skysight-inc/HackerNews huggingface dataset:
"Could you explain to me how the hell fuel in Reactor 4 storage pond at Fukushima 1 went critical?"

I can. The term 'critical' is used to describe the point at which fission events are being caused by the neutrons emitted by other fission events. Also called a 'chain reaction.'

Reactor fuel emits neutrons (actually even 'depleted' fuel emits neutrons see half life). Unused (and spent) fuel is stored in storage ponds filled with water because water is an excellent neutron moderator. Thus any neutrons that are emitted by the natural decay, or by internal fission events of the material are absorbed in the water and converted into a (relatively) small amount of heat.

Air is a poor damper of neutrons, and in fact the chance of a neutron hitting an atom in a gas is greatly reduced.

When the water in a fuel storage pond is removed, the naturally occurring neutrons can reach other fuel that is stored in that pond. If they are sufficiently energetic they can cause atoms in the fuel they hit to fission. If they do cause fission then heat is generated and another neutron (note: it maybe 2 I admit I've forgotten the exact reaction with U235) is emitted which might cause another fission event.

Criticality is controlled by moderating the probability that a neutron will create a fission reaction. If you want to store uranium you can do this by either spreading it far apart or by placing it in an environment that moderates neutron flux. Since the latter is as 'simple' as putting it in water, that is the usual option.

The caveat is that your spent fuel will continue to generate heat, if you don't remove that heat eventually the water will boil. If the water boils sufficiently to allow fuel to be exposed to air, the result can be that the fuel passes its criticality threshold. If you can't keep water cool then you can replace it with something that moderates and doesn't boil.
Haven't people been visiting Pripyat and finding it to be habitable to a lot of species of life? It won't be a wasteland for 10,000 years. And Chernobyl was so pooring designed it is not analagous to everything else (as was the damn that killed 50,000 people).
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People already hate coal because of the pollution and the health problem miners can develop. Public sentiment doesn't have that much further to drop.
> Some would argue that 50,000 have already died from a nuclear incident.

Yes, some WOULD argue, but they would do so without the benefit of factual knowledge.

http://en.wikipedia.org/wiki/Nuclear_and_radiation_accidents...
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30,000 deaths a year?

What you mean to say 30,000 people a year die some amount of time earlier than if we had no coal burning at all. That doesn't mean it killed 30,000 people as they were walking home from the grocery store at age 25 and a wall of coal came crushing down the street because the coal dam broke. So it's not really comparing Apples to Apples at all.
I'd like to see the cost in $ per TWh as another column.
Oskar van Deventer's Rubik's-style puzzles
I wonder if it's supposed to make it clear that it's a dev (i.e. unpolished) build rather than the stable one.
I agree, this will be big for dropbox and they deserve the acknowledgement. However I think a lot of us here feel the same way, which you can deem as somewhat childish. Its the sentiment "we were here first".
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Hopefully the actual point wasn't lost on you: even sitting around not being used, nuclear fuel needs a great deal of expert care and attention.
I have difficulty imagining a person with the mindset "Violence is not the answer, excepting of course that I will fight to the death to defend a man's freedom to throw his trash in another person's car"
Does Moore's law apply to solar cells?
Didn't even mention CSS?
> Benioff predicts sales could hit $100 million this year. (The company declined to comment.)

Unfortunately, a prediction; and also by someone not privy to actual figures...

> Dropbox reportedly experiences well over 10 times year-over-year growth...

Sounds pretty good!

> ...and positive cash flow.

The mildest expression of profitability possible. Though I'm pretty sure they're doing way better than >0.

From scanning many acquisitions, my feeling is of the order of $200 million. Though I'm basing that mainly on business acquisition (e.g. by Oracle), so I might be very off for consumer acquisitions (considering youtube, facebook, twitter etc).
Captain McCains were/are Captain Crunch.
Bootstrapper entrepreneurs aren't often blessed with fat marketing budgets
SXSW: 'Something Ventured' Directors Talk Venture Capital Early Days
I suppose it's issues like this that make tablet PC creators choose a single-tasking (or rather, single-app-controls-the-screen) model?
Around this area: 239 8th Street, San Francisco, California, United States.

