Comment by throwaway_yy2Di | Hacker News Reader

Comment by throwaway_yy2Di | Hacker News Reader

throwaway_yy2Di

Here's the paper.

http://www.nature.com/nature/journal/vaop/ncurrent/full/natu...

They would like to charge you $32 to look at it, nature-ally.

The fusion yield is (?) 14 kilojoules (inferring this from physicist Mark Herrman's "5 million billion fusions" [WaPo], at 18 MeV per fusion), which is a moderate improvement over the 8 kilojoule achivement from last fall:

https://news.ycombinator.com/item?id=6459289

[WaPo] http://www.washingtonpost.com/national/health-science/fusion...

The "1%" energy efficiency figure [a] is misleading: 14 kJ is about 1% of 1.5 MJ of ultraviolet light hitting the fuel capsule. But creating that UV pulse consumed 3 MJ of infrared light, which in turn took 400 MJ from the flash bulbs driving the IR laser. So the system efficiency is more like 0.003% (and throwing in hypothetical turbines to generate electricity, 0.001%).

https://en.wikipedia.org/wiki/National_Ignition_Facility#NIF...

[a] I'm referring to this: "while more energy came from fusion than went into the hydrogen fuel, only about 1 percent of the laser's energy ever reached the fuel."

(update: from yosyp's link, the fusion figures were 14.4 kJ, and 17.3 kJ, on two different runs:

https://news.ycombinator.com/item?id=7227950

Quick summary of the numbers from wikipedia:

    422 MJ     capacitors	      ←────────────┐
      ↓       					   │
     (?)       xenon flash lamps		   │
      ↓                                            │
    3 MJ       IR laser pulse			   │
      ↓                           		   │
    1.5 MJ     UV pulse				   │
      ↓                                  	   │
    150 kJ     X-ray pulse		           │
      ↓        					   │
  * 14-17 kJ   Fusion yield (this story)           │
      ↓                                            │
    7-9 kJ     Potential electricity      →────────┘
                                           system
                                          breakeven

https://en.wikipedia.org/wiki/National_Ignition_Facility#NIF...

wrt. 422MJ->3MJ, xenon flash lamp pumping

As it was already mentioned in the threads like this before, the NIF was built using the technology that was available in those years of the past when NIF was planned and started. Flash lamp pumped lasers are bigger, more expensive and much less efficient, i.e. mere few percents efficiency at best vs. tens of percent efficiency of modern laser diode pumped IR lasers. (Even with such improvement though, i still think laser driven fusion is inferior to many other forms of inertial confinement and much less probable to result in system-level break-even. My personal favorite, Sandia Z-machine is on the scale of 15% efficiency of generating X-ray pulse, and schemes like deep plasma focus or polywell by-pass the energy to radiation conversion stage all together and thus avoid related losses.)

I'm on campus right now and can download the PDF. I'd upload it, but I don't want to pull an Aaron Swartz. <_<

EDIT: Okay here, but I have limited bandwidth so get it while you can: https://mega.co.nz/#!CNgVhZra!JcsLGB5y0FGUffI4rdyNr-BBl82YJD...

They won't get after you because of one paper. Please, do it for the betterment of mankind :).

It's not worth it.

The terrorists won.

By terrorists you mean those illusionary guys that the politicians use as the boogie man, to beat down the rationality of ordinary people by provoking fear, so they are legally allowed to do virtually anything without nobody to stop them?

I want to downvote this. I really do. And I think when I feel justified in doing so that things will have improved.

It would be cool if there were a globally inclusive political movement that continuously stood for election in multiple countries simultaneously.

It could then be called the Terraists and possibly solve the whole issue through discordant namespace collision.

Whether illusionary or real, their goals are the same, and they're winning because people exchange their rational thinking for illusions of safety.

No I think he means the terrorists that want to kill you because you are free to pay for everything.

Much more likely we gonna be killed by diabetes, or falling from the stairs.. the propaganda is unproportional to the size of the threat.. meanwhile, other types of "predators" may scape from our sight.. not minimizing the problem.. just saying that there are bigger ones that deserve more attention .. and overreacting wont help, i think, anybody.. so, back to the original topic..

Or we could talk about nuclear fusion.

Why talk about what might be the biggest scientific breakthrough of the year, when we can regurgitate snarky comments about Elsevier again?

