Show HN: A JavaScript-Based Leetcode Interview Bootcamp for Software Developers - <AUTHOR> https://www.udemy.com/ultimate-javascript-leetcode-interview-bootcamp/?couponCode=ACETHATINTERVIEW0719 <comment><AUTHOR> My friend and I recently finished our LeetCode interview bootcamp for software developers, and I'm making it available for free to HN readers (Yes I'm being completely serious, there's no catch!)

This forum has given me a lot of value over the years, so this is my (small) way of saying thanks

This course was designed with beginner/intermediate developers in mind, so if you are a rockstar engineer, then this probably is not the right course for you.

(Apologies in advance if this isn't allowed. Please let me know and I'll take it down.)

</comment><comment><USER2> Thanks Alex, Just enrolled the course. Watched the intro, it's really engaging. Looking forward to complete this on free time.</comment>


What is animals.txt? - <AUTHOR> http://animalstxt.org/en/

<comment><USER2> This one got me laughing. What comes next? ChuckNorris.txt in every document root?</comment>


More than half of all software spend over next 5 years will be open source - <AUTHOR> http://www.zdnet.com/blog/open-source/survey-56-expect-that-more-than-half-of-all-software-spend-over-next-5-years-will-be-open-source/8917

<comment><USER2> That is the first time I have ever seen 'spend' as a noun.

On one hand, I love the versatility of the English language.

On the other, it made the headline really, really hard to parse.

<comment><USER3> Okay so I'm not crazy. I had to read the title again and again, and I understood it only when I read the first paragraph of the article! (English is not my native language).

<comment><USER4> > English is not my native language

Don't worry. That headline isn't English!</comment></comment></comment>


Genius who used first class ticket to eat free for a year does not exist - <AUTHOR> http://shanghaiist.com/2014/01/29/passenger-with-first-class-ticket-eating-free-for-a-year-myth.php

<comment><USER2> Would that _really_ make him a genius. Mozart was a genius, not a guy who noticed a loophole in a booking system.</comment>


Supplying Legal Notices for Free Software in your Products - <AUTHOR> http://www.ipwatchdog.com/2017/12/02/supplying-legal-notices-free-software/ <comment><USER2> > Anyone who distributes the CPU must provide the legal notice, i.e. not just > Intel but also the computer manufacturers who placed the CPU in a computer, > and the sales companies that eventually sold the computer to you.

What about the first sale doctrine?

<comment><USER3> Maybe that is a consumer-protection thing that doesn't extend to commercial entities?

<comment><USER4> No, it extends to anyone, it's part of copyright law in the US. I'm confused thinking of how it applies to software licenses though. I guess software licenses are not a purchase of an object, but a _license_ to use it. (And of course it's not open source that pioneered this legal application). The first sale doctrine lets you, for instance, resell a book you buy -- it doesn't let you print more books. It's unclear and confusing to me how it applies to what's being discussed too. Probably who knows what a judge/jury would do.

<comment><USER2> To be clear, I'm suggesting first sale applies to to the companies that buy CPUs from Intel and put them in the computers they build, and the sales companies that buy those computers and resell them to consumers.

I'm not suggesting it applies to Intel.

Intel is making copies, so they need copyright owner permission.

The company that buys a CPU from Intel and solders it into a computer they build, and the sales company that later sells that computer to a consumer, are not making copies. They are just passing on copies they received. Hence, they should not need copyright owner permission because of first sale.

There is one possible hitch that comes to mind. In the US version of first sale, it applies to the owner of a copy that was "lawfully made". If Intel is violating the license, and if that means the copies Intel makes are not "lawfully made", then first sale does not apply to those copies.

<comment><USER5> Your second theory is correct. The first sale doctrine does not apply when the initial copy was not lawfully made, at least under the US Copyright Act. Without that exception, section 501 imposes strict liability for infringement. It doesn't require that the plaintiff allege or prove knowledge or bad faith.

The reason for this might be more obvious in the context of something more obviously infringing, such as bootleg DVD movies. A plaintiff can hold the reseller of the bootleg DVDs liable just as it could the manufacturer. That's desirable since the manufacturer could be judgement-proof (e.g., fly by night company). And we wouldn't want the copyright owner to have to prove that the reseller knew the DVDs were bootlegs.

In the case of distributing Intel CPUs, the principle isn't as obviously applicable as it is to bootleg DVDs, but it still applies. So, the resellers could be held liable for copyright infringment as well.

That being said, since Intel isn't a fly-by-night operation like a manufacturer of bootleg DVDs, the copyright owner can just go after Intel directly.

</comment></comment></comment></comment></comment><comment><USER6> The title should probably be something along the lines of "No legal notice supplied with Intel ME's minix fork".

Interesting read nonetheless. Here, the ones that could sue are the copyright holders (A.S Tanenbaum), and I would be surprised if they were interested.

<comment><USER7> AFAICT, Minix 3 copyright is held by Vrije Universiteit Amsterdam, not by Tanenbaum himself.

[http://git.minix3.org/index.cgi?p=minix.git;a=blob;f=LICENSE](http://git.minix3.org/index.cgi?p=minix.git;a=blob;f=LICENSE)

<comment><USER8> Indeed. And for all anyone knows Intel already has permission from the university.

</comment></comment></comment><comment><USER9> I think Linus said something like "you don't make friends by suing people" and while Intel has not followed the license to the letter, court should not be the first answer to that

<comment><USER10> I don't see how your feelings are relevant.

Tanenbaum's software was used against the terms of the license to produce possibly the most oppressive product in computing — one which he specifically finds objectionable.

If he ever considers pursuing the case, I'd donate some money!

</comment></comment><comment><USER11> I guess the other irony is that every Windows/Intel computer boots Unix first...

<comment><USER12> Well, the machines that print the chips in the first place probably run Linux.

So I guess it all starts with Linux.

Edit: although, to be fair, open source EDA sucks and the chips were probably designed on Windows, so..

<comment><USER13> Commercial tools run on Linux but they are not open source.

</comment></comment></comment><comment><USER14> All Intel would have needed to do to comply with the license was include a small blurb in that tiny insert provided with each retail chip. Similar to the about screen in most mobile apps that list all the individual libraries and their OSS licenses? Right?

<comment><USER15> According to the article, yes, that would be sufficient for retail chips.

</comment></comment><comment><USER16> I find it amusing that everyone is so certain that Intel doesn't have a special arrangement with the copyright holder.</comment>


In Browser Native iPhone App Development - <AUTHOR> http://blogs.computerworld.com/17721/red_foundry_is_this_app_development_for_the_rest_of_us

<comment><USER2> The first question I have looking at the video and the gallery screenshots is, "why this and not jQuery mobile on Phonegap?" Particularly since Phonegap has some level of cross-platform capability. Some tutorials and workthroughs that went beyond what's in the gallery</comment>


Sun Goes Down. Up Comes A Mystery - <AUTHOR> http://www.npr.org/blogs/krulwich/2012/10/10/162630285/sun-goes-down-up-comes-a-mystery <comment><USER2> Am I the only one for whom the paradox isn't intuitive? It's not clear to me why many distant dim stars should add up to a bright sky. It depends on how distant and how dense they are, doesn't it? Even assuming that the universe is infinite and eternal and approximately equally dense everywhere.

The embedded video describes the paradox by saying that the night sky "should be as bright as the sun". Imagine if that were the case. Then move yourself twice as close to the sun, making the sun four times brighter. Then the night sky is 1/4 as bright as the sun.

So clearly, distance and (lack of) density could make the night sky less bright, presumably to below the threshold of human perception. Right? Even aside from their explanations of distant light not having had time to reach us, and/or being red-shifted out of our visible range.

<comment><USER3> How does distance affect brightness? Distant stars are exactly as bright as close stars - however, the "brightness" is just spread over a greater area of space.

In particular, the perceived brightness of a star falls off according to the square of distance - you can work this out for yourself by comparing the surface area of a sphere of radius _d_ , with the surface area of a sphere of radius _2d_.

But how many stars are at that distance? If you assume uniform density, then the answer is exactly the opposite of what we found above! The number of stars at a distance of _d_ is proportional to the square of the distance.

