Mongo BSON Injection: Ruby Regexps Strike Again - <AUTHOR> http://sakurity.com/blog/2015/06/04/mongo_ruby_regexp.html? <comment><USER3> > 3 years ago I wrote a blog post about broken regular expressions in Ruby, ^$ > meaning new lines \n.

Are they actually _broken_? One of the first quirks I learned writing Ruby is that you use \A and \z instead of ^ and $.

I know better than to blame security vulnerabilities on "bad programmers" rather than usability problems with a language (or plain old PoLA violations), but changing the meaning of these anchors will be a tough migration, possibly.

<comment><USER4> Why is everybody talking about ruby's regex implementation? ^, \A, $, \Z, \z are standard across many languages, based on PCRE syntax. This isn't a ruby problem; this is simply developers who are not experts with regular expressions not fully understanding how to write patterns with the tool they are using. There are no problems with regex implementations, only problems with regex use.

Anybody interested should have a read through [http://pcre.org/pcre.txt](http://pcre.org/pcre.txt). The syntax presented here is used in perl, php, ruby, python, and many others.

Also, nobody ever uses \A without the /m flag. You use ^, it has the same meaning unless you specifically add the /m flag to allow ^ to match at the beginning of any line rather than at the front of the string only. This distinction will only bite developers who just add flags like /msig for every regex, because again they don't understand exactly what every flag actually does.

<comment><USER5> ruby has half multine mode by default, which causes the issue. Namely, /m only changes the behaviour of "." to match \n, but ^ and $ work the same.

(and incidentally, that would make changing it easier, you can just request that users specify a flag all the time and deprecate the one without).

<comment><USER4> Eww what the hell. I don't use ruby, and if I did I might very well - as a PCRE half-expert - fall into this trap based purely on the assumption that ruby was using PCRE. I just looked at their Regexp class, and it matches PCRE in most regards. The fact that /m makes . match newline \n is horrible - <USER2> PCRE-based implementation uses /s for that, whereas /m only affects ^ and $.

It still falls on the developer to understand the exact flavor of regex available in their language. And yet ruby is doing a disservice to anybody coming to their language with existing PCRE knowledge by having syntax that is almost an exact match to PCRE used in many languages... only to find out someday that it's not. Harsh.

</comment></comment></comment></comment><comment><USER6> To clarify this isn't _Mongo 's_ BSON, it's _Moped 's_ implementation of BSON/Ruby's implementation of BSON (again). The title is fairly misleading making it sound like it's actually Mongo which is vulnerable. Still interesting stuff though.

<comment><USER7> This is not correct.

The vulnerability is in `bson-ruby`[1] which is written by MongoDB and used by Moped (and thus Mongoid), the official Ruby driver from MongoDB, and Mongo Mapper.

The only thing that _isn't_ vulnerable is Moped's BSON implementation (if reasonably recent), but it was dropped in Moped 2.x.

In reality if your using Mongo with Ruby, your most likely vulnerable, unless you happen to be on Moped 1.x.

[1] [https://github.com/mongodb/bson- ruby/blob/84d8acd32ce9067ad6...](https://github.com/mongodb/bson- ruby/blob/84d8acd32ce9067ad646755e52f472a6ad685918/lib/bson/object_id.rb#L285)

<comment><USER6> > This is not correct.

> The vulnerability is in `bson-ruby`[1] which is written by MongoDB and used > by Moped (and thus Mongoid), the official Ruby driver from MongoDB, and > Mongo Mapper.

Then it's in the _ruby gem_ of MongoDB's driver for ruby NOT in _MongoDB_. The title is still misleading for people who do not code in ruby and therefore are not vulnerable to the apparently ever present ruby BSON bug.

> Mongo BSON Injection

A better title would be Mongo _gem_ BSON Injection

I am not trying to nit-pic I was fairly confused when seeing the title because I don't code in ruby and was 99% sure Mongo's core was C not ruby.

<comment><USER8> This doesn't detract from your point, but Mongo is primarily C++, not C.

</comment></comment></comment></comment><comment><USER9> Here's one lurking in javascript:

/A-z/ includes "[]^_`" [1]

Now go search github [2] and see the +1k repos that have this bug in their parsing of base64

Sources: [1]: [http://wtfjs.com/2014/01/29/regular-expression-and- slash](http://wtfjs.com/2014/01/29/regular-expression-and-slash)

[2]: [https://github.com/search?utf8=%E2%9C%93&q=INVALID_BASE64_RE...](https://github.com/search?utf8=%E2%9C%93&q=INVALID_BASE64_RE&type=Code&ref=searchresults)

<comment><USER10> This isn't WTF at all, that's exactly how regexes should work!

<comment><USER11> In case anyone is wondering why this isn't a WTF - See [1]..

[1]: [http://www.asciitable.com/](http://www.asciitable.com/)

</comment></comment></comment><comment><USER12> One way to help protect this kind of issue is to be explicit about validation steps.

This is the buggy code:

        !!str.match(/^[0-9a-f]{24}$/i)

That regex is trying to do three different things: validate the length is 24, validate the string contains alphanums, and ensure the matching is pinned from start to finish.

I prefer code that makes the validation steps explicit and simpler:

        str.length==24 && str!~/[^0-9a-z]/i

<comment><USER13> Its a whitelist. It is "verify the string is a 24-character alphanumeric string".

</comment></comment><comment><USER14> Egor Homakov strikes again. This guy is a _machine_ , just look at the vulnerabilities he's found this year alone:

[http://sakurity.com/blog](http://sakurity.com/blog)

<comment><USER15> Oh boy I'd love to watch this guy in action in a twitch.tv stream, taking down a site (to clarify... white hat stuff!). It would be so damn fascinating to see how his mind works and how he makes the leap from 0 to exploit.

<comment><USER16> Is there anything currently like this for other people?

<comment><USER17> I've been thinking about live coding on twitch but having to think about not revealing any sensitive information would make it a hassle. I will give it a try for some side projects.

</comment></comment></comment></comment><comment><USER18> I suspect that many of these same Rubyists who mistakenly assumed ^ and $ have the normal PCRE semantics would still readily claim to know Ruby, and in many cases, even to know it well. I think this type of vulnerability undermines the optimistic belief that any decent programmer can quickly learn a new language, and further, it shows the danger of adopting new languages generally, especially those with extremely complex and not particularly well-defined syntax and semantics, like Ruby.

I also wonder how many vulnerabilities result just from Rubyists favoring cutesy APIs (or "DSLs," as they call them) that while making for great demos, hide the often times unignorable, crucial details of what they do from their users.

</comment><comment><USER19> Where's the attempt to submit a patch to fix the problem before disclosing?

</comment><comment><USER20> The 1.x versions of BSON are vulnerable, too, FWIW.

<comment><USER21> I tested on our app (which uses BSON-ruby 1.9.2) and was surprised to find that the detection code indicated it was not vulnerable. Turned out it was because we also use bson_ext — bson_ext replaces the vulnerable method with a C implementation which doesn't use regexes.

<comment><USER22> Kinda funny to see a "safe" language saved by C. Just sayin'

</comment></comment></comment><comment><USER23> Added a patch for Moped::BSON in Rails here

[https://gist.github.com/eddanger/9408317d5d508d8e9ba7](https://gist.github.com/eddanger/9408317d5d508d8e9ba7)

</comment><comment><USER24> This has been fixed. Just update moped:

gem "moped", "~> 2.0.5"

</comment><comment><USER25> Is this only an issue if you are defining the BSON _id ?</comment>


Features of the Grecian ape raise questions about early hominins - <AUTHOR> http://johnhawks.net/weblog/fossils/miocene/graecopithecus/graecopithecus-fuss-2017.html <comment><USER2> "An old paleontological in joke proclaims that mammalian evolution is a tale told by teeth mating to produce slightly altered descendant teeth." -Stephen Jay Gould

</comment><comment><USER3> This is the same thing I've been saying for years, "Paleoanthropology must move past the point where a mandibular fragment is accepted as sufficient evidence."

<comment><USER4> It has, according to another part of the article commenting on ardi?</comment></comment>


What I learned about weight loss from a day in a metabolic chamber (2018) - <AUTHOR> https://www.vox.com/2018/9/4/17486110/metabolism-diet-fast-weight-loss <comment><AUTHOR> (Title edited from "What I learned about weight loss from spending a day inside a metabolic chamber" to fit)</comment>


The Man's Essential Library - <AUTHOR> http://artofmanliness.com/2008/05/14/100-must-read-books-the-essential-mans-library/

<comment><USER2> A fine list to be sure, but any attempt to set up a new canon is going to fail like all the other canons have. There is no _one list_ we should read to be cultured.</comment>


Show HN: GitHub Auth for S3 website - <AUTHOR> https://github.com/CanopyTax/s3-file-auth <comment><AUTHOR> Author here. Let me know if you have any questions.</comment>


No Way NSA - <AUTHOR> http://nowaynsa.com/ <comment><USER2> The really terrible part of all of this is that the administration's response has been to put James Clapper, the guy who lied under oath to congress about the scope of these very programs, in charge of reviewing the policies that created them.

He should be facing charges, and instead he's promoted to an oversight role.

[http://www.emptywheel.net/2013/08/12/this-technical- review-g...](http://www.emptywheel.net/2013/08/12/this-technical-review-group- brought-to-you-by-the-booz-allen-hamilton-director-of-national-intelligence/)

<comment><USER3> "Obama announces the formation of a 'least dependent' group to review our capabilities."

</comment></comment><comment><USER4> Really nice site that could get out into social media and spread quite easily! I mean, that combination of animations and potent yet minimalistic text really gets the point through in a small package.

<comment><USER5> It's great more & more people are waking up.

</comment></comment><comment><USER6> Nice - one point, it wasn't at all obvious from the initial screen that you can scroll down. There should be a visual hint.

