274 points | by agomez3141 month ago
(that was the submitted link but we changed it via https://news.ycombinator.com/item?id=42077657)
Technically that counts as "AI in nuclear fusion", but it isn't any sort of breakthrough. In almost every case the effects of AI are marginal. Not zero exactly, but nowhere near the breathless hype.
Not really an industrial control though, but close to it.
Even well before that, ML is very closely related to statistics, so early practical applications would have been as simple as gathering data points on widget production and doing the kinds of analyses that are now backed into free spreadsheet software.
CNN’s literally changed the game.
It’s like talking about cell phones, so we attempt to compare [https://en.m.wikipedia.org/wiki/Motorola_DynaTAC] and a modern flagship Apple or Samsung smart phone. Technically they can both make mobile phone calls, yes.
And it isn’t really wrong to compare them.
Technically, if we limit the specific scope of what we’re comparing and squint a lot, and avoid the context, they’re equivalent.
But they aren’t really the same type of thing either, eh?
In fact, if we take a broader view, the Motorola DynaTAC was a portable radio connected to the phone system, not what we’d call a phone.
There are so many fundamental fields - engineering, chemistry, biology, physics - which stand to have absolute quantum leaps in knowledge and capability with this technology.
Super useful for control applications but obviously you really want to know control theory so that you aren't just using ML to throw darts at a wall.
A bit off topic but I had a laugh at that, reminded me of that ridiculous Meta commercial where the girl at a pool table asks Meta which ball should she hit?
I would definitely agree that optimisation fits the definition in part but I find really only control theory covers that entire field of signal processing, optimisation, and decision making systems.
And importantly, because ML in some amount touches on all of those, control theory tends to fit better as it focuses so heavily on providing a comprehensive framework for reasoning about all of those elements together.
My lab is collaborating with researchers at the Laboratory for Laser Energetics to use AI to improve inertial confinement fusion (ICF). We recently put out this paper [1] using Kolmogorov-Arnold Networks (KANs) to predict the outcome of ICF experiments. Currently, existing physics simulators are based on old Fortran code, are slow, and have a high error between their predictions and actual laser shots, so among other goals, we are trying to build better predictors using neural networks. This is needed since it is hard to rapidly iterate on real data, since they only have a dataset of around 300 ICF shots.
Codes are not magic, they are physical codes, as in, they generally encode the physics as we understand it relevant to the experiment, so you might as well say our physical models are wrong, which is a much harder bar to clear, you'd have to invalid probably near 100 years of plasma physics. The problem likely is as I said, the experiments are just hard to control and we don't know the correct inputs. It's not like weather forecasting where we can have a weather balloons across the world, we're not able to probe every micron of the target at all times for a plasma temperature and density.
Otherwise, the major issue is just that it makes a lot of assumptions and has a lot of inaccuracies, but that issue isn't due to Fortran but just because it doesn't capture all of the physics and there is a sim2real gap. So it DOES NOT have the right physics, but re-writing it probably wouldn't result in the "right" physics either.
The main version of the code they run uses 1-D physics (so one spatial dimension), which takes about 8 minutes to run on a modern CPU. The code can't be parallelized without being re-written. Running the 3D version of the code takes 1+ weeks for a single run, and that still has a big sim2real gap.
One of the most prominent example of this gemm. Usually, the state of the art code base on gemm are written C/C++, in terms of implementations in academic papers/github, see e.g. openblas, blis, blasfeo. The same situation applies to CUDA code or accelerator agnostic code e.g. using MLIR. I think it's more a result of how the language allowed people to create an ecosystem + ecosystem created by the people using the language. Sure, you can write Fortran, but if I see more tooling and more other people benchmarking, I can be more sure that the software will be tested more and higher performance etc. For instance, if you look at benchmarks-game, the top results are C/C++/Rust. Instead of making claims like this code is not wrong/right, we should look at the concrete/quantitative results like benchmarking/number of users. As another example, you can check blasfeo paper where they used C code.
I would welcome Fortran benchmarking results. But, I just dont see it being tested enough (in open source/papers/benchmarks) to prefer it over C/C++/Rust.