I have since learned that it is the norm and possibly fact for locals to realize this area is a bit more sketchy. But like I said, I'm not from Cali!
Yes- we were accepted in the Winter 2010 batch a little over a year ago. We weren't planning on applying at first, but did so on a lark at the last minute. It has, without a doubt, been the best decision we ever made for our business.
Forbes wrote a story on Dropbox last summer. Interesting to compare the two takes.

http://www.forbes.com/forbes/2010/0628/technology-file-shari...
People keep dismissing renewables. Well, they won't get anywhere if we don't invest in them, and that investment has to come from a decrease in spending on other sources. Like nuclear.
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Exactly. This whole chart is irrelevant because what we care about is the expected impact on our health in the future, not the impact on our health in the past.

This is why all those people who say we shouldn't decide what to do about building more nuclear power plants until the events in Japan have stabilized are dumb, because the outcome in Japan has zero impact on expected future outcomes.
My cofounder and I applied and were accepted with exactly zero connections to the Valley and effectively no YC connections (one friend of a friend was a YC founder, but we didn't end up getting in touch until after we'd gotten in). I doubt that's the norm, but we're proof that it's possible.

If we'd been smarter/less naive, we'd have cold-emailed one of the dozens of YC founders who publicly state they'll chat with people who are applying.
My mom came to me earlier asking me to help her install Dropbox. She's about as informed about computer stuff as i am about fashion. That's a good sign for Dropbox :-)
you just need to not get involved they will figure it out eventually. I am not sure at which point my son started to use the home button properly but it definitely happened without our intervention in the last 6 months or so (he also started playing around with it at 2). I am worried that the ipad is bad for things like learning delayed gratification and attention span, as when he is watching dora he will let it finish but otherwise the smallest frustration leads to hitting home and starting over.
IIRC, the reason plants linger so long after decommission is because (at least in the US) it's illegal to reprocess the waste, which really isn't waste and has lots of useful stuff in it.
Obviously you guys were a good fit for YC, both in terms of culture and ability.

What I wonder is, what percentage of applications are completely unsuitable for YC?

What percentage of applications can basically be ruled out as competition?
Awesome. My daughter is 7 and also loves math - I can't wait to get her coding!
> We recently announced that we had also launched the game on the Mac App Store

We did too :) Write once, run on multiple platforms! Awesome.
And if Chernobyl had been a dam burst, it is likely a great many more people would have died, and much more quickly.

EDIT: Despite the downvotes, this is not a trivial point, and is precisely why the OP is getting so much attention.
Microsoft, RIM expected to unveil new, free hosted Blackberry service
7 billion tons per year of coal is mined. 60,000 tons of Uranium is mined (a few tens of millions of tons of ore).
I'm missing (or the article is missing) the timeline that the calculations are based on. Is that yearly? last year? last 5 years?

We have to take a significant time scale on any of these for it to be considered reliable. Though there may have been 0 deaths from nuclear last year, over a 10 year span, would that number be the same?

I believe nuclear can be safer over the long-run, but I'd like to see some more depth in these stats.
Your welcome. Will do.
This is the most common reasoning for people who fear nuclear power. They reason that they can't see where the danger (radiation) is so they can't know if they are in danger or not, whereas with an oil spill, a gas pipeline explosion, or an oil refinery event, they have visible boundaries to 'this area is bad' vs 'this area is probably still safe' (note its not of course, you can have odorless and invisible threats like CO but many of the failure modes are visible in a spectrum our unaided senses can detect)

I don't have a good answer for re-assuring these folks. (carrying a counter with them seems to be a non-starter, but perhaps a cell phone app would be ok)
Fixed. The signup process for the email is now a dismissable 1-field box on the homepage. Thanks for the suggestion.
Is this equivalent?

for(a=1; a < (NbrOfAs*NbrOfAAs*NbrOfAAAs*NbrOfAAAAs*NbrOfAAAAAs); a++){
ExamineAAAAA()
}

Or do I need a nap?
New connection bar in Gmail for iPhone
Old versus new: why work with a start-up?
Interesting take on the benefit of Airbnb as an adventure traveller, so you would like them to suggest some destinations or let you provide additional information?