<comment><USER7> I also missed this just now. Thought it was a one-slide site. Big down arrow please!

<comment><USER8> There is a bouncing down arrow at the bottom middle of the screen, unless it has changed since you posted this comment.

Update: I read lower, and Mike totally DID add it after these comments.

</comment></comment></comment><comment><USER2> "NSA surveillance has damaged foreign relations. Millions are protesting worldwide and European businesses are abandoning U.S. tech companies. Total losses could reach $35 billion."

I'm not sure where WaPo got that $35bn number, but it seems quite low to me.

</comment><comment><USER9> "True patriotism hates injustice in its own land more than anywhere else.

^ Missing the end quote

</comment><comment><USER10> Thanks for all the kind words :) Fixed up the quote and the first slide.

I'm doing everything I can to try and get this in front of people. I'm extremely grateful that a discussion happened on HN and am looking forward to seeing where the site goes from here.

Cheers, Mike

</comment><comment><USER11> Lots of inaccuracies and fallacies.

The NSA Spying is not against the fourth amendment. If you're a lawyer feel free to correct me but the supreme court has made it very clear that they believe the framers were being literal when they said "persons, houses, papers, and effects." and they have said they believe this cannot be extended to non-tangible things like data.

And whether I'm right or wrong it's better to say 'We Believe' it is a violation... because if it was then the NSA would have been forced to stop

The big problem is that the NSA can do this without breaking the law...

<comment><USER12> I've never heard the argument you're making -- that it doesn't apple because it's data. The NSA/gov has said repeatedly what their argument is.. it's because you've entrusted a third-party with it, and therefore there was no expectation of privacy.

<comment><USER11> Yes this is a reason too. Katz v US.

People need to think "Who really owns my facebook account, my twitter account, my dropbox, etc..." If it isnt you (it isnt... trust me) then you're out of luck

<comment><USER13> That is _not_ correct. It is still your data (that's why you need to grant a license to these companies to show your pictures even just back to you), and the third party doctrine _is not_ settled law.

It has backing in precedent, but as ghayes cites above, the supreme court has given some strong signals that they would not agree with it today (e.g. in US v Jones). In addition, the incredibly important US v Warshak had the sixth circuit ruling that email in long term storage on a third party's server had just as much expectation of privacy for the owner as any personally held document. There are several companies now using that as a legal basis for requiring a warrant (which requires demonstrating probable cause) for account content requests (apparently outside of those coming from the FBI/NSA, unfortunately...), so it's likely this will come up before too long, either in Congress (I'd love to see the ECPA reformed but don't have high hopes) or in the Supreme Court, especially if another court of appeals rules differently.

I also have no idea why you cite Katz v US, as that's where the "reasonable expectation of privacy" test itself comes from, which runs directly counter to the later legal theory of the third party doctrine (in e.g. Smith v Maryland), which takes little account for reasonable expectations so long as you're handing off your communications to a third party.

<comment><USER11> My point that "you don't own it" is more from a security standpoint. ..which was pretty dumb to say. I can't verify that companies wont give my data to the feds and I can't trust them not to. It isn't my data to maintain anymore

</comment></comment></comment></comment></comment><comment><USER14> "Off-Topic: Most stories about politics, or crime, or sports, unless they're evidence of some interesting new phenomenon."

</comment><comment><USER15> This is good, but I think a more effective way is to bring up some hypotheticals. You don't even have to make up your own. Just look at history and you will find lots of examples of how secrecy leads to corruption, in- fighting, negative psychological effects, loss of free expressions, fear, oppression, etc.

One neat way to approach this would be to talk about an example that happened in the past and draw parallels with what it going on today. It's difficult for people to understand or see where all this leads, which is why there's so little revolt. Unfortunately, by the time people feel the effects it's too late.

</comment><comment><USER16> "There is no evidence that the FISA Court and NSA programs are effective. Mass surveillance did not prevent tragedy in Boston or aid in identifying those responsible."

I think this part very much weakens your argument and should be removed entirely. First, the NSA has nothing to do with domestic surveillance -- that falls upon the FBI. Secondly, you can collect all of the data that you want, but you won't be able to prevent the lone wolf element (as opposed to organized terrorism), especially with no national database of firearms.

<comment><USER17>
         >the NSA has nothing to do with domestic surveillance

Have you not been reading the news?

[https://www.eff.org/nsa-spying/timeline](https://www.eff.org/nsa- spying/timeline)

[http://www.newyorker.com/online/blogs/johncassidy/2013/06/ns...](http://www.newyorker.com/online/blogs/johncassidy/2013/06/nsa- latest-the-secret-history-of-domestic-surveillance.html)

[http://reason.com/blog/2013/08/05/shocker-nsa-tools-for- spyi...](http://reason.com/blog/2013/08/05/shocker-nsa-tools-for-spying-on- foreign)

[http://uk.reuters.com/article/2013/08/07/uk-dea-irs- idUKBRE9...](http://uk.reuters.com/article/2013/08/07/uk-dea-irs- idUKBRE9761B620130807)

Thanks to the "Patriot Act" and "Threat Fusion Centers," along with other such efforts to streamline the police state agenda in the name of the "War on Terror," government agencies have been sharing information more readily than in the past, apparently to the point of NSA derived intelligence being used in pursuit of drug dealers and tax cheats on US soil.

Of course people are aware of the intended functions of the various federal enforcement agencies, and the fact that these agencies are overstepping their mandate is why people make websites such as the one featured here.

The quotes you refer to are quite relevant, in my view.

</comment></comment><comment><USER18> _According to a recent NSA memo, 1.6% of all online activity is monitored and collected. That's enough to capture more than 50% of all internet communications._

== Leverage

</comment><comment><USER19> I like that the site's design is entirely based on the flag of the Netherlands, famously the country with the highest amount of phone taps per inhabitant.

</comment><comment><USER20> This is awesome! Any chance you can repost tomorrow when it might get a bit more attention?

<comment><USER21> Just a FYI for the submitter: that's a bannable offense, and enforced. Wouldn't want you to lose your account.

<comment><USER22> reposting content is bannable?

Every week I see posts reposted daily - for example Bootstrap was posted multiple times over a time period.

<comment><USER23> Re-posting your own post, not happening to post the same link as someone else.

</comment></comment></comment></comment><comment><USER24> Spying? In MY country?

[http://knowyourmeme.com/memes/x-in-my-y](http://knowyourmeme.com/memes/x-in- my-y)

</comment><comment><USER25> Strange. I immediately looked past the goal of the site and fell in love with how it looks instead. Fantastic work there.</comment>


Microsoft drops "Surface," its tablet product to go head-to-head with iPad - <AUTHOR> http://www.eweek.com/c/a/Windows/Microsoft-Tablet-PC-Surfaces-in-AppleLike-Event-515393/

<comment><USER2> Using the term "drops" generally means to discontinue.

<comment><USER3> Drops can be used in place of release. For example "the new Justin Beiber album drops today." In the tech world it is usually associated with discontinue.

<comment><USER2> In that case the product is dropped rather than the company dropping it.</comment></comment></comment>


Experts Urge U.S. To Continue Support for Nuclear Fusion Research - <AUTHOR> https://www.scientificamerican.com/article/experts-urge-u-s-to-continue-support-for-nuclear-fusion-research/ <comment><USER2> Nuclear fusion is probably still decades away. But I am going tangent here, nuclear fission still have great potentials. Scientists from the Oak Ridge National Laboratory actually helped China to built Molten Salt reactors in the 70s during Nixon administration. [1] And since then thorium based molten salt Gen IV reactors have been having renewed interests around the global. China actually tested the whole system feasibility in Giga Watts scale in recent years. [2]

Nuclear power is vital part of the energy infrastructure to curb worsening environment due to climate change - it's still considered superior than all the other green alternative energies in terms of either 24/7 availability (vs. solar/wind) or massive scale (vs. geothermal) or location restricted (vs. hydro) or carbon-free (vs. biomass/bio-fuel). China realized that in their dire request to transition out their entire energy reliance on carbon-based energies, it's impossible to do without nuclear. Also, newer reactor designs are much safer and last longer so a lot of the concerns of radioactive waste have largely been alleviated.

[1]: [https://news.ycombinator.com/item?id=10229697](https://news.ycombinator.com/item?id=10229697) (2015)

[2]: [https://news.ycombinator.com/item?id=17813614](https://news.ycombinator.com/item?id=17813614) (2018)

<comment><USER3> > Nuclear fusion is probably still decades away.

I wrote that sentence in a 10th grade report on fusion, in 1977. Disappointing that it's likely still true four decades later. In another four decades it's up to you to make this comment.

On the other hand, so much has arrived that I never dreamed of in high school, though I consumed scifi obsessively. Not sure I'd swap the internet for cheap fusion energy. But not sure I wouldn't.

<comment><USER4> Note that we've never spent as much money as we've _always_ known would be necessary to achieve useful fusion power, so the oft-repeated idea that it's been surprisingly technologically difficult is not actually justified by the historical track record.

> Typically, outsiders cannot comprehend how the massive expenditures never > manage to yield energy. Typically, insiders cannot comprehend how little is > being invested in a project that presents such immense technical obstacles > and also such potential. A graph commonly passed around among the > insiders—an enduring scrap of twentieth-century budgetary ephemera—depicts > the 1976 federal plan to build a working thermonuclear reactor. The graph > tracks various scenarios for attaining fusion energy. The "maximum" effort, > the most expensive up front, with initial spending as high as nine billion > dollars a year, was projected to yield a reactor by 1990. The "moderate" > effort, with spending never exceeding four billion dollars in a year, would > take fifteen more years. The fusion community might be easy to criticize for > its many unmet milestones, but for decades the United States has never come > close to even the moderate effort. In 1977, when the American fusion budget > was at its peak, government investment in the research, adjusted for > inflation, was seven hundred million dollars; by 1991, this had fallen by > more than half. It is now half a billion, not appreciably more than the > Korean budget.