Well if Elsever would make it easier to access, we wouldn't have to. $32 to read about what might be the biggest breakthrough of the year?

Sounds cheap.

You would be happy to pay that, if after you read it, you noticed some glaring inadequacies with the science and decided it is a non-article?

I was going to suggest I do the same thing. Well, just upload it somewhere for someone else to find...accidentally, you know.

Those PDFs are normally watermarked with a unique identifier for your account. It's not worth it.

I didn't log in. For almost all of these they detect that I'm connecting from my campus IP block and unlock everything.

Distinguished editors strap Finster into vacuum target chamber...

"Come now, editorial board of Nature. Do you expect me to pay for a subscription?"

"No, Mr. Finster -- we expect you to fuse!"

I accessed over a vpn link into campus, signed-in by my user ID. The md5sum of the link provided above (and the others in the thread) are identical to the copy I downloaded from my campus IP block. Unless you're also on the campus of Iowa State, I don't think they're watermarking this paper.

Upvoted for the sentiment. The actual paper marks just another incremental step in a triple marathon that we seem to be running veeeery slowly.

Also, if you do "pull an Aaron Schwartz" please change the ending - we need a very public Supreme court administered kick-in-the-teeth for all the out of control copyright regime and its criminal sentencing farce.

Agreed. I do not plan to ever go out like he did!

I talked to a friend who works there, this is more of a PR move. Back at the lab it is business as usual.

The PR guys often work on a different schedule than the actual science, but those times do usually correlate well with the funding deadlines for some strange reason... It's probably work as usual at the NIF because everyone is working on a big, long, grinding project that's slowly making progress rather than bashing out stunning Eureka moments complete with Dom Perignon showers like you see in a Hollywood flick.

They are working towards ignition as measured by total neutron output. As soon as they detect significant enough jump to warrant ignition claim there will be Eureka moment with Dom Perignon.

Right now they are 3 orders of magnitude off (10^15 they get, 10^18 or better 10^19 they want).

cheers

https://dl.dropboxusercontent.com/u/26434203/nature13008.pdf

No offense to anyone, but this link should be deleted. You may not like the system, but HN isn't the place to protest IP laws with civil disobedience. A lot of YC companies have their own IP they'd like to protect I'm sure.

Why not let the mods say what should or shouldn't be on HN? No need to speak for them.

Not all IP laws are equivalent. Also, civil disobedience has been known to work in the past.

Your first sentence is a subjective value statement (that I probably don't agree with). Both your first and second sentence are irrelevant to my argument.

How is saying Drug Patents lasting 20 years vs copy write on a tweet lasting the lifetime of the author plus what 80 years a subjective statement?

IMO, IP is a loaded term that distorts the wide range of issues. IM for Intellectual Monopoly is much closer to the truth. To be clear I have no problem with the idea of copyright or a well run power company being run as a local monopoly, but there outside of the normal business. And the goals should be finding rules that best serve society not the owners of said monopoly.

This isn't protesting the law with civil disobedience, it is breaking the law because the direct expected value of breaking the law (people having access to this specific paper) is greater then the expected cost of breaking the law (~0).

Are you a psychopath? In what world does personal expected value versus expected cost of breaking the law ever become a good way to make moral decisions? If you have the chance to get a promotion by killing your boss but have near zero chance of being caught due to some circumstance, would you kill your boss? What the fuck.

Why call your opponent names and become emotional? It's not effective.

In what world does personal expected value versus expected cost of breaking the law ever become a good way to make moral decisions?

There are at least two counterarguments to this.

1) The law is written for precisely this reason. Most people do live by a cost vs benefit mindset, and the penalties of laws are generally tuned until people stop committing the crime. I wouldn't want to live in a world where the penalty for murder was only a week in prison.

2) Anyone who uses the law as a way to guide their own moral compass probably isn't very moral, because throughout history every society has had laws which are later agreed to be evil.

Psychopath is not name calling. It's an honest question.

https://en.wikipedia.org/wiki/Psychopathy

Names which offend people the most are those which are also true. It's still name calling, and it's also irrelevant to your argument in this case.

I suppose my question is, do you care more about expressing yourself than convincing others? If so, then that's detrimental to a message board.

