Google revives controversial cold-fusion experiments | Hacker News Reader

Google revives controversial cold-fusion experiments

nature.com

191 pointsokket155 comments

One of the most iconic images of my childhood is when my scientist-inventor dad attempted to reproduce in his own lab the Fleischmann–Pons experiments of the late 80s. He'd built (I think to spec) an exact replica according to the published designs. Of course, nothing ever came of it, but it still fascinates me to this day thinking of him laboring over that. (The long beard and unkempt hair lent well to my image of him as mad scientist.)

I asked him later about the results of those experiments, and his sort of retort sounded like an embarrassing admission, something along the lines of "nothing will ever come of that."

I still idol the awesomeness of those days though.

> the Fleischmann–Pons experiments of the late 80s

I recall a talk given at an MIT club a few years ago in which a researcher claimed loading was insufficiently controlled in follow-on experiments. I think cold fusion and F-P is probably a fraud, but it sowed enough doubt in my mind so as to make a follow-up, if not reasonable, also not unreasonable.

The cynicism in this threads hurts.

> “This is not just a chase for cold fusion,” says Matthew Trevithick, a research programme manager at Google in Mountain View, California. “If it were, I don’t think we would have maintained an interest of this calibre of team for so long.”

Here's what I see: fusion power would be a step function in human civilization. Such step functions are pathologically hard to achieve, because new modes of thinking are hard for humans to do. Calling it cold fusion is a calling card to scientists who are serious about researching novel approaches to fusion instead of playing the politics of the research paper game. Will it work? Probably not. But that doesn't mean we shouldn't try. Also, from Google's perspective, if they're the company that owns the IP for fusion energy, that's a pretty massive win. Additionally, if they push just a few other companies into funding fusion research, then the odds that we see viable fusion energy production (not cold fusion) in our lifetimes probably increases. I would love to see a private industry race for fusion research, though, the financial requirements of such endeavors mean the game would only be open to a very small number of global megacorps. Still it would be better than not doing it.

The skepticism is not about fusion power, it's about cold fusion specifically, as well role of proprietary IP and patents in scientific research.

Tokamak[1] (and other magnetic confinement) reactors seem much more promising and have seen slow but non-zero improvements for decades[2]. Some reactors like JT-60 have come close to being energy positive[3] but are not yet self sustaining. Large ongoing projects like like ITER[4] have the potential to break past limits and provide invaluable data. There are also advances in plasma physics which improve our ability to run computer simulations[5] of Tokamaks and suggest new hypotheses for how they can be improved[6].

If Google were serious about fusion, they would invest in this kind of mainstream research. Unfortunately, that's too big for them to own end-to-end; the most they could do would be to participate in the international process. But that wouldn't result in proprietary, patent-able technology, so they instead they put resources behind fringe science that they can control. This is reminiscent of the Lockheed-Martin CFR[7], which also chose an approach which was extremely unlikely to result in a scientific breakthrough but which did yield a few patents for Lockheed-Martin.

Frankly, behavior which is only one step removed from straight-up patent trolling justifies a certain degree of cynicism.

[1]: https://en.wikipedia.org/wiki/Tokamak

[2]: https://en.wikipedia.org/wiki/Timeline_of_nuclear_fusion

[3]: https://en.wikipedia.org/wiki/JT-60

[4]: https://www.iter.org/

[5]: http://www.psfc.mit.edu/research/topics/plasma-fusion-theory...

[6]: https://phys.org/news/2019-01-scientists-stabilizes-fusion-p...

[7]: https://en.wikipedia.org/wiki/Lockheed_Martin_Compact_Fusion...

> Some reactors JT-60 have been energy positive[3] but are not yet self sustaining.

Nitpick: I don't believe the JT-60 has actually gone energy positive. They achieved a point where they would be power positive if they had been able to use a 1:1 ratio of D-T fuel instead of their D-D fuel but handling D-T fuel is very complicated and the JT-60 facility doesn't have those capabilities.

Noted; I've edited the above comment to read, "have come close to being energy positive." Thank you.