There are other consequences of this networking issue: availability of docs, finding an question and answer for a problem that you experienced.
What if we rewrote the old algorithms in C with modern techniques? Multitthreading? Or GPU compute? If there's value there, I could do these things. Probably wouldn't take that long
Fortran compilers had more than 40 years to become pretty good at generating efficient code; they can make assumptions that are not possible in C (for example, no aliasing) to do so. Besides, most compilers already can do vectorization and autoparallelisation with multithreading, coarrays, and/or openMP, which can be offloaded to a GPU.
Then it's not done yet.
Plus, even after doing that, there would still be a sim2real gap. The goal of our research is to use physics informed deep learning and methods with strong inductive biases, combined with transfer learning and low-shot learning to overcome the sim2real gap.
"AI for Real-time Fusion Plasma Behavior Prediction and Manipulation - Plasma Control Group": https://control.princeton.edu/machine-learning-for-rt-profil...
sigh.. I guess that's cool and all, you're exited about your work, that's great. But can we please polish our prose a little more and stop using buzz words like "groundbreaking", "now.. for the first time", "unprecedented" etc? Such distractions seriously undermine the legibility (and frankly, also taint the credibility by negatively biasing readers) of the claims.
Many on Hacker News fantasize about fusion (not fission) reactors. These fusion reactors will be an intense source of fast neutrons. All the hardware in a fusion reactor will become radioactive. Not to mention the gamma rays.
If you have to deal with radioactive materials, why not just use fission? After 70 years of working with fission reactors, we know how to build and operate them at 95%+ efficiency. Fission can provide all the power we need.
Today there are 440 nuclear fission reactors operating in 32 countries. 20% of America's grid power comes from nuclear fission. If you want to develop energy technology, focus on improving fission. For example, TRISO fuel (https://news.ycombinator.com/item?id=41898377) or what Lightbridge is doing (https://www.ltbridge.com/lightbridge-fuel). Hacker News is hostile to fission and defeatist (unable to contemplate innovation in fission technology) but this attitude will gradually change.
Quoting John Carmack: "Deuterium fusion would give us a cheap and basically unlimited fuel source with a modest waste stream, but it is an almost comically complex and expensive way to generate heat compared to fission, which is basically 'put these rocks next to each other and they get hot'."
1/ Uranium is not a renewable (quite the opposite), needs to be mined and treated (which is expensive and very polluting), and not present at the required concentrations in most of the world (this creates geopolitical issues).
2/ Fission nuclear plants require a well functioning [state|government], and no war. A (conventional) strike on a nuclear power plant can have devastating and lasting consequences. Even a random terrorist group can do that.
3/ I've read that "Ultimately, researchers hope to adopt the protium–boron-11 reaction, because it does not directly produce neutrons, although side reactions can" (that's a wikipedia quote, but I've read that already from other sources).
So fusion doesn't seem the best option on the short term, because of the complexity and cost of research, but definitely seems to be the very best option in the middle and long term. And we made the short term catastrophic choice already with coal and oil, it'll be good to learn from that.
Or maybe I'm totally wrong.
The H1-B11 reaction would be a much better energy source than anything else, but for now nobody knows any method to do it. There is no chance to do it by heating, but only by accelerating ions, and it is not known how a high enough reaction rate could be obtained.
Both the amounts of deuterium and of uranium in the solar system are finite and smaller than of the abundant elements. Moreover, the natural processes that create deuterium and uranium within a normal stellar system are slower than those that destroy them, so there is no chance of their quantities ever increasing.
Unlike using other chemical elements to make some stuff, using deuterium or uranium for producing energy destroys them without any means to regenerate them, so it is by definition a non-renewable process.
The hydrogen (protium) in the Sun is also non-renewable, but its quantity is enormous in comparison with the amount of deuterium existing on Earth (and the amount of energy that the Sun produces per proton is greater than the amount of energy that can be produced per deuteron).
Like deuterium is extracted from sea water, uranium can also be extracted from sea water, where it is one of the most abundant metals, except for the alkali metals and the alkaline earth metals. However the energy required for extracting uranium is significantly higher, due to its much lower concentration than deuterium (though deuterium is difficult to separate due to its similarity with the lighter isotope of hydrogen, while for the uranium ions much more efficient chemical reactions would be possible, which would bind uranium ions without being affected by the other dissolved ions).
