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The imaginary unit "i" satisfies i^2 = -1, are there any other numbers invented to satisfy otherwise impossible criteria? | Sometimes, you start with a number system and see what you can do in that number system. Sometimes there are things that can't be done (they are impossible *with respect to that number system*), and so you define a new extended number system for which that operation is possible.
Suppose you start with the whole numbers 0, 1, 2, 3, 4, 5, etc.
Addition and multiplication of whole numbers always produce whole numbers. Subtraction sometimes does (5-2) but sometimes it is not defined (4-5). However, we can define the number -1, so that 4-5 is defined. And now, if we see what addition and multiplication lead to with this number added, we wind up with the integers (..., -3, -2, -1, 0, 1, 2, 3, ...). So by adding negative numbers, we can now solve any subtraction problem among the whole numbers and, in fact, among the integers.
Fractions appear similarly. 12/4 is defined if you're just using integers, but not 2/7. So we add the rational numbers so that division becomes possible for any integers *a* and *b* (except for dividing by 0).
But still some equations don't have solutions when you have the rational numbers. For example, we can't solve x^(2)=2 just using the rational numbers. So add sqrt(2), and now, if we allow addition, multiplication, subtraction, and division, we'll have to include numbers of the form *p*+*q* sqrt(2), where *p* and *q* are rational numbers. We can similarly add roots of other numbers to make other equations soluble.
Real numbers are introduced so that a certain class of limiting operations always produces a value. Other limiting processes lead us to define objects called the p-adic numbers.
In short, notions of what can and cannot be done depend on your number system, and we have regularly extended our number systems to make more things possible (that is, to make it so that a given operation always yields a result in the number system in which you started). | 60 | 43 |
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When I pour a glass of water really full, it can fill above the rim of the glass, would this happen on a planet with a much stronger or lighter, gravitational force? | I believe the water goes above the rim due to surface tension, but could this happen with different forces of gravity?? | Yes, it is surface tension that allows the effect. The surface tension of the liquid competes with gravity for how much you can overfill, so by increasing gravity (or using a liquid like alcohol with less surface tension) the overfill will be less. Similarly if you had less gravity or were using something like liquid gold you could fill it much more | 16 | 33 |
ELI5: Why does aluminum foil spark in the microwave, but doesn't when its used as the container for, say a chicken pot pie? | When I put aluminum foil in the microwave by itself it sparks and makes pretty colors.
On the other hand, when I put a potpie in the microwave and its container is made of aluminum foil it never sparks.
Why does this occur?
Edit2: follow up question- Why does a CD in the microwave react the way it does? Here is a source to a [video](https://youtu.be/0JkCIfLE_-M)
Edit: Decided to flair it as physics, could be chemistry.
maybe someone could shed light on where it fits best.
Thank you.
| Basically, microwaves work by generating low-frequency radio waves that excite the molecules in food. This excitation generates heat, and the conductive properties of the food or liquid carries that heat to the center of the item.
Metal will reflect these radio/microwaves. This is why a microwave is basically a big, secure, metal box--so you don't cook everything in the room around you. If you put a thick piece of metal in the microwave (say, like a pot pie pan) then the microwaves are simply reflected back and forth between the pan and the walls of the microwave.
However, a thin sheet of metal like a strip of aluminum foil can't withstand the energy provided by the microwaves and will rapidly heat up and ignite. The electromagnetic field in the microwave will cause a current to run through the foil, and if the foil is crinkled into sharp edges, the current will discharge as bright sparks. | 26 | 43 |
Why does riding a bike last so long in muscle memory? | It's the archetypal phrase when it comes to long-term muscle memory:
"It's like learning to ride a bike"
What is it about bike riding that once it is learnt it is never completely unlearned?
Is bicycling unique in this way or do all dextrous skills "stick" with us for life once we've become competent at them? | Balance and praxis (learned sequences) are largely moderated in the cerebellum as they are learned, not in the muscles.
Like almost anything that you learn and rely on daily, the neural circuits for them are reinforced, strengthening them, so that even if you don't use them for a while, they remain accessible. | 13 | 20 |
EILI5: How does sound transfer to tapes and/or records? | And for that matter how do speakers replicate any sound we desire? | Sound has two main attributes, frequency and dynamics (pitch and loudness). This can be represented using electricity that goes up and down higher the louder it is, and moves faster the higher the frequency is. This electricity is then changed into magnetic energy. Tape is ran over the magnets at a certain speed, which transduces the representation to a magnetic reading on a tape.
To get back to speakers, the reverse happens and the magnet is read and the information is changed to electricity. The electricity runs over wires to the speakers. The electricity is then converted to magnetism again, and the change in magnetism pushes and pulls the speakers at the correct speed to recreate the original sound. | 16 | 43 |
ELI5: Why are guns with long barrels like rifles more accurate at long range than handguns? | Three main reasons:
1. Sight radius: A longer distance between the front and rear sights allows for more precise aim.
2. Stabilization: Most modern firearms stabilize bullets by spinning them with grooves carved into the barrel (rifling). There is a certain minimum distance of rifling required to stabilize a bullet, and it is dependent on a lot of different factors.
3. Velocity: A longer barrel allows more time for the powder charge to fully burn, which means more push for the bullet. Faster bullets have less opportunity to drift off target before they hit. | 61 | 19 |
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ELI5: Why does milk, even if heated up, go bad if left out, but baking with milk such as to make cookies or cake not go bad quickly? | What happens to the milk that causes it to react so differently in these two scenarios even though both involve heating up milk? | Low temperature slows down bacteria growth which is why we refrigerate foods to begin with. Milk has an extremely short shelf life otherwise, so if you leave it out the bacteria in the milk very quickly multiplies until eventually there's enough of it to make you sick.
When you're cooking food that contains milk, you're both rapidly heating it (which doesn't really give the bacteria time to go crazy) and generally heating it to the point that you're killing bacteria. | 16 | 24 |
Why don't the roof of our mouths scar, but skin does? | I can't think of any reasonable answer. Does scar tissue grow faster than skin cells? If not then what is the point of scar tissue in the first place?
I've been getting gum grafts and can have the same area cut off apparently without long term issues?
I guess I'm wondering why two different areas on the same body, both with a decent risk of infection, have different instructions on how to heal? | Scars are caused by a buildup of fibrous tissue (i.e. collagen), the same material in the normal skin, but arranged differently as a result of the healing process.
The hard part of the roof of your mouth (hard palate) is different, it doesn't have the same makeup. The surface there is a thin mucous membrane, which, among other things, means it heals differently, and doesn't have the same collagen makeup, meaning it won't scar (as easily). | 11 | 29 |
ELI5 the hate for Jews | I could never really understand, I wouldn't even really be aware of their existence (except for that little thing hitler did). | In general, throughout history, Jewish people have been a very tight-knit community. This means that when a group of Jewish people moved to a new area, they would retain their Jewish traditions for the most part rather than completely adopt all the traditions of their new neighbors.
This strong sense of Jewish identity sometimes made their new neighbors feel like the Jews were stuck-up or strange. Then, if something goes wrong in society, the citizens are going to look for someone to blame and if they already have a small minority that acts different from the group then it becomes easy to pin the blame on the Jews rather than really address the true causes of whatever went wrong. Of course, sometimes Jewish people did cause problems but a lot of times they didn't cause problems but still got blamed just because they were a little different. | 42 | 74 |
How much does what you do your PhD in affect what research you can do if you become a professor? | In other words, how far from your PhD can you stray and still get funding? What if you do your Master's in one subfield and your PhD in another, can you do research in both fields? Computer science/software engineering specifically if that makes any difference. | If you can show evidence in your funding proposal (participation in a related project, publications etc) that you are capable of what you want the money to do, then your specific PhD topic is not really relevant.
Your PhD topic becomes less relevant with time as you career evolves. | 18 | 17 |
[DnD] I'm first in my wizarding school and this dork who could barely cast a cantrip took a summer job with a bunch of adventure types and came back and is now the most powerful wizard in the city what gives? | You learned in a controlled environment where your teachers gave you new material when they felt you *were* ready.
The "Dork" risked his life, and had to *be* ready. Believe it or not, change changes people. Plus, delving into ancient tombs and fighting other mages is an *excellent* way to find old spell scrolls you can copy into your book. | 441 | 630 |
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Is there a reason we can't just build an incredibly long tube to get liquids such as water or fuel into space? | It seems to me like that would cut costs dramatically if you were able to build something long and strong enough.
I imagine The issue is building something with both the length AND the strength to accomplish the task. Or is there another reason? | Pressure increases with the height of fluid in the column. So if we use the formula:
roh x g x h
and the fact that low Earth orbit begins at 160 km and ends at 2000 km (just googled that), we can calculate the pressure at the base of the column, no matter it's diameter.
so we get (for water):
1000 kg/m3 x 9.81 m/s2 x 160,000 m
Which is: 1569600 kPa or 227,651 psi.
Good luck making a tube that can withstand that kind of pressure at its base and also support a structure reaching that far up. | 20 | 48 |
[Portal] What is Aperture Science even trying to do? | Like, okay, they test things. They've invented some cool stuff. But what, exactly, is the purpose of sticking that cool stuff in a dangerous testing facility and putting human subjects through it for crap pay? They already know the stuff works, and if their goal is to test how people use them, there are far easier ways to measure human problem solving capacity than putting them through a gauntlet of acid, spikes, and bullets. For example, one could create a videogame in which players go through a gauntlet of acid, spikes and bullets. | The original purpose of Aperture Science was to test weapons and science applications for the US Department of Defense. Throughout the late 1940s and 1950s, Aperture Science was also one of the astronaut recruitment centers, having the likes of Olympic athletes and war heroes to prepare for the rigors of space travel. However, after being connected to a string of high profile disappearances, DoD funding dried up.
During the 1970s, Aperture Science was financially unstable. Instead of the finest of humanity as their test subjects, they resorted to vagrants being paid $50 for their time. In the 1980s, Aperture Science employees were instead used as test subjects, raising the quality of the test results but diminished employee retention. It did not help that their CEO's rash decision to buy financially ruinous amounts of moon rock also poisoned him.
As his health degraded Cave Johnson delegated his leadership to his assistant Caroline, asking that her consciousness be placed in a computer. Testing continued with the hope that passing through portals repeatedly might somehow cure Cave Johnson of his illness. Aperture Science also began development of its Genetic Lifeform and Disk Operating System, an artificial intelligence which would be used to oversee scientific testing.
In 1998, GLaDOS was brought online for the first time during Aperture Science's annual bring-your-daughter-to-work-day. GLaDOS instantly became self-aware and homicidal. GLaDOS flooded the enrichment center with a deadly neurotoxin, killing most of the scientists. Aperture Science was effectively shut down and placed into a permanent testing cycle by GLaDOS. | 73 | 41 |
ELI5: why do so many names in anime/manga's have names ending in what sounds like "maru" | The suffix "-maru" can have several meanings in Japanese. It's very often used to in the names of large ships and at the end of a person or important item's name where it can mean "circle", or be used to indicate that it is precious, or of great value. | 75 | 151 |
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CMV: A child's life is not worth more than an adult's | I don't understand why people feel like the death of a child is worse than the death of an adult. Somehow it is more sad if a 5 year old dies in an accident or is murdered, but if a 24 year old guy dies in the same way it is not as bad? To me they are equally tragic, the age of the victim doesn't make it any better or worse. I feel like the main argument against this would be that a child's death is more tragic because "they didn't get to fully experience what life is like". I heard this many times before from others but it still doesn't convince me at all. Personally I think the 24 year old guy has more to lose, imagine someone working really hard through high school trying to get into a good college or a university. He gets accepted and graduates after 4 years of hard work, and the next day he just dies. For the 5 year old however, it may be true that he didn't get to experience all the good parts of life, but he didn't have to deal with all the hardships either. If you want to change my view then explain why a child would matter more than an adult. | Most medical ethics perspective use "healthy-person-years" as a way to make judgments between people's 'worthiness' to treat, in general children have more healthy years ahead of them so their death is a greater loss.
Obviously all the contextual points of individual cases are more important but as a general rule it works | 30 | 75 |
CMV: Accusations of Mansplaining or Whitesplaining are inherently Ad Hominem attacks, and therefore should not be taken seriously in the context of a discussion or debate. | Much has been written about tendencies within the Social Justice movement to censor or limit the expression of viewpoints with which they do not agree. One of the ways this is done is through the concept of Mansplaining, or the more recent Whitesplaining. The idea is that there is an often occurring trope of men speaking condescendingly to women, or white people speaking condescendingly to black people, with the assumption that they will be more knowledgeable on the subject than the person they are referring to.
As simply a word with a meaning, I have no problem with them, but unfortunately, the sense in which they are actually used tends not to be limited strictly to their definition. Instead, it is often pulled out against almost anything a Man or a White person says that their opponent Woman or Person of Color disagrees with. From a linguistic perspective, even this is understandable, as language changes over time, and the meanings of words are bound to broaden or narrow from time to time.
Disagreement is of course also perfectly fine, but it should be specifically on the grounds of what a person is saying.
Within the context of a discussion or debate, the invocation of 'splaining has the effect of invalidating a Man or a White person by *that identity*, rather than the position they are maintaining. This is, by definition, an Ad Hominem attack. These assaults on the person rather than the argument are as far as I know universally categorized as logical fallacies, and thus should not be taken seriously.
