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US Department of Energy: Fusion Ignition Achieved

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Re: US Department of Energy: Fusion Ignition Achieved

#561

Earlier quoted context omitted.

This is a stupid question but I don't know anything about fusion: How is it possible for X energy to create X+Y energy in output? Doesn't that violate some fundamental law of physics?

If you look at the mass before of their fuel, 1 deuterium atom + 1 tritium atom: 2.01410177811 u + 3.01604928 u = 5.03015105811 u vs the mass of the fusion products of 1 helium atom and 1 neutron: 4.002602 u + 1.008 u = 5.010602 u You'll notice that even though we started with 5 neutrons and 2 protons and ended up with the same number there was some additional binding energy that is unaccounted for in the new configu…

And on a total tangent, this fact played a part in worldbuilding done by the author L. E. Modesitt, Jr.

> When I initially decided to write The Magic of Recluce in the late 1980s, I'd been writing science fiction exclusively... I conveyed a certain dismay about the lack of concern about economic, political, and technological infrastructures in various fantasies then being written and published in the field...

> I faced the very real problem of creating a magic system that was logical... Most fantasy epics have magic systems. Unfortunately, many of them, particularly those designed by beginning authors, aren't well thought out, or they're lifted whole from either traditional folklore or gaming systems and may not exactly apply to what the author has in mind.

> I began by thinking about some of the features and tropes of traditional fantasy. One aspect of both legend and folklore that stuck out was the use of "cold iron" to break faerie magic, even to burn the creatures of faerie, or to stand against sorcery. Why iron? Why not gold or silver or copper? Not surprisingly, I didn't find any answers in traditional folklore or even contemporary fantasy. Oh, there were more than a few examples, but no real explanations except the traditional ones along the lines of "that's just the way it works."

> For some reason, my mind went back to astronomy and astrophysics and the role that nuclear fusion has in creating a nova... Each of these fusion reactions creates a heavier element and releases energy... The proton-proton reaction that produces iron, however, is different, because it is an endothermic reaction...

> At the same time, the fact that metals such as copper or silver conducted heat and electrical energy suggested that they were certainly less than ideal for containing electrical energy. Gold and lead, while far heavier than iron, do not have iron's strength, and other metals are too rare and too hard to work, particularly in a low-tech society.

> At this point, I had a starting point for my magic system. I couldn't say exactly what spurred this revelation, but to me it certainly made sense. Iron can absorb a great amount of heat. If you don't think so, stand on an iron plate barefoot in the blazing sun or in the chill of winter. Heat is a form of energy. In fantasy, magic is a form of energy. Therefore, iron can absorb magic and, by doing so, bind it.

https://www.lemodesittjr.com/the-books/saga-recluce/recluce-...

Re: US Department of Energy: Fusion Ignition Achieved

#562

Earlier quoted context omitted.

The advantage would be that you wouldn't need tightly controlled and hard to make materials like U-235 or Pu to make one. I'm not in any way saying that using lasers would be a plausible route to such a weapon, since the NIF facility is huge, but if it turns out that the research needs to focus on how to get more output per shot, which I think it inevitably would since a typical conventional or nuclear power plant ge…

Shiiiit... here I was thinking how cool it would be if they could miniaturize this, having somehow forgotten that my pet solution to the Fermi paradox is that a nigh-inevitable wrung on the ladder to interstellar presence involves discovering One Weird Trick to release a whole bunch of energy pretty easily, even on a DIY basis. Instant end of civilization. Even ant-like societies might have mutated members who'd go r…

any sufficiently speedy spacecraft makes for a deadly kinetic kill vehicle, unfortunately.

Re: US Department of Energy: Fusion Ignition Achieved

#563
post #185

Another good time to remind everyone that the inventor of the maser (which led to the laser), Charles Townes, was discouraged by his department chair (allegedly): "Look, you should stop the work you are doing. It isn't going to work. You know it's not going to work, we know it's not going to work. You're wasting money, Just stop!" A few months later, it worked. [1] [1] https://www.theregister.com/2015/01/29/charles_t…

"If we'd known it was impossible, we never would have succeeded!"

Re: US Department of Energy: Fusion Ignition Achieved

#564
post #362

Earlier quoted context omitted.

I can't agree that funding is "largely the reason" why NASA takes so long to do anything. I doubt funding is a top 3 reason. NASA just isn't about high-risk / high-reward "moonshots" anymore. The overarching political environment doesn't allow it, never mind the office politics. NASA will get back to the moon using easily an order of magnitude more funding than it should have taken, with a launch system that costs an…

> I can't agree that funding is "largely the reason" > NASA just isn't about high-risk / high-reward "moonshots" anymore. The overarching political environment doesn't allow it, never mind the office politics. Why doesn't the political environment allow for it. What could happen. What could regulatory bodies do to NASA for taking a risk and failing. What sort of constricting change could political bodies do in such a…

The funding senator became the administrator of the current moon attempt. The funding insist on using the old technology in the funding. All these sounded bad. If nasa has more freehand. But then the fund will not get back to the states …

Re: US Department of Energy: Fusion Ignition Achieved

#565

Earlier quoted context omitted.