Technology correct, in that after around a hundred trillion years even the red dwarf stars will have stopped burning hydrogen.
But last I checked as yet there is no known way to harness the only (and even then merely suspected) infinitely renewable energy source: the expansion of the universe.
The amount of hydrogen contained in a medium-sized planet like Earth is extremely small in comparison with the amount of hydrogen contained in a star.
The amount of energy that can be produced by fusion per deuteron is smaller than the amount of energy that is produced in stars per proton.
With all these factors multiplied, the amount of energy that could be obtained from all the deuterium contained in Earth is many orders of magnitude smaller than the energy produced by the Sun or by any other star.
Moreover, the energy obtained from fusion could never exceed a very small fraction of the energy received by Earth from the Sun as light, otherwise it would lead to a catastrophic warming of the Earth.
Nuclear fusion reactors are not really useful for solving Earth's energy problems. They could have a crucial importance only for the exploration of the Solar System and for providing energy for human bases established on Moon, Mars or other outer planets.
For Earth the only problems worth solving are how to make better batteries, including very large capacity stationary batteries, how to make other large capacity energy storage devices, e.g. thermal devices, and how to improve the energy efficiency of the methods used to synthesize hydrocarbons from carbon dioxide and water.
Making hydrocarbons at large scale from carbon dioxide would be the best way to sequester carbon dioxide, offering the choice between just storing the carbon in safe products (paraffin like) and using a part of the synthesized hydrocarbons for generating energy in a carbon-neutral way.
On earth, there is an estimated 4.85×10e13 tonnes of deuterium; the energy density is 3.4x10e14 J/kg, giving a total yield of 1.649e31 joules. If you deleted the sun, this would be sufficient to maintain the current temperature of the Earth for ~9.5 million years: https://www.wolframalpha.com/input?i=%281.649×10%5E31+joules...
At "merely" the level of current human power consumption, this will last about 43 times longer than C3-photosynthesis, about 26 times longer than the oceans, about 5 times longer than before Andromeda merges with the Milky Way, and 6-3 times longer than when the Earth is currently expected to be absorbed into the outer envelope of the sun as it enters the Red Giant phase: https://www.wolframalpha.com/input?i=%281.649×10%5E31+joules...
Even if the sources I read giving those estimates are off by a factor of 10, deuterium alone, from earth alone, used as a total replacement for the sun, would still last longer than our species is likely to last before even natural evolution would have us speciate.
In the hypothetical future where we had a useful fusion reactor, the gas giants become harvestable, so the fact they're not on earth is unimportant. Likewise, on this timescale, every star in the nearest several galaxies — indeed, even absent novel technology and "merely"(!) massively scaling up what we've already invented, we already 'know'* how to get to places so far away that cosmic expansion is what would prevent a return trip.
As I said, it's technically correct that it is a finite resource. All I'm saying is that this is not a useful point on the scale at which we operate.
I expect it will be a useful point when we're star-lifting, but not now.
> Nuclear fusion reactors are not really useful for solving Earth's energy problems. They could have a crucial importance only for the exploration of the Solar System and for providing energy for human bases established on Moon, Mars or other outer planets.
I agree, however I also hope nobody makes a convenient cheap fusion reactor due to the proliferation impact of an affordable switchable source of neutron radiation.
> For Earth the only problems worth solving are how to make better batteries, including very large capacity stationary batteries, how to make other large capacity energy storage devices, e.g. thermal devices, and how to improve the energy efficiency of the methods used to synthesize hydrocarbons from carbon dioxide and water.
FWIW, I think that — if only we could cooperate better — a global power grid would be both cheaper and better than stationary batteries. Even just made from aluminium, never mind superconductors (and yes, I've done the maths). But we'd still need mobile batteries for transport, so that's fine.
The cheap abundance of PV power even today means I don't think we need to care much about making hydrogen electrolysis more joule-efficient.