In this case it is clear he is talking about utilitarian expected value rather than personal expected value. He receives no personal benefit by uploading the paper, but reading it provides value to others at ~0 cost to anyone.

Actually, I was thinking in terms of personal expected value (namely a sense of satisfaction and good doing), however, I can see the argument that uploading it is also net positive globally.

Sometimes I think I would do it for no promotion.

In what world does personal expected value versus expected cost of breaking the law ever become a good way to make moral decisions?

In this one, where my taxes paid for the goddamned research.

That's just silly. If you kill your boss, who's going to promote you, and who is going to pay out the higher salary? No, the rational thing to do is to wear his skin to impersonate him and sell all the company's assets. Then eat him.

Why can't it be both? Saying that the law is imposing costs (equal to the value of breaking it here), and that you're against it enough to flout it, is a protest. Protests don't need to be accompanied by a manifesto.

YC companies aren't funded by taxpayer dollars

I don't understand what argument you are making here.

http://en.wikipedia.org/wiki/Lawrence_Livermore_National_Lab...

The point was the research is being performed by a government funded lab not private money.

If the public is paying for the research should they not have access to the published papers resulting from it without paying $32 to a private company for a PDF download?

Except those companies didn't use publicly-funded researchers to both write and review the papers they put in their blogs (seriously, who buys printed copies anymore).

"Lawrence Livermore National Laboratory (LLNL) is a Federally Funded Research and Development Center (FFRDC) founded by the University of California in 1952" [1].

My tax dollars paid for this research I should be able to read it.

As far as YC is concerned AirBNB and Uber encourage people to break the law all the time, some rules are just stupid and outdated and don't make sense and should be broken. This is "Hacker" News after all.

1. http://en.wikipedia.org/wiki/Lawrence_Livermore_National_Lab...

My tax dollars paid for that gun officer, so let me hold it.

I mean, I agree with you, but this is a silly statement. Just because the government pays for something does not allow you access to it.

And that's a silly comparison. Copyright law already excludes work created by official duties of officers of the federal government from copyright.

That's not this work, but arguably the original motives and intent of the law is subverted if what's happening here is the government outsourcing the creation of the work to a third party.

http://en.wikipedia.org/wiki/Copyright_status_of_work_by_the...

I see no parallels to firearm possession.

My tax dollars (well, not dollars) didn't pay for this research. Should I be able to read it?

Can you provide a link to the place where you consider it IS appropriate to protest IP laws with civil disobedience then?

Thank you for doing that.

Mirroring: https://dl.dropboxusercontent.com/u/216352/bigscarylaser.pdf.

Muahahaha Ha! I'm not American. I'll read it TWICE and cost you TWICE the taxpayer dollars, then I'll share it with all my friends and soon all the dollars in America will be GONE. Better call the president and tell him to start enacting measures, cause there are no breaks on THIS terrorist train!

17.3 kJ for the latest shot, according to the paper. But only some 8 kJ of that came from fusion (the balance came from the laser input).

D-T fusions are about 17.6 MeV, but 80% of that is in neutrons, which escape unless captured in a special blanket. The 8 kJ reported was all alphas. So 8 kJ / 3.5 MeV = 1.4e16 fusions, vs. 5e15 in the quote. He was probably talking about a previous shot.

For comparison, a typical AA battery stores 16 kJ.

You're misreading. E_{DT} is not the D+T fusion yield; it is the heat absorbed by the D+T fuel target (sum of external heating and self-heating from fusion alphas). E_{fusion} is the fusion yield.

E_{fusion} is the calculated neutron yield Y_{total}=6.1e15 times 17.6 MeV: 17.2 kJ + rounding. Check out page 3, right column.

Quite right, there were 6.1e15 fusions.

As I understand, they are hoping to achieve fusion ignition, where no additional external energy will be required to generate power. So current efficiency calculations are irrelevant in that case.

Yes, but in the article they also say this isn't possible with their current techniques.

Anyone have a figure that represents how far off they are?

they also say this isn't possible with their current techniques.

That's fine by me, it was not very long ago that we were unable to get more out of the fuel than we put into the fuel. That's step one to fusion ignition, and was done for the very first time last fall, so as far as I'm concerned they are still fleshing out step one.

Doesn't every H-bomb have substantial positive fuel yield?

It makes it all at once, and that's the issue.

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