their son. A lot of people were annoyed, saying it violates body autonomy, but I don't understand why you still have body autonomy when you no longer.... occupy the body. If you know what I mean.
The usual reason why you can't force someone else to have kids is that the person did not choose to have to take care of those kids, but in this case, they don't have to anyway. They'll never know and it won't change anything for them. It may be cruel to bring up children knowing that they'll never have a father but that is kind of a tangential issue.
Basically, you shouldn't be able to control absolutely what happens to your body after death, and only make suggestions. If the reason is good enough and the family agrees then you can do what you wanted to happen, for example for very strongly religious people, to which the body itself is important because of a belief in some kind of afterlife that depends on it. But if you just want a funeral service and then to get buried or cremated, I don't think that should hold any weight legally. The service is fine, since it doesn't necessarily need the body (as with all the soldiers who don't come back from war, but they bury a coffin in their place anyway), but cremating or burying it should only be an option if there's no other use for it (as in, a very old or ill person who wouldn't be valuable to organ transplants or science).
I'm saying ~~mandatory~~ by default organ register from birth, with certain pathways to opt out when it's strictly necessary due to strong religious factors.
Edit: Assuming, like in the UK, that free nationalised healthcare is a thing. For-profit single payer systems are a different unethical kettle of fish. They would have to buy the body off the government once there was determined to be no other use for the body parts remaining.
edit 2: By mandatory, I meant "by default".
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> *This is a footnote from the CMV moderators. We'd like to remind you of a couple of things. Firstly, please* ***[read through our rules](http://www.reddit.com/r/changemyview/wiki/rules)***. *If you see a comment that has broken one, it is more effective to report it than downvote it. Speaking of which,* ***[downvotes don't change views](http://www.reddit.com/r/changemyview/wiki/guidelines#wiki_upvoting.2Fdownvoting)****! Any questions or concerns? Feel free to* ***[message us](http://www.reddit.com/message/compose?to=/r/changemyview)***. *Happy CMVing!* | Allowing organ harvesting of dead bodies creates financial incentives for less-than-stellar care of those on the verge of death, especially with how much certain blood types and organs are in demand and hospitals+ doctors are squeezed more and more to meet demands. | 28 | 54 |
ELI5: How can gambling be illegal in US States that run a lottery? Isn't the lotto just state-run gambling? | Perhaps unsurprisingly, when you are the body that makes the rules, you can make exceptions for yourself in those rules. Lotteries were made illegal for a time and there is no national level lottery. However, many jurisdictions have made government lotteries legal again.
There's no requirement for the government to write an "all or nothing" gambling bill. | 36 | 26 |
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CMV: Even if minimum wage laws resulted in a reduction in jobs, I would still want minimum wage laws. | I will say upfront that the research suggests that, in general, jobs are NOT affected by minimum wage increases.
https://www.businessforafairminimumwage.org/news/00135/research-shows-minimum-wage-increases-do-not-cause-job-loss
That being said, there are many who still push this idea, that it will reduce jobs and hurt small businesses. So, I'll entertain this angle and push aside the research for now, and after thinking it through, I would STILL support a higher minimum wage.
This is all about cost / benefit, the greater good, etc. And above all else, what I want is for any person who works 40 hours a week to live above the poverty line. If we don't consider cost and think about this ideologically, that should be clear and acceptable to all. There is no ideological reason why a person shouldn't be able to live above the poverty line if they did exactly what society expects of them, which is to be fully employed.
The biggest reason why I don't mind the job losses is because I actually WANT a company that refuses to pay a minimum wage to either shut its doors or be forced against its will to not treat its employees like shit. I simply do not believe that most companies CANNOT AFFORD to pay minimum wages for all employees. A company can afford whatever it CHOOSES to afford, and a company that chooses things like more property, product development, or of course more big bucks for the people on top, simply has its priorities screwed up.
To put it more simply, I think a company is morally in the wrong for surviving on cheap labor, and I'd rather force them out of the use of cheap labor or to shut its doors. I don't mind hurting a small business that chooses not to pay its employees a living wage, and I do view that as a choice rather than a matter of survival. A company that would go bankrupt over paying the relatively meager wages of minimum wage is probably doing quite poorly anyway.
CMV. | Become a small business owner and live your values and you may start to see the difficulties these decisions get tied up in. You have not walked a step in their shoes yet want them to run their business as you would have them without knowing any of their constraints or you would have them go out of business. The money has to come from somewhere. | 25 | 28 |
How do recycling centers deal with people who recycle thins incorrectly? | Is there some sort of way that recycling centers can separate straws out of the recycling and other things that don't belong? Or do they just have to throw that whole batch away? | It depends on the technology at the MRF or material recovery facility. At a typical single stream meaning you put all recycling in one bin there are a variety of "screens" material passes through that separate out 2d from 3d things so paper from other material. Screens that separate glass. Eddy currents to pull out aluminum. Optical sorters that can be used to separate plastic types #1 - 7 or glass or different types of paper. However there is always something called residual in the end commodity. Residential would be like plastic straws or caps in a ton of glass sold on the market. Residual in glass has increased significantly since many MRFs have moved toward single stream. Additionally glass ends up being broken in small pieces in single stream recycling and has lower market value. Add increased residual to the situation and glass recycling is a money loss for MRFs.
TLDR yes all economically reasonable attempts to pull out non recyclable commodity items and separate commodities for market are made but not everything that shouldn't be there is pulled out and what isn't is residual shit in a commodity kinda like the ends pieces on a loaf of bread | 34 | 107 |
CMV: Engineers and MDs are not scientists (except those conducting empirical research). | I have seen several examples, in the past few years, of engineers and MDs (medical doctors) claiming to be scientists. Many of these situations have been with friends or acquaintances. I also sense very strongly that engineers and MDs "identify as scientists," by claiming the "science" side in online or televised discussions/debates, and similar behaviors that are not open declarations of the identity but seem consistent with it.
Some engineers and MDs conduct science; that is, they perform empirical research. Those individuals are scientists. However, the vast majority don't, so they aren't.
"Science" has two major meanings. The first is archaic, and it means something like "any structured, disciplined pursuit of knowledge." By that definition there are quite a number of "sciences," including philosophy, mathematics, the arts, public administration, etc. However, the more modern (i.e., past century or more) meaning of "science" is much more specific: the process of using (presumably validly) the scientific method to generate knowledge.
By the more modern (and, by far, most common) definition, engineering and medicine are not sciences; they're technologies. Engineers and MDs, overall, do not discover or create generalizable knowledge by way of the scientific method; rather, they apply knowledge generated by others (i.e., by scientists).
The problems, I think, are
1. "Science" and "scientist" have progressively become cooler or more desirable as labels. Everyone wants to be a "scientist" as scientific explanations increasingly dominate many domains of life.
2. Engineering and medicine are more closely tied to the results of science than most fields. Design, business administration, etc. use science opportunistically but are not locked into it the way engineering and medicine are. Therefore, in important ways, engineering and medicine are more *scientific* than other fields, in that they must use the fruits of scientific research more conscientiously to obtain results.
3. This one is my own opinion, and I can't prove it, but I'm certainly not alone: engineers and MDs (especially MDs) have professional pride and entitlement trained into them, in many cases. They are encouraged, implicitly and (at least for MDs) explicitly to think of themselves as superior to people in other professions in specific ways. This view has a basis in reality, as engineers are probably far better at solving many problems than the average person, and MDs have great expertise in a critical area: the functioning of human bodies. However, spending time around MDs will leave most people with the sense that MDs expect/demand a level of professional/(personal) respect that goes beyond that specific dynamic. Although not as pronounced as the MD case, it is not hard to find hundreds or thousands of cases (see: reddit) of engineers suggesting that complex problems in social, political, linguistic, biological, psychological, philosophical, etc. domains (i.e., not in engineering) could be solved more easily if they were addressed by engineers.