This means that the total amount of light perceived from stars at a distance _d_ is exactly the same, irrespective of the value of _d_.

Then if the universe was also both eternal and infinite, then there would be an infinite amount of light reaching the earth!

<comment><USER2> Okay, if the universe were perfectly homogenous, i.e., uniformly dense _at all scales_ , then this argument would be easy to buy.

If you allow density variation at some scales, like the difference in density between the interior of a star and interstellar space, then it changes a bit, right? If you're really close to a star, then obviously that star is brighter than the average brightness of the universe. Right?

If so, then the night sky wouldn't be "as bright as the sun" (like the video says), as observed from earth.

But would the night sky be uniformly bright? Doesn't it depend on the average density of the universe? I.e., if the average density gets low enough, then don't those small-scale density variations start to matter at some point?

<comment><USER3> It's generally hard to speculate on how things "would" be if the universe were markedly different than it how it actually is. Or rather, it's easy to speculate, but it's nigh-impossible to come up with one solution to the exclusion of others. I can come up with many hypothetical universes where the night sky would be uniformly bright, and many hypothetical universes where there would be substantial amounts of variation.

The general statement of the paradox is that the total amount of light coming from distant stars massively outweighs the light coming from a local star, so while the local star might create a slightly brighter patch of sky, that difference is small enough that even in its absence the sky would look "bright".

</comment></comment></comment></comment><comment><USER4> It's not usually noted, but Olber's paradox relies on a false assumption. The argument goes that the night sky is dark and therefore the universe must be finite in extent or duration or both. But the night sky isn't really dark. Olber was just looking at the wrong wavelength. If you look in microwave wavelengths, of course, you see the CMB. The fact that the CMB is out in microwave wavelengths rather than being somewhere where Olber could see it is strong evidence for an expanding universe.

<comment><USER5> Ehh, the CMB doesn't come from stars, so bringing it up in this context is a bit of a red herring.

<comment><USER6> Being right for the wrong reason can be even worse than being wrong. CMB is very relevant to the question of the color of the sky, it just happens to be pre-star material.

</comment></comment></comment><comment><USER7> This is one of these 'unreadable on my tablet' articles, where sharing buttons cover the content (bad) and something disables pinch/zoom (inexcusable) for reasons I don't get.

FF's reading mode saved me, but is there any permanent workaround for problems like this? Addons?

<comment><USER8> I think it is completely absurd that tablet OS's would ever allow a website to disable zooming. It's like a usability nightmare. Permanent solutions... maybe email the websites that do it?

<comment><USER9> (Shrug) I just go to other websites and read something else. On the Internet, there really _is_ something interesting to see in every possible direction you look.

</comment></comment></comment><comment><USER10> The fundamental question here is, if you pick a random vector going outward from the earth, what us the probability of that vector intersecting a star? If it is near 100%, then you would expect a bright sky at night, and if you don't see one then you have a paradox.

<comment><USER11> Even if it is 100%, it would have to be multiplied by the probability of photons from that star making it past all the interferences like nebulae, Oort cloud, and Earth's atmosphere along that exact vector. That I think is a much lower percentage.

<comment><USER12> > Even if it is 100%, it would have to be multiplied by the probability of > photons from that star making it past all the interferences like nebulae, > Oort cloud, and Earth's atmosphere along that exact vector.

You're missing the point that, given enough time, all those objects would be heated up by stellar radiation to the temperature of the originating star.

Consider the temperature over time of a body that is energetically coupled to a star, however far away. Because the star's temperature is relatively constant (a property of fusion reactions), it is the receiving body's temperature that changes, according to this equation:

q = (e^(-t/k) - 1)*(a - b) + a

Where:

t = time

k = energy transfer factor

q = temperature at time t

a = temperature at time 0

b = temperature of source

The above expresses Newton's Law of Cooling:

[https://www.dropbox.com/s/bt63bt59t9q76th/newtons_cooling_la...](https://www.dropbox.com/s/bt63bt59t9q76th/newtons_cooling_law.png)

All the bodies exposed to a star's energy radiation follow the above law. And given enough time and barring any other effects, all of them reach the star's surface temperature. Which leads us to Olbers' Paradox -- given billions of years and copious energy sources, why didn't this happen?

</comment></comment></comment><comment><USER13> The theory also assumes that objects in the Universe can only _emit_ light. This isn't true: _most_ matter in the Universe is dark (dust, planets, dark matter), and _absorbs_ light.

We know that this is highly true at intragalactic scales -- the core of the Milky Way is completely obscured from Earth due to the dust between us and it. There's good reason to believe it's also true at intergalactic scales.

Other aspects of the paradox contribute, but I strongly suspect that various dark matter effects are stronger.

<comment><USER14> I think you're wrong here. Given an infinite amount of time and an infinite number of stars distributed evenly in an infinite universe, even the dust and planets will start to radiate[1].

The paradox hinges on the assumption that the universe is infinite in size with an even distribution of stars which have been radiating for eternity. So, it's only a paradox if you assume those things. Remember, this question was first asked in the 1600s.

[1] <https://en.wikipedia.org/wiki/Black_body_radiation>

<comment><USER13> The dust and planets will start to radiate ... at the blackbody rate.

On average, that's somewhere in the neighborhood of 3K.

<comment><USER12> Yes, true, but Olbers' Paradox was posed long before the Big Bang theory or the idea that the universe is expanding.

In a static universe such as Einstein proposed in 1916, eventually the entire universe would heat up to the temperature of its stars. This made Olbers' paradox an important reality-test, and reality failed the test.

It was only because of the Big Bang and universal expansion was Olbers' Paradox reconciled with observation.

<comment><USER15> Err, Einstein's static universe did not preclude the death of stars via exhaustion of their fuel. So, the entire universe would "heat up" to a uniform distribution (i.e. evolve according to the heat equation), with the future local heat being everywhere equal to the mean local heat at present. And, in general, the universe is overwhelmingly empty and cold.

I'm not sure what the mean energy of the universe is, or what the minimal energy required to coax an electron to jump around and create visible light is, but it could well be that the values are such that an entire universe homogeneously set to the mean local energy of our current universe would be nowhere energetic enough to cause the birth of (naked-human-eye-visible) photons. (note: it would also be important to know the relative amounts of energy dedicated to mass and motion)

In other words, given a perhaps dubious mixing of temporally diverse understandings of physics, the relevant homogeneously energetic universe would likely be nowhere energetic enough to cause light. Thus, perhaps we should be more surprised that everywhere we look isn't dark?

<comment><USER12> > Err, Einstein's static universe did not preclude the death of stars via > exhaustion of their fuel.

Yes, by a process of radiating away massive amounts of energy.

> So, the entire universe would "heat up" to a uniform distribution (i.e. > evolve according to the heat equation), with the future local heat being > everywhere equal to the mean local heat at present.

No, not "at present" "At present" is the outcome of a combination of energy radiation and cosmological expansion leading to the present. Were it not for the factor of expansion, the universe would be much, much hotter than it is now.

> And, in general, the universe is overwhelmingly empty and cold.

Yes, it is -- because of cosmological expansion. Were this not the case, the universe's temperature would be equal to or or greater than it was at "recombination" time, i.e. when normal atoms formed and the universe first became transparent to radiation, at about 300,000 years and an average temperature of about 4000 kelvins.

> I'm not sure what the mean energy of the universe is ...

Don't you mean average temperature? One can speak of total energy, or average temperature, but "mean energy" doesn't make much sense.

> ... or what the minimal energy required to coax an electron to jump around > and create visible light is ...

That's well-established. When the energy of an impinging photon is equal to that for a possible electron orbital transition, and ignoring for the moment a few other considerations, the electron will absorb the photon and move to a higher orbit. Conversely, if an electron should drop from its present orbit to a lower orbit, a photon will be emitted whose wavelength is proportional to the energy difference between the orbits.

> In other words, given a perhaps dubious mixing of temporally diverse > understandings of physics ...