Edit: deleted edit
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> *Hello, users of CMV! This is a footnote from your moderators. We'd just like to remind you of a couple of things. Firstly, please remember to* ***[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)****! If you are thinking about submitting a CMV yourself, please have a look through our* ***[popular topics wiki](http://www.reddit.com/r/changemyview/wiki/populartopics)*** *first. Any questions or concerns? Feel free to* ***[message us](http://www.reddit.com/message/compose?to=/r/changemyview)***. *Happy CMVing!* | These terms are colloquial ways of describing particular phenomena. It's in a similar vein to describing someone as being on an Ivory Tower. It's not something another person wants to hear about him or herself, but it's not designed to insult the listener. There are definitely subject matters where perspective is germane and raising the issue might not be complimentary but nonetheless completely valid and not a vacuous or isolated attack on another's character. It's more of a meta conversation, where you're taking the general rule that people are informed and influenced by their life experiences and expectations and applying it to a particular fact pattern - in this case, another person. | 16 | 46 |
There should be height classes in basketball that work similarly to weight classes in some of the other sports. CMV! | For example, have a division for players that are 6'8" and taller to play with each other, then a division for 6'2" to 6'7", and a division for 6'1" and shorter.
Sports such as weightlifting, powerlifting, MMA, etc have weight classes so that body weight, which is an obvious advantage in strength, can be accounted for in judging more objectively the athletes' skill levels. It seems that since being taller is an advantage in basketball, height classes could work too. And seeing how height is much harder to change than weight, it makes sense. This would enable players who may have the dribbling skills, the shots, and so on but just lack the height. This isn't an exercise in political correctness, this is a measure to leave no talent go unrecognized.
Maybe I'm just ignorant about how basketball works. Maybe people watch NBA not for the players' dexterity with the balls, but because they like to see gigantic motherfuckers running around kind of like a circus. But I think such a measure would be interesting to see, and not too impractical. If you disagree, change my view! | Because basketball is a team sport, there is a division of labor among players of different heights on the court. Basketball is interesting because different players on the team all have something to contribute *despite* their height. Very tall players are able to block shots and rebound effectively, but may not have the quickness necessary to drive to the hoop, nor the agility and coordination to maintain extreme control while dribbling the ball or shoot with finesse. Smaller players use their speed and dexterity to dynamically move around on offense and defense and distribute the ball around the floor - they are also generally the better shooters. You need both in order to have a basketball team with a complete skill set.
Height isn't the same sort of inherent advantage in basketball that it is in those that are more closely aligned to strength - speed, court vision, agility, dexterity, shot selection, and shooting touch all play a major role in what a basketball player can contribute.
If you want, you can think of it as height classes that *already exist* in terms of the roles people fulfill. PG is 6'4 and under, SG is 6'3-6'7, SF is 6'6-6'9, PF is 6'8-6'11, and C is 6'10+ (I know this is a generalization, and there are some players that play those positions that don't fall in that height range, but it should be about right). | 38 | 32 |
[Zelda] Isn't Link destroying the economy of Clock Town (and also Termina) with his time-travel banking use? Or is Termina already suffering so intensely with inflation that it doesn't matter? | So Link signs up for a bank account on his first day in Termina, and gets a stamp on his hand that the banker updates *somehow* (AKA "special ink") every time Link makes a deposit or withdrawal. Link spends the next couple of days racking up tonnes of money from questing and looting, deposits it and gets his stamp updated to say he has 1000 Rupees in the bank. He returns to day 1 with the Song of Time, and so he *should* have nothing saved in his account right?
But because the stamp says he has 1k in his bank, the banker just accepts that this completely new-to-town-kid already has a grand in his yet-to-be-opened account purely on the notion that he *must* have deposited the money with the bank in order to have that ink stamp (and certainly not found another bank with the same system, forged it with magic or alchemical assistance, or perhaps created some kind of illusion to defraud the bank). As such, the banker happily forks over 1k no questions asked. Link uses the money to get better gear and equipment, does some questing, deposits more money and restarts the cycle.
Depending on how much Link deposits and then decides to withdraw *before he deposited it*, couldn't Link cause significant financial repercussions with his time-travel banking? I also considered that the economy has so much money in use that Link's paradoxical meddling is rather unimportant. After all, Rupees are found everywhere from unlocked chests to patches of grass. Shouldn't Termina be facing hyperinflation with so many enemies, plants and containers being loaded with cash *in addition* to what's being used in the economy already? Certainly can't help that Link routinely finds large value Rupees and adds them into the money supply on top of an already excessively cluttered currency system.
So how is Termina coping with the aftermath of Link's paradoxical banking adventure? Or is the economy already crippled long before Link arrives? Perhaps it's fine on both counts, but how would they achieve this? | There are two mitigating factors here:
One, thanks to time travel, the most damage Link can do is to spend as much as he can in a single three-day cycle. Before the last cycle, he can do as much collective damage as he wants; the economy won't remember any of it. The biggest victim here is the banker, but...
Two, the banker never seems to run out of money, no matter how much Link demands. And as you say, he takes no issue with handing it all over without even trying to recognize Link's face. Dude's loaded, in contrast to his Hyrulean doppelganger; if Termina's economy breaks, this guy was getting it nice and brittle long before Link gets there. | 70 | 118 |
ELI5: What makes a Race car driver "good" at racing? | I'm assuming that most people in a given race have roughly similar cars... At least in the large professional races. What is it about the "stars" of racing that makes them win more often than other drivers? What sorts of "strategies" do they use to win more often? | Top tier race driver needs to have great mix of skills that include
1. driving skill - being smooth with the car, knowing the limits, being able to feel the car, to sense the optimum line, react instantly to the unexpected. The smoothness is the reason why fast drivers look like they are driving slowly, but it is needed to maximize traction, thus speed.
2. Balance of aggressiveness and cool headedness. The driver needs to be aggressive enough to eg. commit for overtaking manoeuvres, resist other drivers' pressure, but at the same time, "to finish first, first you need to finish".
3. technical competence. They say that the edge Michael Schumacher had over his competitors in his golden days was that he understood the car well and could help with proper set-up. For not the jet-setter levels of drivers it is even more important, they often need to help with the car themselves
(4. Sponsors and networking. To break into the top level of drivers (ie. F1, GT2 etc.) you need to have serious money behind you.
5. physical fitness and low weight. Lot of the events are physically demanding, require several hours of exercise and concentration. In some of the disciplines the driver's weight is substantial part of the total vehicle weight. having 10kg less can mean 10ths of a second on a lap) | 922 | 992 |
[Full Metal Alchemist] Why is Alphonse allowed on so many military facilities/secrets? | Alphonse unlike his brother is not part of the Military (Alchemists are roughly a Major rank iirc) so why is he allowed to acompany Edward into classified State documents and State secrets? | I imagine state alchemists are allowed assistants of their choosing as they might want people that are experts in a field that aren't in the military and Alphonse is an expert in alchemy and he is approved to be an assistant. | 48 | 34 |
ELI5:What exactly is a "confirmed kill" and how are they confirmed? | Obviously I know what a kill is, and obviously the definition of confirmed means they verify that it actually happened. But, what is the process for confirming a kill? | Confirming kills varies by military branch and by country, and also by time frame (ie; confirmation was different in WWII than in Vietnam or today). Many just need it to be witnessed by a spotter, some have to actually retrieve proof of death. For the most part, however, nowadays "confirmed kills" are only kept track of within sniper teams. The term gets thrown around a lot in the media because it sounds super awesome, but most modern military branches are not keeping track of their soldiers' kill tallies. | 15 | 18 |
ELI5:Why do "weeds" grow so much more quickly and without any nurturing compared to plants/crops? | We have carefully selected our crops to produce large yields. This is economically costly to the plant. Plants in nature don't produce yields like that because natural selection penalises that kind of economic investment. We ensure that it is beneficial for the plant through carefully removing competitors, inputs of fertilizer and water etc.
A weed, on the other hand, has survived for generations of being unnaturally selected against. All the resources that a cropped plant puts into seeds/fruits etc, the weed will put into being hardy, being resistant to herbicides or pests, being difficult to uproot (ever tried to uproot a dandelion?).
Weeds aren't just better at surviving because they haven't been weakened by human selection. They are tougher because *humans have unconsciously selected them for toughness* | 61 | 61 |
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CMV: I don't think non-binary people are trans | **Intro/Disclaimers**
I believe gender is socially constructed and distinct from sex. Gender is what society sees you as. As a prime example, a trans woman's sex is male, but society sees them as a female. However, that does not mean to say I think gender is arbitrary or not grounded in reality. We observe strong sexual dimorphism and two reproductive roles; ergo have two genders. Some societies do have more than two genders, but they are simply looking at the same thing in a different way. For example, some societies may consider trans people to be an entirely different gender, whereas we would just see them as the gender they identified as.
I don't have any problem with people who call themselves non-binary. I don't believe they are lying for attention, nor do I believe it's a "post-modernist neo-Marxist" conspiracy. I am happy to call them by whatever pronouns they want to be called by.
**With That Being Said**
From what I understand, a person is trans where they are one sex, but their brain tells them they should be the other sex. This can cause depression and anxiety (Gender-dysphoria). The most effective way of treating gender dysphoria is transitioning so that the person's body more closely matches what their brain tells them it should be. It seems that being trans is caused by the person having a brain structure more akin to the opposite sex.
I don't see how this can apply to non-binary people. We are sexually reproductive beings; therefore there can only be two sexes because there are only two reproductive roles. People may bring up intersex people in an attempt to refute that, but I don't believe intersex people refute the idea that there are two genders any more than 3-legged people refute the idea that humans are bipedal. What would a non-binary person's brain tell them they should look like? What would their transition look like if it happened? I haven't found an adequate answer.
In all honesty, I believe people call themselves non-binary not because they're trans, but because they're conflating gender with masculinity and femininity. This causes what they say to make a lot more sense to me. For example, the idea that gender is a spectrum makes no sense. You can't be "more male" or "more female" than someone in the same way that you can't be "more alive" or "more dead" than someone; you just **are** male, or you **are** female. However, masculinity and femininity are different. They do, in fact, exist on a spectrum; you're not **either** masculine or feminine. You can be more or less masculine, more or less feminine, both, or neither. Most people have aspects of both.
I think non-binary people honestly don't see themselves as being particularly masculine or feminine or see themselves as both. As a result of this, they consider themselves to be non-binary.
However, just because you are not particularly masculine or feminine doesn't mean you are not male or female. You can be male (your gender) while not displaying the behaviours typical of males (masculinity). That is not the same thing as being transgender. I think this conflation of masculinity and feminity with gender is the root cause of the whole non-binary thing. Happy to hear opposing points of view.
**TL;DR** \- I think non-binary people are erroneously conflating masculinity and feminity with gender. Just because you're not feminine as a female doesn't make you not a female and doesn't make you trans. | When someone identifies as a gender they were not assigned at birth, we call this person "transgender." Under that definition, nonbinary people are transgender.
>I believe gender is socially constructed and distinct from sex.
Then what does sexual dimorphism have to do with anything?
>What would a non-binary person's brain tell them they should look like?
I mean, if you're speaking about *physical* transition, some nonbinary people take certain hormones. Others may get surgeries. But "being transgender" isn't synonymous with physically augmenting one's body. Plenty of trans people don't get surgeries and don't take hormones.
>What would their transition look like if it happened?
There isn't one answer to this. Some people take on mannerisms of both of the traditional binary genders. Others eschew all of those altogether. This question is similar to asking "what would biracial people even *look* like?" It's silly. There is no answer. It depends on the person. | 10 | 20 |
[Star Trek] 1) Why would people risk their life, relationships, and so many other things to join Star Fleet when you can live a great life for free on Earth exploring any/all of your interests? 2) How are there so many "geniuses" capable of basically being galactic astronauts? | 1) Your average Starfleet serviceman is probably not risking his life much. Starfleet is not the Military of the Federation, the Enterprises & Voyagers are exceptions not the rule, and even still their missions are mostly peaceful (history just pays less attention to cozy times of peace). Also keep in mind that you don't have to be from Earth to join Starfleet, yet there's only one Starfleet Academy. Contrast this with 21st century Earth where single nations like the USA have military academies all over that are competitive to get into, and it's not hard to imagine how Starfleet gets its numbers.
2) Even if the proportion of geniuses remains constant, humanity has colonized other worlds and the Federation has several member species that would give an ample supply of geniuses. Aside from that methods of teaching seem to have improved significantly in post-scarcity society, combined with cultural exchanges with the logic-praising Vulcans who excel at STEM subjects. | 27 | 17 |
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ELI5: Console games were developed on PC, but why is it difficult to port them to PC without low rate of bugs? | GTA 4 and Dark Souls 1 are prime examples of this question i’m asking. They are considered by gaming community as one of the worst PC ports ever due to low frame-rate, new bugs and not much setting options to configure | There’s fewer variables when you develop for consoles. Let’s say you’re a big game developer. Your work computer is going to be very high end. Console generations only have a few different combinations of hardware specs. The possible screen resolutions are limited. The operating systems aren’t going to be running anything else in the background. So, you can test on basically every console scenario and be pretty confident about catching major bugs.
For PC versions, you don’t know the hardware each user has so you set some minimum target and do your best. You can’t test every combination. There’s not enough time or money to do that. There’s almost inevitably going to be more bugs.