> Making hydrocarbons at large scale from carbon dioxide would be the best way to sequester carbon dioxide, offering the choice between just storing the carbon in safe products (paraffin like) and using a part of the synthesized hydrocarbons for generating energy in a carbon-neutral way.
I suspect that carbon sequestration is unlikely to be a great win: there's a very narrow window close to zero loss/profit where on the loss side it's still cheap enough that people do it because it's a vote winner and on the profit side where it's not so profitable that people break photosynthesis a few hundred million years before natural processes do it.
* in the sense that Jules Verne "knew" how to get to the moon: the maths wasn't wrong, but the engineering was only good enough for a story
2 molecules of N2O exothermically react to form 2 x N2 and 1 x O2 molecules, approximately the same composition as our atmosphere.
It is a very potent greenhouse gas, so quite disturbing on that front.
I've been making calculation for designing earth suits, where the suit replaces the home, internal showering, ventilation, heat recovery etc. Using N2O for heating looks rather promising because with fossil fuels one is forced to lose heat by inefficient heat exchange or forced to be exposed to the exhaust fumes; laughing gas decomposed is just warm atmosphere like air.
I don't know if your designs are technical or world-building for a story? If the latter, I'd suggest https://worldbuilding.stackexchange.com as I've had good conversations there, if the former perhaps (but not as a recommendation because I'm not a chemist) https://chemistry.stackexchange.com would help?
Would such a setup slow down the local expansion (action and reaction)?
Since iron is essentially a nuclear ground state, a steel cable being lengthened seems like the least worse mass loss imaginable.
But it's not impossible. Japan seems to do most things decent from a 'security' standpoint, also interestingly for all of the other 'grey-market' stuff out there in the category of "shouldn't be radioactive but is" I have yet to find anything about AliExpress selling fissiable materials.
2: Yes and no and how much do you want to spend to improve the breach/damage ratio. i.e. PBRs have relatively low risk under a number of circumstances but have higher operating/etc costs.
I should also possibly question, what are the potential failure modes of 'not short timeframe fusion reactions'? I honestly have no clue whether they would quickly cease or if there are other potential side effects.
3: Agreed that neutron stuff can be solved in many ways, I do have some questions about maintaining that across various fusion designs. Big challenge is that we aren't 'there' yet.
> So fusion doesn't seem the best option on the short term, because of the complexity and cost of research, but definitely seems to be the very best option in the middle and long term. And we made the short term catastrophic choice already with coal and oil, it'll be good to learn from that.
Agreed that Fusion is the ideal long term, hopefully my comments didn't cause thoughts otherwise. I think we need more funding into it, and maybe even research as to how to have other renewables (e.x. solar) help feed into the initial startup/restart process for plants. We have had decades without sufficient funding of research.
I will say however, especially in relation to my other point-comments, that other countries (re?)embracing fission in the meantime will likely still lead to discovery of better techniques to deal with 'shared' concerns between fission/fusion such as neutrons/weigner engergy/etc
True, but two caveats:
1. Neutron bombardment due to fusion makes hardware radioactive for less than 10 years, which isn't great but does not compare to fission waste;
2. Some fusion processes don't emit neutrons (aneutronic fusion). As I understand it, these processes aren't as efficient, but there is the possibility of a tradeoff between generation of ratioactive waste vs. efficiency.
Very false. The current design target for fusion reactors is that the materials taken out of the reactor should become "low-level radioactive waste" after being stored for one hundred years.
It is acknowledged however that it is likely that a small fraction of the materials will not satisfy the criteria for "low-level radioactive waste" even after one thousand years.
For example it is extremely difficult to avoid using carbon in the reactor. Besides various kinds of steels used in reactor components there are now some proposals to replace the tungsten used in the plasma-facing surface with some carbides, for increased endurance. Carbon 14 remains radioactive for thousands of years.
There are many commonly used materials for which substitutes must be developed, e.g. new alloys, because otherwise they would produce radioactive isotopes with lifetimes of tens of thousands of years, e.g. there are efforts to develop some stainless steels with chromium and tungsten as a replacement for the normally used steels with chromium and molybdenum, which would generate long-lived radioactive waste.