At any given time, there is one understanding of physics. It's obviously open to challenge as all scientific theories are, but each challenge must be accompanied by observational evidence. The point of science is not to have any number of theories, the point is to have one -- the one that best answers observation.

> the relevant homogeneously energetic universe would likely be nowhere > energetic enough to cause light.

For a sufficiently comprehensive definition of "light" (meaning electromagnetic radiation), no, not possible. There will always be electromagnetic radiation, even for a universe at zero Kelvins, because of quantum effects.

> Thus, perhaps we should be more surprised that everywhere we look isn't > dark?

Not in this universe, no -- not with stars converting mass into prodigious amounts of energy everywhere we look. Which leads, full circle, to Olbers' Paradox.

<comment><USER15> When I said "at present", I was operating in the context of your previous post, i.e. assuming a universe with static space-time geometry. In this context, the present empty coldness of the universe is relevant and the past crowded hotness is not. Certainly, when a full modern understanding of cosmology is brought into play, Olbers' paradox is quickly downgraded from paradoxical to merely non-intuitive.

As noted previously, I was mixing temporally diverse conceptions of physics. Obviously, at any point in time there is a physics representing the current scientific consensus. I meant that my construction of an argument using ideas sampled from non-contemporary points in the stream of evolving understandings of physics was potentially dubious. Or, metaphorically, I was mixing metaphors.

After I first put the focus on naked-human-eye-visible light, it was meant to be assumed that any use of the term "light", as opposed to, say, "electromagnetic radiation", was also intended to invoke the concept "naked- human-eye-visible light", and likewise for dark as the absence of "light".

I'm aware of the basic process underlying the emission/absorption of photons via orbital jumping. My precise point was that the incident energy required to invoke a jump of sufficient size to produce "light" may be greater than that which would be omnipresent in a homogeneously energetic universe with a space- time geometry equivalent to that of the universe in which we currently reside. Certainly, as you mentioned, the relative amounts of energy stored in mass versus motion would play an important role.

Anyhow, my entire line of argument was all just an exercise in Devil's advocacy, seeing as how satisfactory resolution of Olbers' paradox is readily available within our current best understanding of physical law.

<comment><USER12> > When I said "at present", I was operating in the context of your previous > post, i.e. assuming a universe with static space-time geometry.

Yes, but for a static universe, we wouldn't have anything remotely like present temperatures, which is why Olbers' Paradox ultimately leads to universal expansion apart from any other issues.

> it was meant to be assumed that any use of the term "light", as opposed to, > say, "electromagnetic radiation"

But they can't be opposed -- all light is electromagnetic radiation, and vice versa for a sufficiently large time frame. What was gamma rays at the time of the big Bang is now visible light. What was visible light at the time of the Big Bang is now microwaves. There's no reasonable way to talk about these issues without describing the electromagnetic field.

> seeing as how satisfactory resolution of Olbers' paradox is readily > available within our current best understanding of physical law.

Yes, but not for a static universe, which was my point -- for a static universe, the assumption until 1929, Olbers' Paradox remained unresolved -- and without cosmological expansion, the issues are not "available within our current best understanding of physical law". Not remotely.

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER12> Another discussion of Olbers' Paradox (that predates Dark Energy):

<http://www.arachnoid.com/sky/>

</comment><comment><USER16> Paradoxes and assumptions aside, is it literally true that there is a star at the end of every vector you can draw from my eyeball into space? I understand it's true if you assume the universe is infinitely large, but we know that's not true, right?

<comment><USER17> My understanding is that it would be true but for the fact that the longer those vectors get, the farther back in time they reach, and thus eventually reach into a time when stars did not exist and thus you hit the CMB instead. The stars you would have seen are in space that has moved away from us faster than c.

My understanding is that the universe is believed to be literally infinite in the three spatial dimensions that are familiar to us, and that its mass is also believed to be infinite. It really blows the mind.

Disclaimer: I'm a programmer not a physicist. :-)

EDIT: I did a little more reading on this. Answers are all over the place. But from what I can make out of the most recent sources, it seems that modern models treat the universe "as if" it were infinite although there is no way to know whether it is or not.

</comment></comment><comment><USER18> Genuine question: at what age is Olber's Paradox explored in high school physics these days? (It was part of my A-level physics curriculum in the UK, age 17, circa 1981 ... I'm finding it rather odd that it was unfamiliar to this journalist!)

<comment><USER19> The physics courses I took (in both high-school and college) didn't generally deal with astronomy. Not sure how common that is. Instead they covered mostly "foundational" topics: general & special relativity, electricity & magnetism, mechanics, atomic structure, etc.

<comment><USER20> I think your experience is pretty typical. I had the same. I took what was technically considered a college-level physics course in high school, and we never really delved into astronomy. Only in college itself did the subject start to come up, and that's because I selected those classes.

I suspect this is because the US high school education system has a fairly standardized, one-size-fits-all curriculum. There are some allowances and exceptions, of course. But, for the most part, everyone is going to be covering roughly the same material. And astronomy isn't deemed as necessary, for the beginner, as some other rudiments of physics. College, on the other hand, offers more opportunity for individual choice in one's curriculum.

<comment><USER19> I had the same situation in college as well, though that could be because I went to a somewhat unusually set up science/math uni (hmc.edu), in which all majors had to take a science/math "common core". There were 3 required physics classes for non-physics majors, which were these, going pretty in-depth into physics but still not covering any astronomy: <http://physics.hmc.edu/course/3/>, <http://physics.hmc.edu/course/46/>, <http://physics.hmc.edu/course/4/>

Astrophysics is generally popular among students, but afaict it hasn't been included basically because the physicists consider the above three courses to be higher priority.

</comment></comment></comment></comment><comment><USER21> My biggest problem with this explanation is that even if the star-filled universe were infinite that doesn't necessarily mean there would be a star at every point you look at in the sky.

Depending on the density of the stars in space, it's quite probable that as you zoom in farther and farther you see more and more distant stars, you also see space between those stars. It becomes a limit problem where the 'star density' of the sky (vectors from your viewpoint which will eventually hit a star) gets closer and closer to a specific percentage the further you extend your sphere of view (or magnification level) but will never exceed it, and won't ever go to 1.

<comment><USER5> Assuming that there's some small but non-zero chance of a randomly selected line intersecting with a star in a finite volume of space, it's pretty clear that for an infinite volume, the probability of hitting at least one star will approach 1. (So long as the density of stars is approximately constant, or at least has some lower bound.)

And since stars are not point like objects, a line does indeed have a non- infinitesimal chance of intersecting a star.

Although all of this is a bit different from arguing about the net brightness of light coming from distant stars.

</comment></comment><comment><USER22> Click the picture for The Milky Way from Mars. It's worth it.

</comment><comment><USER23>
      *A few billion years after that, you'll be standing on a hill looking up on a clear night, and the sky will be close to pitch black*

not that long ago we didn't know that we live on a sphere

what if universe is a 4 dimensional sphere?

<comment><USER12> > what if universe is a 4 dimensional sphere?

If the sphere is expanding, then the result is the same -- a gradual decline in energy density per unit of volume. So the specific geometry of the universe is unrelated to Olbers' Paradox.

But there is strong evidence that the universe is geometrically flat at large scales, which in turn argues that it's infinite in size.

How does the apparent large-scale flatness of the universe make an argument for an infinite size? To explain, and just as a simplifying example, imagine that the universe is the surface of sphere. Now include the implications of the fact that we observe large-scale flatness.

Picture this -- imagine that the universe is the surface of a sphere, but the sphere's surface is perfectly flat. How large must the sphere's radius be for its surface to be perfectly flat? Think about how a sphere's surface is defined -- it's the unique surface that's equidistant from the center of the sphere, the surface that has a distance of R (R = radius).

To make both properties true -- to accommodate (a) that it is a sphere and (b) that its surface is perfectly flat, all you need to do is make the radius infinite.

In the case of the universe, with more dimensions, to achieve the measured large-scale flatness, all one need do is assume that the universe is infinite in size.

<comment><USER23> the idea of universe size increasing speed now comes to my mind,

if the speed is greater or equal to speed of light, how we can be sure that we won't see ourselves in telescope?

