[api]

The amount of cynicism around fusion is stupid. It reminds me a lot of the learned helplessness that surrounded the idea of reusable spacecraft.

A little engineering later:

https://www.youtube.com/watch?v=sf4qRY3h_eo

Fusion is a harder problem than that but we have no physical reason to believe it is not possible and the surrounding technology like compact higher temperature superconductors has advanced significantly since the 1960s and 1970s.

I am typing this on a computer with a ~5nm feature size CPU. Hard things can be done. It takes time, focus, and funding.

[ncmncm]

Cynicism is well justified, given history and the present landscape.

Suppose they get this working, and able to produce, what, 300 MW worth of hot neutrons. They have to capture the neutrons and turn them into heat to boil water to drive a turbine to get out 150 MW. Thus, handle the, what, 1000 tons? 10,000 tons? of lithium needed to capture all those neutrons. And, I guess, sieve it for tritium? Maybe chemically separate micrograms of Li-3H from the thousand tons of pure, molten, radioactive lithium? And, every year replace all the pipes the lithium runs in, weakened by neutron bombardment. By remote control, because strongly radioactive.

This is clearly a bigger job than what needs to be done for a fission plant, where all you need to handle is water and fuel rods. (If you think a 1000 tons of molten radioactive lithium won't need containment, allow me to disabuse you.) But fission is already not competitive with solar/wind + storage. In 10 years, fission will be even less competitive than today. There is no scenario where this ends up economically useful.

[car_analogy]

> Cynicism is well justified, given history and the present landscape.

The history, measured by the fusion triple product, is exponential progress on par with Moore's law [1], despite abysmal funding [2].

[1] Figure 1, https://www.scipedia.com/public/Sanchez_2014a

[2] https://hardware.slashdot.org/story/12/04/11/0435231/mit-fus...

[pfdietz]

If only achieving a high triple product were enough to achieve practical fusion. It's not -- there are serious obstacles, especially for DT fusion, that have nothing to do with plasma physics.

[ncmncm]

The history is of radical overpromising, and continual announcement of "breakthroughs" that do not bring plausible competitive viability any nearer.

The current funding level, given the abysmal prospects for any return, is too high. It was even higher before. We'll never get any of that back.

[car_analogy]

> The history is of radical overpromising, and continual announcement of "breakthroughs" that do not bring plausible competitive viability any nearer.

It sounds like your issue is with the PR, not the technology. Is there something faulty or misleading with the progress made in the triple-product score?

> The current funding level, given the abysmal prospects for any return, is too high. It was even higher before. We'll never get any of that back.

30 years of fusion research is what a single Nimitz aircraft carrier costs. The "even higher" level was one Nimitz carrier per decade. And it only lasted one decade. Eyeballing the funding graph, the US has spent a total of 3 aircraft carrier's worth of funding for fusion in total, since research began.

[ncmncm]

3 aircraft carriers in, 0 kWh out.

[eole666]

"But fission is already not competitive with solar/wind + storage." Any source about that ? It just sounds like an arbitrary anti-nuclear opinion without any evidence backing it. But I'm still cursious if you have anything serious to prove this claim.

[ncmncm]

I could go google that for you. But, why?

Innumerable commercial entities are building out solar and wind farms as fast as they can scare up capital. Literally not a single purely commercially-backed nuke plant has ever been built in 70+ years. Not one. Capital did build and operate coal plants, at a profit. But nobody is building new coal plants, anymore. Even operating an existing coal plant is not competitive any more; coal plants are being shut down with no plan ever to re-open, exactly as fast as solar and wind come on line.

Nukes are made out of steel, concrete, plumbing, and pumps. None of those are getting cheaper. They produce power by blasting steam through enormous turbines, that need regular expensive maintenance, not getting cheaper. Mining and refining uranium is expensive and not getting cheaper. Solar and wind generation cost have been declining at an exponential rate for two decades, and are still falling. Can you even conceive of an exponentially declining cost not crossing any given constant cost?

Suppose you figured out a way to get power from nukes at half the cost, and that was less than renewables just now. How long would it be before they undercut that, again? Would you be able to finish building one, in that amount of time?

There is no future for fission, and even less for fusion.

[eole666]

"Literally not a single purely commercially-backed nuke plant has ever been built in 70+ years. Not one."

Sure, let's check wikipedia to see how this is not true : https://en.wikipedia.org/wiki/List_of_commercial_nuclear_rea...

Also, after googling it: yes indeed, in some countries renewable energies are more competitive than fission. But that's not the case everywhere : https://www.iea.org/reports/projected-costs-of-generating-el... Or maybe you were just talking about the US, in this case your statement might be true.