[http://www.newyorker.com/magazine/2014/03/03/a-star-in-a- bot...](http://www.newyorker.com/magazine/2014/03/03/a-star-in-a-bottle)

The chart was produced by Energy Research and Development Administration (ERDA), which was later subsumed into the Department of Energy and presumably represented the expert wisdom at the time. It can be found, in 1976 dollars, as figure 1 here:

[http://www.21stcenturysciencetech.com/Articles_2010/Winter_2...](http://www.21stcenturysciencetech.com/Articles_2010/Winter_2009/Who_Killed_Fusion.pdf)

<comment><USER5> If there's any technology more deserving of a modern-day Manhattan Project...

</comment></comment></comment></comment><comment><USER6> I suspect we will transition to PV before fusion actually becomes viable. Even if we had a working net-positive-energy-balance fusion plant today, it would be incredibly complicated and expensive to build and maintain. The temperatures and energies involved are simply massive. On the other hand, we already have a giant self-sustaining fusion reaction happening in our sky. We can throw down some solid state and increasingly cheap panels to collect that energy. Regardless, we should continue to invest in fusion, but we should also invest in PV research, especially into ways to decrease cost and complexity of manufacturing solar cells.

<comment><USER7> PV just doesn't scale in the same way. There's only so much surface area to cover in panels. The power density of fusion is so many orders of magnitude larger that even with cheap reliable solar panels I think there will always be a use for working fusion

<comment><USER8> PV scales fine. Do the math, please. There is far more than enough land onto which we can put PV farms. And the cost/W for solar (of which the cost of land is small fraction) is two order of magnitude below current fusion machines.

<comment><USER9> Then there's the ocean.

<comment><USER10> I'm imagining the solitary life of a caretaker living in a little ship that travels the canals between acres of floating cross-linked solar panels, fixing wiring and washing off salt deposits.

Poetically, it would be a tale of isolation out in the middle of the Pacific, but I suppose you'd need to stay close enough to shore that you can transmit the power using wires, unless it's batched up in chemical storage.

<comment><USER11> If you perform electrolysis of sea water the main products given off would be hydrogen and bleach, both of which could be piped or shipped (if you filled an oil tanker with hydrogen, would it be lighter than air?) back to shore. Although a leak of bleach into the ocean may not be very good, it's probably no worse than the damage done from oil.

</comment></comment></comment></comment></comment></comment><comment><USER12> A lot of people are saying fusion is still decades away. That might very well be true but it might be centuries away unless we change the way we fund the research. Nuclear fission and fusion research are still happening but there's no sense of urgency at this point and it's not a very popular topic with politicians given the issues with reactors invented half a century a go. Back in those days there was a real sense of urgency and no cost were spared to get things done. Kennedy says go to the moon. Ten years later it's done. The fear of the Russians getting there first drove the US to do amazing things.

This stuff doesn't happen by itself and will need a lot of investments and planning to get it done. At this point a reasonable question to ask is whether the US will be the one that makes the breakthrough here. They are not the only ones working on this and arguably it's not a big priority in the US to be working on this at all. What happens when e.g. China gets there first? They are working on this as well and they seem to be getting some results. They are also planning to go to the moon pretty soon. And a lot of the clean energy tech we use comes from them as well.

</comment><comment><USER13> Just because deuterium is cheap doesn't mean Fusion energy plants will be anywhere near economically competitive with conventional power sources even most renewables. Many of the presumed benefits such as waste control are not as rosey as most people believe.

It is clear now that plant scaling with known methods are entirely dependent on magnetic field strength. More powerful magnets will mean more hope for tokamaks.

Entirely new designs are probably not what the doctors are ordering because nothing of the sort is anything close to a surefire success in the wings.

So many concepts have come and gone. Tokamak was the closest they ever got. Look at the plant schematics. Its like building a furnace from a humongous collection of delicate swiss watches.

<comment><USER8> Even with powerful magnets, the power density of a fusion reactor is limited by what the first wall can withstand, and will always suck compared to fission reactors. There's little hope a fusion reactor will be able to compete with fission, never mind the technologies that are beating fission.

What high fields might do is allow use to make small, uncompetitive fusion reactors, instead of large, uncompetitive fusion reactors.

<comment><USER13> Correct and 17 tesla magnets are already hugely powerful. Its a tremendous amount of structural stress. If it quenches it can explode!

</comment></comment></comment><comment><USER14> At the risk of inciting a flame war that I might not be able to understand, is there any way to characterize current fusion projects against each other? For example, what can be said about the promise of ITER vs Wendelstein 7-x?

Part of me realizes that there's no such thing as a "failed" scientific experiment and that diversity of approaches is good. The other part of me thinks that a public and competitive spectacle would also be good.

<comment><USER15> ITER will be an actual tokamak fusion reactor producing energy. Wendelstein 7-X is a plasma containment experiment based on the stellarator design. There will be no fusion.

Technology for magnetic enclosure was advanced significantly by both. In this regard, they profit from each other.

Tokamak reactors require a pulsed operation mode. There is no way to sustain fusion for longer time.

The Stellarators design allows continuous operation, putting less stress on the structure. The calculation of the winded enclosure structure is quite complex and it has only become possible to design and implement with sufficient precision recently.

If I'd have to "bet" on a design, it would be Stellarator. If you understand German, listen to this podcast. You won't regret it: [https://alternativlos.org/36/](https://alternativlos.org/36/)

<comment><USER16> People keep saying Wendelstein won't do fusion but that's not the case. _Currently_ the 7-X isn't doing fusion because they're using hydrogen. But they plan to use deuterium later, just like all the other fusion research reactors, and they'll get fusion reactions when they do. There's really no reason not to; you get more data and it's easy. People fuse deuterium in their garages with home-built fusors.

<comment><USER17> Exactly! AFAICT, the trickiest unknown is maintaining plasma stability and not degrading the insides (and then, breaking even on power while doing so.) Wendelstein seems to be on track to steady-state operation; they've held plasma for 100s, and their graphite shielding seems to be delivering cleaner plasma streams.

The design for the 7-X wasn't feasible until supercomputers got powerful enough. We know how to run those simulations; fusion should get more practical as computers get faster.

</comment></comment></comment></comment><comment><USER18> I all for research into potentially valuable tech. but we have to consider the fast-falling cost of renewable energy. by the time fusion gets realized at scale, we might not need it anymore.

<comment><USER19> Fusion (once realized): steady energy regardless of weather conditions, from maybe a few installations per country

Renewables (solar, wind): dependent on weather conditions, would thus require battery farms for backup during wind-still nights or days with overcast etc.

In my mind the ideal future scenario is a compromise between both solutions:

Have fusion always on and provide a base level of energy production sufficient for need plus a few percent. Then have renewables lower the target for energy production through fusion when available. Then we would not need giant battery farms and renewables would get used to the best of their ability/availability while not restricting energy consumption due to them not being available 24/7.

Maybe even leave a select few coal/fission plants available but powered down as a sort of UPS for the energy infrastructure, just in case fusion is N/A and renewables aren't enough to cover the need.

</comment></comment><comment><USER20> We should be funding the shit out of Fusion and molten salt fission reactors. We're gonna also need to build shitloads of carbon scrubbers and water desalinization plants.

<comment><USER21> If our goal is basic research, sure, fusion is great.

But if our goal is to achieve carbon neutrality ASAP, we can't count on fusion to help because we don't know _when_ it will start working. On the other hand, renewables + battery leveling are here today and ready for intensive investment.

Yes, let's do both. But I don't believe fusion research will provide a short- term alternative to CO2-emitting power sources. I think it's fine with to spend 1000x on conventional renewables compared to fusion. We can employ an absolute army of technicians and factory workers _today_ to build out renewable generation infrastructure, while fusion gets a steady research budget for post-docs, career physicists, materials engineers, etc.

<comment><USER22> What about fission reactors?

</comment></comment></comment><comment><USER23> I have no idea if nuclear fusion is feasible in the near future, or what kind of timeline is required, but I don't see any downside to spending money on projects like this. Pure scientific pursuits seem to be fund able at relatively low prices, with massive upsides and no obvious downsides, other than the opportunity cost of the money being spent.

<comment><USER8> Fusion absolutely will not be feasible in the near future. We don't even have the materials that would be needed to build them. In any other field of engineering, lack of materials is a showstopper, and new material development is always painful and slow. And if you examine any of the designs with a skeptical eye none of them seem promising, and all involve lots of handwaving.

<comment><USER24> You are saying that ITER will fail?

<comment><USER8> ITER cannot lead to an economically competitive reactor, even if it achieves every one of its stated operational goals. It's a massive dead end waste of money.

<comment><USER24> Although I happen to disagree, that is a different, more reasonable critique than your original comment.

<comment><USER8> My original comment is entirely reasonable. Fusion faces generic obstacles that are likely unsolvable, and certainly unsolvable in the near term.

Consider the problem of tritium breeding. Fusion reactors have to make their own tritium -- T from fission reactors would be far too expensive -- but tritium breeding blankets cannot be tested without a working fusion reactor. And the requirements for the breeding blankets are seriously constraining. They must achieve some neutron multiplication (from (n,2n) reactions of energetic fusion neutrons) to offset losses, not lose too many neutrons to penetrates/parasitic capture, and be able to give up the produced tritium fairly quickly. And there are very strict limits on how much tritium can be lost to permeation into reactor materials (or lost from the reactor exhaust, since ~99% of the injected tritium doesn't fuse).

No one knows how to do this, or if it can be done economically, or even if it can be done at all. And I repeat: testing it is going to require a working fusion reactor! This circular dependency in development will be painful to run around, and won't happen quickly.