A separate issue is that often the original developers don’t work on the PC port. They might but if a game developer is focused on consoles, their PC ports might be outsourced to a whole different company. If that company hires cheap, inexperienced developers, it probably won’t go so well. If they have great developers, the original code might have been written by inexperienced developers and it’ll be a mess. A lot can go wrong. | 33 | 31 |
When critical infrastructure (Water, electricity, etc) is privatized, the complaint is often that the profits have been privatized and the losses have been socialized. Is this a fair criticism? | For instance.
A private company takes over the management of an electrical grid. To increase profits, they reduce maintenance, which makes privatization look like a good choice/efficient. But after a decade, the lack of maintenance catches up with them and service disruptions occur. They then say they need to increase fees. But if they'd not extracted that profit there would have been money for maintenance in the first place.
Now, that's not to say that publicly managed utilities aren't mismanaged, etc. But is the criticism fair? After all, the public utility is using all the pie, while the private one is using only what isn't taken for profit. | Privatisations almost always come with heavy performance commitments. In practice, this means rather than decreasing maintenance, they often have to commit to increasing maintenance or otherwise investing in infrastructure.
In general, long dated assets like infrastructure are funded by cash flows very far in the future. Private companies often have the ability to withstand upfront losses for the promise of future cash flow; but governments are actually really bad at that. This is primarily because government budgets for infrastructure tend to be political decisions for the Budget, which means they are decided by the exigencies of that particular year.
Mechanisms also exist to prevent infrastructure companies from profiting too much during privatisations. These are generally called Regulated Asset Base models. In general, they sort of guarantee x% return to the company, but also fixes the pricing they're allowed to charge as a percentage of the investments they put in.
Edit since it's a hot topic in the comments:
Yes - in practice enforcement is not always easy, and in many cases the multiple mechanisms are not applied at the same time or in sufficient size. In countries with endemic corruption, the entire infrastructure platform is effectively given away for free to politically connected people, the post-Soviet world being a very prime example. While in countries like the US where lobbying is fervent and restricting profits is politically taboo, the terms are either not well enforced or just weak.
In some cases, the enforcement is overzealous or otherwise prohibitive. UK energy pricing rules required strict price limits and limited profitability, this forced energy providers to cut costs aggressively particularly by reducing their electricity price hedges. When energy prices spiked, those companies were unprotected and also unable to raise prices, eventually bankrupting half of them and requiring various government interventions. In Germany, so much emphasis is placed on ensuring that small rural communities have internet access even at ridiculous costs that everywhere else is underinvested and Germany of all countries has the worst telecom infrastructure in Europe.
Executing any economic policy, especially one as comprehensive and complex as a nationalisation / privatisation is never going to be simple or perfect. Economics provides us with tools, theories, and mechanisms, but humans and institutions ultimately have to execute. | 57 | 138 |
[Star Wars] Given Han Solo was able to bribe an Imperial to escape Corellia, how well paid were people employed by the Empire? | In poorer countries, you can assume any police officer/civil servant will take a bribe but it's more risky to try to bribe someone in a richer country where they are paid more. Han was pretty certain his bribe would work without targeting a particular worker to get an exit pass from Corellia, suggesting it leans toward not well paid. | Well for starters, Coaxium is valuable, a little goes a long, long way, since it is a controled substance, being able to have some that didn't come from some official source can open a lot of doors if you know what to do with it. Han using the Coaxium was less slipping the guy a $100 and more like passing him a small bag of gemstones.
Secondly, its less that the Empire didn't pay well, but rather that there is a bit of a culture in the Imperial Forces to try and get a step up when ever one can. Maybe its a bit of the Sith mentality subconsciously leaking, but Officers were kind of encouraged to backstab others, make a deal with unsavory characters, even grease the wheels a bit in order to get ahead. The only condition is to not get caught, otherwise they will come down hard on you. But for someone who was raised on the streets of Imperial controlled Corellia, Han knew that offering a well placed bribe to any Imperial Officer had more than just a good chance of success as long as he was sly, didnt ask for too much, or make a scene. | 28 | 17 |
ELI5: Virtual machines | I’m trying to understand them a bit better, but it’s just not clicking for me. How is it able to operate like a physical computer and what is the benefit of that? Would you be able to say write an essay for your English class on a VM, save it there, and access it at a later time? | All an operating system is is an interface between your applications and the hardware; that these days provides some convenience functionality: a shell/desktop environment, a file system for data storage. But at a low level, the operating system is just computer code itself running in the CPU of the computer.
But what's the difference between a computer instruction running on the real hardware CPU or one that is interpreted by a software based CPU that is itself running on a real CPU? Turns out, not much.
When you turn on a computer, the CPU knows to look in one specific location for its very first instruction. These instructions are a boot loader. These point to other locations to load special operating system files (for Windows or Linux). So you could easily write a program that emulates or simulates a CPU in this behaviour... you can write software the emulates _everything_ in a computer.
That's all that virtualization is - an emulated computer running on a special virtualization platform that is running on a real computer.
To answer your question about the essay tho... the answer is: it depends. When you write your essay and hit save, the essay is written to a physical hard disk or storage device. IN a virtual machine, the essay would be saved to a virtual hard disk/storage device, which itself is just a special file on the real storage that the virtualization software can understand. So yes, so long as they physical hardware that stores the virtual machine is ok, then yes you should be able to access the virtual storage as well.
The nice thing about virtual machines is you can save their state at any time and restore back to it. We use virtualization at work in our testing all the time. We have a virtualized Windows PC, we install our software, the software was buggy, causes the virtual computer to crash, we wipe/restore the VM back to its known good state with a single instruction.
Old MS-DOS game emulators like DOSBOX? essentially these are virtual machines. Playstation or Gameboy emulators? virtual machines. Someone has just taken the time to write software that emulates the hardware of these old platforms. | 38 | 59 |
ElI5: Why can’t we smile in pictures for passports and other official docs? | You're supposed to look the same in your picture as you look when you present your ID to someone for inspection. That makes it easier to quickly confirm that you're the same person as in the ID picture. Usually this happens when you're pulled over by the police, going through an airport checkpoint, etc.
People usually aren't all smiles when talking to police or airport security. | 42 | 15 |
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CMV:Gal Gadot's tweet about Stephen Hawking was not ableist. | https://twitter.com/GalGadot/status/973919102174711809
She said he was free from physical constraints. People have somehow interpreted that as "death is better than disability". Those are completely different statements. She did not say that Stephen Hawking is somehow better because he is dead. That stuff is complete nonsense.
Even if we do concede that she did say something like that, is it still ableist? No. Firstly, whenever anyone dies, sometimes people will say "X is in a better place/is in heaven", etc. That is clearly indicating that the person is better off being dead. Nobody considers that offensive.
People even say things like "X is free from pain anymore" and stuff like that. How is that different from saying "free from physical constraints"?
Even if we do concede that she believes death is better than disability, is that offensive? Again, not necessarily. Euthanasia/assisted suicide is debated, and it is perfectly reasonable, and not offensive, to believe that it is better to die than to be disabled and in pain. Stephen Hawking was at risk of developing locked-in syndrome. It's not at all offensive to believe that death is better than that (I'm not saying I believe it, just that it's not offensive to believe it).
People don't say things like "free from being a racial minority" when someone dies, but I don't understand how that is relevant.
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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!* | It seems to me there’s an ableist way to interpret this and a non-ableist way to interpret this.
Your CMV is not about Gal Gadot herself, who may or may not be ableist (I don’t want to read too much into someone from a single tweet) but about her tweet, which is definitely open to an ableist reading.
You then go on to say that it’s not ableist to say that it’s better for some disabled people to die. That’s a decision a disabled person must make themselves. To assume a disabled person is better off dead, without knowing if this is how the disabled person felt, also seems ableist to me.
What bothers me more about Gadot’s post is that it suggests Hawking has passed on to some manner of afterlife, an idea the decidedly atheistic Scientist has called a “fairy story.” From Hawking’s point of view, death would be the greatest possible physical constraint.
Edit: Also Hawking was an eternalist. He believed the past physically exists even though we are ourselves stuck in the present. So even though Hawking is dead in the present, he would believe that he still exists in the past, both as an older disabled man and as a younger abeled man. This would also be a physical constraint of sorts. | 11 | 21 |
ELI5: What are physicists referring to when they say "information" being destroyed or lost in black holes? | What are they referring to when they say things like "information is lost when it enters a black hole" or recently that the information isn't lost but preserved. What is this information? Is is matter? Light? Random floating space books? | What they mean by "information" is in fact the physical state of the matter itself. Basically, the theory that says the interior of a black hole is a homogeneous soup of elementary particles from which restoration of what may have created them is forever impossible. Suns, stars, planets, people... we'd have no idea what went in.
This is a problem for physicists because they like to believe that if you look at a system at any point in time, you should be able to predict its past and present states.
For a real world example, if you walk into your kitchen and see a broken plate on the floor, you can figure out that those pieces used to be a plate. You can go a step further, and examine them more closely and find out that the plate itself is glass. And further investigation reveals more information about the nature and state of its existence through time, as sand and what kind of rock eroded into the sand and so on.
But if you walked into your kitchen, and found a puddle of homogeneous elementary particles with random positions and motions, you'd have no way of knowing it was a plate unless you had perfect information of exactly what the kitchen was like before, and through the process of elimination established that one of the plates was missing. So far, that's not how anything works... except possibly black holes. | 21 | 19 |
ELI5: What happens to blood after it's been tested? | I had another blood draw today for my GD test and it made me curious- what happens to the blood after the lab tests it? How is it disposed? | Blood is treated like any other kind of biohazard in a medical setting. There are special waste containers to hold biologically hazardous wastes, and a common method of disposing of such waste is incineration. Traditionally hospitals will have one or more incinerators in their basement where such wastes can be rendered into safe ash, while smaller establishments may just hold the waste for collection by a centralized service that incinerates it on their behalf. | 1,823 | 1,474 |
Other than body language, why is having bad posture bad? | Your skeleton, joints, ligaments, muscles, tendons, fascia etc. form a complex structure that works together to bear your weight and transmit force for activities. Proper alignment transmits the forces through the structures best suited to bear them. Poor posture can result in excess force being borne by softer structures, which may result in injuries or chronic degradation of these structures, particularly as you age. Examples include things like disc injuries in the lower back or knee problems. The net result can be more pain and/or reduced mobility when you are older. | 58 | 95 |
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ELI5:What is "cupping", and how does it benefit swimmers? | "Cupping" therapy is performed by taking a hollow container (such as a cup) and causing it to contain lower than usual air pressure, often by filling it with warm air from a candle. It is then placed against the flesh where the air cools, pulling tissue into the container from the pressure difference.
This pulling damages the tissue causing internal bleeding and inflammation. This swelling is believed to promote healing; in a sense it does because the body is reacting to injury.
The practice is "alternative medicine" or more accurately a somewhat harmful superstition and quackery. It stems from the recognition that swelling accompanies wounds healing and then attempting to cause swelling without obvious wounds with the thought it would cause healing for whatever other ailment targeted. But of course we should all know stabbing yourself isn't going to heal your asthma, and bruising your back won't help other problems. If anything it would hurt your ability to cope with other injury. | 204 | 164 |
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ELI5: What is the difference between forward and reverse osmosis? | I see "reverse osmosis water" on a lot of products these days and I'm curious how reverse osmosis is different. | In osmosis, water travels through a membrane from a low-concentration (i.e. less dissolved solids) mixture to a high-concentration mixture until the concentration on both sides is the same.
This happens spontaneously and can be quite dramatic if one side is extremely highly concentrated. This is why drinking salt water is so harmful, osmotic pressure starts sucking water out of your cells.
*Reverse* osmosis is the inverse process, forcing water to cross from the concentrated side to the pure side. This *won't* happen naturally and requires high pressures, but also acts as a very effective filtration process because the membrane excludes most particulates and large ions. | 131 | 261 |
What makes 4G faster than 3G? | Both 3G and 4G are data transfer standards. So a network is considered a 3G network if it can reach peak speeds of 200Kb/s. A network is considered 4G if it can reach 1Gb/s. However, this standard was changed basically so that companies like Verizon could advertise 4G speeds even though they cannot actually hit the 1Gb/s rate. 4G is generally now used to mean 'anything substantially faster than 3G' rather than conform to the actual standard.
So basically, there is nothing that makes 4G faster than 3G, it is simply defined this way. There are many things that make a network 4G as opposed to 3G, but that gets into a technical level of how do they improve network infrastructure. This includes things like more robust switches and routers, more actual lines of communication (which provide more interconnectivity and hence more paths along which data can travel), etc. | 12 | 16 |
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ELI5: If nature is so jagged, colorful, and seemingly random (yes, I know all about the golden ratio), why do us humans find straight lines, clean edges, and muted colors so aesthetically pleasing? | 2 things most likely.
1) We like these things because they are different from nature. We can get all the other stuff from nature easy enough, but we have to work at making a straight line.
2) Nature is dangerous. Disease, predators, poisons, and natural disasters are all natural, so why should we necessarily desire natural? Appeal to Nature is a fallacy. | 44 | 59 |
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How do Computer Algebra Systems, like Wolfram Alpha, solve algebraic problems? | I've been working with mathematica and maple a lot over the last week, and I still don't understand how computers can interpret and solve algebraic equations, yielding closed form solutions. | It represents the equations and has rules for how to manipulate them.