Do we know how much tritium is needed for a city's energy generation? What about a state etc? Reason I ask is the only uses I have seen for tritium is on old watch dials made in the pre-90's. Curious how much of this resource is out there.

Real Engineering recently made a video that covers fuel needs. https://www.youtube.com/watch?v=BzK0ydOF0oU

And the (otherwise excellent) channel is supposed to soon post an adv... I mean informer... I mean "exclusive documentary" about "repeat after me we're totally not a scam - we just play one on YouTube" fusion startup Helion.

Which I'm going to watch, because even though everything I hear about this company gives me insane Theranos vibes... Well, if they pull it off... They might light a bulb with fusion in my lifetime.

Re: US Department of Energy: Fusion Ignition Achieved

#566

Earlier quoted context omitted.

A pure fusion bomb would produce less (not zero) fallout. Neutron activation would still produce some fallout, but you wouldn't have the fission byproducts like caesium-137, iodine-129 or strontium-90. This is probably a bad thing; politicians might decide the bombs are clean enough to use.

even without actual radioactivity, pure fusion bombs would still be politically radioactive. look at the fallout (so to speak!) from the Hafnium controversy. they nixed all the research and stopped looking, after realizing that nuclear isomers would do little for energy storage (due to emitting energy as gamma radiation) but lots for bypassing restrictions on fissile materials.

To be clear, pure fusion bombs would still emit massive amounts of radiation. Gamma rays, x-rays, thermal radiation, all off that EM radiation would be emitted just like a regular fission bomb. Neutron radiation too. You'd have less (not zero) contamination of the earth itself afterwards, but everybody in the area would still be very badly irradiated.

I don't know enough about the Hafnium controversy to comment on it.

Re: US Department of Energy: Fusion Ignition Achieved

#567

Earlier quoted context omitted.

Have to +1 this. A lot (most?) of NASA's funding is directed toward keeping people employed and skilled, as opposed to accomplishing goals, as with a lot of government money. NASA could do a LOT more with the funding they already have, if they were willing to divest from older technologies and vendors, but the politics of its funding doesn't allow that.

> A lot (most?) of NASA's funding is directed toward keeping people employed and skilled, as opposed to accomplishing goals This is so hilarious wrong I don't even know where to start. > but the politics of its funding doesn't allow that. The post that you are agreeing with says that "funding" is not the reason for their plan.

> This is so hilarious wrong I don't even know where to start.

Anywhere at all would be better than nowhere. I worked for a defense contractor for a few years, so I'm basing my comment on my experience there.

> The post that you are agreeing with says that "funding" is not the reason for their plan.

Not sure what you are saying here.

Re: US Department of Energy: Fusion Ignition Achieved

#568

Earlier quoted context omitted.

> Who are our modern J. Robert Oppenheimer, Enrico Fermi, Richard Feynman, Edward Teller, John Von Neumann, and Stanislaw Ulam? they're working on getting you to click on an ad

They can't exist any more for structural reason. This generation was classically educated, without TV or social media in their childhood. They spent the time we're wasting on HN reading _books_ and following the discipline their elders learned in WWI. They had plenty of occasions to tinker. I claim the brains of those generation was structurally different from ours, and we're talking about the best minds of this gene…

> It's a trope to say that our "best minds are working on ads".

"The last generation was better because they read _books_ and had _discipline_ and didn't waste their time on frivolous garbage" is also a trope.

Re: US Department of Energy: Fusion Ignition Achieved

#569

Here's your most exciting paragraph > LLNL’s experiment surpassed the fusion threshold by delivering 2.05 megajoules (MJ) of energy to the target, resulting in 3.15 MJ of fusion energy output, demonstrating for the first time a most fundamental science basis for inertial fusion energy (IFE). Many advanced science and technology developments are still needed to achieve simple, affordable IFE to power homes and busines…

The question on my mind is: where do I sign up to join this effort?! Edit: I'm Canadian, the question is rhetorical.

[deleted]

Re: US Department of Energy: Fusion Ignition Achieved

#570

Earlier quoted context omitted.

There are like 20 designs of various fusion reactors on the drawing board that need to be built and tested. Scientists also don't work for free. They arent mushrooms that grow by themselves

One of the things that I think I noticed from the press conference, is that funding is going to be the bare minimum to meet some goal for a design they select. This seems like a gross mistake. If we are going to avert a climate catastrophe we will need TW of power to "unburn" the carbon we put into the environment (ocean and atmosphere). Instead of barely hitting this target, we should over deliver since we are runni…

Each dollar diverted to chase nuke wills-o'-th'-wisp brings climate catastrophe nearer.

Money is fungible. Dropping $billions on this means not dropping those $billions on something that works already, works fantastically well, and would work even better with more money. We already know how to prevent (more) climate catastrophe. We just need to do more of it.

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