I hope renewable energies cost will keep decreasing as much as it did those last ten years but I'm not as optimistic as you are.

[ncmncm]

Supposed purely commercial plants are always, it turns out, massively subsidized. At minimum, they are absolutely protected against liability, so do not need to try to find an insurer, never mind pay premiums to one.

And, mining and refining fuel has been massively subsidized.

[mindcrime]

The amount of cynicism around fusion is stupid. It reminds me a lot of the learned helplessness that surrounded the idea of reusable spacecraft.

One of the easiest (laziest?) positions one can hold is simply to be dismissive of anything that hasn't happened yet, and which appears to be moderately difficult or harder. Fusion, AGI, etc... Just dismiss those things as ridiculous and you position yourself as wise, informed, erudite, whatever - to most people.

[kitd]

The first fusion-powered blockchain should push HN to cynicism supercriticality.

[nr2x]

Fairly confident we’ll get fusion before we use a “blockchain” to buy a loaf of bread.

[solveit]

Somewhat famously, the very first commercial blockchain transaction twelve years ago was for two pizzas. Cynicism is fine but you don't have to be lazy about it.

[nr2x]

I was the first person to accept bitcoin payment for a certain class of goods (not illegal, just don't want to out myself) - so yes, I'm aware of the pizza transaction and have friends who retired off of BTC. That doesn't mean I can buy a cup of coffee with what started as a cool currency idea and turned into a speculative asset for tech bros.

In fact, just yesterday had a conversation with a friend and realized at current prices we jointly spent several hundred thousand dollars on VPN services. So yeah, I was there before there was a there.

[pfdietz]

But there are excellent reasons to think DT fusion (which is what these people are trying to do, as well as most fusion efforts) is a nonstarter. And these reasons have been known since at least the 1980s. We skeptics get annoyed at vacuous optimism that just ignores these real arguments.

[omnicognate]

A lazier position is to dismiss the views of a vague group of people as empty posturing without even clearly identifying who you're talking about.

[bell-cot]

With modern nuclear technology, it is quite possible to convert lead into gold. It's been done. Years ago.

HOWEVER, it was also understood that the cost per ounce of the resulting gold was orders of magnitude higher than the cost of gold obtained via lower-tech methods.

So there were no serious attempts to scale up the original process. Nor to improve it. Nor to develop "new and better" lead-to-gold conversion processes. Nor to otherwise squander vast sums and resources chasing the "but it IS possible..." dream of making real gold from mere lead.

[pfdietz]

> we have no physical reason to believe it is not possible

We have excellent physical reasons to think DT fusion will not be practical. The power density will be terrible, so it would be more expensive than fission at boiling water -- and fission isn't competitive these days.

[andrewflnr]

I'm bullish on fusion in general, but there is a lot of hyper-optimistic BS about any particular fusion setup, and it gets tiring really fast. I can't say I don't blame the cynics, since they're helping kill our species, but I do sympathize.

[Gene_Parmesan]

FWIW feature size doesn't really mean what it used to. Due to the 3d mesh manufacturing process, it's become a sort of shorthand for "equivalent in 2D." What really matters is transistor density, and different manufacturers differ wildly in how they relate transistor density to this "feature size in a 2D equivalent metric."

For instance, the M1 has a density of 171 million/sq mm and claims 5 nm 2D equivalent, while Willow Cove from IBM looks much worse at 10nm but its density is 100.

Saying this not to "cast shade" on certain chip fabricators, just saying that it doesn't actually mean that they have taken the same style transistor fab processes from ~10 years ago and shrunk them down to 5nm. I mean, by the time an actual 2D feature would reach ~2nm, we'd be talking about features that were only about 10 atoms across.

[qiskit]

Sure, unwarranted cynicism isn't helpful. But neither is blind optimism. Moore's law has proven itself for decades. Fusion has failed for even longer. A little bit of cynicism is not only called for, but healthy in this case.

[perihelions]

I've never seen "learned helplessness" linked to "technical progress in a scientific field" in such a way. Has anyone written about this analogy? It sounds super interesting. Like a nontrivial insight into how people approach open-ended problems.

(There's that one quote from a startup founder, "we did it because we didn't realize how hard it was", or something like that. From a pg essay maybe?)

[wolverine876]

> the learned helplessness that surrounded the idea of reusable spacecraft

Those were flying in the 1980s.

[dboreham]

The cynicism is due to the framing of these stories, failing to set them in the context of "this is a tiny part of a large number of difficult things that need to be achieved before any of this is useful".