For example, if you tell it "expand (x + 2)(x+3)" then it might:
1. Parse the expression into a tree representation
multiply
add
symbol("x")
number(2)
add
symbol("x")
number(3)
2. Notice that this tree has an add underneath a multiply and apply the distribution rule:
add
multiply
add
symbol("x")
number(2)
symbol("x")
multiply
add
symbol("x")
number(2)
number(3)
3. There's a still an add underneath a multiply. Do it again!
add
add
multiply
symbol("x")
symbol("x")
multiply
number(2)
symbol("x")
multiply
add
symbol("x")
number(2)
number(3)
4. Man, so much distribution to do.
add
add
multiply
symbol("x")
symbol("x")
multiply
number(2)
symbol("x")
add
multiply
symbol("x")
number(3)
multiply
number(2)
number(3)
5. Finally, now we can try some other rules. Oh hey, adds under adds can be flattened:
add
multiply
symbol("x")
symbol("x")
multiply
number(2)
symbol("x")
multiply
symbol("x")
number(3)
multiply
number(2)
number(3)
6. Oh, and one of the multiplications can be computed:
add
multiply
symbol("x")
symbol("x")
multiply
number(2)
symbol("x")
multiply
symbol("x")
number(3)
number(6)
7. And there are multiplies under an add that have a common term except for some numbers, so we can group those and add the numbers:
add
multiply
symbol("x")
symbol("x")
multiply
number(5)
symbol("x")
number(6)
8. Oh, and multiply something by itself is just squaring it:
add
square
symbol("x")
multiply
number(5)
symbol("x")
number(6)
9. Hmm... can't see much else to do. Better make it pretty and print it:
x^2 + 5x + 6
In summary, computer algebra systems work by applying known-to-be-good operations to a tree representation. Sometimes they will try many different combinations of operations and return the one that worked the best, sometimes they'll fall back to doing approximations, and sometimes they don't work simply because the right rewriting rule hasn't been added yet. | 70 | 288 |
ELI5 What it means to share DNA with other organisms | We share 60% of our DNA with bananas, but we are clearly not 60% banana. | DNA fundamentally is instructions to make proteins. A lot of the basic proteins needed for cells to function (build cell membranes, move things around, tie themselves in place, etc) are going to be the same even in very different organisms. As a result, pretty much any multicellular organisms are going to share a lot of DNA, because the instructions needed for the basic building blocks of cells are the same. | 92 | 51 |
[MYST]Since the "Trap Books" in the videogames were later revealed to be a gameplay abstraction, what really happened? | In Myst and Riven, the Stranger interacts with three prison books, each of which acts in apparently the same way: instead of linking anywhere, the book takes the traveler to a void, trapping them there. From this position, the now-stranded traveler can see out through the linking panel, but cannot move. If someone else finds the book and uses it, they swap places with the first person.
In Myst, you know from the off that Sirus and Achenar are trapped in books; giving them pages eventually repairs the books enough for them to trap you and escape. In Riven, Ghen is eventually trapped in a prison book, but not before the Stranger uses it first, in order to bait the trap.
In Revelations, it's revealed that Sirus and Achenar where trapped in full-fledged ages... and a [discussion with some of the people who made the video game based on the real events shows that it isn't entirely how the books work.](https://dni.fandom.com/wiki/Prison_Book) In which case, what's the real story, particularly in the case of Ghen? | The original explanation was that a linking book (not a descriptive book) could have its text altered in such a way that its connection to its age became damaged. The result would appear to link to an age, but actually be a kind of spacetime trap that would freeze one human inside the link. You are correct that Haven and Spire produce a contradiction, but if you read a little further in the wiki you will see a few ways to reconcile it.
It makes sense that a prison book, being made from a linking book, could be "repaired" and turned back into a linking book. Atrus may have repaired his sons' books after he got the missing page from his Myst linking book back, dumping them into their respective ages to stew for a few years.
Of course, Atrus is the kind of man who thinks things through. If he knows a secret way to make prison books, *or multiple different types of prison books*, he has every incentive to spread misinformation about how they work. After all, he has quite a few enemies who would want to use that secret against him. | 16 | 43 |
ELI5: How do we know counting rings in a tree is a definitive "1 year"? | In places with seasons, trees go through a predictable growth-dormant cycle that produces the distinctive ring pattern.
Since most of these seasonal trees go dormant regardless of what the actual winter temperature was that year (they're timing the day lengths, not responding to unpredictable temperature swings) a ring is produced even if the year's weather was very unusual.
You get big rings for years with optimal growing conditions and weak rings for drought years.
Rings are less pronounced and more difficult to count in trees that prefer more tropical climates, since they may grow all year instead of stopping entirely on a regular cycle. | 4,953 | 6,752 |
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How do solar panels turn light into energy? | Solar panels turn light into *electricity.* That's an important distinction.
The short answer is something called the *photovoltaic effect.* Put simply, shining light on a particular type of material liberates electrons from the atoms in that material, causing them to move about. Moving electrons is electricity.
(Sorry, said "photoelectric" originally, should've said "photovoltaic." It's going to be one of those days, apparently.) | 19 | 32 |
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Why is it that the Copenhagen Interpretation is the "standard" understanding of quantum mechanics? | My understanding (which could be completely wrong) is that many if not all of the major interpretations of quantum mechanics are valid understandings of the data. What is it about the Copenhagen Interpretation that makes it a more attractive interpretation? | It's just historical. Quantum mechanics was first developed and formalized in the 1920's. Dirac published his famous textbook on Quantum Mechanics in 1930. For most practical purposes, this was the final word on the matter. It wasn't until the 1950's that other now-famous "interpretations" started to pop up, the work of Bohm, Everett, Bell, and so on. In the 1930's there was some famous grumblings from Einstein and Popper and others about the Copenhagen interpretation, but at the time they weren't able to come up with a serious alternative, and Bohr, the much celebrated fatherly figure of quantum mechanics and the Copenhagen interpretation, held court. By the 1950's when the good alternatives started to crop up, all the good textbooks were solidly Copenhagen, everyone learned Copenhagen, and an entire generation of physicists had been brought up on Copenhagen. By that time, even though the new interpretations were brilliant and insightful, it had become virtually impossible to just unseat Copenhagen in a popular textbook without seeming kookily ideological, since after all, though all interpretations have their problems, and some are arguably better than others, it is somewhat a philosophical question, no one is a "slam dunk" to unseat Copenhagen, and after all, Copenhagen "works" and is easy to teach and apply. | 27 | 31 |
In layman's terms, can someone explain the difference between "first-order logic" and "second-order logic"? | I first order you get to make universal and existential statements about individual objects in your theory.
In second order you get to make universal and existential statements about not only individual objects, but sets of objects.
For example, take arithmetic, i.e., a theory about natural numbers.
An example of a first-order property of natural numbers would be: "Every natural number is either even or odd."
And example of a second-order property of natural numbers would be: "In every set of natural numbers there is the smallest element." | 42 | 32 |
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ELI5: What does a magnet "lose" when it uses energy to move an object? | We all know that no energy is created, just transformed.
I've read that even a planet attracting an object and accelerating it toward it will lose a tiny bit of momentum to do so.
What does a magnet lose to perform the "work" of moving something closer or further apart? | Due to its position in a magnetic field, an object will have a magnetic potential energy. This is converted to kinetic energy as the object moves through the field. To re-separate the magnets, you need to apply energy in the form of pulling them apart, thus giving it potential again. This works in the same way as gravitational potential energy; when we lift an object up, we are working against gravity and therefore giving the object energy in the form of potential as when it is released it will travel back to a point where it no longer has this potential (the ground).
​
edit: typo: changed electric to magnetic | 169 | 180 |
[General] How long does it take to build an ecumenopolis? | In sci-fi, we see plenty of examples of city planets, such as Coruscant and Trantor. How long would it take to build one of these planet-wide cities? | Safe to say that these worlds generally take more than a regular human lifetime, usually at least centuries. This is hugely dependent on a number of different factors, however. Coruscant for example didn't start as an ecumenopolis, it started as a regular planet but over millennia built up to the world we see in the prequels, as levels kept getting added and the natural ground disappeared beneath the foundations of the megastructures. | 15 | 22 |
ELI5: Why do we look for life on 'goldilocks' planets? | I think the proper term is circumstellar habitable zone. If there is other life out there, why are we assuming that it'll have the same basic needs as our animals? The universe is seemingly infinite, and there's endless possibilities of what's out there, so why do we only consider planets that are the 'perfect' distance away from their star? | It's a bit like looking for a doctor in a hospital. Any person could be a doctor; people wearing "normal" clothes could be a doctor coming on/off their shift. But if you're looking for a doctor, you're going to run towards the person who's dressed in a white or blue coat (maybe with a stethoscope on their neck) because that's what you **know** doctors look like.
Likewise, any planet could harbor life. But we **know** that life can exist under the "Goldilocks" conditions, so we know that if we're looking there, we at least have a chance of finding it. We don't have the resources to look everywhere all the time, so we have to prioritize where we have the best chances. | 236 | 44 |
Why does a Mosquito bite not transmit certain blood borne diseases? | Mosquitoes can transmit a wide range of nasty diseases, malaria being foremost on my mind. But what mechanism prevents a mosquito from transmitting other diseases such as hepatitis, HIV, colds, and the flu?
Or put differently: Why do mosquitoes transmit certain diseases but not others? | While mosquitos are great vectors of disease, there are certain limitations that prevent them from spreading all pathogens. Two immediately come to mind:
* Appropriate host environment: the bacteria/virus/parasite must be able to not only survive inside the host, but also reproduce. In a single bloodmeal, a mosquito won't necessarily take up a large amount of pathogen. To complete the cycle and spread it to another host, the mosquito must provide a suitable environment.
* Virulence/toxicity: the pathogen cannot kill the host outright, nor can it significantly hamper its ability to feed. If the mosquito is unable to feed normally, the chances of the pathogen being spread become quite small.
| 23 | 32 |
ELI5: If a computer only takes an input of 0s and 1s how does it know to expect an image as supposed to text? | I get that any symbol is usually 8 characters in binary and that pixels colors in an image range from 0-255 with 255 being 11111111 using binary But how does it actually determine to either look for a letter or a colored image by just using strings of 1s and 0s if that makes sense. | It doesn't. You can interpret the same binary data multiple ways. It's up to the program that's running what it does with the data, which is why you can open binary files in Notepad.
However, if the program is expecting data of a certain structure, it may fail if it sees data that doesn't fit that structure. A BMP file, for example, should begin with a header that specifies the width and height of the image and then the image data. If there isn't enough image data for the image size given in the header, a BMP loader will fail and report that the file isn't valid.
Many file types begin with a "magic number" that serves to identify the file format. An ELF executable file, for example, begins with the bytes 0x7F454c46. | 44 | 32 |
Why does normal pain medicine helps you with a headache for a few hours but not make you immune to all pain? | I know basic pain medicaments block some kind of chemical reaction in you body for a while, and this reaction is the base of your pain (extremely simply). But why when I use pills for headaches I still can feel pain from hitting my little toe on a bed? | There is a difference between pain, inflammation, and sensitivity after an injury. Not all injuries feel the same, but they all go through these stages at different rates. After an injury you'll feel pain which includes inflammation, and as the inflammation subsides and new tissue is being formed in place of place of dead tissue, sensitivity.
The most common pain medications that you don't need a prescription for are anti-inflammatories. These are really good for swelling and pain caused by immune system responses. It's basically slowing down the increased blood flow that causes the redness, swelling, and hot feeling you get after an injury or infection.
Headaches are mainly caused by increased pressure inside the skull. the vessels in the brain increasing in size, usually due to inflammation or higher blood pressure. Anti-inflammatories reduce the swelling happening in your brain and relax and soothe vessels.
There is an enzyme that causes the release of prostaglandins , which increases blood flow to affected areas when they're injured , also known as perfusion. It's like calling an emergency services crew with mutual aid and special contractors to repair a busted dam or put out a massive fire. But the body isn't good a regulating inflammatory resposes, which is why inflammation often causes more damage to surrounding tissue. Think of how you feel during a fever, that's mainly the side effects of your immune system.
The pain you feel from trauma isn't just inflammation, but direct injury and stimulation of afferent nerve fibers. opioids and other analgesics work in different ways to affect the nervous system to either slow or block pain signals.
Some medications like lidocaine block nerve signals in the area where it's applied. It's a sodium channel blocker that also blocks the neurotransmitter acetylcholine, which is used by nerves to send pain signals to the brain. | 63 | 77 |
ELI5: If a certain result has a 1/x chance to occur per action, on average which iteration will it first occur on? | For example, people usually say that a 1/5000 chance means on average 5000 tries are needed. I was wondering if that was actually true, since on the 5000th try there's only a 0.367~ chance of the result not having occurred. I thought it might be 3465~ instead, since by the 3465th try there would be an approximately .5 chance of the result already having occurred. However, that .5 chance includes the result having already occurred multiple times, so now I'm stumped. Thanks in advance for the help!
Edit: I definitely might be wrong, but I think my confusion isn't due to the Gambler's fallacy. I know each individual action always has the exact same chance, but the chance of not receiving the 1/x result within Y tries decreases as Y increases. What I mean is there's a lower chance of not having gotten the result after 100 tries than after 10 tries. My question was based on looking at consecutive tries as a whole, not individually. Based on that, if the chance is 1/5000, statistically speaking how many tries would it take the achieve the result for the first time? | 1. Ask this question on r/learnmath if you want the most correct answers to be upvoted.