So, you must think one of two things, then:

1. Google, with all of the subject matter expertise they can avail themselves of, is completely wasting their money on this research that has no hope of success.

2. It'd be a bad thing for the world if we got cold fusion, but Google made some money off of it.

Is that right?

It would be a bad thing for the world if we got cold fusion and Google controlled the entire stack, yes.

This is because in the long, long term, allowing a company to dictate how a technology this important is used could hamper our ability to build on it or improve it. Over a long enough timescale, it would be better if we delayed getting cold fusion so that we could get the same technology later in a less encumbered form.

If cold fusion is possible, and Google stops working on it, we can still get it through other means. Other people can pick up Google's slack. If Google manages to crack it, and as a result is able to put legally enforceable restrictions on how it's used, then that's it. There's nowhere to go from there.

Those legally enforceable restrictions last for less than two decades; it's already been 30 years since the Pons and Fleischmann fiasco.

It's also assuming they would do something untoward with the monopoly, rather than just building a thousand new power plants and then making ten trillion dollars by being the lowest cost provider of zero carbon power generation for twenty years.

I don't know how the math works out exactly, but it seems not unlikely that the optimal rollout for curbing carbon emissions as rapidly as possible is not the same as the optimal rollout for maximizing value to shareholders.

Why not? If someone is buying power from coal instead of you when you have lower costs, that's money you're leaving on the table.

I'm sure there's lots of ways it could happen. Off the top of my head - you can't just snap your fingers and start selling power, you need to build the reactors, scale out infrastructure, etc etc. There's huge expenditure involved. If you have a giant pile of money in the bank, earning interest, it might not be worth your while to spend it on that.

Another point - how much do you charge for the power? If your goal is to get people to switch, the answer is "as little as you can". If your goal is to make money, the answer is "as much as you can".

> If you have a giant pile of money in the bank, earning interest, it might not be worth your while to spend it on that.

But that's the case either way. If the technology was public domain, somebody would still have to pay to build the reactors, and then it's even harder to raise capital because with more competition there is less profit.

> If your goal is to make money, the answer is "as much as you can".

But "as much as you can" really means "just under what existing alternatives cost" -- because getting people to switch is how you make money. You don't make money by losing customers to competitors.

I have a feeling that if Google is successful at something along the lines of cold fusion, most governments will ignore any patents. The genie will be out of the bottle.

Google can do what they like, of course. Perhaps they'll even make some money off it and create some useful device. I doubt Google has any greater access to SMEs - which in this case would be academic physicists - than ITER or CERN. I do believe that a dollar invested in tokamak research is more wisely spent than a dollar invested in cold fusion.

To me it sounded like olooney was arguing a third option:

3. Google will fail to achieve cold fusion but possibly get some patents which will make them money, but do little to advance overall scientific progress towards economic fusion.

This tabletop research is orders of magnitudes cheaper than hot fusion. It's a huge reward for tiny risk.

Ah, yes, the good old Pascal's mugging[1].

I am aware that cold fusion experiments are both much cheaper, and if successful, considerably safer and cheaper than hot fusion. Yet, there is no plausible mechanism for fusion to occur at room temperature. For two protons (hydrogen ions) to fuse, they must be brought to within 10e-15 m of one another. This requires overcoming the Coulomb repulsion between the two positively charged protons. This in turn requires a great deal of energy, roughly 6 KeV even once quantum tunneling is taken into effect. This corresponds to velocities of roughly 10e6 m/s, or roughly 0.5% the speed of light. This is is called the Gamow energy or the Gamow peak[2]. In hot fusion, this is accomplished by heating a gas to something like 10e7 K, at which point the average energy of any given proton in the plasma is roughly 6 KeV. Not coincidentally, this is also roughly the interior temperature of stars. It has been shown time and again that fusion does occur in a tokamak reactor... just not quite fast enough to overcome the cost of creating and containing the plasma.

