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Scientists Say Their Giant Laser Has Produced Nuclear Fusion

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Re: Scientists Say Their Giant Laser Has Produced Nuclear Fusion

#151

Post by gizmo686 »

voodoomagicman wrote: post #140
leobelle wrote: post #107

Earlier quoted context omitted.

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.

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.

Re: Scientists Say Their Giant Laser Has Produced Nuclear Fusion

#152

Post by drjesusphd »

Oculus wrote: post #22

> led NIF's critics to label the facility an enormous waste of taxpayer dollars > government shifted NIF away from its fusion goals to focus on its other mission: simulating the conditions inside nuclear weapons I think right there lies the problem with our world. People take up more issue with a multi-billion dollar research facility for science than one for military applications. If we spent a small fraction of the…

Fusion is and always has been a PR excuse for NIF.

Their purpose never been anything but "Stockpile Stewardship". Anyone who has been paying attention has known this for decades.

Re: Scientists Say Their Giant Laser Has Produced Nuclear Fusion

#155

Post by yen223 »

wavesounds wrote: post #124
leobelle wrote: post #81

Earlier quoted context omitted.

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.

"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"…

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

Re: Scientists Say Their Giant Laser Has Produced Nuclear Fusion

#156

Post by beefman »

throwaway_yy2Di wrote: post #142
beefman wrote: post #128

Earlier quoted context omitted.

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 A…

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.

Re: Scientists Say Their Giant Laser Has Produced Nuclear Fusion

#157

Post by cenhyperion »

bcoates wrote: post #138
sliverstorm wrote: post #93

Earlier quoted context omitted.

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.

Re: Scientists Say Their Giant Laser Has Produced Nuclear Fusion

#158

Post by suprgeek »

Finster wrote: post #73
throwaway_yy2Di wrote: post #54

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]…

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...

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.

Re: Scientists Say Their Giant Laser Has Produced Nuclear Fusion

#159

Post by ACow_Adonis »

leobelle wrote: post #81
yosyp wrote: post #77

Earlier quoted context omitted.

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.

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

Re: Scientists Say Their Giant Laser Has Produced Nuclear Fusion

#160

Post by dredmorbius »

YokoZar wrote: post #129
yaur wrote: post #89

Earlier quoted context omitted.

An old article on exactly that which I found interesting http://physics.ucsd.edu/do-the-math/2011/07/galactic-scale-e... To sum it up "Free energy" buys us about 300-400 years of growth before thermodynamics kicks our ass.

It is a tiny bit unreasonable to project continuous exponential growth in human energy usage on such a ridiculously long timescale. It's like arguing that Moore's law will continue for another 200 years.

However that growth is precisely what the present human civilization and economic system are predicated on.

That growth will stop sometime and a considerable amount of present pain seems to be that global growth is slowing markedly (and has been since the 1970s).

Globally, economic activity and energy consumption are still tightly correlated: http://www.reddit.com/r/dredmorbius/comments/1vlksg/economic...

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