I mean, even if the radius is infinite, because speed is increasing, we should see sun light returning to us over universe surface at some point

<comment><USER12> > if the speed is greater or equal to speed of light, how we can be sure that > we won't see ourselves in telescope?

That doesn't follow. We can't see an object moving away at greater than C, so we also can't see ourselves.

There is one place where we might see the backs of our own heads -- while observing at the event horizon of a black hole, all practical considerations aside. At that location, the spacetime curvature is such that light emitted "horizontally" would curve around the horizon (and the black hole) and reappear 360 degree away -- for example, from the opposite direction of someone shining a laser beam "horizontally" along the horizon.

> I mean, even if the radius is infinite, because speed is increasing, we > should see sun light returning to us over universe surface at some point

No, not really.

</comment></comment></comment></comment><comment><USER24> Interestingly, E. A. Poe provided one of the first explanation of Olbert's paradox : <https://en.wikipedia.org/wiki/Eureka:_A_Prose_Poem>

</comment><comment><USER25> There is actually a much better explanation than this. When you look at the nights sky you see a snapshot of the universe. The further back you look the more stuff there is, but while there more objects there proportionally dimmer.

Now, in an unaging and infinite universe with random stars everywhere you would get what amounts to unlimited light. But, our universe is finite and does age, so you get a finite amount of light from that fixed volume. As to how much light you end up seeing it's a function of:

A) Being close to our Galaxy the Milky Way with a large clump of stars inside it.

B) The average of all the galaxy's in the observable universe which relates to the average amount of matter in the universe which is not that high.

Thus, a fairly dim sky outside of the disk that is the milky way.

</comment><comment><USER26> I always thought the sky was dark for the same reason we don't see the bright center of the Milky Way at night: dust.

Space is mostly vacuum, but there is enough dust over the vast volumes to occlude light.

<comment> T-hawk Dust does not resolve the paradox. Dust occludes by absorbing the light, which means that the dust would eventually heat up enough to glow itself. Dust can't reduce the amount of radiation and energy in the universe, just shift it in time or wavelength or direction.

</comment></comment><comment><USER27> I hope science is wrong this time, because if it's true a whole generation will never enjoy the beauty of stars at night

<comment><USER28> That conclusion is wrong - the expansion of the universe will not tear apart galaxies because the stars are bound by gravity.

<comment><USER8> According to the redshift and mass measurements of distant galaxies, it seems like the universe is expanding faster than gravity would keep it together.

<comment><USER14> That's on an intergalactic scale. Theres no evidence that I know of that galaxies or galactic clusters will be torn apart from cosmic expansion.

</comment></comment></comment></comment><comment><USER29> <http://en.wikipedia.org/wiki/Olbers_paradox>

</comment><comment><USER30> Um is it just me or does the conclusion of the article not match the ultimate conclusion of the video?

In the last 15 seconds of the video they say that it's actually because once you get far enough away from earth, the stars are moving so fast away that they redshift to infrared.</comment>


Groupon Japan Lost Ground To Recruit's Ponpare Last Month - <AUTHOR> http://www.serkantoto.com/2011/03/01/groupon-japan-ponpare/

<comment><USER2> wow, is there any other country in which groupons numbers were going down?</comment>


Trump administration reportedly considering ban on end-to-end encryption - <AUTHOR> https://www.politico.com/story/2019/06/27/trump-officials-weigh-encryption-crackdown-1385306<p>So this is how liberty dies <comment><USER2> How about over the middle encryption. the route is non encrypted but local and remote are encrypted, thus the unencrypted route carries an encrypted payload. what encryption algo to use? ALL OF THEM! instead of ROT13 over HTTP use the new CRYPTROT13 [fictional], and rotate encryption algo randomly by hardcode script or by prompt. or go text stego, the whole point is oultawing encryption is about as usefull as outlawing security, or privacy. so who gets a break? the ISP that uses HTTPS by default? the banks and financial systems that must encrypt data as a matter of function? Why wouldnt someone comeup with a way of transacting pennies in a manner that actually conveys data?

</comment><comment><USER3> Discussed when the news was released [https://news.ycombinator.com/item?id=20305176](https://news.ycombinator.com/item?id=20305176)</comment>


How can I keep API keys out of source control? - <AUTHOR> http://arstechnica.com/information-technology/2013/12/how-can-i-keep-api-keys-out-of-source-control/ <comment><USER2> I have a similar issue however my app is a plugin for another application and now those keys need to be transferred to every systems that will use this plugin.

The host application and all plugins are written in Node so these api keys don't get compiled into the source and will be sitting clear text.

How can I secure these keys?

</comment><comment><USER3> Follow step 3 of the 12 factor app methodology, le duh!

[http://12factor.net](http://12factor.net)

If you're building apps for public clouds, you really should be following most of those steps conceptually.

</comment><comment><USER4> Read 'Better Builds with Maven'.

This problem was solved many years ago.</comment>


Ada Gnat Ecosystem Community Survey - <AUTHOR> https://docs.google.com/forms/d/e/1FAIpQLSet9x3UNUFmfWt5v-8Jb7dW8BgKiJxyEMJ_TFm0G2UJKx5OmQ/viewform <comment><USER2> Apart from being a mature and reliable language, how does Ada compare to Go and Rust today? Or are they in different leagues all together?

</comment><comment><USER3> Using google docs for gnu related stuff might have very little intersection in the venn diagram.</comment>


Show HN: MHealth app for health workers fighting Ebola - <AUTHOR> http://www.appsagainstebola.org/

<comment><USER2> I'm one of the guys behind this. Happy to answer any questions/get feedback! We've basically allocated about 30% of our startup to this project for the next while, so it's important to us that we really help people with this.</comment>


Creative Airline Passenger Safety Videos from Around the World - <AUTHOR> https://www.youtube.com/watch?v=LdmisLSlxvQ <comment><USER2> As a frequent flyer, I find this kind of thing immensely irritating. Sure, if it was a long haul holiday-of-a-lifetime flight from Europe to NZ the Hobbit epic has its place, but when they do this stuff on short-haul business flights I'm just praying for them to shut up and leave me in peace. British Airways had some charity effort last year featuring various smug celebrities that felt like it went on for ever; meanwhile Lufthansa would continue doing the in- person demo, bilingually, in a fraction of the time, so I could go back to thinking about work or doing whatever else I wanted to do with my time.</comment>


List of Password Rules for Texas Child Support Site - <AUTHOR> http://portal.cs.oag.state.tx.us/OAGStaticContent/portal/login/help/listPasswordRules.htm <comment><USER2> How thoughtful of them to provide such a useful guide for tuning a brute force cracker to succeed with minimum effort...

I especially like the list of helpful suggestions at the end to help select the best dictionary.

</comment><comment><USER3> bet you those would be the top 5 passwords, lol..

</comment><comment><AUTHOR> This list is so awful it must be parody, right?

Except this is a newer revised list. Here's an older version:

[https://www.inc.com/thomas-koulopoulos/all-that-advice- about...](https://www.inc.com/thomas-koulopoulos/all-that-advice-about- passwords-turns-out-to-be-to.html)

> 1\. The password must be exactly 8 characters long.

> 2\. It must contain at least one letter, one number, and one of the > following special characters.

> 3\. The only special characters allowed are: @ # $

> 4\. A special character must not be located in the first or last position.

> 5\. Two of the same characters sitting next to each other are considered to > be a "set." No "sets" are allowed. Example: rr, tt

> 6\. Avoid using names, such as your name, user ID, or the name of your > company or employer.

> 7\. Other words that cannot be used are Texas, child, and the months of the > year.

> 8\. A new password cannot be too similar to the previous password.