At room temperature, the fraction of protons traveling at 0.5% of the speed of light is zero for all intents and purposes. Thus, spontaneous does not normally occur at room temperature, which we can all agree on. For cold fusion to proceed, there needs to be some other mechanism capable of making up this difference, either by somehow accelerating protons to an extremely high velocity, or otherwise encouraging them to fuse, perhaps by lowering the Coulomb barrier by some unknown mechanism. For the Fleischmann–Pons experiment (the original "cold fusion" experiment in the 1980s) this was hypothesized to be achieved by the crystal structure of palladium[3]. However, after the failure to replicate the original experiment, this hypotheses appears to have been falsified. In fact, no experiment has ever shown a measurable rate of fusion occurring at low temperatures.

And yet, there is the precedent of the Gamow factor. The classical potential for the Coloumb barrier is 3.4 MeV. Therefore, in a purely classical model, it is literally impossible to get two protons to fuse unless they collide at close to the speed of light. Yet Gamow showed that fusion could occur, with some probability, at much lower energies, thanks to a well known phenomenon called quantum tunneling. Why could there not be some other way taking this further? Furthermore, there is the precedent with fission. In the 1930's, many notable scientists were fission could ever be used as a power source. They were aware that fission could be effected by alpha particle bombardment, but this did not seem "energy positive." Sound familiar? And yet, when Hahn and Meitner[5] discovered spontaneous nuclear fission occuring due to a chain reaction in uranium in 1938, it immediately became apparent it could be used as a massive source of energy, and Einstein immediately warned FDR and the Manhattan project began.[4] Why could not a similar story play out for fusion? Cold fusion is tantalizingly plausible and the experiments, as you say, can be conducted on a tabletop. Why not try?

My answer, which is of course a subjective judgement, is that good science happens by searching where the light is, exploring the implications and edges of existing theories, not out in the dark, trying things completely at random. Rutherford wasn't bombarding gold foil for the hell of it. Randomly trying things in an atheoretic way in the hopes that a previously undiscovered and unsuspected piece of new physics will drop out is closer to alchemy, and just about as likely to be successful. More than 2,000 years of randomly combining urine and lead resulted in not one ounce of gold. (I grant you that tabletop cold fusion experiments may very well find a new bit of chemistry.) But the argument against is simply this: 6 KeV. It's simply too much. No chemical or electrical process is going to get you that, unless it first turns your experiment into plasma, in which case you're back to hot fusion! It's like throwing pebbles at the moon and calling it the Apollo program. It's not a matter of just getting the right pebble. You can try quartz and obsidian, rough and smooth, for as long as you like, but you're not even beginning to address the invariant in the room, which is that you just can't impart enough kinetic energy to your pebbles to even get them out of Earth's gravity well, much less to the moon. That is why I believe that a dollar spent on cold fusion actually has lower expected payoff than a dollar spent on hot fusion.

[1]: https://en.wikipedia.org/wiki/Pascal%27s_mugging

[2]: https://en.wikipedia.org/wiki/Gamow_factor

[3]: https://en.wikipedia.org/wiki/Fleischmann%E2%80%93Pons_exper...

[4]: https://en.wikipedia.org/wiki/Einstein%E2%80%93Szil%C3%A1rd_...

[5]: https://en.wikipedia.org/wiki/Otto_Hahn#Discovery_of_nuclear...

What about “Bubble Fusion” or some other physical process that you can’t foresee, could that pass 6KeV ? Localized?

Coulomb forces are much weaker at the ends of highly elliptical nuclei. We've always assumed atomic nuclei are spherical. They are not. Iron nuclei have ends where the Coulomb forces are two orders of magnitude lesser than assuming a spherical shape would predict.

>Google, with all of the subject matter expertise they can avail themselves of, is completely wasting their money on this research that has no hope of success.

This isn't actually as silly as it sounds. There's a certain culture around self-absorbed futurism alive and kicking within these companies that produces weird and nonsensical projects.