To sum up, engineers and MDs share a close relationship to the fruits of scientific research and a sense of professional pride or even entitlement. This, coupled with the increased coolness of "science," has led many engineers and MDs to self-identify as scientists. However, with the exception of those conducting empirical research, they are not scientists.
Note: Not being a scientist doesn't mean a person (or their profession) is of lower worth, though Westerners have had a weird hierarchy, historically, of valuing the "thinking" professions over the "doing" professions (which, IMO, is crap). Being a scientist isn't a "better" thing than being a technologist -- science has few benefits without the armies of individuals innovatively applying it, and scientists are generally not trained for that. However, we have decided that "scientist" sounds really cool, so I think we have some biases, here. But that's all they are, biases.
*Edit*: It's noonish Eastern US time and I should do some real work. Because apparently I have a real job. So I'll get back to this later tonight, I think. Thanks to everyone who has commented; my views have, indeed, changed to some extent, and perhaps they will more, later on. | Engineering and medicine are applied sciences. To get a degree in either requires a huge amount of scientific study and understanding of the scientific method.
I don't think it's true that engineers *only* apply knowledge generated by others and *never* conduct empirical research or use the scientific method. It's an integral tool in the arsenal of an engineer. Sure you try to use established knowledge when possible, because that's practical. But the complexity of large projects means that you will inevitably be asked a question that will require methodical research to answer.
*Why are we losing 5% efficiency off the expected performance of this widget? How can we work around this problem? Will this problem increase as the project progresses and we add more widgets around the widget? What is the risk of failure with this problem, what is the risk of failure with our solution?*
You can't look the answers to these questions up in a reference book, and you can't professionally answer the questions without empirical research.
| 72 | 100 |
ELI5: Why do aircraft cockpit windows only face upwards? | I get that the pilots need to see the sky above them, but don't they need to also see below? In photos, it seems pilots can barely see the runway when landing, and when flying cannot visually scan the horizon below the aircraft. | Pilots don't need to look down for the same reason drivers don't need to look under the car while driving: once a threat is "under" you, it's too late to do something about it. And most threats come from ahead and from the sides.
It's not a bad comparison since, during landing, a plane is not much different than a car. Finding the runway and lining up with it happens well before landing and requires looking ahead, not down. Any "potholes"/threats on the runway are only relevant if you can dodge them so, again, you need to see them long before you hit them, not when you're on top of them.
[edit, based on exceptions that others have mentioned below: some helicopters, and older bombers, have wraparound windows or see-through floors precisely because they DO need to see "under". They are landing vertically or need to be above the bombing target. Those exceptions prove the rule. Standard planes have no such need.] | 83 | 55 |
In which European countries are faculty well paid? | I'm a tenured prof in a STEM field at a major university in the US. I make around $130K per year plus summer salary. After taxes and benefits, that works out to about $8K per month on avg plus around $1.5K per month contributions to my retirement account.
I am well paid and like my job, but don't like living in the US and don't want my kids to grow up here.
I looked into jobs in Europe, but many countries seem to have much lower pay for faculty. I'm willing to take a lower salary to live in Europe, but not half of my current salary!
In which European countries could an STEM faculty (equiv to associate prof in US) expect to receive at least 6000 Euros per month after taxes? | If you manage to get a W3 professorship in Germany (its tough out there), you'll likely have something between 6k and 8k € (gross!) per month, and a 13th salary at the end of the year. This doesn't mean you'll get a net amount of at least 6k on your bank account (if you have 8k gross, its probably going to be around 5k net), BUT there are some perks:
-healthcare is 100% free (e.g., paid with a small amount out of your gross salary, and as you are a public servant, you are "privately" insured and get the best healthcare possible)
-you don't have to pay a single € into a retirement account (only if you want to). As you are a public servant, you'll automatically get ~70% of your last salary as a pension.
-many many other things as others mentioned (free college, free education, subsidized daycare, no guns, etc. etc. - this is for you to google).
Hence: you'll likely get less money on your bank account each month. Your quality of life will be at least the same, if not better. For further information, google "W3 professor Germany". Be prepared to learn some German, although English is commonly/increasingly used in the educational sector. | 75 | 36 |
How did Einstein figure out relativity in the first place? What problem was he trying to solve? How did he get there? | One thing I never understood is how Einstein got from A to B.
Science is all about experiment and then creating the framework to understand the math behind it, sure, but it's not like we're capable of near-lightspeed travel yet, nor do we have tons of huge gravity wells to play with, nor did we have GPS satellites to verify things like time dilation with at the time.
All we ever hear about are his _gedanken_ thought experiments, and so there's this general impression that Einstein was just some really smart dude spitballing some intelligent ideas and then made some math to describe it, and then suddenly we find that it consistently explains so much.
How can he do this without experiment? Or were there experiments he used to derive his equations? | In his own words, he was "saving classical electromagnetism" when he came up with relativity. There are two constants in electromagnetism that set the strength of the electromagnetic interactions in a vaccuum: the permittivity (ε0) of free space and the permeability of free space (μ0). When the theory of electromagnetic waves came out, it was found that you can calculate the speed of light from these constants, i.e.:
c = (1/ε0μ0)^1/2 = 3.0x10^8 m/s
But now you have a problem; what happens if you are in a moving vehicle at constant velocity in a straight line and you do electromagnetic experiments? If the speed of light changes in that reference frame it would also mean the *constants* of electromagnetism would change and therefore the whole theory of electromagnetism would break down (the equations would all become velocity dependent whereas the formulation of say, the electric field, isn't normally).
This problem can be solved by assuming that the speed of light is constant. If this is so then the free space constants are also invariant and the laws of electromagnetism will still work properly in any inertial reference frame. | 2,434 | 3,485 |
ELI5: How do touch-me-not plant seeds "explode"? | Seed pods* | The cells of the plant on on side of the seed pod fill themselves up with water, using osmosis to transport the water within the cells. This causes pressures of up to 1 Megapascal pressing against the seed. (Atmospheric pressure at sea level is about 100 kilopascals) The plant forms a brittle structure, so that the seed pod will break before it ever bends. Then, the seed pods shatter, the seeds are launched, and water is sprayed everywhere. | 11 | 22 |
ELI5: If a person that works under cover is killed, what is told to the family of that person (especially if that person lived a double life and the family had no idea)? | Like for police work? Just like any other family of another cop, they have to be ready for a possible death. Families are informed that their loved ones are going undercover just not informed of the details. So, it's not like cops live double lives. | 23 | 57 |
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Can Hegel be understood without having read Kant? | So, brief rundown:
I'm studying Marxism a bit and I want to read *The Phenomenology of Spirit* as an accompanying piece of literature. This said, Hegel is the Dark Souls of philosophy. I've heard that understanding Hegel helps if you understand Kant, but for me that's a problem.
I've admittedly never read Kant but nothing I know of his philosophy (or ~~racism~~ anthropology) particularly excites me. In fact I profoundly disagree with a lot of it. So, going back to the question - Just how understandable is Hegel sans Kant? | You're going to have a bad time. It's probably worth at least reading the Prolegomena to get a handle on Kant's metaphysics and epistemology. As a bonus, it'll make almost everything written after Kant (at least in philosophy proper) easier.