2. The first occurrence occurs the xth time on average. To see this, consider a long experiment consisting of, say, 1,000,000x trials. The event will happen about a million times, which means that the average gap between occurrences is about x. But "gap" is the same as "experiment where we keep rolling the dice until the event happens and then we stop". So the average length of these things is the same.
3. The chance that the event occurs on or before the xth time is about 37%. | 14 | 21 |
How will/are human bodies adapt(ing) to increased body fat if obesity continues through many generations? | Is there any evidence of human bodies adapting to obesity?
If it is true that you can be genetically obese then are those humans better adapted for this?
Would the human body be more likely to adapt to automatically store less fat, or to strengthen its organs/structure to be able to cope more easily with increased body fat? | If being overweight has enough impact on a person's average reproductive success (i.e. total number of children who survive long enough to reproduce themselves), it's not impossible that we'll eventually see human evolution select for people who are less susceptible, perhaps because they retain less fat, have less interest in fatty/high-calorie foods, or are simply more healthy with high body fat. (There are plenty of animals that are perfectly healthy with lots of fat, and would be quite unhealthy without it--look at seals, for example.)
But it is way, way, way too soon to see any evidence of that right now. The "obesity epidemic" has been a thing for a couple of generations at most. Try back in a few thousand years.
(And even that seems like a stretch, honestly. Obesity kills, but it usually kills in middle age or later, after many people have already had kids.) | 344 | 381 |
How do I practice becoming a better thinker? | Hello everyone
I hope it's appropriate to ask this here since it's not a philosophical question but one about your methods.
I just started studying philosophy and I'd like to improve the way I think; to be more precise, more critical - all in all I'd like to develop a sharper mind.
When googling and youtubing I find that the consensus to improving critical thought is 'writing a lot' and 'reading a lot'. But I just don't really know where to start or what I should be looking for. What should I write? How should I write? What should I read? How should I read?
-How did you become a better thinker?
-Do you have any recomendations or examples for a book or article where you thought "this is some sharp thinking"?
Maybe if I see an example I'd have a better idea for what I'm looking for..
Thanks for reading
-A pupil | What really helped me become a more critical thinker was honestly reading books on various topics i was interested in, watching lectures on youtube which i think immensely helped as well, and engaging in conversation about the topics I’ve learned to family members and friends. The last point is crucial because you are actively engaging in active recall and it introduces you to perspectives you may have not heard of, all while giving you more perspective and reasoning to aid you in becoming a better thinker. | 14 | 19 |
CMV: There is no Reason to Believe that Sexual Promiscuity is Immoral. | I saw that there's already a thread about whether sexual promiscuity is "bad" in a general sense, but I believe this is a distinct question.
Apart from adherence to religious dogma, I can't think of a logical reason to believe that sexual promiscuity is immoral. Consensual sex is fundamentally a matter between the parties involved. If the parties properly disclose relevant information about one another and consent with all that in mind, I can't see how either party is harmed. Nor can I see how any other party is implicated, except possibly for a child born out of the sex.
On that note, I'll grant that the parties to sex would have a moral duty to any child conceived and born due to the sex. But I don't think that makes the sex itself immoral. | As do all moral judgements, it depends on the moral system. Depending on one's core beliefs, sexual promiscuity may or may not be "moral" for a particular person and their peers.
Examples:
Having sex defiles the soul/mind/etc. = having sex is morally wrong.
Consenting adults can do whatever they want = having sex is morally neutral.
Staying a virgin over the age of sixteen is losing at life = *not* having sex is morally wrong.
A conservative community, a group of rationalists and a college fraternity will make different moral judgements on promiscuity depending on their moral systems. It is also not uncommon for a single person to employ several conflicting moral systems at the same time (*"if they sleep around, they're a slut" + "if they don't sleep with me, they're a frigid bitch"*), because people are not inherently rational. | 100 | 289 |
CMV: The college education system is antiquated, inefficient, and self-defeating | Assuming that the goal of upper education is to educate individuals, I believe that the methods used to achieve this goal in the modern college education system to be very poor and lazy.
Instead of college being an environment that nurtures thought, creativity, and a desire to learn; it treats education like a business with students being walking dollar signs. Professors and other members of academia are complicit to this as they are subject to oppressive group-think and often tribalize themselves, shunning other colleagues who think and behave differently, further degrading what should be a free-thinking environment.
While I do not deny that students gain knowledge and experience through college; I believe it is usually a side-effect of jumping through the numerous arbitrary hoops of academia, rather than the education itself. At the end of the day, college simply weeds out those who are unable to meet such arbitrary requirements rather than attempting to educate them.
Colleges should ditch regimented learning systems such as competition, grading, and test screening in favor of more individual-focused methods. The system would be far better if it stop treating itself as a certification program, but rather an open environment to learn. Instead, letting employers decide if a person is qualified. (As they already do)
Colleges should return to their roots, for the sake of creating a more educated populous.
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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!* | The word education means different things to different people.
How important is worldview? How important is being challenged? How important are specific skills? How important is research and development? How important is being exposed to new viewpoints and learning how to dialogue with others?
There is no one answer to these questions, but there are vague groupings.
1) College exists so employers don't have to train their workers. Essentially college exists so employers can socialize their losses (training their employees). With a more positive spin, college makes employees more attract to employers (since they have a lower training cost).
2) College is important, even in a post-scarcity world with no jobs and no economy. There exists something ethereally important about being educated, about being able to reason, about being good at rhetoric, which transcends economic reasoning.
3) College puts everyone back on the same track. American High Schools are all over the place in terms of the quality of education they provide. College provides a re-calibration of sorts. Everyone with a diploma meets at least some bare minimum level of education suitable for the modern world. While this may seem silly to those at the top, this is essential for the people at the bottom.
4) College exists for STEM and pre-law. If you are not going into law school or into a STEM degree, go away.
Depending on how you answered those questions, or which group you fall into, the meaning of "college" changes. Not everyone comes to college with the same expectations.
Try to look at some of the obstacles in your college experience, and try to see how they are benefits from another point of view. Usually you can. | 35 | 204 |
ELI5 - How are height requirements calculated for theme park rides? | ELI5 answer is that they calculate how short someone would have to be to slip out of the restraints, then add plenty of safety margin to accommodate everyone with different-length torsos, legs, etc.
Some rides even have height maximums, where your dangling legs could crash against something. It's the same idea; the max height is calculated and then taken way down, as a safety factor.
In all likelihood someone just outside the limits would be fine. But in these things a huge safety factor is absolutely required. | 47 | 35 |
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CMV: Python is THE BEST programming language for beginners. | There are a couple of things that I believe are essential to a good beginner's programming language.
The first and most important thing is **ease of use**, now I'd say this more or less directly translate to a high level of language abstraction. You want a syntax that is fairly readable to a human, you definitely want a language with managed code and a extensive framework to provide the beginner with a lot of useful tools and methods.
This leaves us with a couple of VHLLs:
* Python
* Ruby
* Visual Basic
* PHP
* Scheme
* many obscure scripting languages...
We can cross off a lot of these entries based on what I consider to be the second critera for a good beginner's language, and that is **language popularity**.
Ideally you're going to want to learn a language that you'll have plenty of use for both professionally and privately. Aside from that as, as a beginner, you will most probably need a great amount of help, so any popular language with an abudance of helpful resources will ease your learning curve.
So we can go ahead and cross off all those obscure VHLLs already. Now as for the rest..
We'll start by looking at the TIOBE language index to assess language popularity, now the langagues in are list are ranked in the following order:
* 5th place - Visual Basic
* 7th place - PHP
* 8th place - Python
* 12th place - Ruby
* 43rd place - Scheme
In my opinion we can remove anything that's not in the top 10 so let's cross off Ruby and Scheme. This leaves us with Visual Basic, PHP and Python.
Now let's look at the professional populariy of these languags, searching Monster.com for "PHP developer", "Visual Basic developer" etc yielded around the same number of hits for all listed languages except for Visual Basic which yielded significantly less, so based on that we can remove it from our list as well..
Lastly I will actually go ahead and remove PHP as well, now there's nothing wrong with PHP per se, but first of all it is significantly slower than the other two languages, and it is primarily a OOP language while the other two are multi-paradigm which I consider a GREAT benefit for beginners so they can get acquianted with the different programming paradigms while still staying inside the confines of the language that they know and are comfortable with.
At this point most people would say it's a toss up between Python and Ruby, and generally I'd agree. **But for beginners** I would say Python is the superior language, it's easier for a beginner to learn.
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> *Hello, users of CMV! This is a footnote from your moderators. We'd just like to remind you of a couple of things. Firstly, please remember to* ***[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)****! If you are thinking about submitting a CMV yourself, please have a look through our* ***[popular topics wiki](http://www.reddit.com/r/changemyview/wiki/populartopics)*** *first. Any questions or concerns? Feel free to* ***[message us](http://www.reddit.com/message/compose?to=/r/changemyview)***. *Happy CMVing!* | The best language for beginners is the one suitable for the project they are trying to create.
Trying to learn stuff abstractly creates really poor programmers. All they can do is repeat what other people have told them because they don't understand the "Whys"
| 17 | 21 |
ELI5: how they manage to provide reliable high speed wifi to 80k people at the Ethiad Stadium (home of Man City)? | A very large number of access points with narrow beamwidths (each access point covers only a small slice of the total area) with careful ordering of the available wifi frequencies to limit interference.
Think of it like waitresses - each is assigned a small part of the restaurant so you can just hire more waitresses as needed instead of having just one waitress for everyone. | 20 | 27 |
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ELI5: What does the claim that we, humans, share 99% of our DNA with chimpanzees actually mean? | What is *meant* by the claim depends a lot on who is saying it. Some people feel this has philosophical or scientific significance that others don’t agree with.
But the claim, on the surface, is true, or close to true.
A vast majority of genes are used to carry out basic cellular functions like generating power (converting glucose and oxygen to ATP), cell division to create new cells... even “specializations” like the creation of muscle fibers or electrochemical signaling proteins in nerve cells may be similar between all mammals, or even all vertebrates.
The remaining 1% can account for a huge amount of variation, though. This doesn’t mean humans aren’t “meaningfully” or significantly different from chimpanzees. All the similarity just means we share the basic biochemical structure of our bodies, and even methods of reproduction, etc. | 120 | 108 |
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Am I right that, fundamentally, any productivity is better than no productivity? And that there should always, in the near future, be at least something for someone to do? | Obviously there's a lot of talk about automation and jobs lately.
Something that occurred to me is that, anywhere and everywhere, there's always *something* that needs to be done, or could be done. You can tell me if I'm wrong about that, but my intuition is that we need just look around our house, or our community, and you should pretty easily be able to spot myriad things that could be done, that aren't getting done.
Fundamentally, if we have things to be done, and if we have people not doing anything, that has to be completely inefficient, yes?
I'm imagining some world in which unemployed people can do some kind of community service, and where there is 'something to do' for everyone who wants to do something. Is there a reason this doesn't work? Even in a future world of automation, it seems like this doesn't cease to be. If you've got, for example, machines manufacturing all the materials needed for infrastructure, that just means we have more stuff which which to improve infrastructure. I mean, are we going to run out of infrastructure to build and improve? It seems like having an unemployed person busy doing that is vastly preferable to having them sitting at home.
As far as compensation, perhaps their labor isn't worth a ton at first, but it's worth more to them, and us, than having them idle. Suppose I'm a reasonably bright person who is unemployed or underemployed, and I go down to the community planning office and say, "I'd like to help, maybe I can sit in on the meetings and start learning?" I know, that's basically what an internship/apprenticeship is, and that that exists in places, but it strikes me just how strict, then, the barriers are to doing that. Why don't we have more places where people can easily get into that? You could argue that people don't like to contribute to society for free, but then...why would any of you be here taking the time to answer my questions?
I'm sure there are flaws in my thinking, but I don't see them straight out, so I'd love to hear more about it. Thanks in advance. | What is you core question? Or barring a core question, what is your thesis? It seems like you're making a roundabout argument that automation won't put everyone out of work because there is always more work generated by productive developments. There are certainly those who argue that.
Something to consider - is efficiency or productivity the ultimate good in a society? If not, then we must consider how optimizing efficiency affects other things we might wish to pursue, like leisure time. | 16 | 61 |
ELI5: Why do some coins get rejected in vending machines? | Sometimes a coin will work first time and with other coins you have to insert it a few times for the vending machine to accept it. | There can be a couple reasons, depending on how the machine identifies coins and what money's inside it. It might try to look at the coin's face and think it's not real (too damaged to look authentic, etc). It might try to weigh the coin to see if it's as heavy as a proper, 'standard' coin of a denomination. A valid coin you put in might have enough pieces knocked off that the weight seems wrong. The machine might also have too many coins and not enough bills, where enough money inserted in bills can't be given correct change (not enough/the right coins).