One only has to look at Ray Kurzweil who turned from genuine inventor into some sort of nutrition supplement cyber guru and apparently still is employed by Google. There's also a lot of general silliness in the 'smart city' space, or cryogenics and lifespan enhancement. What all of those projects usually have in common is that they predominantly sound like something out of science fiction novels that the people would read who go on and found tech companies.

You could argue that this is exactly the type of research that should be funded by private industry: high-risk, high-reward, and unlikely to get government funding.

High-risk is something that private industry rarely to never does (except on vanity projects). All of the venture capital in Silicon Valley is really chasing medium-risk, not high-risk.

Beyond big tickets like fusion, I would direct you to things like initial drug investigations (almost all done in University labs with government grants), or rocket development (almost all done under government grants). In all of these cases the initial development of things that are unlikely to work out are done on public funds, and once it looks like it is just down to the details (still a big undertaking) then private funding steps in. The pattern here is almost always: socialize costs/risks, privatize gains.

> If Google were serious about fusion, they would invest in this kind of mainstream research.

They do.

https://www.theverge.com/2019/1/29/18201220/nuclear-fusion-e...

Just because they also look into other alternatives doesn't mean they are ignoring the more mainstream research. They are approaching it from every angle, because as pointed out, any discovery here can help in other places too.

> Frankly, behavior which is only one step removed from straight-up patent trolling

Google, for as big as it is and as many patents as it owns, has never once used its patent portfolio offensively, so assuming that they want to patent-troll is extremely unfair.

These two projects look great, and are exactly the kind of projects where I can see Google making an impact. I think it is extremely likely that we will struggle to build working reactors until we have an "AutoCAD for magnetic containment" which is able to accurately simulate real world plasma physics, after which I expect that a working design will be discovered within a few years, and then constructed within a decade or two. This follows from the simple observation that the build-test cycle for real world reactors is something like a decade, and for simulated reactors something like 1 day - a 36500X decrease in iteration time is a game changer. Such a program is very non-trivial and no one today knows how to write one.

And that's exactly the kind of stuff Google is trying to accelerate. One tangential but highly relevant example is their work on predicting molecular properties [0]. They were basically able to use neural networks to speed up the simulator by 300,000x, taking something that would take hours to less than a second. As you mention, this entirely changes the way you work and iterate. Here's a video of Jeff Dean talking more about it [1].

[0] https://ai.googleblog.com/2017/04/predicting-properties-of-m...

[1] https://www.youtube.com/watch?v=rP8CGyDbxBY&t=16m43s

How can something like this even conceptually make sense? I'm sorry, but can someone explain to me how a neural network could approximate physically-deduced laws of nature (as had-coded into the classical simulator as I imagine) "without any distinguishable error"?

This is the biggest bs I have ever heard, since an molecular physics simulator that is beat by a neural network can only just be unoptimized as hell.

I think this is an example of something similar: https://www.sciencedaily.com/releases/2019/05/190517145112.h...

> Machine learning speeds modeling of experiments aimed at capturing fusion energy on Earth

I'd believe Lockheed Martin's CFR claims more if they didn't say things like this:

> Energy created through fusion is 3-4 times more powerful than the energy released by fission.[0]

Which is just confus(ed/ing) on a fundamental level... More Powerful energy? So each Joule from fusion is actually 3-4 times better than each Joule from fission, in some way? I really can't work out what they are trying to say here.

0. https://www.lockheedmartin.com/en-us/products/compact-fusion...

I think they’re saying that a single fusion event produces 3-4x more energy than a single fission event.

Do you mean a single _fusion_ event?

Yes, thanks. Brain no function beer well without.

But even that is pretty vague, since a single Uranium atom fission event releases about 200 MeV of energy, whereas most of the Hydrogen/Deuterium/Tritium/Helium/etc. fusion pathways release around 10% of this per fusion event: D + T -> He fusion gives 17 MeV, 4 p -> He gives 27 MeV, D + D -> He is 12 MeV and so on. Now, the energy released per nucleon greater for fusion, but I'm not convinced that's a useful or intuitive metric?

How about energy per kilogram?