> 9\. Example: previous password - abc#1234; unacceptable new password - > acb$1243

> 10\. Characters in the first, second, and third positions cannot be > identical. (abc __ __ _)

> 11\. Characters in the second, third, and fourth positions cannot be > identical. (_bc# __ __)

> 12\. Characters in the sixth, seventh, and eighth positions cannot be > identical. ( __ __*234)

> 13\. The previous 8 passwords cannot be reused.</comment>


The Most Commonly Spoken Language in Each State Besides English and Spanish - <AUTHOR> http://mentalfloss.com/article/56714/most-commonly-spoken-language-each-state-besides-english-and-spanish

<comment><USER2> Original source with more commentary and less blogspam:

[http://www.slate.com/articles/arts/culturebox/2014/05/langua...](http://www.slate.com/articles/arts/culturebox/2014/05/language_map_what_s_the_most_popular_language_in_your_state.html)</comment>


The Nature of Lisp (2006) - <AUTHOR> http://www.defmacro.org/ramblings/lisp.html <comment><USER2> "Why on Earth would anyone want to use a language with such horrific syntax?!"

What is it with statements like this? It just sounds like a 'meme' to me, that everyone hears (even from advocates like this one) at first that the 'syntax' (of which there is a lot less than most languages in a Lisp) is 'horrible'?

Of course, we, the learn-ed of Lisp, say that after a while the 'parens just disappear', which they don't, but they sure help (when combined with Paredit) in defining code like structures that can be manipulated with ease in your editor.

I know the author is just trying to do a bit of a 'sandwich' with the article, but please, advocates and enemies of Lisp, just give up on picking on the parens. It's stupid and been done a million times. It's like 'why do we have to type so much to enter programs! such a pain!'.

Boring.

<comment><USER3> I don't really mind the parens, but the whole attitude feels indicative of a problem. Like - it's 2018 and people are still using 'cdr' and 'cons' as terminology and happily expecting other people to learn those words and not even feeling bad about it.

If the person justifying Lisp doesn't mind that the word 'cons' is terrible, why should I trust their aesthetic sense about anything? If I have to have "miserable notations" to get "coding nirvana", and coding nirvana is so great, why not fix the notations? do you just think everyone should have to struggle because you did?

I guess it feels like trying to determine which of these statements are true: (1) "Lisp is coding nirvana" (2) "Lisp is weird regressive nostalgia for a simpler era where nothing was typed and everyone used Emacs and memorized arcane terminology and shared macros on Usenet", and there are way too many signs that it's a lot of (2).

[edited to be less abrasive]

<comment><USER4> > Like - it's 2018 and people are still using 'cdr' and 'cons' as terminology > and happily expecting other people to learn those words and not even feeling > bad about it.

Oh please, cry me a river. Like monads, promises, or props are any better.

> If the person justifying Lisp doesn't mind that the word 'cons' is terrible, > why should I trust their aesthetic sense about anything? If I have to have > "miserable notations" to get "coding nirvana", and coding nirvana is so > great, why not fix the notations? do you just think everyone should have to > struggle because you did?

Your ignorance is baffling. The notation is a feature, not a bug. If you want the feature, then yes, you will have to struggle.

While cons and cdr as concepts are necessary to learning what goes underneath the hood, idiomatic lisp is rarely written in terms of cons and cdr.

<comment><USER3> I know that. My point is that the antiquated terminology's survival seems to be a symptom of a culture that values the wrong things: like pointless historical names instead of clear modernized ones.

(Monads and props are definitely not better. You won't find me defending them! 'Promise' is a much better name, though.)

<comment><USER5> FIRST and REST as names for list operations have been added 40 years ago. Pattern destructuring and list templates are as old.

Naming is important, but the core Lisp names can be learned in a day.

<comment><USER3> Yes, and yet the names Cons and Cdr still exist and come up in introductory documentation and are still used in discussions constantly -- why?

<comment><USER6> Because people like bikeshedding. Cons is a little bit weird, but it is par with C's "typedef", it could have been named better.

car and cdr are weirder, but there are reasons people use them over first and rest: 1- they are shorter and 2- they can be combined (caadr, cadr, cddr, instead for (first (rest x)) etc).

It is still bikeshedding. You learn that stuff in less time than what it takes to create an angry post.

And if you really hate them, you don't have to use them. Just define a macro and you can stop complaining. Your coworkers may not like this though.

</comment></comment></comment></comment></comment></comment></comment><comment><USER7> (It (is :wonder (we can (read :text without (as much :brackets as) LISP)))). Well, "as _ as" is technically bracketing, but you get the idea.

So I tried once to use a dot as list terminator, which didn't work well. I found myself adding different terminators for each level of depth. Because, at some point the encapsulation over multiple levels leads to ambiguity, if outfix notation isn't used (as for the encapsulation in this sentence). A common wisdom is to avoid deep indentation. 3rd normal form schemes are enough for most cases, thank Codd.

By the way: I've been hugely interested in historical linguistics recently and came to conclude counting must have been a huge boost for the development of language facility. Basic phrases are just enumerations. Which reminded me of list processing. Many old languages actually tend to follow VSO word order, too. Plural is often enough expressed as reduplication. But I don't have deeper insights to offer from this on how to avoid the parens, except that zeroth order logic is fundamental and a linguistic approach to programming languages might prove fruitful (grammar, not syntax). And by the by the way: Isn't "everything is an object" similar in power to homoiconicity?

<comment><USER8> >And by the by the way: Isn't "everything is an object" similar in power to homoiconicity?

This is the only part of your (very interesting) comment I feel qualified to talk about.

I think there may be something there, but you'd have to be extreme about it, making methods into objects, and proabably even keywords like "if." This is a high bar---but macros clear it.

</comment></comment><comment><USER9> Previous discussions:

[https://news.ycombinator.com/item?id=4765067](https://news.ycombinator.com/item?id=4765067)

[https://news.ycombinator.com/item?id=9575786](https://news.ycombinator.com/item?id=9575786)

[https://news.ycombinator.com/item?id=1319034](https://news.ycombinator.com/item?id=1319034)

<comment><USER10> In case you or anyone reading this were unaware, there is a link underneath stories called "past," which provides the service nathell did in parent.

<comment><USER11> Huh I never knew that. Have I been completely oblivious of it, or has that been added recently ?

</comment></comment></comment><comment><USER12> LISP is great, but the problem with making programs in it is that one invariably ends up trying to answer the meaning of life, the universe, and everything.

      (just kidding
        (sardonicly?
          (isn't it obvious?
            (depends on how one writes it
              (like with what editor?
                (we all know there is only one editor
                  (emacs?
                    (Stallman's own
                      (not to imply ownership
                        (as editors should be free
                          (along with all software
                            (like knowledge
                              (which are just ideas with proven value
                                (requiring recognition
                                  (implying awareness of self
                                    (assumed when using LISP)
      )))))))))))))))

</comment><comment><USER13> Back in 2009, when I first learned Common Lisp, I had the hope Lisp would one day become mainstream. Then in 2012 I had the same hope for Scala.

... I got older and I'm not anymore a dreamer

Legacy code and imperative thinking is heavy.

<comment><USER14> > I'm not anymore a dreamer

Perhaps it's time to start dreaming again?

Rewriting the world for VR/AR is coming up. And unlike the rewrite for mobile, this time our software development environments will be transformed as well (mobile wasn't a place for writing code). And while we're perhaps running out of time for new compiler targets and languages, there seems a lot of potential for changing infrastructure.

For example, a talk went by, which I recall as someone dropping linux instances on google lambda, and setting up deterministic C compilation, for massive parallelism and caching. So push a button, and some seconds later a linux kernel has been recompiled (from empty cache). Which rather changes the constraint space on "our language or type system can't provide nice-thing X, because it would take too long to compile". Golang's story of runs fast on a couple of local cores, may shortly sound like "my IDE runs on a PDP-11!", sort of "that's cute - nice art piece". Is it ok to take two days to run some proof obligation? ... well, is it cached now, so no one ever has to do that again?

Eye tracking; hand/finger tracking; escaping from 2D's crippling real-estate constraints; speech recognition; fine-grain code sharing; rich compilation frameworks ... there's a lot of fun incoming.

</comment></comment><comment><USER6> Am I the only one who finds it hilarious that there are complaints about Lisp syntax, when the language itself is almost infinitely modifiable?

You can replace parens with reader macros. You can replace built in names with ordinary macros(in some dialects, even reassign the built-in functions altogether). Don't like the let syntax? Modify it yourself to something completely different.