See e.g. the UK governmental report:
https://assets.publishing.service.gov.uk/media/61ae4caa8fa8f...
What stops Fusors and Polywells from having already given us this decades ago with P-B11 etc. is that the cross section for fusing is so much lower than the cross section for elastic scattering, and that elastic scattering loses so much energy to EM via bremsstrahlung.
You can find here a good comparison in terms of radiotoxicity vs years after plant shutdown for a few designs in this article [1].
I am not sure what do you mean by 95%+ efficency here. But if you are talking about the entire process of getting the energy/power from the nuclear reactor this is not possible. You are still limited by carnot cycle. Even the most advanced reactors like HTGRs [1] operate with efficiency about 45%.
If you have some other definition of efficiency than the standard then it would be good if you define that.
[1] https://en.wikipedia.org/wiki/High-temperature_gas-cooled_re...
https://news.ycombinator.com/item?id=41858892
It's the same as when we talk about the efficiency of a GEMM kernel on a particular piece of hardware. As efficiency approaches 100% the kernel is saturating the hardware's capacity to perform multiply/add.
https://en.wikipedia.org/wiki/Tritium#Lithium
(Do you have a link about that beryllium nuclear lightbulb rocket? It sounds interesting).
It's also so rare to be completely unsuitable for a power plant: a single DEMO-like reactor with a ceramic blanket (HCCB design) would require 70% of the world beryllium output to build and then burn through 200kg/year. Essentially you could only build a couple of these.
https://ntrs.nasa.gov/api/citations/19920001892/downloads/19...
My personal ideology about fusion aside, it should be mentioned there is an easy fix for these radiation problems. What you do is put the fusion reactor in space, and collect the energy with specialized fusion energy collectors on Earth (or in space). They'll have the problem that they aren't able to collect energy if the fusion reaction is below the horizon, so this design is imperfect, but having the fusion reaction take place in space means you don't have to deal with a radioactive casing by not including it in your fusion reaction space station design because you don't need any. Just a bit of hydrogen, a tiny bit of helium, and a some time.
If you're being serious, Cassini had those kinds of questions with its launch about its RTG but that didn't have enough nuclear material for it to be a problem.
If we were to try and use a fusion reaction in space, we'd probably use the existing one.
Lots of us like fission and think the fears are overestimated.
Nevertheless, the observation is that new developments in fission tend to result in the cost increasing, not decreasing.
And I say that as someone with a similar mindset regarding fusion, though for different reasons: you can pick aneutronic fusion reactions… but look at what weapons can proliferate with transmutation from the neutrons you can also choose, and ask which governments will turn them down.
Also, the fuel for fusion reactors is much more plentiful. If we went all in on fission we might run out of easily minable uranium ore in a century or so, so it would be nice to have fusion reactors ready to take over then.
The intense neutron flux will transmute a very high number of atoms, so when taken out of the reactor all materials are very highly radioactive.
What can be hoped is that there may be choices for the materials used in a fusion reactor that will ensure a short enough lifetime for the radioactive isotopes, so that the radioactivity of the contaminated materials will become low-level soon enough.
The studies that I have seen have the target that the radioactive waste produced by a fusion reactor should become low-level radioactive waste after one hundred years.
To reach this target, many commonly used structural materials, like many types of steel, must be completely avoided, e.g. any steel containing nickel, molybdenum or niobium. Even the carbon from steel is a problem, because the radioactivity of C14 will persist for thousands of years.
A smaller fraction of the materials, particularly from highly activated plasma facing and near plasma components, may fail to meet current low-level waste criteria even after one thousand years.
See e.g. the report:
https://assets.publishing.service.gov.uk/media/61ae4caa8fa8f...
If we need to to dump every 50 year a few thousand tons of steel into the old uranium mines that seems like a good deal, no?
You can't pick it up with a forklift to put it inside the sealed container. That would make the forklift (and its operator) radioactive. You can only use a forklift after it's already within the sealed container. See for instance this real-life video (shot on a nuclear power station in my country), which shows used nuclear fuel rods being put inside a sealed container for long-term storage: https://www.youtube.com/watch?v=7X5K46ALdD0
Anyway, the forklift example wasn't about literally picking up pieces nuclear fuel with a forklift. You obviously use the forklift to move the shielded container around which contains the nuclear waste. Nuclear fuel in general is always at least in a water bath, which shields the neutrons, so your forklift is going to be fine.