OK, so 235 kg of U_235 has the same number of fissile units (N atoms = 1000 x N_a) as 5 kg of D-T has of fusible units (2N atoms of combined weight 5 amu, or 1000 x N_a pairs) so (ignoring the N_a for now) one kg of U_235 gives 200 MeV / 235 = 0.85 MeV and the D-T fusion gives 17 MeV / 5 = 3.40 MeV

So, yeah, that's exactly four times the energy per kilogram. Now, why couldn't they just say THAT on the web page instead of the confusing and meaningless "this energy is 3-4 times more powerful than that energy" nonsense? But, thanks 'mikeash for clearing that up for me!

Humanity can already access more energy than is healthy for our planet. Even if you had a zero-greenhouse-gas source of energy, all that energy is eventually dissipated as heat, so it would not be safe to use an unlimited quantity of it.

I looked at the numbers about 10 years ago and iirc I concluded that waste heat is about 10% the impact of greenhouse gasses, so not insignificant. I don't remember how I got that number though, and I could have easily messed something up.

If we had near unlimited energy, we could find a way to trap heat energy and remove it.

Where would the heat go?

To the orbital ring, then to its radiators.

Alternatively we can tone down the sun with the shade satellites.

Into the Sun of course!

> Will it work? Probably not. But that doesn't mean we shouldn't try.

The fact that it "probably will not work" (where "probably" = "almost certainly") is a strong argument for not doing something.

If I told you I had this idea for an over unity generator that "probably will not work", would you invest a million dollars into it?

Research is an investment, resources are extremely limited and they must be allocated prudently.

While LENR and CANR research has seen a significant amount of charlatans, there's a large body of papers available and there's yearly meetings. More details here: https://lenr-canr.org/

I've yet to make up my mind about 'cold fusion' but since there are interesting results and research is still being funded, there's clearly something we don't understand yet.

I invested two weeks with in-depth analysis of the available papers and came to the conclusion that there is no good evidence. Usually the produced quantities where below the error margins of the background noise, or they put in so much energy that the measured effects could have come from any reaction, or it was not reproducible by others.

Fair play to them

It seems they really did their homework and tried pushing it as well as they could, with new techniques and studies.

The chances of success were slim, but the chances of having missed something 30 years ago were also non-negligible

And even if your main experiment failed, if you could still take out some new techniques and knowledge from it, the better it is

Fair play to them

Hello neighbor... I assume.

I like it. I don't believe they will achieve cold fusion, but who knows? If there's even a slim chance for it to work it's worth looking into by respectable scientists that will enable other labs around the world to replicate their results, unlike the dubious experiments we've seen in the past.

And even if they don't find a way to achieve cold fusion, the electrochemistry they're researching is still worthwhile to explore for other applications.

This is the hope I have for the reactor I designed.

Cursory exploration of the idea has shown promise, but it needs some real brainpower and equipment for an in-depth scientific analysis and prototype.

I have a strong belief that it will work, but that's irrelevant. Eventually it will succeed or not based on reality.

What amazes me about cold fusion is that anyone, even the cranks, think it's plausible.

I mean, look at it from a conditional probability point of view. Initially, before any of the furor, the chance of it being real would have been very low. Then P&F have their fiasco. Their results were wrong. But somehow this was taken as meaning Cold Fusion was more likely than it had been previously. But how could that be? Their results, properly interpreted, were negative. Negative results can only reduce the probability something is correct, not increase it.

I thought they meant the programming language for a moment

That would be "controversial".

This kind of stuff makes me so happy to own Google stock. Even if it drives the stock analysts crazy.

Back when Pons & Fleischmann made their claims, the best indicator of widespread acceptance was the commodities futures market for platinum (and perhaps palladium - don’t recall if there were Pd contracts then). It was interesting to compare news coverage from various media - science, serious, popular, and tabloid - with the markets.

This makes perfect sense: - 10 millon usd to Google is close to nothing. - payout if success would be huge and there is place for unexpected derivative technology. - there is still lots of wiggle place in physics, think for example superconductors or meta-materials.