Then there's the matter of materials that can withstand prolonged exposure to fusion neutrons. These materials have not been developed, in part because this again requires something close to a working fusion reactor (at least, something with Q at least ~0.1), and much painful rebuilding as that reactor, built with less adequate materials, destroys itself over time. This material development will not be fast, so we will not have working, practicl fusion reactors soon.

Even when all that is solved, the fundamental problem of fusion -- low volumetric power density -- remains. That alone seems insurmountable. When you see a fusion reactor design, ask what this power density is. For ITER, it's 0.05 MW/m^3. For ARC or Lockheed's design, it's around 0.5 MW/m^3. These are very bad compared to fission reactors.

A final point: the complexity of the irradiated part of a fusion reactor (the part that's too radioactive for hands-on maintenance) will be MUCH higher than that of the similar part of a fission reactor. Reliability is going to be an enormous problem. Making fusion reactors reliable enough for them to be practically interesting, even if all other problems were solved, will take much experience and time.

</comment></comment></comment></comment></comment></comment><comment><USER25> Fusion is a materials science problem and materials informatics (machine learning methods for improving properties and / or devising new alloys) will help immensely once a new generation of digital-native scientists comes into the working force. Fusion might not become economically viable for a long time yet, though, so investments could very probably be moved elsewhere sooner than later. Healthcare for aging populations in the West and a new space race from China come quickly to my mind as powerful "distractions" from ITER part II, in the case part I ignition goes well by 2030. Smaller, more efficient reactors would not solve the energy problem even if they go successfully past the laboratory stage, in that being out of question imho.

<comment><USER8> Distractions from ITER would be welcome. The power density of ITER is ~0.05 MW/m^3, some 400x worse than the power density of an LWR reactor vessel (and 2000x worse than the power density of the LWR core inside that reactor vessel). It's a project where research money goes to die, and new materials are not going to help that.

<comment><USER25> Power density is irrelevant for fusion, though: you will never exhaust fusion "fuel" on planet Earth. It will never be an efficiency problem, like it is for fission aka uranium.

<comment><USER8> No, power density is very important, since it directly affects how expensive fusion reactors will be. The cost of a machine is a function of its complexity and size; fusion reactors will be both much larger and much more complex than fission reactors of the same power output.

<comment><USER25> Possibly yes but, even the case, the US, the UK, Japan and France would switch to fusion immediately, if feasible, to get rid of fission and its waste. Renewables & nuclear are the perfect mix to contain greenhouse gases emissions, that's why the debate is so hot.

<comment><USER8> No, nuclear and renewables do not mix well at all. Intermittent low cost sources of power shoot nuclear's baseload business case in the gut. The reactors cannot sell power at high enough price enough of the time to make sense.

<comment><USER25> You know, it is renewables to lose, apart of local places blessed by any sort of competitive advantage (water, silicon, etc.). However, I am not here for politics and you simply cannot beat nuclear by numbers, though.

<comment><USER8> Nuclear is being beaten by the numbers as we speak. That's why renewables are being installed worldwide and, with a few exceptions, reactors are not.

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER26> > A fusion power plant, it estimated, "could use only 5 kilograms [11 pounds] > of hydrogen to generate the energy equivalent of 18,750 tons of coal, 56,000 > barrels of oil or 755 acres of solar panels."

Translation: The coal industry, the oil industry, and the solar industry do __not__ benefit from fusion. Using history as a reference, it's fairly safe to presume they will use their influence to sway any decisions in their best interest.

</comment><comment><USER27> I get that fusion can theoretically transform vast quantities of stuff into useful energy. Can anyone comment on how scalable it would be if proven viable? Can it be built on a large scale profitably? Can it be built to serve remote locations off major grids? Can we ship it in reasonably sized space ships and use it to build bases elsewhere? Can we write off low energy costs to just churn on some sort of climate saving terraformer?

<comment><USER7> Fusion scales incredibly well. For a given working reactor design, efficiency increases with size. I think viable working fusion would lead to a more interconnected grid because of this as opposed to smallscale fusion reactors being deployed in semi-remote areas. On the other hand truly difficult to reach places would be perfect for fusion as once it's built it takes very little fuel to run.

<comment><USER8> Fusion reactor economics get worse as you make them bigger (assuming the smaller one works at all). That's because their power output is limited by what the first wall can withstand. By the square/cube law, their power/volume must decline as they are made larger.

</comment></comment></comment><comment><USER28> The full report can be read at :

[https://www.nap.edu/read/25331/chapter/1](https://www.nap.edu/read/25331/chapter/1)

</comment><comment><USER9> Is terrestrial fusion even desirable, I understand it will not use the same "clean" reaction as stellar fusion (deuterium-tritium or D-D vs ordinary hydrogen).

Can someone with more knowledge comment on whether this report is accurate? [https://thebulletin.org/2017/04/fusion-reactors-not-what- the...](https://thebulletin.org/2017/04/fusion-reactors-not-what-theyre- cracked-up-to-be/)

To me it seems to annul the entire enterprise (other than as a pure research project) if true?

<comment><USER29> Stellar fusion isn't really clean in the way you imagine; there are lots of reactions in the star core that produce free neutrons, they just get reabsorbed by something else because they can't realistically exit the system like they can in a tiny reactor.

Nor is it realistically achievable, anyway. Fusing products out of bare protons just isn't productive enough at achievable temperatures.

<comment><USER8> In a star like the Sun there are very few free neutrons produced. There are non-exploding stars that produce some neutrons, but they are AGB stars where the core gets hot enough for (alpha,n) reactions to occur.

<comment><USER29> Hm... maybe I'm misremembering, but I swear I saw an analysis that showed neutron loss from a small (i.e. reactor scale) blob of solar core plasma would be comparable to what you get from existing power reactions. It's true that almost all the energy production in the sun happens from reactions that don' t involve neutrons, but the neutrons are flying around nonetheless (and, in a reactor, would fly right out of the containment).

<comment><USER8> What nuclear reaction in the solar core are you imagining would produce neutrons?

<comment><USER29> Something endothermic? Are you really asserting that no such reaction exists? They clearly do, the question is whether the cross sections are high enough. The list of reactions you find in typical explainers are just the ones involved in energy production.

And I'm no expert, so I'm not going to be able hand you the evidence here. But like I said I swear I've read this analysis somewhere, and something about your tone tells me maybe you are misunderstanding the point.

<comment><USER8> The most likely would be 13C(alpha,n)16O, but the rate of this would be very low at the temperature of the solar core.

You might also point to (alpha,n) reactions on Li, Be, or B. But these should be slower than (p,alpha) reactions on these elements, which destroy them at temperatures well below (by a factor of ~3 or more) that of the center of the sun.

Let's see how far I can push your argument. There will be some 7Li produced by a side branch of the PP cycle (although it is quickly destroyed). Also, 4He produced by the various fusion reactions will initially have energies in the MeV range (~1000 mean thermal energy in the core), so it's possible (alpha,n) reactions could occur from them as they slow down.

</comment></comment></comment></comment></comment></comment></comment><comment><USER30> Lets be honest about fusion - Experts urge the US to continue employing them for another 20 years. And thats coming from someone with a physics background. The fusion industry (and thats what it really is) has managed to string the public and policy makers along for 60 years so I guess why stop trying now. Fusion will never be cheap and won't be clean either.

</comment><comment><USER31> If we want to really colonize other planets then we need fusion reactors.

<comment><USER8> Why would we need fusion reactors for that? Describe the use case for which they are essential, and I will then tell you why they aren't.

</comment></comment><comment><USER32> While I agree that there is too little money in Fusion research, I would recommend building Thorium reactors. Thorium reactors could be in a production setting, if financed, in less then 5 years.

</comment><comment><USER33> "Nuclear fusion is still decade away" ... heard that before. Decade before.

</comment><comment><USER34> A well-built modern fission plant is far safer and more environmentally- friendly than almost all the other solutions out there save for solar/wind/geothermal.

Fusion is the holy grail, though, and with good reason. At least with fusion (as with flight 100+ years ago), we have only to look up during the day to know it's feasible because it's being demonstrated, live, every day!

<comment><USER35> The sun's fusion is powered by the gravitational attraction of ~10e30 Kg of matter. That is not even remotely an option on Earth, so there is no evidence of feasibility about the energy produced by the sun, aside from the fact that it demonstrates that fusion _as a concept_ makes sense.

<comment><USER34> > there is no evidence of feasibility about the energy produced by the sun

Don't the most recent fusion experiments have _almost_ the same energy return as input? That is "no evidence"?

<comment><USER35> What I said was that there is no evidence that fusion on Earth will work that can be derived from simply looking up at the sun. Context matters.

</comment></comment></comment></comment><comment><USER36> This feels like hydrogen fuel cell tech — "something better on the horizon" that will keep you from investing in the obvious: free energy from the fusion reactor that already works in the sky. I would put every dollar of public fusion research money into solar and battery storage. That works now. The only thing fusion research accomplishes, like HFC, is prolong dependence on carbon energy.

<comment><USER37> Funny comparison. If you like batteries, fuel cell tech would be one of the places you would want to be putting some of your primary research money.

<comment><USER36> There is no naturally occurring source of hydrogen. That's why you see ads for HFC from Shell and Chevron. Hydrogen must be made from oil or gas. Salt water electrolysis doesn't really work at scale as it requires even more oil and gas. Even if you do SWE with renewable energy, it's about 22x less efficient than putting the electricity in a battery. We have fusion. It's in the sky. We don't need it on earth.

<comment><USER37> I'm talking about fully reversible fuel cells for grid storage, not a hydrogen fuels economy. So this kind of thing - [https://www.energy.gov/sites/prod/files/2014/03/f11/rev_fc_w...](https://www.energy.gov/sites/prod/files/2014/03/f11/rev_fc_wkshp_anderson.pdf)

</comment></comment></comment></comment><comment><USER38> I don't think we have a choice. Human activities are currently completely dependent upon the availability of energy. Right now most of that energy comes from non-renewable sources and is limited. Our only other choice besides nuclear technologies is covering large portions of our planet's surface with solar panels, which in itself might cause problems because they will shade out plants and change weather and climate patterns as they scale. Traditional nuclear plants get us quite aways farther, but have their own risks, and still require absolutely enormous mining fields which isn't ideal. Fusion power however is the holy grail of energy production. We can go pretty much anywhere and find plentiful sources for fuel.