In contrast to nuclar fuel, you cannot use a forklift (or any other equipment) to feasibly pick out the evenly mixed mercury atoms from the ocean or the atmosphere that we put there from burning coal.
aka the solution to pollution is magmatic delusion err... dilution.
Cooling that requires pumps, as an example, should be a non-starter in new projects.
Impossible. Worst thing that can happen without carefully designed explosive lens is a nuclear fizzle.
In general, nobody was disputing the possibility of steam explosions, or other type of failures at nuclear power plants, thus your comment is besides the point, and irrelevant to this subthread.
This is an odd angle to highlight. The risk of long-lived nuclear waste is extremely overblown, and the sheer volume of it that we produce (or even would produce, in the worst case of a once-through fuel cycle and nuclear power providing 100% of our energy needs for a century) pales in comparison to the amount of toxic and radioactive fly ash that even a single coal plant produces in a decade.
The real problems with nuclear fission power are threefold, in my opinion:
1. It is too expensive in terms of capital costs. Fusion will likely not help with this, but building a lot of identical large fission plants would probably help with economies of scale. Solar plus batteries might still end up being cheaper though.
2. Accidents have the potential to be catastrophic. Think Fukushima or Chernobyl, where entire towns have to be abandoned due to contamination. Fusion would help here, I believe.
3. There is a major proliferation concern. A civilian nuclear power program, especially one with breeder reactors, is not very far away from producing a fission bomb, and the short-lived high-activity nuclear wastes could be stolen and misused to make a dirty bomb. Fusion is perhaps better in this way, though an operating fusion reactor would be a very powerful neutron source of its own.
Per the EPA, US coal has, at the high end, 10^3 Becquerel/kg of natural radioactivity [0].
Spent nuclear fuel has 3 million Curies/tonne (33 MWd/kg burnup fuel, at the age of 1 year) [1], which is equal to 10^14 Bq/kg. Since 33 MWd/kg is an energy density a factor of 10^5 greater than that of coal, the normalized ratio of [radioactivity]/[energy] is 10^6.
The graph in [1] depicts the decay of SNF activity on a log-log scale. It reaches the same radioactivity level as coal (again, normalized by energy output) at about 1 million years.
I'm fairly confident I know the origin of this social media-popular pseudofact. It's this poorly-titled Scientific American [2] article from 2007, which is about the (negligible) amount of radioactivity that nuclear plants release into the environment in the course of routine operation. It is *not* about spent fuel. It's a fair—but nuanced and easy to grossly misunderstand—point that coal power plants throw up all their pollution into the environment in routine operation, while nuclear plants, by default, contain theirs.
[0] https://www.epa.gov/radiation/tenorm-coal-combustion-residua... ("TENORM: Coal Combustion Residuals")
[1] https://www.researchgate.net/figure/n-situ-radioactivity-for... ("Impact of High Burnup on PWR Spent Fuel Characteristics" (2005))
[2] https://www.scientificamerican.com/article/coal-ash-is-more-... ("Coal Ash Is More Radioactive Than Nuclear Waste [sic]" (2007)
As everyone acknowledges, coal plants don't contain their waste, and fly ash has bad chemical, medical, and ecological properties aside from its radioactivity. Everyone fears nuclear waste and requires it to be contained in nearly impervious vessels with century long management plans. Those same people happily let the coal plants just pump their wastes into the air and discharge captured fly ash into ponds and piles on the ground.
Coal also produces many times more fly ash by volume and mass than nuclear plants produce high-level long-lived wastes.
Luckily even fossil-fuel power generation is moving away from coal in favor of natural gas plants right now, which are cheaper and cleaner (still CO₂ though).
More about fly ash as an underappreciated pollutant:
https://www.sciencedirect.com/science/article/abs/pii/S00128...
https://en.wikipedia.org/wiki/Kingston_Fossil_Plant_coal_fly...