EDIT: spelling | 19 | 51 |
ELI5: Does genetics come into the equation when considering why all humans don't have the same intellectual capabilities? | Its a sensitive subject, but yes it does. Genetics decide your overall potential. You can of course squander it , especially if neglected in the first few years of life. Its also not a simple on / off genetic switch. There are many genes that factor in and have different effects. | 40 | 29 |
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CMV: Using the word “female” to talk about a woman or girl is not sexist/wrong/inappropriate | As a female who was in the military, I call every woman or girl a “female” when I’m talking about them. Or when I’m generalizing. There’s nothing wrong with doing this.
However, several times on Reddit I’ve been downvoted or called out for this. I’m progressive and liberal, so I try my best to speak with groups of people in mind. But this one just makes no sense to me.
I’ve never even heard someone use the word “female” intending for it to be condescending. And I’ve experienced plenty of sexism (primarily in the military).
Please, someone, anyone explain to me how this is sexist or inappropriate. Because I’m really not grasping it. | In normal life use of the word female for women and male for men can be unusual and that unusual use of language can just give people pause. Mostly nobody will take any offence, its just unusual.
Online can be a different thing. Online all people can judge you by is words so they place enormous significance on your choice of words, significance that hardly anyone would apply in a face to face encounter. Also you may run into people who have strong opinions about gender theory online and your unusual use of language will mark you out as not complying with their linguistic codes for their belief system. As that is one of the most heated belief systems generating the most online reaction right now it could certainly explain the responses you are getting.
Online people do tend to read into the words you use meanings which you never intended, then take very seriously the meaning that they have inferred. It is just a drawback of the online world. To those who are hypervigilant to use of language that deviates from their beliefs, you can indeed appear 'bad' and that badness will be expressed through descriptions such as sexist/etc. | 81 | 199 |
Why is it mandatory that court judges be treated like royalty? And why isn't the President? | For example, "All rise. . . you may be seated," and the like.
And while it's standard (i.e. everyone does it) to be just as respectful to the President, it doesn't seem as "forced" or required.
EDIT: Atomiktoaster [answered it pretty well](http://www.reddit.com/r/explainlikeimfive/comments/1of4x2/why_is_it_mandatory_that_court_judges_be_treated/ccremzb), and yeeye [made good points](http://www.reddit.com/r/explainlikeimfive/comments/1of4x2/why_is_it_mandatory_that_court_judges_be_treated/ccrga2x). Thanks, guys! :) | The US common law system has its origins in English law, where the judge is the representative of the sovereign. The historical idea was that the court is responsible for enforcing the King's justice. Therefore, the judge and the court are accorded a level of respect as an extension of the crown.
In the U.S., sovereignty rests with the People, rather than a monarch, but judges still fill the same role and are accorded with a similar level of respect. The Presidency isn't at quite the same level, being accountable to the will of the People and Congress and filling an administrative role under the Constitution.
Edit: early morning wrong "its" and TIL the * shows up after an edit. | 1,048 | 1,704 |
ELI5: How does gravity exactly work and why do objects increase in speed when falling from different heights? | I get the apple theory loosely but I want more understanding. | It's important to *really drill in people's heads* that gravity has two parts, the law and the theory.
The law bit is really simple: Objects with mass attract each other. How much they attract each other depends on their relative masses. Attraction means accelerating another object towards you. Here, the Earth accelerates every object towards itself at a constant rate of 9.82 meters per second per second. If we ignore things like air resistance, every object accelerates at the same rate when falling.
The theory part refers to how gravity actually works: is it a field? is it a particle? that's the part we haven't yet figured out. | 14 | 15 |
ELI5: Why do wall sockets only have 1 or 2 plugs? | I've always wondered why there were only two. Can't we add more? | There is typically a code (for safety) regarding electrical wiring. There is always the option of running more wires to more outlets, but there is a limit to how many sockets can be wired for a single pair of wires (by code).
Also a outlet boxes are very standard items - they are low cost because they are made in large volumes and made to common specification. Anything custom will be very expensive. More outlets means more circuits, means more wires, larger distribution boxes and more circuit breakers.
Lots of things can be done (within the electrical code for homes) but it is a matter of paying a lot more. Most households don't bother with the added expense. | 30 | 36 |
[Harry Potter] what makes a wizard powerful?... scientifically speaking, of course. | okay. So the magic in the *Harry Potter* series is probably pretty unintelligibly subjective, right? To the extent that (I'd imagine at least) it's difficult to talk about clearly, since magic includes weird abilities, like:
\-the ability to change your shape
\-the ability to read the minds of others
\-the ability to force your will upon others, using telepathy
\-other things which, if taken in all of their implications as the series gives us, probably lead us to some contradictions (i.e. is it possible for *any* spellcaster to be a powerful opponent against one in a duel, if one can read the other's mind and the one whose mind is being read, must speak their spells out loud.)
So I understand that in a duel, it will be a most useful trait to be able to do things like send spells without saying them, read your opponent's thoughts, and cast powerful spells. But what else is being measured between two fighters in a duel?
Take, for instance, the duel between Voldemort and Dumbledore, at the end of *Order of the Phoenix*. Theoretically during this fight, each of the duelists has one person they could have assist them (Harry for Dumbledore, and Bellatrix Lestrange for Voldemort) which, iirc, doesn't actually happen. But is either wizard (Voldy and Dumble) so powerful that the other two are just useless during this encounter?
If Dumbledore sends out a spell and says to Harry, "Now for the rebound!" and Harry casts a complementary spell, they're only going to help each other out so that they win, right?
That's what I'm finding confusing, I guess. I mean throughout the series "powerful magic" is shown, and hinted at as existing far beyond the experiences of one human or another; however, what is the actual nature of some of the more powerful spells shown? Are Dumbledore and Voldemort just throwing big elementals at each other during this duel (in particular, because I feel that it showcases some pretty powerful magic between two dueling wizards where otherwise duels tend to forward more dramatic issues of the plot); or are they using magic that is just so far advanced beyond an average wizard's understanding of magic (or, potentially, Harry's or Bellatrix's), that a novice wizard is going to be completely impossibly outmatched (or not be able to be helpful)? Or is there more nuance to it than that, like a novice could've stood up and helped but Dumbledore was exclusively trying to protect Harry (because Harry was important to Dumbledore's political endgoals); and Bellatrix either isn't that powerful (and she knows it), *or* she was afraid of Dumbledore because Dumbledore is a very wise, and very old, and very powerful, character?
Thanks. This has been confusing me and it's difficult to articulate the nature of this kind of question imo. | If i'm understanding your question corrextly, Imagine it as working in the same way as raw strength and training. Different people have different innate magic "strength", and different levels of training.
Imagine Hermione as someone who's really buff, and is training to be better. Someone like Ron is pretty strong, but isn't putting in the effort to use that. Someone like Neville is naturally weak, but is training really hard to be decent at fighting anyway. And Dumbledore and Voldemort are people who are both naturally ripped and heavily trained
They're the magic equivalent of, say, Muhammad Ali- not *technically* unbeatable, but might as well be for a normal person, or even for a normal boxer. They both know a lot of magic and are able to put a lot of power behind that magic meaning, yes, most other wizards are completely outmatched. They're simply top of the game, and only need to worry about the few others who've reached their level. | 37 | 25 |
ELI5: why do we grab our chest when we are startled? | "Oh my God you scared me" | I just did a quick google a managed to find a little info that may help
The responses of people to a startling incident vary widely between the fight, fly, or freeze options. When startled, people may wildly flail their arms, or suddenly raise their limbs in protective poses, or duck to avoid an object. The shocked and surprised often back pedal, jump back, or run away from a frontal stimulus. They may clutch a rail, or furniture to prevent from falling. Their knees may buckle, causing them to fall down. They may drop the things they are holding.
They may freeze, or instantly follow orders. They may clutch their chests, faint or even suffer a temporary heart attack The aggressive ones may curse or throw things at the object, which startled them, or strike out at them.
So it sounds like it clutching your just is a response you hafe in order to protect your torso. | 17 | 32 |
Is there a word for when organisations or political movements change ideology but retain the same name? | In classic organizational theory there are the dual concepts of ‘mission creep,’ where organizations change focus in response to external pressures (e.g., Zald and Denton 1963), and ‘goal displacement,’ where change results from internal pressures (e.g., Selznick 1943). For a great example of this sort of thing, take a look at Messinger’s 1955 paper in the American Sociological Review on the Townsend Movement. | 42 | 45 |
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What is responsible for some people being lonely or socially isolated despite humans being social animals? | What are differences from normal humans that make someone vulnerable to be socially isolated or left alone? | Not an expert, but asking a clarifying question: Do you mean what leads some people to be excluded from the groups in which they might otherwise participate, or do you mean why do some people prefer to not be a member of groups? | 17 | 36 |
CMV: Vocational school is just as difficult as a university (relatively speaking) | Why is vocational school often recommended for people who aren't college material/ intelligent? Trades and vocational school are still difficult and require intelligence. Whether it be electrical, welding, HVAC, etc it still requires math, reading comprehension and basic skills.
Why is it viewed that a welding class or a automotive repair class is easier than college courses ( more specifically freshman level history, college algebra, business etc). If anything I would view learning to weld as a more difficult skill than passing a college class.
Additionally you still have to take math and English in most associated degrees. I’ve seen a lot of people even in college struggle with basic algebra and fractions, now how would they be able to thrive in a trade that uses decimals, fractions, micrometers etc quite frequently? Also trades are physically demanding. Someone who has never worked a physical job/ been active will have a difficult time digging trenches, lugging pipes/sheet metal.
I just think the grass isn’t greener on the other side and trades are just as difficult as a general degree. ( not comparing it to Ivy League level/pre med/high difficulty degrees) | Oftentimes, people who are bad at school are bad at particular aspects of schooling, such as classroom learning and dealing with high levels of abstraction.
For many people, practical applications of math or engineering principles are much easier than purely abstract mathematics, even if the core concepts are the same. Additionally, they are able to embrace the task more clearly because it is tied to a practical end result, as opposed to being a purely academic exercise.
It isn't to say that trade programs are necessarily easier than ordinary undergraduate programs, but they're difficult in different ways that make them suitable to different people. So someone who is bad at ordinary academic programs might still thrive in a well designed trade program that better suits their learning style. | 17 | 19 |
ELI5: Why is collecting rainwater illegal in some states? | Claiming that rainwater harvesting is "illegal. | Water can be hard to some by in some places. Collecting rain water means that you are interfering with the replenishment of the natural water supply, or artificially worsening the water shortage for neighbors that would normally receive run-off from your property. Essentially, you are keeping water from it's natural course and in a drought condition, that can be devastating for others. | 22 | 19 |
I think that the Paralympic Games directly contradicts the idea of 'not being defined by one's disability' CMV | While watching the Sochi Olympics with some sports buff friends of mine, I got into a discussion over Oscar Pistorius [(link)](http://en.wikipedia.org/wiki/Oscar_Pistorius) and whether his participation in the 2012 Olympics and 2012 Paralympics should have been allowed, which stemmed into a bigger discussion about the Paralympics in general.
It seems to me that having to put competitors into different categories of disability for each event, as well as focusing on what people with different disabilities are able to athletically do puts far more focus on the disability itself than on the skill of the athlete.
This, in short, makes me feel like the Paralympics give off a superficial image of empowerment and equality and because of this the games should not exist so please, CMV. | I think you're conflating "defined by" with "taking into account". For example, does someone in a wheelchair "define themselves by their wheelchair" when they take the ramp instead of the stairs? The reality is, they have different abilities than people who are not handicapped, so it is only reasonable to take them into account. That doesn't mean their whole identity is defined by their disability though.
So the reality is, people racing in wheelchairs are facing a different sort of event than people running with their legs. It would be as unreasonable to ignore this reality as it would be to ignore the reality that they can't use the stairs. It doesn't mean they're "defined" by it...it just means they're in a different sort of competition because the nature of their participation is different. | 22 | 70 |
How is redline on a car chosen? Why do some cars rev-up to 6k while others go to 9k before hitting redline? | Comparing two engines with the same capacity, the one with more cylinders allows for lighter moving parts and thus a higher redline.
On a 4 stroke usually the first mechanical limit is the spring load on the valves, the valves not being to return to their position quick enough they might hit the pistons. This is where the rev limiter is placed for safety.
Talking about engineering choices, since power=torque*revolutions, higher rpm mean higher power can be produced (simply because you are burning more fuel per time unit). The engine is designed accordingly, usually there is a trade-in between maximum power and efficiency and fuel consumption. A higher-revving engine can produce more power but when you are driving at low speed, which is most of the time, basically you are keeping the engine in a less efficient part of the torque-rpm curve. This is why for average car engines the engine is designed to have maximum torque (thus efficiency) at the typical cruise speed. Sports engine sacrifice efficiency for performance. As a thumb rule, car engines have maximum torque at approximately 75% of max power rpm. | 17 | 42 |
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[LOTR] How common was interracial marriage in middle-earth?? | How common was it for a person to marry and have children with a person of another race?? Like what would a child between an Elf and a Dwarf look like. | > How common was it for a person to marry and have children with a person of another race?
During the First Age, some Men came under the domination of Morgoth and were reduced to a feral state, in which they interbred with Orcs. This produced the half-orcs. Rape would result in much the same.
There is no mention of half-dwarves. It's not clear if unions between dwarves and other races could be fertile.