Edit: to elaborate, at least part of what Hegel's reacting against is the the thing-in-itself (the unknowable thing that grounds the experience of an object) and Kant's categories.
Edit 2: You could probably read Hegel's Lectures on the Philosophy of History without Kant which would probably be immediately more helpful for Marx and an easier introduction to Hegel. That's where I'd started with him. | 55 | 73 |
What happens when light passes through a strong electric field? | Since photons have no charge, the light beam shouldn't bend, but will there be constructive/destructive interference between the external electric field and the light beam's electric field?
For example, if the E-field of the light wave is oriented along the z-axis and the external E-field is applied in the +z direction, then will there be constructive interference to half the wave and destructive interference to the other half? If so, how does this affect the properties of the light wave? | Electromagnetic theory is a linear theory, meaning that light, electric, and magnetic fields simply superimpose atop each other without interaction. This breaks down when the light is very, very high frequency (gamma rays), because quantum mechanics permits the gamma rays to spontaneously form electron-positron pairs which then can interact. As mentioned above, the presence of matter such as a crystalline lattice can modify the expression of a photon to a form that can be influenced by an electric field.
So a) nothing, b) unless the photon is very high energy, or c) you're not in plain vacuum. | 16 | 25 |
How can freezing water break matter? | I'm not sure how to put it exactly so here is a simple, "ideal" scenario:
If I put a bottle of water in a room and start removing heat from the room, the water will first lose its sensible heat until it gets to 0 C.
Then, the water will give up its latent heat and start freezing. Since ice is less dense than liquid water, it will start to expend in volume as well.
But if my bottle is closed, the ice will build pressure inside it until it breaks. The ice will do "work" on the bottle.
My question is: how could the formation of ice break the bottle if the water is already giving up energy as heat? Is there a force known as "work energy of crystal formation" that would explain it? How could it be explained on an atomic level?
Thank you for considering this. I couldn't find a satisfying answer by myself. | Phase transition "water -> ice" produces heat, but it doesn't mean that it *has* to produce heat. Unless heat is actually taken away from the water, it will not freeze. Unlike, say, a radioisotope source which constantly produces heat as a result of radioactive decay of its fuel, and will just heat itself up if left fully insulated; a bucket of water in the process of freezing will not heat itself up though.
Freezing happens because as you continue to take energy away from liquid water around 0°C, its molecules can collectively occupy lower energy states by becoming a part of crystal lattice. The phase transition can only happen if this extra energy will dissipate, usually through thermal contact. However, there's nothing that prevents you from using the energy to do work instead! Stretching the bottle and heating the freezer around the water bottle are not two independent processes, they use the same energy released in the process of crystallization. | 14 | 31 |
Professors of AskAcademia who supervise grad students - do any of you lack expertise in your student's chosen research area? | I'm currently trying to decide between two CS programs for my grad studies. I was admitted to my top choice (Masters with Thesis) and will be working on machine learning in the context of autonomous vehicles - this is a research area in an interdisciplinary project that definitely has me excited. However, a former student has told me that while the lab and program is great and that I won't regret it, the prof has almost no expertise in machine learning. The school however is a top 10 for CS in North America.
The second program offers a PhD and is from a school that's not really known for its Computer Science program. However, the prof and his lab seem like amazing people to work with and I've been offered a very generous stipend. The prof also has published papers in the research area I'll be working on. However, while I do like the area of work I don't find it as exciting as the one offered by my top choice school above.
I'm mostly comfortable working independently and enjoy flexibility but I also like to have some guidance from time to time, especially when I get stuck. For this reason, I'm having a problem deciding between the first option and second and would really appreciate your perspectives on this situation. Thanks. :) | You'll get a variety of opinions on this, but mine is that you should evaluate a PI on a managerial rather than an intellectual basis.
Most of the questions you'll need answered are contained somewhere in the literature if they can be answered at all. No professor - no matter how brilliant - can ever hope to know more than a small fraction of what is contained there. So the individual brilliance of your professor can easily be replaced.
What can't be replaced is your professor's ability to maintain a functional lab, help you through the hurdles of your career and secure stable funding.
For me, the easiest way to judge this is to take a look at your prospective peer group - the grad students you'll be working alongside. If they interface well together, are generally happy in their work and seem to be advancing well in their careers, you want to work for those professor - even if they're not the leading expert in your field. In contrast, if those grad students are working every other semester at Starbucks to pay their rent, hate each other and regretting their choice to attend grad school, you probably want to avoid that professor. | 44 | 24 |
ELI5:What does it mean when hawks and eagles have better eyesight than us? Does it mean they can literally zoom in on creatures on the ground, or do they just see things in a higher resolution? | They can see more detail- they have the equivalent of 20/2 vision, they can see clearly at 20 feet away what a normal human needs to be at 2 feet away to see clearly. They also see a broader spectrum of light than humans, so they can see more colors than we can. | 59 | 93 |
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ELI5 : If we never manage to create a true absolute zero, how do we know that it sit exactly at -273.15 °c instead of ,uh, -273.69 or something else? | Background: As temperature drops, the pressure that a fixed volume of gas exerts on its surroundings drops. As temperature increases, pressure increases.
Basically, the relationship between pressure and temperature of a gas is really well understood and well defined. We can take various pressure measurements at various temperatures and plot them on a graph. That plot shows a perfect straight line. We then just follow that line down the temperature axis until we see where pressure drops to 0. You can't have a pressure below 0, and so at that point we know the atoms of the gas have basically stopped moving, which we define as Absolute 0. | 64 | 22 |
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[Star Wars] Has technology peaked? It seems barely to have advanced in over 4000 years. | The droids are just as intelligent, the ships travel at the same speed, lightsabers, blasters, and bowcasters have never gone out of style...
Seemingly the only change is that the government in power occasionally decides to build a bigger weapon. Not a better one, just a bigger one. | Technological advances are still made, quite often, in fact. Across the Galaxy, there are scientists everywhere, and they're all working on something. New medicines are being researched. New droids are always being developed with higher clock speeds, more storage, better power consumption and so on. Ships also get incrementally faster, new navigation methods are developed. The only way a rational being could look at the scientific advances in our Galaxy and think of stagnation would be if they came from a world developing so quickly as to go from beasts of burden to spaceflight in half a century. | 290 | 262 |
[Smallville] Why does Red Kryptonite make Clark evil? | Red kryptonite causes kryptonians and/or humans that are affected by it to become reckless, evil, and dangerous, under the premise that it removes inhibitions. But Clark was raised by the Kents, who are basically superheroes in parenting, and taught him to be a good person. If it just removes his inhibitions, instead of going from good to evil, shouldn't he go from good to chaotic good? | It all comes down to what you think is under the surface. Nature Vs nurture kind of stuff. Is Clark good because of the goodness within him, or because of the guidance of John and Martha? There have been realities where Kal-El has not met with such fortune when arriving on Earth and has on occasion become quite the tyrant. Even under the stewardship of the Kents, he is not beyond having his "one bad day" that breaks him.
So if you strip away all the social nicities, the guilt, the obligation and duty... What Clark lies underneath? Maybe that's what Red Kryptonite exposes.
Does that make Clark secretly a would-be enemy of Earth, waiting to explode in alien rage?
Maybe. But maybe that's all of us under the facade and it's our willingness to maintain that facade that makes us truly good. | 17 | 18 |
Do all planets receive the same wavelengths of light from their star? | We observe our world through the light visible to our eyes, however there are know organisms who see different wavelengths, bees for example can see ultraviolet light. Could there be planets where potential lifeforms might have to evolv to see x-rays or microwaves in order to observe their world?