Of course this is assuming small fusion reactors will ever actually work, but we have yet to find a hard limit or insurmountable barriers. We have been progressing slowly but consistently but the payoff would be world changing, potentially even galaxy changing int he longer run.

<comment><USER39> _covering large portions of our planet 's surface with solar panels_

Have you calculated it? If I recall correctly, it's actually not a large portion at all. It's large in the sense that it would be a large infrastructure project, but it's not larger than the combined area already covered by buildings.

<comment><USER38> That is assuming we keep similar power usages as today, but many of our largest industries are consuming unaccounted for fossil fuel energy. Fertilizer for example, fossil fuels are used as a reagent in creating artificial fertilizer, on top of already huge energy costs. The energy required to make fertilizer out of the air and water, rather than fossil fuels, is 100x more at best case. 60% of our total crop yield is the result of artificial fertilizer. Then look at plastics, how much more energy is required to create nonfossil fuel hydrocarbon precursors? You can make hydrocarbons from trees, but it might take an entire tree just to make a few cheap plastic containers.

Many other industries are also powered by mined and drilled organic fuels and minerals, but are still fairly limited in availability, at least for such cheap prices/energy requirements anyways which will rise into the future.

Building solar panels to power our planet today isn't insurmountable, but what about 20 years from now? 50? 100? Power costs are the limiting factor in many industrial processes, including farming, steel and aluminum production, aviation and rocketry, indoor farms, plastics, and nearly every other form of material synthesis.

Don't get me wrong, im not advocating against solar power in anyway, however I don't think it is an effective source for powering our largest industrial processes into the future. Even a small 10 man ceramics shop can draw enough power that they need to call up the local power companies before they turn their large furnaces on, I see no reasonable way of storing and supplying those kind of immense power requirements with solar panels and current storage technologies in any economical way.

</comment></comment></comment><comment><USER40> Do we even had a model for Fussion that is energy poasitive? The only Fusion reactors we know to work, work by converting gravitational potential energy into light/heat through fusion this is how stars operate.

All fusion reactions so far require an external input of energy not only to start them but often to sustain them and even those which are self sustaining for a short period of time grind to a halt once you try to extract energy from the system.

So in all honesty while I'm not by any stretch of the imagination an expert in fusion physics I can at least understand conservation laws, does any of the current experiments even relies on a model that is at least proven in principle to be energy positive?

<comment><USER41> Stars simply do not "work by converting gravitational potential energy into light/heat through fusion." The "light/heat," or energy, that stars produce comes from the mass defect of the fused atoms. Basically, the binding energy of He is less than the binding energy of the (net) 4 H atoms that go into the reaction. It works so well in the sun because of the long confinement times and the long transit time for energy to get from the center of the the star to the exterior.

"...while I'm not by any stretch of the imagination an expert in fusion physics...I can at least understand conservation laws..."

I don't think that you have a firm a grasp on their application as you seem to suspect, though I agree you don't understand the physics of fusion. Your reasoning is analogous to neglecting the contribution of smokeless powder to the performance of a rifle, because a rifle is just "converting" the energy stored in the hammer spring into energy in the bullet.

That's the best I can do for you. Good luck!

<comment><USER40> Again gravity is what maintains the reaction going, without it the gas would expand and the reaction would stop.

I understand how fusion works, what you neglect is that gravity is what allows you to counter the nuclear forces to cause protons to fuse in the first place, and what keeps the entire thing from blowing out.

Hence stars are in constant balance between gravitational collapse and their outward pressure caused by fusion.

"An interstellar cloud of gas will remain in hydrostatic equilibrium as long as the kinetic energy of the gas pressure is in balance with the potential energy of the internal gravitational force. Mathematically this is expressed using the virial theorem, which states that, to maintain equilibrium, the gravitational potential energy must equal twice the internal thermal energy."

On earth we exchange gravitational potential with electromagnetism but we still need to apply the same force to counter the nuclear forces and the pressure from the reaction once it starts.

All I want to know is if we have a proven net positive model for this reaction because so far I haven't been able to find one.

Because as far as I know the vital theroem stands so it doesn't matter if it's gravitational potential or any other force it still needs to be twice the thermal energy of the reaction.

But you can continue to downvote without actually addressing anything while ingoring everything we know about stellar fusion and the fact that is triggered and constantly maintained by gravitational collapse.

So no I don't ignore the role of gunpowder in a gun, you ignore the energy needed to create the gunpowder and cartridge in the first place.

That's the best I can do for you. Good luck!

<comment><USER41> "...the fact that is triggered and constantly maintained by gravitational collapse."

What you have written is not a fact. Forces only do work when they act through a distance. Gravitational potential energy only comes into play during the ignition of a star. After equilibrium is reached, to the extent that the star's diameter is "static" potential energy calculations no longer come into play. No "potential energy" is being "converted" into fusion energy. It's just not a thing.

"...stars are in constant balance between gravitational collapse and their outward pressure caused by fusion."

Because of this balance, no work is being done by gravity. That is, no energy is being released by the force of gravity moving a mass through a distance.

"All I want to know is if we have a proven net positive model for this reaction because so far I haven't been able to find one."

It's literally E = mc^2, but it's not "net positive." It's net zero. Matter is converted into energy. That's it.

"So no I don't ignore the role of gunpowder in a gun,..."

It's an analogy, and it's straightforward enough that the onus is on you to work out the pieces a little better than you have. HINT: The "energy needed to create the gunpowder..." _is_ the binding energy in the various nuclei.

<comment><USER40> >Because of this balance, no work is being done by gravity. That is, no energy is being released by the force of gravity moving a mass through a distance.

I didn't say it extracts energy from gravity, gravity is constant and it is what keeps the reaction going.

This balance is dynamic equilibrium, gravity continues to counter the gas and radiation pressure of the star's fusion reaction if you remove gravity from the equation fusion stops because the pressure would cause it to expand until the reaction stops.

If the reaction slows down then the collapse continues until fusion of heavier elements can happen, degenerate pressure can counter it or if neither of those happen you get a black hole.

>It's literally E = mc^2, but it's not "net positive." It's net zero. Matter is converted into energy. That's it.

I didn't ask you how much energy any given unit of mass has, I asked you for a net positive model for a fusion reaction.

We need to invest energy to make fusion happen then we need to invest more energy to keep the reaction going.

So again I understand where the "excess" energy comes form when two protons fuse into a neutron, however proton fusion isn't spontaneous and it requires you to expand energy to bring them close enough so they could fuse.

Now in say hydrogen plasma you need to overcome a lot of forces to do that, and more so when the reaction starts since the energy release wants to expand the plasma outwards what I want is to see a net positive model for this reaction.

So far I only hear crickets.

<comment><USER42> Might as well ask where the energy comes from the burn wood - each oxidation has an activation energy which must be paid before the heat from burning is released.

However, as long as the released energy is greater than the activation energy (the reaction is _net_ exothermic), some of the excess energy from each reaction (through heat) goes into powering future reactions. Which is why physicists talk about "ignition" \- there's a very strong analogy to igniting a fire with an initial spark of energy.

> So far I only hear crickets.

So far I see lots of people spending a lot of time explaining high school physics to you. Do at least try to be polite while this is going on.

<comment><USER40> Again you seem miss understand I'm not saying that the Sun extracts energy from gravitational potential but you cannot have stellar fusion without gravity it's not part of some initial condition that is then irrelevant it's a constant factor.

A good analogy would be walking it's very easy to do so on earth under constant gravity but it doesn't mean that you extract energy form gravitational potential which is when you stand on the surface of the earth is for all intents and purposes zero. However if you switch gravity off you wouldn't be able to walk.

If we want to simulate gravity in say space there will be an expense to that in terms of say rotating a drum which means we need to expand some energy to do so.

Now with fusion it's exactly the same we need to bring in the elements into a condition in which fusion can happen and we need to sustain the reaction by not allowing it to expand and cool.

This requires energy so instead of trying to explain me high school physics you might want to answer my original question do we have a model which allows for the extraction of energy form a fusion reaction that does not cool it down until it stops. And does this model including the confinement energy is energy positive or not.

I didn't asked where the energy released form the fusion comes form it's a stupid question all energy in the universe came form a single source that is the Big Bang there is no more or less of it in the universe today than there was 15 billion years ago.

<comment><USER41> Must. Not. Pick. At. Scab...

> Do we even had a model for Fussion that is energy poasitive? The only Fusion > reactors we know to work, work by converting gravitational potential energy > into light/heat through fusion this is how stars operate.

> All fusion reactions so far require an external input of energy not only to > start them but often to sustain them and even those which are self > sustaining for a short period of time grind to a halt once you try to > extract energy from the system.

That was your original question. It contains, as everyone is aware, your original statement that stars work by converting gravitational potential energy into light and/or heat through fusion. This claim is patently incorrect. It is false. It is misleading. It is a red herring, and a canard. You seem susceptible to it, for some reason. My only advice is to just set it down, over there, and don't play with it. The only winning move is not to play.

> And does this model including the confinement energy is energy positive or > not.

Sigh. There is no "confinement energy." This is a physics-sounding phrase that you seem to have coined. Set "confinement energy" down over there next to your original question. It's poison.

> This requires energy so instead of trying to explain me high school > physics...