They didn't look at sonofusion, though, did they? That involves room temperature apparatus, but extremely high local temperatures -- due to collapsing bubbles. (Similar to sonoluminescence)

I remember this from the late Robert Apfel's work at Yale -- because wouldn't it just be swell if bubbles could be the basis for fusion and clean energy? The problem was that bubbles need to be perfectly symmetrical for sufficient collapse power and that is only possible in zero gravity.

Here is a paper from Oak Ridge National Laboratory.

https://www.sciencedirect.com/science/article/pii/S002954930...

> The problem was that bubbles need to be perfectly symmetrical for sufficient collapse power and that is only possible in zero gravity.

Then wouldn't that work to power a spacecraft?

maybe free-fall? A bunch of them on a ferris-wheel like gizmo (but maybe more oblong up and down), some "active" while falling and others "inactive" while returning to the top?

Only if the spacecraft never accelerates.

I'd love to learn more about the actual methods they're pursuing. One I like and related to cold fusion is muon-catalyzed fusion. Theoretically, it should be possible and dramatically lower the temperatures required for fusion. Muons are like electrons but much heavier and less stable. When a muon replaces an electron, it allows nuclei to get much closer together, lowering the energy requirement for fusion. The practical challenge is creating muons with less energy than you get from fusion.

https://en.wikipedia.org/wiki/Muon-catalyzed_fusion

There are also fusors which you can make at home http://discovermagazine.com/2010/extreme-universe/18-do-it-y...

Not exactly a "cold case" as there are regular conferences on work in "LENR" (low energy nuclear reactions). Given the bulk of the work, and the results AFAICT it is slowly shedding some of the 'snake oil' reputation and developing a "definitely something here which is not explained by the current understanding" sort of vibe. As it points out in the article, this is a group effort to come up with a solid, reliably reproducible experiment, that demonstrates the effect. In that way everyone can baseline to a common phenomena and a common experimental setup for comparing notes.

Looks like research has been going on from 2015. I wonder why Google decided to keep this a secret... and I wonder how many such long-term projects exist.

Maybe it's the possible upside that motivated the secrecy

Unlikely. More probably, they kept it quiet because there’s still a stigma around the work.

One reason was probably the "taboo-ness" of the research. Reference Mr. Close's comments in the article. Attitudes like his hinder scientific advancement.

Have they if I recall correctly they were thought to be one of the investors in Rossi's Ecat machine

They often do early research in secrecy to keep the pressure off the team. If you announce "We're going to ship cold fusion in 2020" or even "We're looking into cold fusion approaches", then suddenly everybody's interested in the research team, there's a huge amount of pressure on them, and they no longer have the freedom to tinker with different approaches and critically look at the data. If you keep it secret then it's just a bunch of really smart guys being funded to look into some intriguing idea.

In this case they got a negative result, so the secrecy was probably warranted - would they have had the courage to put out 9 peer-reviewed papers detailing a negative result if everybody had been asking them "So, when are we gonna be able to use cold fusion" since 2015? The cynic in me thinks that the project was just canceled, which is why Google is going to the press now - they have no more vested stake in the outcome, but it'd be beneficial if somebody else tried it and did manage to find an approach that works.

I've only skimmed this thread, but I don't see this perspective, in case people are still reading.

The common thread in practitioners of this stuff, and people attacking those who call it out as rubbish, seems to be rejecting nuclear physics while claiming to be observing (or supporting the possibility of) nuclear processes. I don't mean just established nuclear theory and experiment. Convincing evidence for reaction products is missing -- both nuclear and chemical ones -- and I'd expect detecting reaction products to be relatively easy compared with accurate calorimetry. People qualified to do make such measurements doubtless won't be considered sufficiently neutral, shall we say, about the physics. Anyhow, rather than say "it doesn't happen" they would be able to put a decent limit on the rate of such processes, whatever their a priori attitude. "Science doesn't care what you believe", as I recently saw on a T-shirt.