If some planets received a different composition of light waves than ours I suspect it might be possible but I don't know if that is physically accurate.
I know there are different types of stars and I know that the consensus is that a planet needs to be in the 'goldilocks zone' of a star to support life.
Thought I might ask here and hope it's not a completely stupid question haha thanks. | The "spectrum" of a star is what we call the distribution of brightness over different wavelengths. Hot blue stars have a spectrum that has more on the blue/ultraviolent end, and cool red stars lack the blue/UV but still have red/infrared.
In the "main sequence", where stars spend most of their lives, the blue stars are brighter and the red stars are dimmer, with yellow in the middle. The goldilocks zone is where the light from the star is bright that the planet is warm enough for liquid water to exist, but not so warm that it boils the water away instantly. You have a goldilocks zone around any type of star - it's just closer to a dim red dwarf than it is to a bright blue star.
So yes, a planet can be in the goldilocks zone of a star with a totally different spectrum. Even though your temperature might be the same, if you're in the goldilocks zone of a bright blue star, you'd getting hit with a "hard" spectrum with lots of UV - more UV than you'd get from being closer to a red dwarf star. If you're near a red dwarf star, you don't get as much visible light, even though it's fairly warm. This could have a big effect on the viability of life and its evolution.
(Side note: there are also bright red stars, i.e. red giants. But these are a short lived phase at the end of a star's life. Here the star gets a "softer" spectrum as it gets redder, but also becomes a lot brighter, enough that it would shift the goldilocks zone.) | 18 | 16 |
Why is philosophy so concerned with individual philosophers when science isn't concerned with individual scientists? | Philosophers seem very preoccupied with studying the views of specific past philosophers, and this is thought of as philosophy and not history of philosophy, but there seems to be no corresponding preoccupation in science. This is an uncontroversial observation -- isn't it? -- but what's the explanation?
I couldn't find anything on this by searching, but then I didn't really know what to search for. I'll appreciate being redirected. | Because scientists contribute small parts to a very large common theory.
Most philosophers, on the other hand, often contribute relatively large, self-standing parts to a pool of alternatives.
You'll notice that when certain philosophers contribute to a specific debate, or to a large theory, you will tend to concern yourself with the field as a whole, and with only the specific arguments of the philosopher that interest you. And it's not so rare that you're one of a very few major authors that take a specific stance on the subject. If you're the biggest-and-only name defending a contentious position, you can expect people to address *your* arguments specifically for lack of alternative.
However, since there is no commonly agreed way of establishing the philosophical value and accuracy of a certain philosophy, the cleverest of papers will not simply be accepted as a whole: there are many specifics, many of which another philosopher may criticise you on. This is rather different from science where scientific value and accuracy can be appreciated uncontroversially through mathematical validity of proofs and data treatment, and absence of systematic error in experimentation.
>This is an uncontroversial observation -- isn't it?
That's actually pretty controversial. Outside long dead 'greats', it's not clear how much philosophy is interested in philosophers as a whole rather than their separate answers to specific questions. This is especially true of contemporary academic philosophy where relatively few philosophers attempt to build a complete system which covers as much philosophical ground as possible - most limit themselves to a single-to-a-handful-of subfields. | 61 | 71 |
ELI5: Why is all soap foam white, regardless of the color of the soap? | Color can be made a few different ways. When sunlight goes through colored glass, some of the light doesn’t get through and the color we see is the stuff that did get through.
A colored bar of soap is that color because when light hits it, some bounces off but not all of it, and we see the combined colors that did bounce off.
Soap bubbles work slightly different to both of these. Rather than absorbing any of the colors, they just sort of bounce the light off equally in all directions and that just looks like white. The surface of the bubble is mostly made of things in the soap that aren’t colored, and some water. So you’ve got barely any of the colored stuff in the bubble, and the way the bubble itself behaves with the light makes it look white. | 71 | 111 |
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ELI5:How does Thermal Imaging work? | Heat sources emit electromagnetic radiation with a frequency respecting to their temperature. The visible spectrum of EM radiation ranges from red to violet. The sun's surface is about 5000 Kelvin hot and our eyes happen to see this light. Infrared means that the frequency of the EM radiation coming from an object is below the visible specrum due to lower temperature than the sun, anyway it can still be detected and it's frequency measured pretty accurately.
But How do we get a picture we CAN see?
Like digital cameras have light sensitive chips that render visible light directly to true red- green- and blue information in their memory, we can build a chip that detects light of lower frequency and renders it to any other colour and intensity value in real time.
It's just a microchip doing real time calculus, mapping the gathered frequency and intensity information to another color map we can display and see. | 664 | 1,587 |
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What language do deaf people think to themselves in? | Just as the title asks. | As /u/42sthansr said, they think in schemas - but this is only true up until they develop sufficient language skills, then they think in sign language:
"...the inner code hypothesis was tested to see if deaf signers were prone to the same sorts of confusions and slips of the tongue that hearing people make - only in their case, of course, with signs. For example, signers were made to grip building blocks tightly in their hands while memorising a list of words. This had the same disruptive effect as making hearing people repeat the nonsense phrase "Jack and Jill, Jack and Jill" during memorisation tasks. Signers also tended to make mistakes like confusing the word "vote" for the word "tea" - words which look quite different when read during a memory test but which have almost identical handshapes when coded in the internal language of signers. Further proof that signers think in sign language came from the way deaf people would sign in their sleep or 'think aloud' with fluttering hands when struggling to answer a difficult test question."
With the advent of new brain scanning techniques in the 1980s, neurologists, such as Dr Ursula Bellugi of the Salk Institute in the US, have discovered that signing uses the same left hemisphere processing centres as spoken language. Up until a few years ago, oralists had been able to dismiss signing as inherently second rate in the belief that, being a visual language, it must be processed in the ungrammatical right hemisphere."
| 81 | 164 |
ELI5: Why can English speakers efficiently communicate with most other English speakers (regardless of dialect) but a lot of Mandarin speakers can't communicate likewise between the various dialects of Mandarin nearly as efficiently? | Because there is no clear distinction between 'language' and 'dialect'.
An important aspect of differentiating between a dialect and a language is mutual intelligibility. If two people who speak the different dialects cannot understand each other, then they speak different languages.
However, in the real world languages don't exist in isolation. They are connected to culture, history and religion, and and all these aspects are also important in whether a dialect gets to be called its own language. For example, speakers of Hindi and Urdu can easily communicate with each other. In fact the Hindi pop culture produced in India is consumed by Urdu speakers in Pakistan and vice versa. However, because of historical and religious reasons, the speakers of Hindi and Urdu like to consider them different languages. The reverse is true for Arabic. An arabic speaker from Western Africa and one from Saudia Arabia would have difficulty understanding each other. But because of cultural and religious reasons, both would claim they speak Arabic.
So why are different dialects of Chinese not mutually intelligible. Because while they are considered the same language due to historical and cultural reasons, they are as varied as the Romance languages in Europe. Wikipedia states:
> The varieties of Chinese are usually described by native speakers as dialects of a single Chinese language, but linguists note that they are as diverse as a language family. The internal diversity of Chinese has been likened to that of the Romance languages, but may be even more varied | 58 | 43 |
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ELI5:How can prison inmates gain so much muscle when their diet contains low amount of protein and lot of unhealthy food? | While there's no requirement that prison food tastes good or that it's especially healthy, most jurisdictions do require prisons to serve a required number of calories per day and a specific minimum nutritional need (carbs, proteins, vitamins, etc). At least in most US states and most first world countries that's the case to some degree. There's plenty of controversy in the US right now around prisons serving nearly inedible food or shirking those mandated requirements, but in general prisoners are required to be served a reasonable amount of food with specific dietary requirements.