I love Dropbox too!
The single most important point, to actually code, is right at the bottom.

In fact, I'd remove all other points: the only way to become a good coder is to code, plain and simple.
If he really works for free and just got 200 pts on HN, then his time costs too much of mine.
>If nuclear didn't linger such a long time after the plants are decommissioned

It is at least theoretically possible to eliminate nuclear waste. I'm confident that with research into yet undiscovered reactor types we can reprocess and reuse the long-lived radioactive byproducts into byproducts with lifespans measured in centuries rather than millions of years.
I tried to ask them but there's always so many blocks. I have to explain so much just to get them to do something. It's like an inefficient bureaucracy with lots of red tape. I can't really contact any of my relatives because they are in another country. I think they're hostile to the idea because my grades have been low (although they are improving) ever since we moved to a new state over winter. They are also worried about my vision...

Understood. Another option would be to setup some sort of online "donation box" thing (like some open source projects do) and just put the word out "help a high-school kid get a VPS / domain / books" and see if you can raise a few dollars. I know I'd chip in a few bucks to such a cause myself.

And, as others have mentioned, a summer job is an option. But it doesn't necessarily have to be mowing lawns or whatever. You already have some coding skills, and apparently have a computer and a 'net connection... maybe you can find a scenario where somebody will pay you to build them a basic app or website or whatever. Unfortunately you probably can't use ODesk or anything due to your age, but you might be able to set up an "under the table" deal and get paid via Paypal or something. Hmm... not sure if you can have a PayPal account if you're < 18, but maybe your parents would be willing to help make that happen, if there's an age limit?
He also says

"The condenser mic in my iPad (again, first generation) is acceptable, but leaves something to be desired, particularly on the high end"

If the mic on the iPad is acceptable to the reviewer. it goes pretty far to show how he reviewing the product (not as a DAW. but as a really awesome toy).

TouchOSC + your choice of DAW is going to be pretty common for a while I think.
I see what you're saying and it's an important point to remember, but rather than one way be wrong, I think it depends on the question. "I need to get from New York to L.A. Which is the safest way to do it?" is about comparing two travel methods (or three if you want to think about trains) for the same distance. The time based answer is suited to your vacation quandary where you have a week off and you wonder whether to drive somewhere or fly someplace else.
typical pay day loan shark would charge "outrageous" 300%-1000%, yet they would loan pretty much to anybody, including very high-risk borrowers.

Wonga wants 4000% for loans to the top 30% applicants. Nice try.
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> They can't give Linux security updates

Google Chrome on Linux has already received updates for the latest flash vulnerability....
Dropbox it's certainly one of the most helpful startups for the average guy.

I put into use at the last company I was working for (a non-tech company) and everyone got immediately hooked on Dropbox. It made their file-sharing much easier.

So I honestly understand this article, even though for us it's been around for so long.
I can't help you with that first one, but

perl -e 'while(1){print 9;}'

A bit of a cheap shot as that is basically printing infinity without actually calling it infinity, but I'm going to float this by on a claim that your boss won't know the difference. "It's just not done yet, sir! Keep waiting. It's printing a really big number."
Ask HN: Trust and remote work
We've recently started building a team of remote developers for our startup; but I'm having some trust issues and would like to hear how people have resolved similar situations.

We've been hiring to work on a new side project which I feel is going too slowly. The team I have working on the project are very good and I'm quite impressed with whats coming out but its just taking a little long. I could easily replicate the amount of work they are getting done in just a couple hours per day.