Sigh, again. How much energy, quantified, in the mathematical language of physics and engineering? How much in comparison to the energy released quantified, in the mathematical language of physics and engineering? While these are technical questions, the answer, given by physicists and fusion researchers since well before ITER, is: "We get way more energy out. Full stop. Solved problem. Tokamaks work, with a lower size limited by magnet _technology_ , but not by first law _physics._ (Implicitly, people who question this at length are cranks.)"

You simply have no basis to go around demanding "a model." If it hit you in the face, you wouldn't recognize it. You, personally, can't quantify this "require[d] energy." You, personally, therefore have no reason, other than obstinance, to think you have some relation between the amount of energy released from a fusion reaction and the energy necessary to create the conditions for fusion. None. No other reason. Pure mulishness. The question is dumb. You are dumber for having asked it, and I am dumber for having read it. It is contagiously, toxically dumb. Please stop. There is no longer any nice way to say any of this to you.

And the one thing you need more of is high school physics, not less.

> ...do we have a model which allows for the extraction of energy form [sic] a > fusion reaction that does not cool it down until it stops[?]

Which fusion reaction? Where? So, you can set a solar panel up to do "extraction of energy" from the Sun. Experimentally, this has not shut down fusion in the Sun. So, yes? We have a model? Further, there's no way to _not_ "extract energy" from a fusion reaction, whether or not that "extraction" shuts it down. You, and I, generally exist at a lower temperature than fusion reactions. Ergo, we are extracting energy via radiation from every fusion reaction in the Universe, via heat transfer.

> If we want to simulate gravity in say space there will be an expense to that > in terms of say rotating a drum which means we need to expand some energy to > do so.

There's a legitimately beautiful and elegant answer to all this energy nonsense in that thought experiment. The answer leads to even more beautiful math about energy, momentum, ground states, and stability. It would be wasted, here.

I'm going to go have a shower, and maybe a drink. This has been an awful waste of time.

<comment><USER40> >That was your original question. It contains, as everyone is aware, your original statement that stars work by converting gravitational potential energy into light and/or heat through fusion. This claim is patently incorrect. It is false. It is misleading. It is a red herring, and a canard. You seem susceptible to it, for some reason. My only advice is to just set it down, over there, and don't play with it. The only winning move is not to play.

That was a gross simplification but technically correct, without the constant force of gravity which confines the gas there is no sustainable fusion reaction in stars.

On earth we replace gravity with magnetic confinement.

>Sigh. There is no "confinement energy." This is a physics-sounding phrase that you seem to have coined. Set "confinement energy" down over there next to your original question. It's poison.

If I phrase it as the energy required to maintain the magnetic confinement field in a fusion reactor in order to maintain the fusion reaction would it be better? Because now you are arguing semantics.

>Which fusion reaction? Where? So, you can set a solar panel up to do "extraction of energy" from the Sun. Experimentally, this has not shut down fusion in the Sun. So, yes? We have a model? Further, there's no way to not "extract energy" from a fusion reaction, whether or not that "extraction" shuts it down. You, and I, generally exist at a lower temperature than fusion reactions. Ergo, we are extracting energy via radiation from every fusion reaction in the Universe, via heat transfer.

Which is exactly my point the, what confines the nuclear reaction in the sun is a complex process which involves the inward pull of gravity this is what prevents the sun from blowing out until it cools down, you constantly keep ignoring this fact.

On earth we use magnetic fields those magnetic fields require power now I agree that in a reaction that is an equilibrium there is no work between the field and the plasma as both of them are opposing and equal but we still need to power that field if we power it by the excess heat from the fusion reaction the question is then is there any other excess heat that can be used to generate electricity in addition to what is required to power the magnetic field, and this is with a hypothetical 100% efficient model.</comment></comment></comment></comment></comment></comment></comment></comment></comment>


Crater believed to be formed by asteroid impact 66M years ago - <AUTHOR> http://www.bbc.com/travel/story/20181111-the-buried-secrets-of-the-deadliest-location-on-earth <comment><USER2> I liked looking at maps as a kid and I remember thinking it was funny how the lakes in our region kind of forms a circle.

I later learned that my home town is on the edge of Europe's largest impact crater. [https://en.m.wikipedia.org/wiki/Siljan_Ring](https://en.m.wikipedia.org/wiki/Siljan_Ring)

Most people seem to just... not care. :)

<comment><USER3> The Chesapeake bay is another one.

[https://en.m.wikipedia.org/wiki/Chesapeake_Bay_impact_crater](https://en.m.wikipedia.org/wiki/Chesapeake_Bay_impact_crater)

<comment><USER4> And linked from there, the Toms Canyon impact crater:[0]

> The crater dates to the late Eocene geological time period (about 35 million > years ago), and may have been formed by the same event as the larger > Chesapeake Bay impact crater (and possibly the Popigai crater in Siberia), > 320 kilometres (200 mi) to the southwest at the mouth of Chesapeake Bay, and > also dating to the late Eocene.

0) [https://en.m.wikipedia.org/wiki/Toms_Canyon_impact_crater](https://en.m.wikipedia.org/wiki/Toms_Canyon_impact_crater)

</comment></comment></comment><comment><USER5> Wow, So Dinosaurs began 230 million years ago and ended just 66 million. So they dominated for a significantly longer period than mammals have so far been dominant. And all the eras of the evolution has involved proportionately shorter time periods. Puts the various exponential processes of human development in some kind of perspective.

[https://upload.wikimedia.org/wikipedia/commons/7/77/Geologic...](https://upload.wikimedia.org/wikipedia/commons/7/77/Geologic_Clock_with_events_and_periods.svg)

<comment><USER6> Another kinda humbling illustration:

[https://upload.wikimedia.org/wikipedia/commons/7/79/Geologic...](https://upload.wikimedia.org/wikipedia/commons/7/79/Geological_time_spiral.png)

<comment><USER7> That's a really great illustration. Haven't seen it before. Thank you.

<comment><USER6> It's from here [https://en.wikipedia.org/wiki/Timeline_of_the_evolutionary_h...](https://en.wikipedia.org/wiki/Timeline_of_the_evolutionary_history_of_life)

which I found again via [https://en.wikipedia.org/wiki/List_of_timelines](https://en.wikipedia.org/wiki/List_of_timelines)

</comment></comment></comment></comment><comment><USER8> Probably an overall better read from three months ago:

"What Caused the Dinosaur Extinction?" [https://news.ycombinator.com/item?id=17738051](https://news.ycombinator.com/item?id=17738051)

</comment><comment><USER9> It's time to hunt space rocks.

[https://www.scribd.com/document/374712301/20180227-David- L-G...](https://www.scribd.com/document/374712301/20180227-David-L-Goldfein- Letter-SC)

</comment><comment><USER10> 66 mya. Never forget.</comment>


Why the Ukraine Crisis Is the West's Fault - <AUTHOR> http://www.foreignaffairs.com/articles/141769/john-j-mearsheimer/why-the-ukraine-crisis-is-the-wests-fault

<comment><USER2> _Foreign Affairs_ is an interesting periodical, but it might be worth bearing in mind that it's something of a talking shop between various International Relations academics and policy wonks. It's not uncommon to see people completely contradicting each other in successive issues or even the same one - which is not altogether unreasonable since International Relations is far from an exact science and seeing the different viewpoints is educational in itself. However individual articles can often come off as tendentious - sources are not required and arguments are often implicitly based on a worldview that is expected to be known to regular readers, whether or not it is agreed with. It's not a scholarly journal, despite the scholarly affiliations of many contributors.

This article strikes me as unusually shallow - while I agree with the basic premise that Vladimir Putin finds western encroachment on Russia's borders intolerable, the author argues as if he had little choice other than to annex Crimea or to announce a referendum and then move it to an earlier date, twice. One might ask why Putin didn't go through the motions of presenting his complaints to an international body like the UNSC or levying sanctions, even if only as a fig leaf for his eventual strategy.

Lastly, I think it's quite reasonable to have some articles about this complex topic here on HN, even quite partisan ones. It's not just that it's generally newsworthy, but the strong possibility of international conflict casts a long shadow over topics that hackers care about, from network security to surveillance to path-dependent technology trends. If, as seems likely, we are headed for a new and protracted cold war, or worse, some sort of hot one, there will be major feedback effects in the sphere of technology - which is, after all, where the West's major comparative advantage lies.

</comment><comment><USER3> One can judge if the author is honest or not for himself.

I would offer the readers the essay he penned 21 years ago in 1993: [http://johnmearsheimer.uchicago.edu/pdfs/A0020.pdf](http://johnmearsheimer.uchicago.edu/pdfs/A0020.pdf)

There he goes at length to explain why Russia is very likely to try and re- conquer Ukraine. Interesting how he comes up with a whole different set of reasons for this eventuality today.

<comment><USER4> Heh, this completely contradicts this recent piece. Thanks.

</comment></comment><comment><USER5> Can we try and leave politics to other sites ? There are many great technology stories under /new that don't make it to the front page because of flamebait like this.

<comment><USER6> Guidelines state that we shouldn't complain about the appropriateness of submissions. Just flag them and move on.

Don't forget to flag clutter like this to keep HN on-track.

</comment></comment><comment><USER4> This strikes me as blatant Putin apologism. Would Mearsheimer rather the US and NATO turn away, let Ukraine and its people slip behind Putin's Teflon Curtain, and encourage him to continue his empire seeking in other former Soviet dominions, like Finland or Hungary?

Blaming the US and Europe for "provoking" Russia's aggressive foreign policy is no better than blaming the US for "provoking" Bin Laden. It reeks of the worst kind of moral relativism that puts Putin's unmasked and shameless colonial ambitions on par with America's interests in protecting free trade and human rights abroad.

<comment><USER7> I don't see the article _apologizing_ for Putin, it's simply explaining where he's coming from and _why_ he views the West's overtures to Ukraine as such a threat to his own interests.