And of course, there can be extra food going around. It used to be that the #1 item in prison black markets was cigarettes. Nowadays I've read that it's instant ramen. Which again goes back to "lots of prisons are serving bad food, so people get more when they can."
But at the end of the day, so long as you're getting the required calories and some degree of protein, you can build some muscle. And when you're in prison and there's not a lot to do, your daily exercise time probably becomes a big thing. An hour or two of exercise a day is more than most people take, so a decent regimen over time combined with weight loss - again, as food is only meeting minimum requirements, it might not be easy to stay overweight - would make anyone start to look more muscly. | 22 | 22 |
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Are there any philosophers that studied the mind in that state where two or more conflicting intentions are being held and what makes one `win` over the other, so to say | Take smoking for example. A person knows that smoking is bad for their health and for their sense of taste and smell. Knows that it actually makes them more anxious, not less. That it is costing them a lot of money to indulge in that behavior. What's the most important is that they have made the conscious intention of quitting and yet they are unable to. | Frankfurt's theory of first and second order desires might interest you. He specifically uses the example of addiction and how it relates to freedom of choice. The addict is not 'free' when they act in a compulsive way because their first and second order desires are not aligned. | 40 | 56 |
ELI5: What do the numbers and letters mean/represent on a camera lens? | For example: 24-105mm f/4L IS | The numbers before mm = focal length, the fact that there are two indicates that this is a zoom lens. A small number = wide field of view, a big number = small field of view.
f/4L = maximum (biggest) aperture. This is the size of the opening in the lens to let light in. It is always a ratio to the focal length. A small number ie f/1.4 is a big hole which lets in lots of light. A big number ie f/22 is a small hole which lets in not that much light.
As indicated before, since this is the maximum aperture, the lens is actually capable of something like f/4-f/22. f/4 being the most light the lens can let in.
As a side note, aperture controls how much is in focus. at f/1.4 (big hole) there is only a small distance set which is in 'acceptable' focus. at f/22 (small hole) there is a large distance which is 'acceptable' focus.
IS = Image Stabilizer, this means the engineers have put in something to detect movement and do some fancy magic to let the lens minimize this effect, letting you handhold at a slower shutter speed than you normally could and not get a blurred image. | 17 | 40 |
What is a "grant"? | Sorry for asking such a question, but my first language is not English and people here talk a lot about grants. What is a grant? | A grant is a monetary award, usually from sort of governmental agency, that you usually have to apply for. Sizes vary. Small grants of several hundred dollars can be used for traveling to conferences. Grants of several thousand dollars can be used to purchase some inexpensive equipment or a computer. Large grants can be for hundreds of thousands or millions of dollars and can be awarded to individual researchers, groups of researchers or departments/institutions. These are often used to pay staff, hire postdocs, and purchase expensive equipment. | 29 | 21 |
What is the difference between magnetic and electric fields? | What exactly is the difference between magnetic and electric fields? I’ve got the impression it’s basically the same thing accept electric fields are produced only by electricity and magnetic fields are produced by magnets
(and electricity?). Could someone just explain it simply, preferably without using too complicated sciency words! Thanks. | They are closely related, and even transform into each other under changes of reference frame. But there are some important differences.
Assuming static fields (ones that don't depend on time), electric fields are sourced by **charges**, while magnetic fields are sourced by **currents**. (If you allow time-varying fields, then time-varying electric and magnetic fields are also sources for each other.)
Another difference is in how particles respond to the fields. Electric fields exert forces on any charge, while magnetic fields only exert forces on *moving* charges. | 35 | 16 |
ELI5: Where does the skin on the body stop being skin and become something else? Openings in particular. In the case of the face does it end at: lips? tongue? throat? | In the case of the rectum I assume the anal sphincter is the last skin hurrah before its all about intestines. Correct me if I'm wrong. What about the nose, the mouth, the ears.. etc. | Skin is a specific type of tissue- epithelial tissue. The other tissue types are connective tissue, nervous tissue, and muscle tissue.
Epithelial tissue covers body surfaces and lines most of our internal cavities. Connective tissues function for support and protection, such as bone, fat, cartilage, blood, and lymph. Nervous tissue receive stimuli and conduct impulses (neurons). Lastly, muscle tissue makes up, well, our muscles- skeletal muscle, smooth muscle, and cardiac muscle.
When considering the rectum to the anus, the rectum is lined with epithelium and the anal sphincter is made up of both a smooth muscle component and a skeletal muscle component. There are tissue transitions at these junctions, so the tissue will slowly become less epithelial in nature while also taking on more qualities of the smooth muscle until it is eventually all smooth muscle and no longer epithelium. | 10 | 27 |
How do we know the basics of mathematics are true? | How do we know that 2+2=4? The times tables, square roots, formulas of area, velocity, volume, and the other basics of mathematics are true? How do we know that they are not wrong, and what would happen if some of this was wrong? | The thing about mathematical truths is that they're true by definition or by construction. Mathematics works by starting out assuming certain things, called axioms, are true, and then everything else is of the form "assuming those are true, ...". | 24 | 15 |
Why don't researchers introduce cancer to colonies of bacteria repeatedly until they evolve a way to defeat it? Then copy their solution? | (dumping it down a bit, this is just the major concepts, there are many exceptions)
Cancer is beneficial to the cell it affects, so single celled organisms are unaffected by it. Cancer is basically cells that have mutated to ignore all signals that would cause the cell to commit suicide (such as rapid growth in places it's not supposed to be).
The problem occurs when that single cell is located in a complex multi-celled organism (all animals and plants). These organisms are characterized by having cells performing different functions, all dependent on each other. You have different cells in your skin, muscles, nerves, fat, liver etc. all performing different functions. There's at least 210 cell types in humans, and their location is crucial to their function too (you want lung cells in your lung and liver cells in your liver).
Due to the complexity of this, there's multiple safeguards to prevent cells from growing places they are not supposed or if they start behaving in a way they are not supposed to, and to make them commit suicide if they do.
Problem with cancer is that ONE cell of one of these cell types mutate in a way so that it circumvents these safeguards.
It will keep growing, eventually suppressing all the normal cells. It might also have cells break off the tumor, travel with the blood to other parts of the body and then start a new tumor there. This causes the organism as a whole to cease functioning and then die.
Problem with your question is that bacteria colonies doesn't have this complexity. It's just a bunch of the same bacteria clumped together. There's no dependency on other cells or structure to the colony, so 1 rampant bacteria wont kill of the colony but rather make it stronger, leaving no evolutionary advantage to prevent it. | 68 | 34 |
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ELI5: Why did two sexes become the norm for species instead of three or more? | The whole reason for sex (and therefore sexes) is to offer greater diversity of genes which help make a species healthier.
But if you added 3 or more sexes, then the process of sex becomes complicated, too complicated to make the extra diversity worthwhile.
Two sexes is a happy middle ground between diverse genes with not too much complication. | 34 | 15 |
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How many senses do we have, I have heard there is more than the five children get taught | I know there is more because if I spin in a chair and try to stand up one of my senses is screwed up but it ain't one of the main five.