To be honest if they're just a little slower I'm alright with that -- my main concern is simply that they're not working as hard as they could be. I know it could be a motivation problem but I don't really have any clue how to solve that remotely? Maybe I just need to challenge them on their speed, but I feel that could end badly.
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No, the point isn't lost. And reactor ponds are not the 'best' way to store old fuel, they never have been. They were originally only needed during the refueling cycle and the spent fuel was to be removed off site.

Spent fuel you're not ever going to use again can be melted into boro-silicate glass and not only will it never go critical again, it can't leach into the environment, etc etc. If you've read the Yucca mountain documents I believe they make a pretty good case for 10K yr life expectancy for keeping the fuel out of circulation.
This company is evil, but something I've always wanted to do is start a deposit bank where all the account decisions are made by algorithms. When a customer emails with a problem, an algorithm analayzes the message and makes the appropriate decision (refunding fees, chargeback, etc.) The amount of money saved by not having any customer service people would allow the outcomes to be more customer-favorable (sure, we'll refund that) without affecting profits.

(The prerequisite I'd need to get started with this is an archive of emails-to-the-bank with their outcome.)
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Have you checked your credit record? - it doesn't seem to make sense to pressure someone who doesn't have a loan, it seems more likely that someones commited identity fraud and used your details to get a loan.
Looking for advice on software escrow services vendors
Does anyone know of a good review of source code escrow services in terms of features, costs, key terms of agreements, etc.? I'm looking at a few including:

(a) Iron Mountain. http://www.ironmountain.com/Escrow
(b) InnovaSafe. http://www.innovasafe.com/SourceCodeEscrow
(c) Escrow Associates. http://www.escrowassociates.com/Software

My specific use case is to periodically provide source code uploads during the 9-12 month development process of a custom application for a single client.
I'm a woman, and I want to be a founder.  Please don't assume you know why.
they prey on the people like a single mother of five trying to make to the payday and who isn't in the state of mind to do the math or other people in the similar "impaired" [for the lack of a better word as i don't mean narrow drug/alcohol impairness] state of mind.
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An example: A bus driver job is far more secure than a pilot job.

When comparing activities we should relate spent livetime not distances to risk.
Well, Congress is fed lie after lie every day anyway, so what's one more? And it's not like we really have "government of the people, by the people and for the people" anymore anyway (if we ever did at all.)
Time Machine or Future? Pick your choice.
The premise of the existence of Time machine is that, there exists a future where a time machine has been invented or in the past, time machine was invented but never revealed or went unnoticed.

But, lets consider the Future:
If indeed there is a future where time machine has already been invented, then there would already have been visitors from the future.

From this reasoning, two conclusions can be made.
1.) Time Machine is impossible to make.
2.) Or, there is no future. Just Past and Present

So either Time machine and time travel is an impossibility or the concept of Future does not exist.

--OR--

Time machine has already been invented, visitors have already travelled, but they are doing an incredible job of concealing it for reasons their own.

What do you think?
No e-books without authors, Margaret Atwood reminds us
Major report debunks alleged link between piracy and terrorism
There is life, to be sure, but it's not 100% healthy. The area is still too radioactive for humans to dwell in without shortening their lives and it's not going away any time soon.

We'll see in the next 50 years how it goes having nuclear power plants operating in Africa, Indonesia, the Middle East, etc. New reactors are better designed, but I still don't trust 80% of the governments or corporations in the world to responsibly operate anything nuclear.
basically you want to start a typical bad bank where one would spend half-a-day trying to get through the menus to solve a simple account mistake/issue
As stated after that sentence, I'd definitely recommend a USB mic to anybody recording at home. When you're on the go and need a built-in mic, the bar is pretty low.
The common conception is that nuclear waste stays for a long time and thus 50K immediate deaths would be translated into 500K+ deaths later.