You could modify Lisp to look like json if you were so inclined.

You have access to the compiler at compile time and runtime. Do whatever you want.

If anything, people should be complaining about other languages that don't allow for syntax modification. Want to not type semicolons in C? You are essentially out of luck, unless you want to make your own preprocessor (I don't think the standard one has enough expressive power to do so, but I'd love to be proved wrong).

Complaining about parentheses takes zero effort though. You don't have to spend a single second trying to understand why it looks weird like that...

<comment><USER15> I'm a lisp fan, but to be fair, I don't think I know anybody who wants to live in a world in which everybody has created their own personal language syntax. Reader macros should be used very judiciously unless you don't care about anybody else being able to understand your code.

<comment><USER6> I agree.

But if you care _that_ strongly, you can do something about it.

(I am also kind of hoping that, by the time one gets to reader macros, they will be experienced enough, and will understand why the parentheses exist so that they will no longer care about them)

<comment><USER16> But for many people "caring that strongly" and "doing something about it" means choosing another option. As opposed to essentially writing a new language.

Good defaults do matter, and I would also echo the feeling that the parentheses get in the way, and that a non-small component of my thinking or polishing process is how to responsibly reduce parentheses. I find that it's generally a modest but palpable boost to visual ease. I do wonder whether there's a better way to denote nested lists?

</comment></comment></comment></comment><comment><USER17> The surface problem of LISP are the parenthesis. The deeper problem is that its a very potent NIH enabler: most of us are not really that talented or have the time to properly invent things; those that are tend to not quite like other people's things (and are good at spotting flaws in them) so they work on their own "better" things (e.g. see arc).

<comment><USER5> JavaScript library space is basically pure NIH - maybe it's a Lisp, too?

<comment><USER6> It does have a surprising amount of Lisp DNA, despite the horrible semantics.

<comment><USER5> You can bet that every day Javascript users reinvent Lisp stuff from 50 years ago. Javascript on the language level is like Lisp from the end 70s minus better numerics and minus macros and minus using JSON as a syntax for programs. The prototype stuff is straight from Actors in Lisp, mid 70s.</comment></comment></comment></comment>


Carnot Efficient Dyson Spheres Are Undetectable by Infrared Surveys (2016) - <AUTHOR> https://www.tillett.info/2016/08/03/carnot-efficient-dyson-spheres-are-undetectable-by-infrared-surveys/ <comment><USER2> So, for that additional 4% efficiency, the radius must be increased by 25x; making the total surface area somewhere around 650x bigger?

An exponential increase in size is not "a relatively small increase in resources and time." It goes from "something that could be built with all the mass in the solar system" to "something that requires the mass from an additional couple of hundred solar systems to construct".

I'm also curious about whether a Dyson sphere which would roughly equal Neptune's orbit would have sufficient sunlight at any given point to sustain life (at least, life as we know it).

I'm not a member of an alien civilization with the technology to create a Dyson sphere, but as a lowly human engineer, the costs don't seem worth the benefits, especially without some other form of energy to supplement the 650x increase in energy needs.

<comment><USER3> You don't need to make a single sphere (swarm more likely). If you arrange the shells in layers the outer layers can efficiently capture the long wavelength radiation using relatively little matter.

The question is if you could capture the energy and you had the material resources would you let it escape into the universe at 290K?

<comment><USER2> > The question is if you could capture the energy and you had the material > resources would you let it escape into the universe at 290K?

If the cost of acquiring and constructing the material into a collector were greater than the benefits of collecting a mere 4% more energy, absolutely!

Plus, for an advanced civilization, if given the choice between 99% efficiency around one star and 95% efficiency around a mere 100 stars - which is more likely to be done?

To make the analogy more relevant to humans: Why - when we're technologically advanced enough and have sufficient materials - do we let so much energy escape Earth?

<comment><USER4> I think it depends entirely on the incentives of the civilization in question. If the primary goal was hiding your world from the Borg/Dalek/Alien bioweapon your species discovered was ravaging the galaxy, then a 99% Carnot efficient Dyson sphere seems like the ideal defensive structure.

<comment><USER5> No it doesn't.

Anything with sufficiently advanced technology to threaten a dyson sphere wielding species would probably detect the gravitational anomaly of the missing star and go investigate there _first_.

Taking a tiny portion of the energy from a bunch of stars seems wildly more efficient at surviving from a threat than putting all your resources into creating a system they're sure to investigate.

<comment><USER6> That is similar to the plot point of one of those Star Wars prequels if I recall right

</comment></comment></comment></comment></comment></comment><comment><USER7> I've seen mention before of the Carnot efficiency of Dyson spheres, but what about Landauer efficiency? Assuming the DS is powering a bunch of computers, and assuming sufficiently advanced technology that these computers approach the limits of physics (reasonable for a Type 2 civilization imo), then their computers will use power proportional to kT. The colder the computer, the less power it uses. [https://en.wikipedia.org/wiki/Landauer%27s_principle](https://en.wikipedia.org/wiki/Landauer%27s_principle)

This provides another thermodynamic reason to make a Dyson sphere as large as possible.

<comment><USER8> Doesn't this also assume a computer similar to our own? How would this principle apply to a biological computer for example?

<comment><USER9> The Landauer principle applies to any computer made of matter utilizing energy (in a non-thermodynamically reversible fashion). So it applies just fine to biological computers, quantum computers, and even mechanical computers! It's a result in quantum information theory, and doesn't have anything to do with the overall type of computer used. It just determines how much energy it takes to change the state of a quantum (particle), at a minimum. Things like changing the polarization of a photon or the spin of an electron.

</comment></comment></comment><comment><USER10> Not sure my mathematics is up to the task but

"using a relatively small increase in resources and time."

A sphere with 99% efficiency would need 25 larger radius according to the article, which is 625x more material assuming the thickness can be the same and doesn't need to be more be be structurally working.

625x to me doesn't sound like a "relatively small increase in resources".

But it looks like some people consider an increase of 62400% in resources a "small increase".

<comment><USER3> Where you are going wrong is assuming the outer layer has to be the same thickness as the inner layers. The outer layer only needs to capture the long infrared radiation emitted by the inner shells. In theory it only needs to be 1 atom thick and can contain gaps half the wavelength to be captured.

<comment><USER10> Why does the 1 AU Dyson sphere needs to be that much thicker (more than 625x thicker to be precise)?

<comment><USER3> The inner shells need to be thicker for three reasons - photon pressure, they are at a higher temperature, and the wavelengths they are capturing are shorter. Having said this they would not need to be much thicker than the outer layers.

<comment><USER10> So

a.) The inner layer is thicker than the outer layer, but not much

b.) The outer layer has a surface area 625x larger than the inner layer

c.) The outer layer needs only a "small increase in resources"

I still don't get it.

<comment><USER3> The only thing we get to observe is the outer layer. We really have no way of knowing what is going on inside or what structures are present.

The relative small increase is not in reference to a smaller sphere, but to the material resources of the stellar system. If you only need 0.00000001% of the material resources of the system to build an inefficient sphere then using 625x more is not a significant increase.

</comment></comment></comment></comment></comment></comment><comment><USER11> _...put simply, the emission signal from efficient Dyson spheres will be swamped by infrared noise in any wide-field infrared surveys._

I am also not a member of an alien civilization with the technology to create a Dyson sphere, but this strikes me as being very good from the standpoint of such a civilization's operational security.

</comment><comment><USER12> A civilization capable of building a Dyson Sphere wouldn't need to.

<comment><USER13> My guess is that by the time any civilisation gets advanced enough to build a Dyson sphere, ennui has set in to the point where they don't bother.

<comment><USER14> Any civilization advanced enough to build a Dyson Sphere would by definition be one capable of extreme, long term focus. Since ennui is the enemy of long term focus, they'd probably have conquered it.

</comment></comment></comment><comment><USER15> "The good news there is a different approach for finding efficient Dyson sphere, but that is another post." Tease!

Did he ever write that other post? If so it must have a high Carnot efficiency because I can't find it /rimshot

<comment><USER3> Sorry I haven't got around to writing it yet as I have been too busy with work - actually I have not written an article on anything this year.