EDIT: Dammit bad grammar in the title, pls don't be too cruel | Humans have more than five senses. Although definitions vary, the actual number ranges from 9 to more than 20. In addition to sight, smell, taste, touch, and hearing, which were the senses identified by Aristotle, humans can sense balance and acceleration (equilibrioception), pain (nociception), body and limb position (proprioception or kinesthetic sense), and relative temperature (thermoception). Other senses sometimes identified are the sense of time, itching, pressure, hunger, thirst, fullness of the stomach, need to urinate, need to defecate, and blood carbon dioxide levels. - Wikipedia | 47 | 35 |
Modern Islamic Philosophy | Are there any current schools of thought in Islamic philosophy?
EDIT:
https://www.reddit.com/r/islam/comments/59ogrs/modern_islamic_philosophy/?st=iusq3gt5&sh=28eb9aa9 | What do you mean by Islamic Philosophy? It's a kind of ambiguous term. There were traditions of Islamic platonism and scholasticism in the medieval period, and today there are certainly intellectuals who speak and write about Islamic law (fiqh) and Islamic perspectives on politics and world events, but the Islamic world is more diverse than ever and there are few if any universally agreed upon authorities in the Islamic world, so there aren't really universally respected Islamic intellectuals. Some popular ones in the West that come to mind are Sheikh Hamza Yusef and Sheikh Omar Suleiman, as well as Nouman Ali Khan and Mufti Ismail Musa Menk. But are they philosophers? Not necessarily in the traditional sense. In fact, whether or not there can be such a thing as Islamic Philosophy is itself a controversial subject. There are schools of Islamic jurisprudence, i.e. implementations of shari'ah, and there are differences between Shi'a, Sunni, Salafi, Wahabi, and Liberal Islamic outlooks. You may get a better answer in /r/Islam, /r/philosophyofreligion, or /r/progressiveislam. | 11 | 21 |
What are the ways to make a program faster and "lighter" | During my high school years I have been taught how to write good looking code, sorting it and using indentations, using comments when necessary...
But how do you optimize your code? ELI5? | Use efficient algorithms. Don't do work more than once. Weigh the trade-offs between keeping stuff in memory and keeping stuff in a database/file system, doing the work once and stashing it to save CPU or doing the work multiple times and never storing it to save memory. Learn to use your profiling tools.
Practice this for 30 years and you'll still be learning optimization tricks. | 50 | 39 |
CMV: As modern medicine and technology develop, natural selection applies less and less to humans | As medicine becomes more and more successful at keeping us alive, it allows detrimental genetic mutations to continue to exist in the human genome as well. If someone with a certain genetic mutation were to typically die without medical help, that mutation would eventually be eliminated from the human gene pool in the absence of modern medicine. Those without the mutation would possess an evolutionary advantage over those that have it, eventually out competing them and passing on their traits. This is natural selection, and throughout history it has been the driving force behind evolution.
As medicine, technology, and society keep those with a condition alive and able to reproduce, their genes that contain the mutation remain in the human gene pool and prevent it from being naturally selected out.
For example: take cystic fibrosis. Let's put morals aside for now. With modern medicine, it is common for people with this condition to live well into the reproductive stages of their life, allowing for the passage of the CF genes to their offspring. As such, these genes are not being selected out of the gene pool as a result of the success of modern medicine. In a scenario before modern medicine, I assume that the life expectancy of those with CF would be much lower, leading to less reproduction among those with the trait and the eventual elimination of CF from the gene pool.
This view also applies to adaptive mutations. If a genetic mutation were to give an evolutionary advantage over those without it, natural selection would eventually eliminate those without the mutation, and the mutation would become part of the genetic code present in all humans. However, in the modern world, technology and society eliminate the need to compete for resources, allowing those without the mutation to survive, therefore humans would never evolve to wholly possess the beneficial mutation.
In summation, there is no "survival of the fittest" among the human race anymore. Instead, it is now "survival of the not-unfittest." Modern society/technology/medicine, for the most part, prevents evolutionary pressure from eliminating "bad genes" from the human gene pool.
Disclaimer: This is in no way an advocation for the practice of eugenics.
CMV | If medicine and technology continue to advance, so will our ability to modify genes. Arguably, we are taking the first steps towards an evolutionary path that doesn't require natural selection at all. Survival of the non-unfittest is one way to describe what's happening, but may not be wholly accurate within a few decades. Rather than that allow the "unfit" to survive, we will be making the "unfit" fit. At least, in an ideal future... Obviously various dystopian options are likely as well.
Even if at this moment we are in a lull where it seems like we are accommodating "bad genes" without the ability to "fix" them, you could argue that this shift is part of a changing cultural understanding of biology no longer wedded to purely Darwinist outcomes. We no longer judge and/or allow the exclusion/death of people due to their natural limitations, but rather we include them because they are a part of the whole - namely, the human race. We do not let the vagaries of the natural world decide who lives and who dies, but instead treat every human as a unique and valuable contribution. This change, while at this moment may seem like it is allowing "bad genes" to survive, also seems like a key shift in our cultural understanding of individual's value to our shared genetic future. One that, alongside advances in genetic engineering, will allow us to include every individual in that future.
So you are right - natural selection will apply less and less to humans, but that will not be the bad outcome that you suggest. | 75 | 386 |
ELI5: why do people get sleepy from 2-5PM but wide awake from 2-5AM sometimes? Why isn’t it the opposite always? | When you eat, your body has to do work to digest the food. This is why you sometimes feel tired after lunch.
Most people don't eat in the middle of the night, so this isn't going to be a problem then, but when it's dark and quiet, lots of people get worried about things that they are too distracted to think about in the daytime, so they feel awake thinking about them because worry makes you alert to look out for danger. | 29 | 68 |
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Would blowing a meteor up as it enters atmosphere lessen the damage to Earth? | Or just turn it from a cannonball into grapeshot? | In principle, it will help. Of course it's all going to depend on the details - how fast it is, how big it is, how dense it is, how big the chunks are etc. So whether it's a significant difference or a small difference will depend on the situation.
Basically, the drag force on a bunch of small objects is (usually) bigger than the drag force on one big object of the same total mass. Drag force is proportional to the cross-sectional area of the object. If the chunks are roughly spherical, then the cross-sectional area is proportional to the *square* of the radius of each chunk. So if each chunk is half the size of the original meteor, it has 1/4 of the cross-sectional area. But the *mass* of each chunk is proportional to the *cube* of the radius.
So, if you halve the size of a sphere, you get 1/4 of the drag-force acting on 1/8th of the mass. From F=ma, that means that each chunk has 2x the deceleration from drag.
Now, you aren't actually going to blow up a spherical meteor into perfect spheres. But you should expect things to roughly scale like that - the smaller the chunks, the more drag force you get, and the faster the chunks will slow down.
(Note that if you sliced up the meteor in some contrived way, the effect can be smaller - if you chop it into long thin cylinders, you still have a small cross-sectional area per mass. But this is not what you expect to happen if you blow something up.) | 45 | 21 |
[General Powers] Are there any downsides to the Superpower of precognition? | Precognition, but only to a minor degree like a few mins. I was discussing this with a peer that every power has a bad side. My argument is that your brain could not comprehend the infinite possibilities that you would experience! He says I'm stupid | I guess it would depend on how much control you have over your ability.
Some stories with precogs who can see into the future without having much control over when they see it (like random flashes, or visions whenever they touch something) and how far they see into it portray the ability as a burden cause it diminishes their ability to live in the present, due to the content and scale of the visions being so overwhelming/disturbing/evoking a significant sense of futility to life itself.
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Does government assistance (welfare) really provide more dependent society or is it just GOP party's scary tactic? | Lately, lots of Republicans have self-entitlement and they don't realize how much the government helped them (financial aid, water, road, FDA, etc.) and they don't like to help the poor, because they fear that this might make people lazy.