Also, 50K deaths all at once for any given energy source would also freak people out. I think that most people would unconsciously consider a coal mine disaster or a broken dam as "death from occupation" or "death from random accident" rather than "death from energy source". The unknown-ness of nuclear power tends to make people credit it directly with the deaths around it.

And yes, people have a psychological fear of the unknown. Evolutionarily, this is rather clearly justified.

If the education level in all industrial countries was raised to the point that the average person felt they had a strong understanding of nuclear power, the fear of it quite possibly would subside. But the cost of this might be considerably greater than the cost of converting to an "alternative" energy source.
Should I join a successful startup or work on my product?
Looks very nice, reminds me of the Elements app for iPad.

P.S. I don't know about you guys, but it still bugs me whenever I don't see Pluto.
The article points it out, but the text comes in from different directions depending on whether you're clicking on the planet or scrolling to it from the side.

Nice touch.
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Are you joking? It's only 'habitable' in the sense that wildlife doesn't drop dead the moment it enters the exclusion zone. The animals are still receiving substantial amounts of radiation, and will continue to suffer for decades. The worst areas will be dangerous for centuries.
There's this tunnel vision that propagates in highly specialized communities like HN. Stepping back and viewing things from the bigger picture is a skill that is highly underrated.
That being said, from my personal observations, Dropbox is knocking on the door and about to have a push outside of the core tech community. This article is just another sign that Dropbox is about to make a big push.
I think this article is perfectly valid.

Of course it is. My bigger surprise is that it doesn't feature what I now think of as the ultimate Dropbox evangelising line: "It's a folder. That syncs".

[ http://news.ycombinator.com/item?id=2153046 ]
From the Source Material:

"Uranium mining is a lot safer because insitu leaching (the main method of uranium mining) involves flushing acid down pipes. No workers are digging underground anymore. Only about 60,000 tons of uranium are needed each year so that is 200 times less material being moved than for coal plants."
In addition, uranium mining tends to use acid leaching, which doesn't send as many people underground.
I believe it is called an "internship"
And here's what it looks like in IE9: http://twitpic.com/4a3kyw/full
Quora engineers accused of vandalizing a clone’s website
Google Docs Get 'Wave'-Like Comments
Talks about the various networks small businesses should join, with a BIG warning on how time can also be wasted there.
Spot on. I am incredibly optimistic about Dropbox's future. It constantly blows my mind that home users don't have any file sharing running on their network. The go-to solution is to email files to each other, even while sitting on the same network. When I learned that Dropbox supported LAN sync, I immediately started recommending it as an alternative to emailing files back and forth. Just drop files you would normally email to each other in to the Dropbox folder, and magically it will appear on the other computer. BONUS! If you make changes, they're automatically shared in the other direction. Keep it under 2 GB and you get this for free.

The response I get from users is consistently that of complete astonishment. Registering for and installing Dropbox is, for many people, a more straight forward process than getting file sharing working. Dropbox scratches a very common itch.
It should come out of coal. If we were willing to nationalize all of our energy, start phasing out coal plants, and go fully nuclear to replace coal, over the next 50 years we could get substantial savings over coal and put those savings into renewables.

And in any case, as this graph shows, renewables are not a panacea. Hydro dams cause significant environmental damage, and even wind turbines have their issues.
>It was a serious and looming mistake for the web to rely so critically on the identities of content publishers

How else are you going to make a decentralized identifier?
Sure, if you conveniently ignore all of the children born in the Ukraine and Belarus with birth defects due to exposure, the plant workers and soldiers who were sickened or died heroically trying to shutdown the reactor, the increased incidence of cancer, the poisoning of prime agricultural land, I guess Chernobyl was no big deal.

And by the way, dam-building for power generation isn't exactly a popular practice today, particularly in areas were unmaintained industrial revolution era dams burst every few years.
Lego For Adults by Jean Yves Lemoigne
Lego For Adults by Jean Yves Lemoigne