I remember when the Fleischmann and Pons stuff first appeared. It was so obviously pathological science that it didn't seem worth devoting resources towards it. Did you know that palladium is a particularly useful target for nuclear physics? Then I was doing spectroscopy on fusion reactions with it (and we had probably the best gamma-ray, neutron, and recoil nuclei detectors). There was no evidence of any anomalies associated with palladium. Apropos possibly burying evidence against established physics: those measurements demonstrated that the conventional wisdom about aspects of the processes was wrong. In contrast, I studied fusion reactions for which actual nuclear physicists presented evidence against the basic compound nucleus model; better measurements and calculations supported the model. The work was peer reviewed in the usual nuclear physics journals, of course.

Fine with me. Maybe this will put an end to the conspiracy theories about suppression of of cold fusion experiments.

You may be underestimating the thought processes of conspiracy theorists.

Google have admitted to spending multiple millions over a number of years on a cold fusion team yet the team are still only publishing negative results? No one does that unless there are results they're not publishing...etc etc.

In the article it points out that although the results are negative when it comes to cold fusion, they had positive results about connected themes like materials research.

Next on the docket: turning lead into gold at room temperature.

No more far-fetched than turning matter into energy which has been done for decades.

Bah, that's trivial with modern science. You just bombard the lead atom's core with a precise beam of electrons until you knock out two neutrons and a proton. I have the schematics for a very elegant apparatus to do that, but this text box is too small to contain them.

I have been wondering what to do with the bucket of free electrons I've been keeping from my other experiments.

Doesn't that just give you Thallium?

Maybe it's a dead end, but the it sounds like they found some promising avenues for improved battery tech along the way. Something about hydrogen storage...

Like anyone else, I'd love to see fusion harnessed for electricity. One step closer to post-scarcity, but I can settle for more compact phones.

Is there an ELI5 of why cold fusion is so difficult to achieve?

In a nutshell, the reactants (small nuclei such as from deuterium or tritium) have to be brought into intimate contact, against electrical forces that tend to push them apart. The primary effort to achieve fusion has been to overcome those forces and increase the sheer density of nuclei in a way that is not more costly in energy than the fusion energy that can be extracted and used, and without the experiment obliterating itself and its surroundings.

Even on a small scale, lack of measurable excess heat is not necessarily a show stopper, because fusion should produce other signatures such as by shedding extra neutrons. The lack of neutron evidence is what generated strong doubts about early reports of CF.

The simplest answer is: It's not real. There is no such thing as cold fusion.

It's not a matter of "so difficult", it's not actually possible.

Are you asking, why is there no such thing as cold fusion? If so then in the simplest way I can explain it:

Atoms are like little magnets that repel each other.

To get fusion you need to get the atoms to touch - but you can't, they repel. So you have to press them together really really hard, to force them.

The only way we know to do that involves lots of temperature and pressure. Cold fusion simply doesn't press them together hard enough.

The idea of cold fusion was that certain metals would act like magnet-shields, stopping the atoms from repelling. But all known science says that that is not actually a real thing.

There does appear to be fair bit of research in LENRs going on right now, note this article claims its the fusion of hydrogen atoms producing the extra heat:

https://spectrum.ieee.org/energy/nuclear/scientists-in-the-u...

As far as I remember the idea is that you substitute a heavier particle for the electron which causes its orbit to be small enough for fusion to happen at room temperature. The problem is that the particles have a small but non-zero chance of disappearing and it costs a lot of energy to create them, so the process is a net energy loss.

That's called https://en.wikipedia.org/wiki/Muon-catalyzed_fusion it's not the same thing as cold-fusion.

> Atoms are like little magnets that repel each other.

Is that a good analogy? I wonder because the first thought that popped in my head is that magnets also attract each other.

Your edge case is correct, but I think it's a useful first order approximation for an 'ELI5" type answer. What's another common situation where two things physically repel each other because of an invisible force?

> is that magnets also attract each other.

Electrons attract atomic nuclei (which is the part of the atom that fuses), normally they are too far away to matter, but if you replace them with muons (which are basically heavy electrons) then you can actually help the atoms come close enough because the muon attracts both.