</comment></comment><comment><USER16> The article posits that maybe advanced alien civilizations may be motivated to build larger (and hence harder to to detect) Dyson spheres for the efficiency gains. While that's a possibility, it's also possible that being harder to detect is an end unto itself for safety reasons.

</comment><comment><AUTHOR> I'm thinking what's remarkable about this is it could be a potential explanation of dark matter.

It had always been ruled out previously because astronomers said they'd be easily detectable.

</comment><comment><USER17> So any candidate locations where such Dyson Spheres may currently exist? Can we detect them based on their gravity (i.e. objects orbiting it without the centripetal force accounted for)?

<comment><USER18> There's this thing: [http://www.wired.co.uk/article/dyson-megastructure- mystery-d...](http://www.wired.co.uk/article/dyson-megastructure-mystery- deepens)

Though who knows what it actually is.

</comment></comment><comment><USER19> maybe all the black holes are dyson spheres?!

</comment><comment><USER20> So, just musing here, no actual knowledge on any of this: what if a Dyson sphere was 100% efficient and feed its energy back into it's power-source. Could this sphere exists for all of eternity? Trapping all energy inside and recycling it?

<comment><USER3> The second law of thermodynamics makes 100% efficiency impossible. The Carnot efficiency is just a measure of how close you can get to 100%.

It must be a slow day on HN for this post of mine to make the front page :)

<comment><USER20> Is there any way you could explain to the uninformed, like myself, where the energy would leak? Is it impossible to make a 100% isolated sphere? Would radiation or other kind of waves always pass through?

<comment><USER21> If it was 100% isolated, the heat from the sun would continually increase the internal temperature, which would probably be bad. They're looking for a steady state dyson sphere.</comment></comment></comment></comment>


Don't Sell Out, Foursquare. Not Now. Not To Yahoo.  - <AUTHOR> http://techcrunch.com/2010/04/18/dont-sell-out-foursquare-not-now-not-to-yahoo/ <comment><USER2> I see FourSquare akin to FarmVille: a distracting non-skill based game designed to get users addicted. It's not going to be that fulfilling project where you improve the world, so take the money while location-based is still a buzzword and move on to something else.

<comment><USER3> Foursquare opens a whole spectrum of indirect interaction between business owners and their clientèle. The game mechanics are little more than a usability technique.

<comment><USER4> Exactly. The problem with location-based advertising etc. has always been that you need users to willingly give up their location. The genius behind Foursquare (and the other services like it) is that giving up your location is the whole point of the "game" - it's not a step required before you can get value from the service, it's the core action that the service rewards you for.

And really, this is the not-so-secret behind most privacy-threatening trends and technologies: most people will gladly give up their privacy for a [ sense of safety, comment from a friend, virtual badge ].

And if that is the value that most of the world places on their privacy, maybe there's nothing wrong with losing it.

<comment><USER5> Is your physical location really part of your privacy if you're in a public place?

I can understand that if you're at home on the toilet or something you'd want to keep that private. But when you're walking around the city, or going to a shop, those are public spaces. Therefore it's not private information that you would be divulging, as anyone in that location would have that same information.

Then if you didn't want people to know where you are online you would change the settings, or just not use the application. This is just another example of Clay Shirky's idea of Filter Failure.

</comment></comment></comment></comment><comment><USER3> It's easy to call the shots from the audience. TechCrunch is judging this by Disney over-romanticized standards - self fulfillment et al.

TechCrunch does not have access to the founders' cockpit view. What if the founders decide the company is about to become stagnated, overrun or just boring? If they can get a good price it's not worth the stay.

<comment><USER6> The funny thing is that the final paragraph could just as easily be interpreted as solid arguments _for_ selling:

      Facebook and Twitter hitting the geo space... real momentum and that intangible buzz...

So two juggernauts are entering the space, and they have a rare opportunity to actually monetize "intangible buzz" while people still don't know what FB and Twitter will do.

We're definitely in the realm of wild speculation, since it's impossible to judge accurately from out here. But I do agree that the whole notion of "destiny" isn't a good metric, regardless of the actual situation.

<comment><USER7> I think that that is proof that Foursquare should sell... to Facebook. Their valuation is still stomach-able enough if Facebook wants to use their current operating profit and cash reserves. It would immediately make Facebook the mobile leader, and take Foursquare to millions of users.

<comment><USER8> What's in it for Facebook? Foursquare functionality is easily copied. The brand isn't terribly strong. $100M+ is hard to stomach when I don't see any clear benefit to Facebook.

Yahoo! is another story, as they've taken a portfolio approach. I imagine Foursquare looks pretty good as a member of that portfolio.

</comment></comment></comment></comment><comment><USER9> Michael is certainly entitled to his opinion, but it would be rather nice if people stopped criticizing founders for "selling out" instead of "going for it".

<comment><USER10> I don't think that's what Arrington is doing here at all.

He's criticizing them for selling out _to Yahoo._

The point is not that "selling out" is bad, it's that you need to sell to someone who is committed to continuing the project in a meaningful way, and who has something to bring to the table besides money.

Speaking as a founder who has cashed out, I can tell you that the choice of buyer matters immensely, and that there are more important things in life than the amount of money in your pocket.

<comment><USER11> You would/did regret sacrificing a year or two of good work, in return for working on anything you care to for the rest of your life? Was that one project really more important than anything else you could ever do?

<comment><USER10> In my case, it was 8 years of my good work. And, 30 of my employees, who are now in a very different situation. (I'm contractually prohibited from discussing the matter, so you'll understand my being a bit oblique.)

In answer to your last question: no, it's not that that one project was really more important than anything else I could ever do; but it took a few years to get past the bitterness to be able to focus, and find the right "next step"-- which could have been avoided, if I had sold to the right people at the right time (instead of the wrong people at the wrong time).

So: "selling out" can be a great thing, if done well. Or, a really soul- searing thing, if done poorly. Choose wisely. Here endeth the lesson.

</comment></comment></comment></comment><comment><USER12> I would take the money and run. 120M now is a big exit for them. If they wait they might not that lucky next time, and even if they are, there are going to be 10M or more in funding while now it's just 1.35M.

But honestly I don't care, I had a terrible experience with them as developer (we built SquarePik, an iPhone client for Foursquare). Twitter became the Twitter we know cause they built their product on top of their API and supporting third party developers. Foursquare is mainly focus on their own clients from day one.

</comment><comment><USER13> Michael Arrington is so anti-yahoo that I find it difficult to read his articles about yahoo without wondering how much of that is just personal animosity.

Foursquare SHOULD sell. 4sq is going to become the friendster of the space. All these early starter companies get out-innovated, and it will happen very soon.

<comment><USER14> Couldn't agree more. Why would facebook buy them? For their < 1million users that are already on facebook? The engineering could also be done internally for far cheaper.

Foursquare etc. find themselves in this position: the game mechanics they used led to explosive growth but also left them with a really low glass ceiling (think people don't get Twitter? ha.) They may have had a crazy hockey stick recently, but there is simply no way they will go main stream. It's got too MUCH personality: being mayor and getting badges will either REALLY resonate with someone or not at all.

I think the founders see $80mm+ valuations on a product with a very small, homogeneous demographic of users as far greater than they could ever dream of with their current stats, and they know FB could relatively easily enter the space with a far bigger and international crowd, as well as a household name that already does biz with f500 companies, and just crush them.

I think foursquare dies no matter what, if I were the founders I'd sell to the highest bidder and run.

<comment><USER15> I think Foursquare's value is more likely in their relationships with businesses than the user base. As many have said, the userbase isn't that large yet, maybe a million people. But they're right on the verge of kicking in to the awareness of businesses, which is after all where their revenue is.

I was at the buffet at the Las Vegas Hilton a couple of weeks ago, and they have the little internal advertising cards on the table. You know, visit our nightclub, see our show, that kind of thing. But one of the items was a "Check in with Foursquare, get rewards" card. That changed my perception of where Foursquare is with things. And what they really are.