Like the article says, "Imagine the American outrage if China built an impressive military alliance and tried to include Canada and Mexico." To stretch the point, what if Canada held a referendum where its people voted to resign from NAFTA, join a Chinese free-trade block and offered land for Chinese bases? Do you think the US would stand by idly? Remember, we came awfully close to World War 3 when the Soviets put a few silly missiles in Cuba.

<comment><USER8> Those missiles were hardly 'silly'.

The entire thing may be a silly example of human squabble, but it was a squabble where the power to end it all, was held in the hands of a few men, not leaders of nations, but the military leaders in charge of the troops who's jobs were to handle, use and guard these weapons that could have wrought untold devastation...

Its worth remembering that 1 single man prevented the first hostile use of a nuclear weapon since WW2. Its quite likely most of us owe our lives to [http://en.wikipedia.org/wiki/Vasili_Arkhipov](http://en.wikipedia.org/wiki/Vasili_Arkhipov)

<comment><USER7> The US had around 5000 missiles pointed at the Soviet Union; having 40 missiles pointing back in and of itself did _not_ pose an existential threat to the US. But Kennedy & co _chose_ to play a very public game of chicken over them, and fortunately for the world, Khrushchev blinked.

</comment></comment></comment></comment><comment><USER9> blah blah blah the US Is evil blah blah. Same old trope.

</comment><comment><USER10> I like the part where he's ignoring the wishes of the countries joining/trying to join NATO/EU. The fact that Russia does not want them to join is not an excuse for Russia getting buttmad when they do.

</comment><comment><USER11> People love writing articles about how everything that happens in other countries is inevitably the west's fault. Just go up the causal chain far enough 'til you find a westerner doing something and _bam_ , it's the west's fault. Non-western people in this worldview have no agency, they simply react to the things the west does, so it's no surprise that everything is always the west's fault.

Inevitably "the West's fault" in these sorts of articles should always be read as "the fault of Westerners with whom the author disagrees politically". When people blame "the west" it's always those _other_ westerners buggering the west up for everybody, not those westerners of whom the author is one, who have the _correct, enlightened_ political opinions.

</comment><comment><USER12> dear colleagues, just keep in mind that there are hundreds of PR agencies in Russia (and hired agencies around the word) hardly working on formation of public opinion today. This is a good example of it. The subject is a common "mem" that seeded by the campaign and used in official western oriented Russian public rhetoric.

IMHO the right approach for that -- ignoring and downvoting as non relevant.

Yes I'm Russian and I'm watching the situation [or situation watching me :) not sure]. And I'd like to keep this site political free as well.</comment>


Amazon.com stays up while AWS goes down - dev-joebar Curious exactly what scaling mechanisms were in place that kept amazon.com up while much of AWS was down. <comment><AUTHOR> It was Amazon S3 US Standard (us-east-1) region that went down. This caused quite a lot of pain throughout the internet because people were using S3 as storage for their application and/or their static assets.

Other AWS services were affected, but this was mostly limited to creating, updating, and deleting AWS resources (EC2 instances, RDS instances, CodeDeploy deployments, etc.). There were no issues I'm aware of for already-provisioned resources. There was also some issues with the AWS console.

So Amazon.com was able to weather the storm because it did not have a hard dependency on S3 US Standard. They may not use S3 behind the scenes, they may be using another region, or they have cross-region replication to serve files from redundant regions.

EDIT: Another option, they may have put S3 behind a CDN and were able to lean on the CDN's cache while S3 was down.</comment>


The Myth of the Millennial as Cultural Rebel - <AUTHOR> https://newrepublic.com/article/136415/myth-millennial-cultural-rebel <comment><USER2> Millennials are not rebels. They are tools of the political establishment of the left. The rebels are the Conservatives, Republicans, and Libertarians that go against the current narratives being shoved down our throats by the mainstream media.

<comment><USER3> Careful, you might need to preface that comment with a trigger warning otherwise you could inadvertently cause discomfort to someone lol....</comment></comment>


BookLiberator Lets You Make E-Books Cheaply - <AUTHOR> http://blogs.forbes.com/firewall/2010/07/19/bookliberator-lets-you-make-e-books-cheaply-and-is-definitely-not-intended-for-copyright-violation/?boxes=Homepagechannels

<comment><USER2> It looks like they did a nice job with the image capturing infrastructure, but the side note about using OCR to process the text is misleading.

Most OCR packages, including the ones cited, do a bad job of text conversion, even with high-quality images.

There's usually a significant amount of proofreading and retyping that needs to be done.

</comment><comment><USER3> Now they need some kind of robot gizmo to do the page turning....

<comment><USER4> I'd rather see a gizmo to help automate the picture taking first. My friend pointed out that they're just clicking the two camera shutters simultaneously.</comment></comment>


Whilst you were sleeping: Congress approves spooks retaining data forever - <AUTHOR> http://meanderful.blogspot.com/2014/12/sec-309-procedures-for-retention-of.html

<comment><USER2> I think this is a great idea.

We as citizens of the world should also be allowed on the same terms to keep government communications on record as well.

As soon as government emails (eg like sony emails this week) start appearing in public and torrented in a "never to be private again" format then I think politicians may choose at such time to vote that perhaps keeping emails/phone calls/meta data on record indefinitely....isn't a good idea.

<comment><AUTHOR> Maybe it has already happened but somewhat privately?

It should be easy for the spooks to apply pressure, perhaps indirectly via lobbyists, based on known personal or familial communications to anyone in Congress or the Senate.

Thus Sec 309 gets passed.

This seems a far fetched conspiracy fantasy until you realise it has already happened many times before: Hoover, Nixon, etc

I'd imagine a patriotic spook could be confused that they are just doing the right thing by their country.

Apathy wins at the end of the day. People get periodically interested but then move on with their busy lives. We've kind of got disinterested and moved on from Snowden. Plenty of other things in the world to worry about. The security apparatus wins by being relentless.

Sec 309 is a good example of such a lack of vigilance from a disinterested community.</comment></comment>


Ask HN: What is the best way to learn a language? - <AUTHOR>

A spoken language, that is. I know immersion is the best way overall, but what's the next best way if that's not an option? <comment><USER2> I found that using the foreign language regularly was the only way it "stuck". So as you say "immersion".

I've married a Finnish woman, and we go through phases where we speak only Finnish at different times. We also agreed she'd never say "no" if I spoke Finnish, so I started with all the obvious things to say "One black coffee, please", etc.

</comment><comment><USER3> I recommend against most tv and movies because the level is too advanced. You want material that is slightly beyond your level. This is why I recommend reading books. There are graded reading books. Eventually you also need to find a native speaker to practice with. You can do a language exchange or offer something else in return.

</comment><comment><USER4> The best way if you have the opportunity is to travel to a country where you want to learn the language from. This way gives you lots of advantages because you will feel forced to speak to be able to move around. Practice makes the difference!

</comment><comment><USER5> Assimil is superb.

I have used their system for multiple languages. Far better than Pimsleur, easier than Linguaphone and pretty cheap. Small bite sized lessons entirely in the target language, with parallel text. Quirky humour.

</comment><comment><USER6> I once heard about a system based around a game: Where Are Your Keys? ([http://www.whereareyourkeys.org/](http://www.whereareyourkeys.org/))

</comment><comment><USER7> You should give Duolingo a try. It can take you to the A2/B1 CEFR level. After that, read native language books and watch foreign Youtube videos.

</comment><comment><USER8> Use a proven program like Rosetta Stone.

Then while you are learning vocab, grammar, etc., watch movies/videos in that language with subtitles.

</comment><comment><USER9> Livemocha is pretty cool. They offer lessons to help you exercise the four major skills -- reading, writing, listening, and speaking.

</comment><comment><USER10> Watching movies/TV in that language with subtitles (also in the language you're trying to learn) really helps

</comment><comment><USER11> Have someone Spanish read you a story every night before bed.

</comment><comment><USER12> Get a bilingual significant other. :P

<comment><USER13> My French teacher in the eighties told us the best way to learn French is in bed with a native speaker.</comment></comment>


Ask YC: Building a music platform for public domain recordings. - <AUTHOR>

Hi all.
I got this killer idea, I just can't code it, so if you can code, please do drop me an email.
The idea is simple - on Rdio and Spotify there's thousands of albums by all the blues, folk and country legends of 1930's, 1940's etc. The guys that invented rock and roll!
If you look for any old time blues great on these applications, for example John Lee Hooker, Robert Johnson etc, you'll see literally hundreds of albums show up. The music is public domain, so I think anyone can profit from selling these; I don't think the families of these guys see a cent. And if they did, geting that cent would take a fair few Spotify plays anyhows ;)
There's over 400 John Lee hooker albums available, 146 Robert Johnson albums and 1007 Billie Holiday albums. Not even Frank Zappa has cut that many records.
My idea is to build a music streaming platform that serves up exclusively public domain music to fans of older music, like blues, folk, jazz, country etc. and it exists solely to pull in money from subscribers and divide it in a better way then rdio and others do. Most importantly, the money would go to surviving families of these artists and operate as a non profit entity.
I have an idea of how a payout model could work for this more effectively then current streaming models used on rdio etc.
Please do get in touch if you'd like to help put this together. <comment><USER2> I actually like this idea. But the non-profit angle loses me entirely. Good luck though.

There are also plenty of public domain films out there.</comment>


Startup Math: 1 + 1 = 1/2 - <AUTHOR> http://foundread.com/2007/12/19/startup-math-1-1-12/ <comment><USER2>
     // Sorry, couldn't resist...

     #include <iostream>
     using namespace std;

     class Integer {
       public:
         int value;
         Integer(int rhs) {
           value = rhs;
         }
         int operator +(Integer rhs) {
           return value + rhs.value;
         }
         int operator /(Integer rhs) {
           return value * rhs.value;
         }
     };

     int main(void) {
       Integer one = 1, two = 2;
       cout << ((one+one) == (one/two)) << endl;
       return 0;
     }

     // Output:
     // 1

</comment><comment><USER3> This reminds me much of Fred Brooks's The Mythical Man Month. Good to see that things haven't changed too much over the years...