Lots of Republicans "friends" argue that what Obama is doing right now is creating a government dependent society (which we are, I depend on government for water, highway, security, etc.). Also, they argue that there will be more people taking advantage of the system (i.e. they won't work hard, because they know the government will take care of them)
I wanted to refute them, but I didn't have any paper to disprove them otherwise.
Is there a study that relates government spending (excluding military and foreign aid) and number of people taking advantage of the system (if it's possible to find the number of people taking advantage of the system).
Alternatively, is there a paper that relates government spending on welfare and growth of private sector (that doesn't depend on government contract)?
| You're asking for studies, but you need a rhetoric lesson. Knowledge does not come only from paper, and the type of paper you're suggesting would be hard to write for the reason you say here: how do you quantify, much less measure, "people taking advantage of the system"?
And that is your tack to take. When your Republican friends are saying to you whatever the most recent GOP opinion machine talking points are, ask yourself how one might measure the things they're talking about. Hell, ask them too! You'll get evasions and huffy defensiveness because they haven't thought about it, and don't really know how to, but don't want to say so.
Work with them to *define their terms*, and then *define a way their claims can be tested*. They will either do this in good faith with you, and you can then 1) look up those studies which have actually been done and 2) point out that these talking points are very selective in whom they target, or they will huff and leave, in which case you've shut them up for awhile. When they come back the next day repeating the next thing Hannity and Limbaugh said, repeat the process: demand consistent use of terms and testing statements. Eventually they will either become libertarians or stop talking to you about their politics, either way you win. | 36 | 23 |
ELI5: How did wearing caps and gowns at graduations become a thing? | Originally, the cap and gown was a practical uniform for medieval university students, much like monk's robes and nun's habits. The design was meant to be practical and warm while distinguishing scholars and teachers. There are many traditions of rank and specialty which are actually remeniscent of military uniforms.
Of course people don't wear the cap and gown every day anymore, but it has retained a tradition on formal educational occasions.
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How is online gaming possible if there must be some delay? | Online communication always has a delay, especially when people communicating are on opposite sides of the US. If that's the case, then how are fast FPS video games, like Call of Duty, possible to play online? | Modern games tend to employ two different techniques simultaneously in order to compensate for lag, but players with lower latency will still have a small advantage.
1. **Server state rewind**: You're playing an FPS at home and you pull the trigger. At that moment, the stuff you see on your screen is already out of date by 20-50ms. And the command to fire your gun doesn't reach the server for *another* 20-50ms. But the server knows *when* you fired the gun, so it just rewinds the game to that exact moment to find out what you hit.
2. **Client-side prediction**: Certain actions that you perform in the game (firing, moving, jumping, whatever) don't actually execute until the server receives the command. But the game would feel terribly sluggish if your client were to wait for official confirmation. So your client *simulates* the command locally under the assumption that the server will allow the action. You pull the trigger, and your client immediately plays a gunshot sound and draws tracer rounds on the screen. You *feel* like it executed immediately... but other players in the game actually don't see your shot until 100ms later.
These techniques allow games to feel responsive and accurate, but they can still cause conflicts. Sometimes you pull the trigger, but you're already dead on the server (somebody shot you and you don't know it yet) so the action isn't actually performed. You feel like the game robbed you of a kill because that's what it looked like on your screen. | 147 | 44 |
ELI5: How are LEDs brighter and more powerful, yet use so little energy? | Ex: Police Lightbars, they're so bright but use so little of the cars battery. Much less than the classic rotating lights. | You know a lot of light is invisible, right? Infrared, for example. You can't see it, but you can feel it on your skin with your eyes closed when you're standing near something really hot.
Take two lightbulbs that consume exactly the same amount of electric energy, but one produces only visible light, and the other products half visible light and half invisible. The second one will look much dimmer.
The old-timey incandescent filament lightbulbs, the ones that burn your fingers to the touch, they produce mostly infrareds! To the tune of 90%!
That's why so much progress has been done. Because there was so much room for progress.
LED lights produce mostly visible light. Do this is it. There won't be much progress anymore. We're there. We can focus on other things now. Cool, hey? | 26 | 18 |
To Professors, how do you prepare your lectures? How do you design them to teach? | Hello professors of Reddit! I am a college student, and right now I am trying to learn my course material better by trying a new study technique. I've heard that if you can teach the material for a topic, then you probably know the material for said topic. So, I've decided to set up a camera and a whiteboard and make personal lecture videos on the topics my professors have covered in class. In order to make these self-lectures better, I want to know how real professors prepare for their lectures: especially those in the STEM related fields. I especially want to know how you go about reviewing the material you are about to teach before you actually do the lecture. Thanks for any and all help! | You might be better working in a group of peers, or assisting a peer or someone in years below who needs some guidance.
This way you get feedback and are able to see issues in teaching and learn how to explain problems/solutions to people.
This is how most profs start out teaching, maybe as a TA etc.
Reciting to a camera alone won't teach you much about teaching. | 31 | 41 |
ELI5:Why do we get car sick as a passenger and don't as a driver? | When you are driving, your body basically identifies the car as a tool you are manipulating. Your actions have direct effects on your motions and what you are seeing, so even though the kind of motion isn't one we evolved for, the brain is ok with it.
When you aren't driving, none of that is true. The brain identifies really fast motion completely divorced from any actions it takes and concludes you have been poisoned. Standard protocol for poisoning is vomit. Because evolution is annoying that way. | 48 | 26 |
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Why is it that a single good deed isn’t enough to pardon a life of evilness but a single act of evil is enough to condemn a life of good deeds? | This was a quote in a movie. But this seems to be true in real life as well.
By extension, if we quantify good vs evil, does this imply effect of 1 unit of good < effect 1 unit of evil?
And depending on the answer, do utilitarians take this factor into consideration? That, for example, harming 1 person may irrespectively outweigh the good caused to the other four because of the above fact? | From the point of view of moral psychology, it's to do with trust.
Our conceptions of morality and especially our moral intuitions serve to structure our social interactions. When we think about people being good or evil, that informs our interactions with them. We don't just enter into every social interaction with a blank-slate absence of expectations. We form opinions of people, gossip, share information, and create reputations, all to inform us what to expect when dealing with one another, and how to treat each other. If someone is a war criminal, we want to *know* that before going for coffee with them.
Now, 'good' and 'evil' aren't just value-neutral valences on a scale, like +1 and -1; they're qualitatively distinct. When someone not only fails to do good but acts in a way that can be described as evil, this *undermines* much of the credit we might otherwise give them for the good they've done.
As other commenters have suggested, the more general psychological phenomenon of negativity bias might also be a factor. We're more alert and sensitive to threats than we are to the positive counterparts of negative stimuli or experiences, because evolutionarily speaking, the cost of missing a warning sign can be a lot higher than missing something potentially good. Applied to people's characters, it's safer to err on the side of condemning evil.
This only works up to a point, though, namely so far as to not make trust and cooperation impossible. If everyone is *too* quick to condemn each other, let alone enact revenge, social cooperation collapses. I'd say that's why the quote is a bit overly simplified. There is an asymmetry there, but it's not fully one-sided. | 147 | 307 |
ELI5: How do cells and bacteria see each other | How do bacteria and cells see each other? I've seen some videos like this [white bloodcell chasing bacteria](https://www.youtube.com/watch?v=3KrCmBNiJRI), but also [a nanobot picking up and moving a sperm cell](https://www.youtube.com/watch?v=d36synYX18w). How can they see or sense each other considering they don't have eyes? | The cells do it by basically using smell to snuff out the bacterium of interest. They detect the molecules and their concentration, and the bigger the concentration, the closer to the targeted object. This is used to orient the cell. Sometimes the chemical is released by the bacteria itself, sometimes by the damage the bacteria causes and sometimes by another cell releasing an "alarm signal".
