191–200 of 289 posts
We need to focus on building hundreds if not thousands of nuclear fission reactors and to reduce the population growth through birth control outside the Western world.
Still unconvinced why this is such a major breakthrough - it may be the first net-positive controlled fusion, but the distinction between controlled and uncontrolled fusion is a bit academic in this case. In uncontrolled fusion ( https://en.wikipedia.org/wiki/Thermonuclear_weapon ), you are using a nuclear fission primary stage to generate enough energy to start the fusion reaction in the secondary stage. In the NIF,…
You greatly underestimate the order of magnitude difference of produced energy in these two examples. You can't contain a bomb's hydrogen fusion reaction in a chamber for the simple reason that you need a nuclear fission warhead just to ignite it. So if you want to produce useful, controlled energy outside of killing things, the lasers are your only shot for inertial confinement fusion. Yes they still get damaged, bu…
We've been able to reliably trigger stable fusion in controlled experimental facilities since before I was born in 1966. People have literally been claiming fusion power is just an engineering problem longer than my entire lifetime, and I'm no spring chicken. Ring me when they reach engineering breakeven, although optimistically the chances are it'll be my grandkids that take the call.
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This is actually a significant step, not a tiny step. Achieving fusion ignition, ie including the 2021 shot, is THE non-linear scaling effect needed to make fusion a viable energy source. The other items needed to make this practical would’ve been premature to fund without this significant advance. https://physicstoday.scitation.org/do/10.1063/PT.6.2.2022121... EDIT: Being down-voted, why? Previous steps to actually…
Uh no. For sure, you can’t even consider the possibility of a fusion power plant without the core reaction producing power. That they figured out how to do the energy equivalent of getting the coal to actually light (finally!) in this context, is indeed useful. But it is a tiny, tiny step towards an actual working fusion power plant. And it does nothing to fix the economic issues here in competition with all the othe…
No one needs to talk about delaying solar deployment, obviously that would be stupid. No one should be arguing for that, I certainly am not, and trying to do this whole thing where we attack genuine advances just because they aren’t the thing we prefer is super counterproductive to progress. Shameful to do that, no matter how common it is on social media.
This was built as a machine to test fusion, not to generate electricity. It did that, and doing so is a significant advance.
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Yup, here’s the one: https://physicstoday.scitation.org/do/10.1063/PT.6.2.2022121... Credit: Mark Herrmann/LLNL From this article: https://physicstoday.scitation.org/do/10.1063/PT.6.2.2022121... Clear qualitative difference. Additionally, this is laser energy, but the lasers aren’t used directly. They produce X-rays which are the ones that actually drive the ablative implosion of the fuel pellet. If you used X-rays d…
It should be noted that even if the lasers were 100% efficient, this result is not sufficient to achieve a practical fusion power plant. That target could produce maybe $0.02 worth of electrical energy. That's nowhere close to paying for the plant, even totally ignoring operating costs. A real plant would need target yields 100 to 1000 times larger, with all the engineering issues that would entail.
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> You can't contain a bomb's hydrogen fusion reaction in a chamber You certainly can, if you use a large enough chamber. Pacer was exactly this. You just have to accept high proliferation risk.
Thank you for pointing me to Pacer, that was a fascinating read. They were apparently also considering digging a new panama canal with fusion bombs... In 1972 they decided it wasn't economical based on fuel price compared to yellowcake, but fissile fuel isn't the primary cost of fission power and the engineering costs of pacer would seem to be much lower.
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Thank you for pointing me to Pacer, that was a fascinating read. They were apparently also considering digging a new panama canal with fusion bombs... In 1972 they decided it wasn't economical based on fuel price compared to yellowcake, but fissile fuel isn't the primary cost of fission power and the engineering costs of pacer would seem to be much lower.
There's some old Asimov "Big Book of Science" sort of book I've got hanging around somewhere (dude definitely had aides/ghost-writers on some of that non-fic, right? Surely? At least researching and first-drafting for him to come through and punch up? Especially the more generic ones like that? I don't see how he'd have had the time to physically write that many words, otherwise, let alone also think about the words,…
It’s practical proof that in a single pulse we can get more energy out than we put in. We do spend a shit ton of energy setting up the pulse, and we haven’t figure out how to get that energy out and make electrons move, but it’s been proven possible. The “breakthrough” is the proof that it’s possible. Everything else is now optimisation and engineering, and needs mostly time, sweat and money.
Isn't additional stages in fission/fusion bombs just upping the mass with the result being higher yields? "higher yield" being a bit of an understatement as the range is like 100KT to 100MT (and beyond).
Can a multi-stage pellet be formulated? Ignition of an outer pellet provides some energy to get a more powerful inner pellet ignited.
/not even close to being a layman, let alone expert, on the subject
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We can debate the importance, but it’s clear that they’ve made a qualitative leap in their technology the past few years — a “breakthrough”. https://en.wikipedia.org/wiki/National_Ignition_Facility#/me...
Not to diminish the achievement, but not making that graph log scale was deeply dishonest.
Everything i have heard about this makes it sound more like a milestone than a breakthrough. I.e. its great it happened and an important step, but its not shocking that we eventually did it. When i hear breakthrough i think of something more unexpected. I.e. figuring out how to solve a problem we had no idea how to solve.
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"This news shows that practical fusion is now only an engineering problem, not a fundamental physics one..." Yes, I'd agree with that statement that it's only an engineering problem, but with a laser energy of 2 million joules and a fusion yield of only 3 million joules and an overall input of nearly 300 million joules to produce the lasers then I've no expectation of ever seeing a total net positive output in my lif…
The 300 million joules to produce 2 million joules was almost entirely due to 2->3” implies. Some labs are already working with 20% efficient lasers, so hypothetically, Fusion is closer to “10->2->3” which is just amazing.