</comment><comment><USER4> Smart startup math. 1+1=2 . It is crucial when you first launch your company that you hire people who will train you rather than you training them</comment>


Ask HN: Become a freelancer/contractor or keep working on product in free time? - <AUTHOR>

Hi all,
After reading through the recent thread on freelancer rates (http://news.ycombinator.com/item?id=3420203) I'm once again considering making a go of freelancing, but am worried that it will take my focus away from the product I'm building in my free time. Here's my situation:
I'm 26 and I have an awesome day job. We do rails consulting and I'm surrounded by incredibly bright people in very good working conditions. There's really
nothing to complain about. The pay is good, but not enough for me to save for anything substantial before I turn 30 (or fulfill my goal of moving back to Japan with my wife before I turn 30 either).
To achieve my goals, last May I started work in my free time on a side project ((blog.)japanalicious.com). It's subscription-based app that helps you learn to read Japanese. I'm not convinced that it will be the product that will help me achieve my income goals but it's serving to teach me a hell of a lot about building/desigining a product and marketing. Because it's in my free time, it's like a startup in ultra-slow motion; sometimes it feels like I'm making hardly any progress and that perceived momentum is important for morale.
At the same time, freelancing/contracting/consulting is something that I think I could be good at. I'm not afraid of networking with clients, figuring out how to provide value and then charging accordingly for delivering it. I may be overconfident with this, but I'm pretty sure that given a couple of years I could build up enough of a client base and savings to move back to Japan and do remote work exclusively.
I read a lot of comments from people on HN who have apparently decades more experience and I keep seeing the theme of 'transitioning to selling my own products'. If the end goal is to make your own products, then perhaps I should just keep working on the products and skip the contracting/consulting phase entirely? This obviously assumes that I am extremely lucky and japanalicious (or one of my next few ideas) is successful in making me in the region of 10,000 USD per month.
So for those experienced technical consultants/freelancers, in my situation what would you do? If you could go back in time to your 26-year-old self, would you just focus on building products or would you still go the route of freelancing first?
Thanks in advance for all feedback. <comment><USER2> I work as a consultant and a CTO for two people startup building a product(asp.net mvc,sql server).Here is what i'm doing : Week days:work for two hours /day on the product no matter what(early on the day or after cosulting job hours). Saturday: 8 hours on the product.

the difference beteen me and you is that i have a cofounder taking care of the marketing ,business side.May be you need your wife help on that or get a cofounder and give hime some equity.</comment>


Hackers broke into Sony Pictures using an unpatched security hole - <AUTHOR> http://www.engadget.com/2015/01/20/sony-pictures-fell-to-zero-day-flaw/

<comment><AUTHOR> Unlikely they purchased an "expensive" 0day. It is more likely they would develop their own or purchase locally as they would have access to cheaper markets than the west. See [http://www.forbes.com/sites/andygreenberg/2012/03/23/shoppin...](http://www.forbes.com/sites/andygreenberg/2012/03/23/shopping- for-zero-days-an-price-list-for-hackers-secret-software-exploits/)</comment>


Brazilian Kids Learn English by Video Chatting With Elderly Americans - <AUTHOR> http://www.adweek.com/adfreak/perfect-match-brazilian-kids-learn-english-video-chatting-lonely-elderly-americans-157523 <comment><USER2> Okay totally unrelated to the open-source stuff BUT.

That brought tears to my eyes. It was such a joy to see the expressions on the faces of both the Brazilian and the hip elderly person on the other side.

Bookmarked under "Things that will make you smile"

<comment><USER3> Someone could knock up an app using web RTC. A perfect opportunity for some hacker out there. Some hacker that reads HN.

The trick is avoiding it becoming the next chat roulette :/

<comment><USER4> Honestly, I don't think building tech here is the hard part. It is finding the right audience (Elderly people & Kids who want to learn English)

</comment></comment></comment><comment><USER5> As someone in another comment already pointed out, YC previously funded a company called "Verbling" ([https://www.verbling.com](https://www.verbling.com)) in their Summer 2011 batch whose original selling point was to provide an instant, one-click 1:1 pairing of language learners with native speakers via videochat.

I'm not sure how well that concept caught on though... And if you check out their website, they seem to have pivoted to a more traditional "livestreamed language classes" model.

</comment><comment><USER6> There's a well-known problem in Brazil with English acquisition. This is due to the actual need for it (or rather lack of), the false "become fluent" promises by the language schools (like CNA, Fisk, Skill, Wizard, etc.), the cost of taking a course for the student, the methodology of said schools, and the lack of daily contact with people from other cultures in Brazil (tied to my first point).

As for the teacher, working in a school like the ones mentioned, you get low pay (not too many years ago it was about $7/hr) and no leeway in terms of hours and method. Being a private, one-on-one teacher, though, one can command higher prices ($30-50/hr in the largest cities) and have more control over everything (just not always whether the students keep their appointments).

Nonetheless, cool video in the link.

</comment><comment><USER7> The title change of this submission means that many early comments now make no sense. Original title was something like "Ask HN: Is anything like this available as open source"

<comment><USER8> Thanks, wouldn't have caught it otherwise.

To whoever changed it: why didn't you just make a second thread?

</comment></comment><comment><USER9> News like this just make my day better. It's much more rewarding to read about technology being used for tangible benefit to the people involved instead of for getting rich.

<comment><USER10> This isn't news, it's an ad for a language school. It's being displayed on a website devoted to showcasing advertising and all of the advertising production details are listed below the video.

So it's not underhand at all but it's also not an objective display of this program. It's an ad, designed to give you warm fuzzies and, if you're in the target demographic, consider signing up as a fee-paying student at the school featured.

As others have said in this thread, similar projects have been tried and have not really gained traction. Not saying that some such project may not eventually succeed but given that there is no objective data being given on the success of this program in the video, one should probably be somewhat sceptical that this is anything more than a marketing tool.

</comment></comment><comment><USER11> (EDIT: original title asked if there was something like this as open source.)

Nice. It's basicly a well managed chatroulette clone.

(EDIT: not quite, it also needs to record.)

Or try "web video conference server open source"

[https://code.google.com/p/openmeetings/](https://code.google.com/p/openmeetings/)

[http://bigbluebutton.org](http://bigbluebutton.org) (can record too)

Greggman mentioned WEBrtc, that would probably be cleaner/simpler, but it's p2p right, so the server can't record? perhaps try [https://www.webrtc- experiment.com/RecordRTC/](https://www.webrtc-experiment.com/RecordRTC/) ?

<comment><USER12> In addition, the video session gets captured and evaluated afterwards.

<comment><USER11> Good point, added bigbluebutton.org

</comment></comment></comment><comment><USER13> I vote this idea of the month and feel it should be greatly expanded upon.

If there were an organized platform where people could chat with speakers from all over the world in order to learn their language and culture it would be a fantastic thing.

</comment><comment><USER14> [http://www.ted.com/participate/ted-prize/prize-winning- wishe...](http://www.ted.com/participate/ted-prize/prize-winning- wishes/school-in-the-cloud-sugata-mitra)

Someone else came up with the idea. "School in the cloud"

<comment><USER15> Related, but I see them as being really different application and goals. "School in the cloud" is aimed at poor and remote places where kids can benefit from real time learning interactions (while the "teachers" do not seem to get much materialistic benefits).

This on the other hand, is geared toward helping anyone who wants to learn a new foreign language and connecting them to ones who do speak that language and they benefit from having someone who is willing to talk to them. So the goals, and users/usage are very different, aside from one is aim towards one to many, and the other more one on one.

</comment></comment><comment><USER16> What part do you want to be open source? The software that runs the matchup? I think most browsers support WebRTC so that problem is mostly solved. People can use Facetime or Google+ Hangouts for free. So all that's needed is a way to meet people. I suppose pretty much any live chat for pr0n software would do the job as well.

I know there are other companies doing this. My friend is learning English through [http://langrich.com](http://langrich.com) which connects students of any age in Japan to people in cheap labor countries that speak English like the Philipeans for example.

<comment><AUTHOR> No. Basically I want a site / service that can connects specifically elderly people with people trying to learn English. Actually don't have to be open source, neither free. I expressed bad myself, sorry.

<comment><USER11> Oh, then it's much more of a management problem.

There's plenty of technical solutions already, you may just want a little glue with good ux design, fast internet, and good support staff, especially for the elderly.

In this example, someone setup a relationship between a retirement home and an English learning school. Outside of that, it would probably turn into a chatroulete.

<comment><AUTHOR> Exactly! :)

</comment></comment></comment></comment><comment> amaral-herberth I'm a native Brazilian and I practice my english by writing texts that aren't meant to be published and talking to myself when I'm walking home. This could be an excellent alternative to improve my english. I'll certainly get in touch with CNA people in my hometown :-)

</comment><comment><USER17> this article is very sad. it's about elderly people who have noone to talk to, but also Brazil is poor country with a growing demand for having users speak English.

so this "chat-roulette clone" has a lot if impact.

</comment><comment><USER18> Check out Lynckia a WebRTC framework( [https://github.com/ging/licode](https://github.com/ging/licode) ) it includes a MCU that allows recording and more...

</comment><comment><USER19> Watching the video is the closest I've ever come to crying from something I saw on the internet. Moving stuff.

</comment><comment><USER20> That does what exactly? Video chatting?

<comment><USER21> no, pair you with someone to chat. Elderly people tend to be lonely, so they are a nice target. And students learning that language. This is genius.

<comment><USER22> Why do you think that is a technical problem?

<comment><USER21> I didn't mean it that way, I meant it as a response to what he's asking about "That does what exactly?"

</comment></comment></comment></comment><comment><USER23> Is the name of the app pervert by any chance?</comment>