This is called chemotaxis. | 51 | 43 |
[Star Trek]why are the Romulans considered a separate species to Vulcans when they only split off from them 2000 years ago? | There's tribes that have been isolated for much longer than that, we still call the people in them human beings | Human tribes have been separated for longer, but on the same planet. Same light, same radiation, same atmosphere. Species change over time, but differing environments will have them changing faster. If the new environment on Romulus has certain factors and older Vulcans either die off or don't reproduce, the new Romulans will take their place. Differentiation can happen faster on two separate planets than on one.
Also, what you consider a separate species needs to be taken into account. We traditionally say that two animals who can no longer breed are a new species. But that definition won't work for Star Trek. Cardassians and Bajorans can interbreed, so can Klingons and Humans or Vulcans and Humans. | 95 | 129 |
Advice for a young professor dealing with academic burnout and needing to revive a flagging career? | I started this job four years ago and they have been really hard ones for me. Between the demands of my academic job, a difficult department/institution, and some really tough family stuff, I am just wrung out.
I am the only child of elderly parents who have had a continuous set of alternating health emergencies over the last four years. Two or even three times a year a parent required a long hospitalization and a complicated recovery that I had to take care of. A year ago my father passed away leaving the control of everything in the family to me (my mother has dementia among other chronic issues). Settling his estate and making sure my mother is cared for has been a very big job (not to mention dealing with the grief when I have a bit of time to do so, we were very close).
Superficially, my department was understanding, saying to take the time I needed and family comes first, etc. In reality (and perhaps understandably), though, they saw my reduced productivity and attendance in the department and were not pleased. I just can't be the high-performing academic they want. I kept thinking that after each crisis, things would smooth out and I really get things done, but then another would come up. I've had a few painful and frank conversations with my chair and the provost. I think they could have been more supportive, but they weren't, and it's better not to think of what could have been and concentrate on the regular situation.
I've managed to do all the service and teaching required, but that is not valued much. I tried to revive my research many times with collaborations and taking on new students. None of the students have worked out, they learned a lot but I ended up needing to redo all their work. (This could be my fault as well, not supervising them enough.) I have a lot of great collaborations, but that work has also been massively disrupted by my family issues, and they have lost patience with me (also understandably). Just down to it, much of the issue is that I do not have the energy and focus research requires.
I need a new job, I just cannot perform at the level needed here, but I find myself feeling too burned out to go through the faculty job search process again. Also, I have not published in *years* and my last grant ran out in 2017, I have not had a new one (applied for a couple but no luck). My CV looks pretty sad right now. I should be manuscript-writing my ass off, job-applying my ass off, grant-writing my ass off, but I find I can barely get four hours of work done in a day.
(As an aside, I'm not alone in all this. I have a husband, but he actually has had almost identical issues with his family and is also exhausted and grief-stricken. Additionally, he hates his job, whereas for me it feels more like my job hates me. I have seen a therapist and a psychiatrist. I am on anti-depressants and though I am not really depressed I think it maybe helps somewhat. They have both been sympathetic and helpful in some ways, but the consensus among them is that things are just really hard and my issues are a normal response to continuous stress.)
Any advice on how to recover and revive? | Is anything you're dealing with covered under FMLA? A colleague of mine stopped the clock for reasons of family disaster, and made tenure in the end. She did however go a year without pay, and had benefits through her spouse, so it may not be viable. (This assumes you are in the USA, of course.) | 38 | 119 |
Is it possible to have an orbit that doesn't bisect the planet? | An orbit around just the middle of the northern hemisphere.
Most satellites I see appear to go right around the "middle" of the planet. I figure that is just because it is easiest, but is it the only realistically possible way to have an orbit without continuous adjustments. | An orbit must have one focus on the centre of the primary body. Also, orbits lie in a plane (orbital plane) and the focus lies on this plane. So this plane must intersect the equatorial plane. In particular, unless the orbit lies exactly on the equator, part of it will be in one hemisphere and part in the other. The points where the orbit crosses the equatorial plane are the nodes (ascending and descending) and the line connecting them is the nodal line, which is also the intersection of orbital and equatorial plane.
No escaping this! | 29 | 113 |
With the talk of possible habitable planets, Could the human body withstand a world with twice the amount of gravity? | I made a post [here](http://www.reddit.com/r/explainlikeimfive/comments/1hxfkd/eli5_with_the_talk_of_possible_habitable_planets/) and someone suggested to ask here.
Lets say somehow, someway we manage to make it to an earth like planet and it can support life but it has twice the amount of gravity than the earth, would humans be able to safely travel around the planet?
(I pretty much have no clue what I am talking about so if this question makes absolutely no sense, please inform me! It's super interesting!)
To add a little more information that I've read is that the human body can withstand two/three times gravity of earth, but for how long? long exposure sounds like it would be bad.
edit: I guess I should have phrased the question slightly different. The question should been something along the lines of "With the talk of possible habitable planets, Could the human body withstand more gravity for a long duration on another planet?" | If we look at known effects from weighlessness and invert, it can be imagined that the increased load on the body structure would prohibit movement at first and then cause growth of muscle possibly beyond what the body can comfortably accomodate. The increased strain on the bone structure could lead to increased density to cope.
What would concern me most is the effect on internal organs. First of all, the heart would need to work harder to get blood around and it would likely grow. The extra pull on all the organs, that don't have a strong structure themselves, would be a probable source of complications but someone with more medical training would have to comment on that. | 278 | 862 |
CMV: Psychology should be taught to children as part of an education. This would help to adress abuse or neglect, increase mental health (individual and collective) and enable more healthy relationships (social and romantic) | Newest remark :
My title was incorrect, as psychology isn't completely suited for the things I had in mind, what is probably an mixture of interdisciplinary fields ranging from psychology, to sociology and social work.
Any CMV pros got tips how to proceed as I can't change my title?
Additional Remark:
From the comments it's clear that the term psychology is very polarizing, but I only chose it, to cover a larger area of topics, than are mentioned. It seems most welcome the idea to prepare kids with real life matters, but they would call the subject differently. In the UK there is PHSE (personal, social and health education) under which these matters of the mind could be taught.
End remark
Psychology as a science is a little bit obscure and hard to verify, but with increasing advancement in technology and social science, we are learning more and more about how our mind works and how our and the mindset of others dictates our social interactions.
Children should be exposed to this knowledge in an age appropriate way, as those concepts may help them understand their experiences in life.
It will help them not only to recognize their neglect or abuse, but that of others too. By preparing them with the basic tools to articulate theses matters, we make it easier for them to seek out help.
Also like Sex education is thought for the body, there also should be Relationship education for the mind.
Edit: Yes, psychology is a complex science, like physics or chemistry. All I'm suggesting is creating a subject called psychology, that helps kids adress some challenges in life.
Edit 2: Psychology is probably a too narrow scientific field, since some of my proposed topics are rather covered by sociology.
From Wikipedia:
"Psychology is the science of mind and behavior. Psychology includes the study of conscious and unconscious phenomena, as well as feeling and thought." | knowing psychology doesn't change human nature, it might allow them to notice things, but it more then likely would give them false positives and false negatives as they are not trained in psychology, (turns out psychology is a field not something you can teach in a few weeks)
the danger isn't no knowledge its a little knowledge that thinks its a lot of knowledge. | 25 | 193 |
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