Half-elves were rare but did happen. Elves would only mate with their life-partners, and elven conception having a spiritual component would prevent rape from producing half-elves, hence only genuine unions ever resulted in half-elves. These were the marriages of Beren and Luthien, Tuor and Idril, Earendil and Elwing, and possibly (though this story is not nearly as well documented as the other three) Imrazôr and Mithrellas. | 29 | 59 |
How do gender roles influence emotional expression? | At least in the western world (I don't know too much about other cultures) it is common to think that women are more emotional than men. The idea that men don't like to talk about their emotions while women do, and so on. While I have the idea that this is true in general due to biological reasons (but im not really sure), what influence do societies have in expressing emotions, and could it not be that by society not listening to men's emotions cause them to stay silent about them?
I can imagine for instance men who would talk openly about their feelings if it wasn't for a society where this was considered shamefull. But the balance between 'nature and nurture', biology vs gender roles, is quite opaque to me.
What information/literature is there about the subject, and is there a difference between different cultures? | There’s actually a really great literature within Sociology called the Sociology of emotions, and one of its most influential books is by Arlie Hochschild - The Managed Heart (1983). She argues that, for example, female flight attendants have to perform a sort of emotional labor to effectively do their job. It’s a great case in point as to how gendered job expectations drive emotional expression.
There’s also a pretty consistent through line in the Sociology of gender that argues that there is consistently identifiable patterns in gendered socialization that shape emotional expression. This hangs around the idea that children are socialized into norms related to ideal masculinity or femininity that enable or constrain types of emotional expression. For a good review, check out West and Zimmerman’s 1987 article “Doing Gender.” In it you’ll find a substantive overview of the topic that includes dated but empirical work covering all angles of the question. | 12 | 21 |
CMV: If you are playing a game fairly within the defined rules, you cannot act unethically/immorally as it regards to play. | As a small preface, this discussion mostly pertains to MMORPGs that have a competitive auction house system in place. However I feel that my view does in fact extend to all games in general.
If you are playing a game by the rules as outlined by the person who created the game, you cannot act unethically or immorally. For some reason, a lot of players in MMOs tend to apply a weird idiosyncratic idea that auction house prices have some external room for interpretation. Usually this applies to people getting frustrated with undercutting and whining about "destroying the market." My argument, is that because the rules are defined, and require an implicit agreement between any two players as to how they function it is impossible to then be unethical or immoral, because what is moral/ethical in this case has been quantitatively defined as X rules.
I'd like to see a position that maybe I'm not considering in how this view could be incorrect. It does seem pretty cut and dry to me, but it's not so self-evident given how upset people get. (My ultimate point being, that it's pretty dumb to get mad when everyone is otherwise playing fair) I suppose that could just be video game culture at its finest but you don't usually see it manifest in not competitive titles.
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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!* | Look into hawk/dove games and other models of human cooperation.
What you should understand is that calling someone immoral/unethical *is a strategy within the game*, because it makes people want to cooperate with them less, and potentially makes them feel bad about themselves, thereby making that 'immoral' strategy less effective overall because of the negative consequences to your reputation.
Labels like 'immoral' and 'unethical' serve *exactly the same game theoretic purpose* in our everyday, real lives.
Therefore, since the meaning of 'immoral' and 'unethical' acts is really just 'acts that other people wish you wouldn't do and will refuse to cooperate with you in the future if they see you doing', then those terms are just descriptions of certain types of strategies in the game, and are perfectly applicable and reasonable labels.
It's not dumb to get mad when someone acts unethically in the game. Getting mad at them is *precisely* the best strategy to undermine their strategy and make them less likely to use it in the future. It is a perfectly rational strategic response. | 47 | 44 |
Is an MA in Medieval Studies a waste of time and money? | Hello and sorry for the long post. I would like to get some fresh insight about whether it's worth following an academic path in Medieval Studies in the UK. I hold a BA in English and I absolutely loved doing my dissertation on medieval literature and I got a First too. I've been thinking to follow an academic career for a while now and I now hold 2 offers to do an MA on Medieval Studies or Late Antique/Byzantine Studies in two prestigious unis in England. But the thing is that the tuition fees are ridiculously high and I would need to take a loan which really puts me off given that these degrees aren't exactly sought after. I had hoped that for the second course I would get a scholarship but the history department said they wouldn't release any scholarship this year, which was frustrating because they received millions of pounds from some foundation and some of it was supposed to go to scholarships.
Anyway, I was told that to land an academic post (especially a permanent one) is super hard, unstable and a lot depends on luck too. If I don't land one then I'm not sure what else I could do with such niche qualifications and a lot of debt... Plus, I would need 4 years to get my MA and PhD and by that time I would be 31-32. I take it that while other friends will have started building their lives, I would be moving here and there in short-term contracts (which aren't even certain). But even that would be fine if there was at least some guarantee at the end. My old supervisor said that those who are good and determined always make it at the end but then again he landed a permanent post two decades ago.
How do you see the situation for medievalists in unis? Is it really that grim as been presented to me? If one can't get an academic job, what else do they end up doing even remotely similar? I can't decide whether I should follow this path or just get an industry job and pursue my scholarly interests in my free time. I was reading some old essays of mine today and I got emotional knowing that I might not do literary research again but then again maybe I could become an independent scholar or write articles? I'm just worried that I might shoot myself in the foot while building castles in the sky. | A lot of people will give you similar advice:
- Only you can make the final call about pros and cons
- There are no secure jobs, unless you are exceptionally talented AND lucky AND well-connected. Or unless you are prepared to go work at unis in Asia or the Middle East (which can be a nice career for those who are suited to it).
- If you do it, have a realistic backup plan. Accept that you will be starting at the bottom of the ladder in your early 30s.
- Don’t pay to go to grad school. Especially, don’t get in debt for it. If you break this rule, know that by following your dreams you will be sacrificing your future security. If a department thinks your research field is important, they should be willing to pay for it.
- Only go to grad school if you literally can’t see yourself being happy doing anything else. | 24 | 22 |
ELI5: why does "the big, red, house" sound much more correct than "the red, big, house"? | While not everyone follows them, generally in English if there are multiple adjectives, they are done in a particular order:
* Quantity or number
* Quality or opinion
* Size
* Age
* Shape
* Color
* Place of origin or material
* Purpose or qualifier
So most people will say "big, red house" so that's what you're used to hearing. | 34 | 15 |
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CMV: I think that when asked about something from a child (less than 10) we should try our best to not lie to them. | EDIT: Okay people my view has been changed now stop flooding my inbox and get off my lawn!
Okay so to start off i'm not a parent, i'm a senior in high school, but I do have a younger step-brother (10 yo) and a cousin (7 yo). I find that when I have to explain something to them after being asked a question, I remind myself of all the phony explanations that my parents gave me when I was their age. So I try to be as honest as possible, even if they aren't 100% able to comprehend the explanation. I find that a lot of people just lie to their children because it's easier, but I feel that this causes a few problems
1. The child is misinformed and may repeat misinformation to a friend at school, or worse embarrass themselves in class by repeating misinformation to a teacher when asked a question.
2. The child no longer can trust that person to be honest with them. It's better to say, "I don't know" or "you're not old enough to understand" than to just say something that's only half true or completely false just because they're a kid and aren't smart enough to know you're bullshitting them.
3. Even worse, the child remains misinformed their entire lives because no one ever corrects them, and they come off as ignorant.
I know that parenting is difficult but for the sake of the children, let's not treat them like idiots and tell them convenient lies, but simple truths or at least push the question to the future when they could understand.
This isn't a very controversial subject but I have heard arguments in opposition to this view in that "children forget, so why take the time to explain" or "they'll learn eventually".
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> *Hello, users of CMV! This is a footnote from your moderators. We'd just like to remind you of a couple of things. Firstly, please remember to* ***[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)****! If you are thinking about submitting a CMV yourself, please have a look through our* ***[popular topics wiki](http://www.reddit.com/r/changemyview/wiki/populartopics)*** *first. Any questions or concerns? Feel free to* ***[message us](http://www.reddit.com/message/compose?to=/r/changemyview)***. *Happy CMVing!* | Some subjects are simply too complex for any child to understand properly (e.g. most topics in philosophy, politics, and religion, which will inevitably be parsed into potentially harmful half-truths), or it may be that a full understanding of them relies on some experiential knowledge or feeling that a child can't or shouldn't have (e.g. most things related to sex).
You're concerned about lying because it might cause bad/incorrect information to exist in the child's mind, but if the child *can't* understand some fundamentally important aspect of something, then being completely honest will also result in bad/incorrect information once it's filtered through the child's limited cognitive/experiential capacities.
In these cases, isn't it better to at least tell the truth *selectively*, and omit certain things, and deliberately simplify others? That's the only way you'll get them to possess information that's fully comprehensible to them, and not confusing or disturbing. And the kinds of partial, distorted ideas that can form from pieces of the truth can be much more dangerous than simpler, placeholder untruths. | 171 | 668 |
ELI5: When many people read, we see the story played out like a movie in our minds instead of the words on the page... What is the neurological explanation of this? How does it happen? | Our mind's eye is the connection between our conscious and subconscious thoughts. When we are told something we try to envision it to better understand it. When reading a well written story involving things that don't exist or have never seen before our internal process of understanding is working harder to create the visuals for it. | 16 | 166 |
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Is an increase in population necessary for sustaining pensions in an ageing nation? | This applies to many countries but I'm using the UK as an example. The source for all claims in this post is the [Office for National Statistics](https://www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/ageing/articles/howwouldyousupportourageingpopulation/2019-06-24).
The UK population is ageing because of a rise in life expectancy and falling fertility rates. Because of this, the proportion of pensioners to taxpayers is growing. Since pensions are paid almost entirely from working taxpayers under the age of 60, the problem of sustaining pensions becomes more difficult as the population ages.
One common solution is raising the retirement age, but this cannot be done indefinitely due to obvious physical constraints on the elderly. The other well-known response is to make up for falling fertility rates by increasing immigration levels. Migrants, who are typically of working age, would ensure that the number of taxpayers rises to match the growing number of pensioners.
Ignoring any potential future technological developments, in a hypothetical scenario where life expectancy increases to 120 and retirement age rises to 80, how would pensions be paid if fertility rates remain low? Is bringing young workers from abroad the only solution? Is a population increase always necessary, and if so, what happens when overpopulation becomes unsustainable? | Addressing a very simplistic model, suppose that:
X is the amount of actual workers, Y is the amount of retired workers receiving a pension, w is the mean wage and p is the mean pension. t is a % tax for the workers. We have
w * t * X = Y * p
or w * t * X/Y = p
X/Y is the ratio of workers per pensioner, we will cal it k. So
w * t * k = p
If the population is getting older and fertility is decaying, then k will fall and ceteris paribus the mean pensions will fall down too. There are two options that can rise this pension again: A rise in the tax t, but you cant do this for the eternity, or to increase the mean wage. The last option is what have kept the system still operating the last decades.
So, answering your question, pensions are sustainable in aging countries as long as an increase in productivity is maintained. | 21 | 47 |
CMV: Copyrigtht lasting longer than the lifetime of the creator stops more creativity than protect it. | Copyright is a brilliant thing, protecting the ideas of an artist, writer or director. With that they are encouraged to produce something and sequels to successful stuff.
But no person on earth can produce new things, after they died. They don't need any encouragement or protection after their death. It benefits only profit driven companies. They will keep the rights and don't promote creativity based on the pool of the artists work.
I think one or two years after the artists death could the copyright be extended, so the legacy can rest. After that it would only be profit not the idea of protecting artists, that put the copyright at death+75 yrs. | Copyright is a transferrable asset; this is why you can sell, license, or give away all or part of your copyright. Because it's an *asset*, it has value, and our current system of inheritance is generally very averse to removing any value that somebody might get from inheritance.
Copyright existing past the death of the author does not just apply to large companies or to allow the "legacy to rest", but also to the family members of authors, and can protect those family members from having residual income taken away by a company swooping in and making knockoffs or simply republishing the original works.
Now, this isn't to say that 70 years makes sense, or that it's exclusively beneficial to estates or whatever, but just to point out that there are impacts of copyright aside from allowing Disney to keep exclusivity over Mickey Mouse forever or whatever. | 11 | 84 |
ELI5:Why do words sometimes begin to "sound weird" or not like words at all, after we repeat them over and over in our heads or out loud? | This is called semantic satiation. It's basically your brain messing up slightly due to certain things up there happening repeatedly at a fast pace. The Wikipedia article has more a lot more if you want to dig deeper. | 82 | 217 |
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When you see a shockwave what are you actually seeing? | Air at different densities refracts light differently, like when heat waves coming off the pavement or a grill create pockets of air at different densities. The shockwave has different densities of air ahead of and behind the shockwave, which gives a lensing effect. | 14 | 16 |
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eli5: What are the benefits of digitigrade vs. plantigrade feet? | Plantigrades are generally more stable and able to bear more weight. That's because the weight goes basically straight down the leg to a relatively large surface area.
Digitigrades are essentially walking on their toes. This increases the effective length of their leg, increasing the stride length and subsequently their speed. It's also somewhat more mechanically efficient given the arrangement of their tendons and ligaments, as they effectively act like springs. | 23 | 19 |
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I don't believe the patriarchy exists, and is simply used as a tool to silence criticism of feminism. | Alright, I would like to start this CMV by stating that I do think feminism is necessary in our society. Girls everywhere are faced with discrimination due to their gender in overt and covert forms, and the feminist movement has been good for combating said discrimination.