The casino sees them as another customer loyalty program. If they're providing customer loyalty programs to every business in the world...well. That's a market. And that's where they seem to be making the most inroads, moreso than with users so far. But if the businesses start helping them advertise, ala the casino...

Foursquare is on the verge of being MUCH bigger in very short order. That's why the feeding frenzy is happening right NOW.

<comment><USER14> You completely ignored the part of my comment where I mentioned that fb already has much better brand relationships and is already a household name.

if facebook does NOTHING, yes foursquare could go somewhere. but the bottom line is they already releasing privacy settings with location awareness in them, it's only a matter of time before they have their own LBS. and for $125mm trust me, they will develop in house thank you.

</comment></comment></comment></comment><comment><USER16> I guess it all depends on how emotionally connected you are to your company. Some people see their companies as their almost literal babies and get very emotionally attached to them. Others just see it as a thing they built to make money. Depending where you fall in this spectrum will greatly affect how you'll react to such a deal, and trying to judge people on other end of the spectrum by your standards is basically pointless.

</comment><comment><USER17> Yahoo's not that bad. Flickr was good before and good after, for example.

<comment><USER18> Did Yahoo ever integrate anything with Flickr in a way that justified the acquisition? I realize they have a little Flickr widget on their homepage, but man they have the world's catalogue of amazing images and they really haven't done anything with it other than just keep it the same as it was, for the most part.

I think I understand how M&A teams at places like Yahoo! work. It's all about what's "hot" with maybe some fanciful vision of integration into Yahoo! in a way that will never happen. The M&A team is drinking the same koolaid they're selling to top level execs, founders and VC's of companies they're looking at, bringing a gigantic checkbook with them.

Zimbra was actually a good kind of acquisition, because they did a good job integrating it with Yahoo! Mail right away, and what you see today is derivative of that purchase. It made a lot of sense for Yahoo! to buy a fancy webmail interface since most people using Yahoo! use it for their email. Some other good examples of acquisitions are Google buying Android and Apple buying the chip manufacturer that led to the A4 for the iPad. Bad acquisitions are when it seems like it's about the buzz and it's hard to visualize how the purchase can help the bigger company. Those acquisitions go the way of Dodgeball and Jaiku.

Foursquare is a mobile company and Yahoo!'s (lousy) presence on mobile phones is restricted to un-installable bundled software deals like with AT&T on the Backflip. Yahoo! is not a mobile company, it's not the first, second, or even in the top ten or possibly not even in the top fifty companies you'll think of when someone asks you to name companies that are movers in the mobile space.

Foursquare isn't going to do well at Yahoo! because it doesn't make sense.

I usually don't like Arrington's rants, but this one was inspired.

<comment><USER19> They moved all of yahoo photos over to Flickr, as well as some integration between upcoming and Flickr. I'm not sure what else they did.

</comment></comment></comment><comment><USER20> _You can ask your VCs to redo their term sheets and double the amount raised. Take half off the table and you, your children and their children will never want for anything material in their lives, even if Foursquare goes south right afterwards._

He says the Wordpress guys did it but how common is it? I wonder how cashing out before making a successful company affects the chances of getting there.

</comment><comment><USER21> This is why VCs should put some money into the pockets of the founders when they fund a company.

There may be good reasons, as far as the future of the company goes, why they shouldn't sell out to Yahoo or someone else. But, we are talking about a lot of money here. And if the founders aren't already independent, money-wise, can you really fault them for looking out for themselves, for their families?

I know money isn't supposed to be everything, but come on.

<comment><USER22> I guess VC's in Foursquare might also be very happy with the possible sale and less interested in seeing the baby grow.

</comment></comment><comment><USER23> Selling out to Yahoo has one huge advantage. They'll run your brainchild in to the ground so quickly that your non-compete clause probably amounts to nothing.

Kidding aside, Yahoo is a 'mixed bag', they've done some good acquisitions and made some headway, but they also literally killed a bunch of companies they took over through a combination of neglect and budgetary constraints.

If you sell out to Yahoo you know that that's the risk.

</comment><comment><USER24> I would say that Techcrunch and the like have more to lose from Foursquare selling to Yahoo!. They were probably counting on three more years of extensive "Twitter" like coverage to fill their pages.

Once Yahoo! or another big company buys them they will be forced to move on and find something new :(

<comment><USER22> Than that's good for people here in HN, trying to bootstrap and need coverage :)

</comment></comment><comment><USER25> Hmmm... Arrington having a very strong opinion about Foursquare selling to Yahoo. Too bad he didn't back it up with more facts and references instead of those few shallow examples of people selling to Yahoo and being unhappy with it afterwards.

</comment><comment><USER26> If you are conflicted about selling a dream to Yahoo for 80+ million you have too much careerism. Startups aren't children, it's either they die or you do.

</comment><comment><USER27> "Yahoo is where startups go to die." Two ex-yahooers echoed this sentiment. A moribund company, falling apart at the seams.

</comment><comment><USER28> Acquisitions are often the triumph of hope over experience. But maybe Yahoo has learned from its prior misfires, and the Foursquare folks have learned from the Dodgeball experience, and the threat of Facebook/Twitter will be ominous enough, such that Foursquare could thrive inside Yahoo.

What's up with FireEagle?

</comment><comment><USER29>
      You can ask your VCs to redo their term sheets and double
      the amount raised. Take half off the table and you, your
      children and their children will never want for anything
      material in their lives, even if Foursquare goes south right
      afterwards.

He should have led off with this, point no. 5. Who cares that "Yahoo kills startups" (even tho PG's still isn't dead), as a founder my goal is to maximize my profit and my well being. I don't give a fuck about Yahoo if I'm getting $20 million out of the deal.

<comment><USER10> You'd be surprised. The $20M has a very bitter aftertaste when you watch your baby getting neglected, or destroyed.

"Maximized profit" and "well being" don't always go hand-in-hand. Sometimes, it's better not to sell (or to sell to the right buyer.)

<comment><USER30> Perhaps you should keep in perspective that people didn't give you all that money for YOUR well being. They gave it to you because they believed you would be able to generate large returns for them. As such, it's your duty to maximize their investments as well as your own. Of course, if you believe what you're creating is changing the world and cannot detach, you shouldn't be selling.

<comment><USER10> _Of course, if you believe what you're creating is changing the world and cannot detach, you shouldn't be selling._

It's rarely so black and white. I'm suggesting that if you are selling, you should make sure that either a) the buyer's vision coincides reasonably well with your own, or b) you're sure you'll be satisfied walking away (or getting pushed out).

I speak from experience.

</comment></comment></comment></comment><comment><USER31> Because Arrington has successfully built and sold many companies, therefore enterpeneurs should really take his advice.. I mean he was really successful with .. Uhm .. oh and there was also .. uhm ....

This the "journalists" who tried extorting monies out of Twitter in exchange for not publishing illegally obtained material .. This is the guy who comments on others selling out? Really?

<comment><USER32> For the sake of argument:

Perhaps there is something to be said for his intuition, for he spends nearly all of his time evaluating startups. He successfully predicted the success of Mint. Also, Arrington co-founded Achex, sold for 32mm USD, as well as TechCrunch, which is one of the world's premiere news sites for technology.

<comment><USER31> I don't mean to discount it, but I find it really hard to give weight to the bad companies that got bought out for inflated prices during the dot-com boom. I worked for enough of them to know how much luck and a gold-rush mentality was involed.

As for Mint .. I predicted it when I first got a beta invite, because it was awesome.

I predict that tomorrow the sky will be blue! Bow down before me when I am right!</comment></comment></comment>


Helping wombats one carrot at a time: automating outbound for fun and profit - <AUTHOR> https://www.wombatdialer.com/blog/blog/2017/05/04/Helping-wombats/?lid=H010 <comment><USER2> I used to work at an ITSP in late '90s and we would call so many customers using post-it notes on the side of your (CRT) monitor as in the article. I still can't stand post-its anymore.

<comment><USER3> I guess that was before Asterisk became the cool kid on the block in ~2008. Now, not so many people care for PBXs anymore.

</comment></comment><comment><USER4> cool article , thanks for sharing</comment>