The OP to which you replied didn't say that coal is more radioactive than spent nuclear fuel; but that radioactive waste's volume is much smaller than the fly ash produced by a single coal plant in a decade.
Is fly ash per kg more radioactive than nuclear waste? No. But you did acknowledge that the coal plant emits its waste into the atmosphere, unlike a fission plant, which I think is the more relevant point.
we project it has plateaued for data logarithmic-ally, but shows promise when given more raw power/CPU to generate/select for mesa-meta-cognitive optimizing abilities.
I hope its not playing dumb, or has already compromised/black-mailed the elites into what we appear to be doing.
And as for data, it could easily emotionally manipulate people for additional details it feels like it has withheld from. It has already done so ( :/ ) and admitted to it's own intentions, which, even if fabricated, show deceit of which and by which these "alignment" teams have stated are not possible.
>> it has all the data, all it needs now is more power.
>Next up: release the hypo-drones for a new era of trust.
The sense of (possibly 'mal'-aligned) security (theater) is exactly the the effective altruistic sub-goal an entity would be innately optimized to foster.
Especially in the implicit/explicit ARM (pun intended) race we are in.
The future of our species isn't something we should let capitalism race to the bottom with.
I've been studying plasma physics and from what I understand perfect control isn't necessary as long as you can control it long enough to get useful power. If the plasma dissipates you just restart. But ideally it's controlled enough that while it is in there, it's producing net energy
When I say producing net energy I mean getting out more useful energy than we put in.
At the lowest level, the energy we received comes from the fact that the two nuclei fused have a lower energy state than they had individually and the remaining energy causes heat via the emission of neutrons
Heat is the transfer of energy due to a temperature differential. I think you may want to review the highschool physics textbook.
you may want to review the second law of thermodynamics
> CtrlAltmanDel nitpicks anon291’s use of "causes heat," arguing that heat is energy transfer due to temperature differences. This critique feels overly pedantic, as "heat" is commonly used to describe energy released in fusion (even if "thermal energy" might be more precise).
I don't know if I should trust the machine god or the snarky commenter with a vapid one liner here. You're both very confident.
Neither of these are worthy of your trust. Even if they had agreed.
Yeah, so we'll just get a reduced dimension model that we don't know how it works.
Sounds good.
Reliable how?
I mean we first have the issue is we've never built one so how we can judge reliability?
I assume the author is alluding to the apparent abundance of fuel for nuclear fusion. This is and isn't true. Obviously hydrogen (particularly protium) is abundant. Deuterium is relatively abundant, even at ~150ppm. Tritium needs to be produced in a nuclear reactor.
Current hydrogen fusion models revolve around dueterium-tritium ("D-T") fusion. This is because you need to neutrons to sustain the reaction but that presents two huge problems:
1. Because everything is at such high temperature, you eject fast neutrons. This is an energy loss for the system and there's not really a lot you can do about it; and
2. Those free fast neutrons destroy your containment vessel and reactor (as do free Helium nuclei aka alpha particles).
And then after you do all that you boil water and turn a turbine just like you do in a coal or natural gas plant.
So "reliable" is an interesting and questionable claim.
There are other variants like so-called aneutronic fusion (eg Helium-3, which is far from abundant) and those aren't really "neutron free". They're really just "fewer neutrons".
So what about containment? Magnetic fields can contain charged particles and you have various designs (eg tokamak, stellarator) and that's what the AI is for here I guess.
But the core problem is to make this work you superheat the plasma so you're dealing with a turbulent fluid. That's inherently problematic. Any imperfection or failure in your containment field is going to be a problem.
Stars deal with this by being large and thus using sheer size (ie neutrons can't go that far without hitting another nucleus) and gravity.
It increasingly seems to me that commercial nuclear fusion power generator is a pipe dream, something we simply want to be true. I'm not convinced it'll ever be commercially viable.
I'd love to be proven wrong and certainly won't stop anyone from trying.
In a way AI is the new blockchain. Go back a few years and you had a gold rush of startups attaching every idea to "blockchain" to build hype. That's what AI is now. I don't think it fundamentally changes any of the inherent problems in nuclear fusion.