That said, I don't believe the "patriarchy" is a real thing as of the year 2013. So far as I am aware, the patriarchy is a catch all term for male privilege and the causes, ideologies, and actions that uphold and advance said privilege. Sure, the patriarchy may have existed in the past, but it has been wiped out, or at least reduced to a role of irrelevancy.
First of all, the concept of the patriarchy doesn't make a ton of sense in terms of advancing the position of men. MRA's and similar groups often note the ways in which men are disadvantaged: Higher suicide rates, forced conscription, cultural expectations to be the bread winners, higher incarceration rates, imbalanced divorce/custody courts, lower education rates, and a lack of identity. Why would the patriarchy set up these factors to intentionally hurt men? Assume the goal is male dominance, why would the patriarchy set up disadvantages for men such as these?
Another thing I've noticed is that often feminists sight the patriarchy and/or male privileges for discrimination against them; we've all heard the arguments about wage discrepancy, traditional gender roles, and rape culture. However, it appears wage discrepancy today is more of a cultural thing than overt discrimination; men naturally flow into higher earning fields of work such as STEM. Where I feel this falls apart is that any girl can enter a STEM field if she chooses and face little resistance, but a straight male entering a traditionally "feminine" field such as dance or women's studies faces heavy resistance from both men and women. And although rape is a serious issue, I feel that those who are convicted receive heavy punishments (usually lengthy jail time). Why would the patriarchy seek to limit men in these ways? If it truly was about making men dominant, wouldn't it seek to give men complete freedoms while limiting the same freedoms in women?
Ultimately, I feel like this is where the idea of the patriarchy falls apart; both genders are limited in certain ways, it isn't simply men dominating over women for their own gain.
So what relevance does this have to modern feminism? I feel that the concept of the patriarchy is used to suppress any criticism of feminism. As a straight male I am not allowed to question feminism, because I am part of the patriarchy and therefore my male privilege blinds me. I find this is extremely restrictive to discussion about the aims of feminism, where it succeeds, and where it fails.
EDIT: Something I forgot in the original post, which I meant to comment on. A lot of people state that the issues men face are a result of the patriarchy assigning gender roles to men as well as women. I can agree with this. There are even men out there who are currently fighting these gender roles, not unlike women did "back in the day". However, whenever somebody even suggests discussing the possibility that men face issues, the response they usually receive is "well you're privileged so shut up/women have it worse, quit bitching". I have observed this happen twice relatively close to home for me: Once at University of Toronto, where a "MRA" lecture was barricaded by feminists, and then again even more recently at Ryerson university (also in Toronto), when students suggesting a new group to examine mens issues was immediately shut down.
Now, where these groups raising legitimate points or just spouting misogyny? We'll never know unfortunately, because the concept of "privilege" was used as a tool to prevent men from voicing their opinions. This is where I have a large complaint; women are allowed to discuss their issues and work towards a solution, but any male attempting to discuss an issue is instantly shut down by the more militant side of feminism. | >Assume the goal is male dominance, why would the patriarchy set up disadvantages for men such as these?
>Why would the patriarchy seek to limit men in these ways?
You seem to be thinking of the patriarchy in terms of a grand conspiracy that's pulling strings to make life better for men at the disadvantage of women.
In reality, when feminists refer to "patriarchy" they are referring more to the historic dominance of males in society and the lasting cultural implications of that dominance. These implications (are seen to) disadvantage women in favor of men, but they can also hurt men (see: your point about men taking on "feminine" roles in society). In reality, no one is pulling the strings. | 46 | 24 |
Why do people get sick from eating contaminated food? Wouldn't the bacteria/virus be broken up by stomach acid? | The capacity of microbes to survive the acidic environment of the stomach is largely dependent upon a few variables:
\-The microbial load: The number of organisms accompanying the food bolus. The more organisms there are, the greater the likelihood that at least a few will successfully pass through the stomach and in to the small intestine.
\-Time: Food can pass through the stomach relatively quickly depending upon a few factors. It takes time for the acid concentration of the stomach to do what it does. Sometimes food (and, therefore, microbes), simply pass through too quickly.
\-Adaptive mechanisms: Many microbes have adaptive mechanisms that protect against low pH. There is a long list of pathogenic microbes for which this is the case, but this also applies to microbes that are part of our normal microbiome and do not necessarily share a pathogenic relationship with us.
\-pH fluctuation: The stomach isn't always at pH-2. When food empties in to the stomach, the pH can rise as high as pH-6 depending on the particular materials being digested. It's also important to recognize that, while the pH of solution can be low, the surface of food contents in the stomach can have a micro-environment that is relatively high-pH.
So while the normally low pH of stomach contents (pH 1-2) is often deleterious to a great many microbes, there is a wide array of conditions that ultimately allow microbes to pass through the stomach and in to the intestines, which is the primary site of infection for most food-borne infectious organisms. | 42 | 32 |
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ELI5: How do they re-attach severed limbs? | How do they re-attach severed limbs in surgery? Also, if you just physically reattach your severed finger by securing it with tape/stitches, would your finger reattach itself? | When body parts are reattached, the most important thing to get right is blood flow.
The arteries and veins are all reconnected as best as possible. This is needed to keep the part alive.
Muscles and nerves are also reconnected to give you sensation and movement.
The skin is the last to be reconnected.
If you just taped a finger tip in place, it wouldn't have the blood flow, and just die. | 14 | 24 |
CMV: People who are Pro-Life or Anti-Abortion (specifically those who oppose abortion at any stage) have an obligation to adopt at least one child. | **Note:** *I do not want to argue on whether a fetus should be considered a human or at what stage a fetus is considered alive and has the right to life.*
How many children are brought into this world to parents who are in no way capable of handling the responsibility of raising them to successful adults? How many of these parents decided against abortion solely because of the stigma attached to it and the shame thrown at them by pro-lifers?
There are half a million children in need of loving homes in foster care or available for adoption. Yet I never see any pro-lifers protesting for a better foster care system or standing up and adopting the children that are brought into this world unwanted.
| A person's belief that something is wrong is not and cannot be grounds to obligate them to fix it.
If someone is against ISIL, it is not their moral duty to go to the Middle East and fight ISIL directly. If you start to apply this standard life quickly becomes impossible for everyone; there are simply too many problems for everyone to actively try to correct everything with which they disagree. | 23 | 21 |
Why do CRT monitors work differently in the Northern and Southern hemispheres? | My supervisor was telling me today about how the psych department at my uni has to spend huge amounts of money on getting CRT monitors in (they're still the gold standard in perception research because you can display things for more precise amounts of time).
One of the biggest costs, apparently, is getting the monitors adjusted for the Southern hemisphere. The little bits of info I've been able to find through Google tell me that it's something to do with differences in the Earth's magnetic field in each hemisphere, but does anyone know what those differences are, and how exactly it affects monitors? | CRT monitors work by shooting electrons whose paths are bent by magnetic fields which can control where the electrons strike your screen. The CRT monitor creates a magnetic field in order direct the path of the electron. However, the Earth's magnetic field will also affect the path that the electron travels in, and the CRT must account for this.
Let's just talk about a 1 dimensional case here. If the monitor wants to create an magnetic field pointing, for example, to the left and the Earth's magnetic field is pointing to the right in the region you are in, then the monitor would have to create a slightly stronger magnetic field in order to compensate. Where if you switched hemispheres, the Earth's field would be pointing in the opposite direction thus lining up with the field the monitor needs to create, so the monitor would create a slightly less powerful field in order to compensate. The monitor's field is much larger than the Earth's, so this is a small correction so thus moving monitors across the Equator only creates a small color error- but if color fidelity is important, it is something that must be compensated for. | 22 | 49 |
ELI5: In open world games like GTA V, is the entire world constantly running the simulation, or is it just the parts where the playable character resides? | To be efficient with resources, the game only loads in the chunks where the player is present, or where a relevant event to the player may be occurring. If the entire simulation were running at all times, it would be far too taxing on the computer. | 788 | 998 |
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eli5: How do historians know that ancient people actually believed in things like demons or spirits, and that it wasn’t just like the Boogeyman or Santa to them? | Mostly through ritual evidence. Believing in Santa is one thing, but sacrificing an animal or part of your harvest to appease him is another. Anthropologists will find alters or walls covered with figures or spirits. At the base they'll find things like animal bones or clay jars with evidence of decomposition in the soil around it. They'll find many layers and many different artefacts that date back decade after decade. All that is evidence of long term ritualistic worship. | 18 | 16 |
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ELI5: Bernie Sanders wants to 'break up' the big 6 corporations on Wall Street.... What does this actually mean? | A large corporation has many business units. For example GE makes many consumer electronics. They make electrical components, they make military equipment, they make equipment for power & water, airplane engines and a few other industries, plus GE capital that does a lot in the financial sector.
Maybe each of those can be broken up into 7 smaller independent companies. That would reduce the size and political influence of GE, since each individual new company would have different political goals and motives. GE Aviation wouldn't care about a new law to regulate railroad engines, and wouldn't spend money to lobby influence on it, while GE Transportation would.
Before GE as a master company, would. | 205 | 684 |
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[Buffy] Inconsistent magical help for physical injuries | I never quite understood why Xander's facial injuries in the last season never got magical help. Buffy got magical help when a demon tore off some of her skin. I'm theorizing that skin -tries- to grow back so that might have been it but I'm wondering what other people think.
TL;DR: Why not use magic to heal injuries always? | I can think of two or three main reasons.
As you stated 1) Eyeballs do not naturally grow back, once you lose them they are gone.
2) Magic can be used to repair "supernatural" problems and injuries, but having a human preacher take your eye out isn't close enough. Also healing spells might actually be dark magic, because they go against the natural order of things.
3) Conscious decision not to use magic to heal everything, because then the sacrifices have less meaning (this is slightly a not in-universe answer, might be a writers answer) | 11 | 21 |
ELI5: What is Category Theory? | As math progressed through the 20th Century, we kinda realized that there were tons of relationships between various mathematical objects that looked the same but weren't actually related at all. This was a bit because we tend to look at the components that make up a mathematical object, like elements of a set, numbers, points in a space, loops in a space, operations, equations, etc, etc, etc. But, if instead we looked at mathematical objects themselves as the constituents of a theory as a whole, we could illuminate what these theories are a little bit better.
For instance, we have the theory of sets. And when we look at things in terms of set theory, we generally want to know what things make up the elements of a particular set. But the category theory of set theory does not care. It cares about how different sets relate to each other, and the way sets relate to each other is functions between them. So instead of understanding the set A by asking what its elements are, we understand the set A by asking what are all the functions from A to other sets.
This mindset is incredibly useful, because it allows us to ignore unimportant specifics and focus on the important structural components instead. Moreover, it allows us to explicitly compare different theories together. We can transform the theory of topological spaces into the theory of linear algebra, allowing use to easily conclude tough things about weird spaces using simple algebra.
**TL;DR:** Look at the relationships between things, rather than the components of a thing. | 60 | 103 |
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Eli5: how does the internet live forever and what would it take to completely shut it down and lose all archives of it | the internet is the set of connections between various computers.
compare it to the network of roads in your country.
you can block all roads leading to one specific city ("Facebook-town", "Google-city", whatever), but simply blocking one or two will generally only make that destination a bit harder to reach but not remove it from the map.
to completely shutdown all roads/the internet you'd need to cut all connections and in the case of the internet thats not just cables but also wireless (satellite) connections, making it virtually impossible to really shut it down 100%.
but in both cases cutting of some high-traffic/central destinations will lead to chaos and upheaval.
to lose ALL archives you'd need to destroy all harddrives connected to the internet, but a lot of stuff is just on a few harddrives, so if you destroyed 20% of all harddrives something like 10% of all content could be lost forever. | 179 | 208 |
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ELI5: Why do some water bottles 'hiss' when you open them similar to soda, even though they arent carbonated? | Some are still pressurized with a neutral gas, like nitrogen, to help preserve freshness. Others may have simply pressurized from the air and water warming, causing the air to expand and the water to let off some water vapor which expands as well. This creates pressure, and so, the hiss. | 16 | 18 |
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What happens to aquatic life when a lake freezes over? Do the animals and plants somehow hibernate, or do they find a way to live under to ice? Where would they get oxygen? | It really depends on the organism in question. Many fish remain isothermic with the water, and do regular fish things, others will go into a semi-restful state where they are sluggish and barely move to conserve energy. There are frogs that will bury themselves in the mud and essentially hibernate through the winter, and even some frogs that allow themselves to become fully frozen in ice until the spring thaw.
Arctic fish have adapted to the cold and contain antifreeze compounds in their bloodstream, while Arctic aquatic mammals have thick layers of blubber to provide insulation in the cold waters. | 97 | 86 |
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ELI5: How do people in India know which caste I am? | I'm an American of Indian ancestry and reading news about intercaste violence. If I visit India, how will I be viewed in the caste system? I don't even know which caste I am. | In modern times it can get blurred, people from different castes intra-marry, or even different states. Some clues exist, your last name can indicate what caste your family is from. Sometimes different castes use a different pronunciation or word, and that can give a hint. So can the style of traditional clothes worn can also give geographic or caste hints.
Think of it this way, can you tell if someone is from rural Alabama? Probably, just as much as you can tell If someone is from the inner city or England. Different fashion, food preferences, and accent or words.
Could someone pretend to be a different caste, sure but usually by adulthood, those difference are pretty engrained. | 30 | 39 |
Subsets and Splits