RE: https://mstdn.social/@stshank/117162806916390598
This is of course where the private equity bros are pivoting to next, to hide their stolen loot (once the data centre bubble pops).
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CFS seems quite real. I know a number of people working there. Looks like a good mix of plasma physicists and engineers. (About the other companies, I know little or nothing, and thus have no opinion.)
The physics is straightforwardly in CFS's favor: tokamak size scales with magnetic field like 1/𝐵³ (and the power density like the inverse 4th power). They've demonstrated novel high-temp superconductor magnets (yttrium/barium/copper oxide) at 20 Tesla field strength. They have built the manufacturing capacity to make a bunch of them, and are doing so now. Apparently they supply such magnets to other sites, as a little side business.
The test reactor is being built in Danvers Massachusetts. It's designed for a Q of 11, i.e., 11x more power out than in.
Details on reactor size vs field strength:
https://iopscience.iop.org/article/10.1088/1741-4326/ad2425
A recent talk by Clauser on tokomaks including the CFS SPARC being built now; scaling equations on slides 26-35:
https://suli.pppl.gov/2025/course/Clauser-tokamaks-2025-v2.pdf
@cstross I thought they were all about the quantum computing bubble next. Someone should start some FOMO rumour for them about AGI’s imminent invention of warp drive 🤣🤣🤣
@cstross I was so sure it'd be quantum computing.
That with all the talk about how quantum effects and consciousness might be connected.
That with all the talk about how quantum effects and consciousness might be connected.
@markus Right now they're in throw-money-at-ALL-the-walls-and-see-what-sticks mode. The stench of panic hanging over the markets (aggravated by Trump's latest Canada tariffs hitting toilet paper prices).
@cstross
I'm less angry about that. Some physics and engineering may come out of it.
Whereas using staggering amounts of energy to produce BS...
@iinavpov This is a complete 180 from my position a very few years ago, but right now I don't believe we need another nuclear power source. Fusion isn't inherently clean, can be used to breed plutonium for weapons, and relies on large centralized generators—heavy industry, in other words, with its toxic political and economic side-effects.
@cstross
Now, I don't have a strong view on that, except I have little belief that there will be any machine actually operating coming out of any of these startups.
I just think that it's a vastly less destructive way of spending money when compared to AI.
I think that if any breakthrough happens, it'll serve in some form many decades from now...
There have been some legit advances in fusion lately, most notably at the National Ignition Facility.
I'm OK with fusion reactors. They've been working on it so long they've earned a win.
It would be galling of course for present day crooks to take all the credit. That's what happened with recent neural net breakthroughs, after decades of work by real scientists.
@cstross I have a friend who works for CFS and I have learned about so maybe different ways that welding two pieces of metal can go wrong in the past couple years. I also learned about the Massachusetts Board of Boilers, which I think would be a great name for a villainous organization in a novel (not to tell you how to do your job)