Since the muon is heavier it orbits closer to the nucleus of the atom, which helps it cancel out the repelling force.

It's too bad muons cost too much energy to be useful this way, or we'd already have commercialized fusion.

> Since the muon is heavier it orbits closer to the nucleus of the atom, which helps it cancel out the repelling force.

Even this is hard for me to wrap my head around when I try to also remember that these particles are really just quantum field phenomena.

Heavier means a smaller (shorter) wavelength, bend that wavelength into a circle around the nucleus, and it's smaller, since the circle is smaller, it's closer.

Because at an atomic level "cold" means "slow" and under the standard model you need to slam protons into each other fast if you want them to fuse.

Here is a true "Explain it like I'm five:"

Kid: I want candy!

Mom: There's candy inside the pinata.

Kid: How do I get it out?

Mom: Hit it with this stick. If you hit it hard enough, the pinata will break and candy will come out.

Kid: gently taps pinata with a stick Mom, it's not working.

Mom: well, you have to hit it hard enough to break it. Try swinging the stick faster.

Kid: But I don't want to swing it fast. I want to swing it slow!

Mom: Then you won't get any candy.

Kid: crying

Cold fusion is based on the belief that there is some way around this fundamental limitation. This would not be based on any of the known laws of physics (the standard model) and would be by definition new physics. If we discount certain discredited experiments which could not be reproduced, then there is no experimental evidence that this ever occurs, nor is there any unexplained phenomena that would require such new physics. Nevertheless, some people feel the search is still worthwhile.

I give a more detailed account (ELI22+) with and physics and numbers above: https://news.ycombinator.com/item?id=20034550

They should do polywell fusors next.

This seems to be in keeping with Google's "Moon Shot" philosophy — investing in some projects with potentially high payoff, but low probability of success.

If Tesla were pursuing a project like this, they'd probably announce that they were expecting all their cars to ship with cold fusion reactors by 2020 — and then start hiring a team ;-)

There's an Iron Man story arc lone from a few years ago where Tony Stark starts a car company using his repulsor batteries as the energy supply..

sometimes it seems as if Elon thinks Iron Man is a prophesy about his life...

In this case I think the arc is new enough that it likely was inspired directly by Elon.

Musk and Stark are coroutines...

an ex-gf of mine use to say Elon was an alien and needs humans to help him develop the technology he needs to get back home.

"They are already here among us – they just call themselves Hungarians."

https://en.wikipedia.org/wiki/The_Martians_(scientists)

Like David Bowie in The Man Who Fell to Earth (1976):

> [Bowie's character] uses the advanced technology of his home planet to patent many inventions on Earth, and acquires tremendous wealth as the head of a technology-based conglomerate, World Enterprises Corporation, aided by leading patent attorney Oliver Farnsworth. His wealth is needed to construct a space vehicle with the intention of shipping water back to his home planet.

https://en.wikipedia.org/wiki/The_Man_Who_Fell_to_Earth

Seems like a good example of https://tvtropes.org/pmwiki/pmwiki.php/Main/ReedRichardsIsUs... .

No one ever thought cheap energy might be helpful before a few years ago? It's still not useful outside of cars?

The story line actually covers it quite well in having him struggle with the thought of whether or not he can make them safe enough (e.g. he's other places talked of the battery in his chest having the energy of a small sun) to make them accessible.

The story line in question comes after one where someone has scavenged his tech from broken parts of Iron Man armor and used them in terrorist attacks, and at the same time as he's put together a purely "defensive" Iron Man suit for Pepper Potts called Rescue, and he decides to rebuild his company around civilian applications of the underlying tech,

Iron Man is actually quite interesting in that respect, as a lot of the story lines delve into him struggling with whether or not he should produce weapons to stop bad guys or come up with a design to find a counter to them before a bad guy comes up with the same design, vs. finding civilian applications without inadvertently handing bad guys new weapons. Some of those story lines make poor arguments, but at least the Iron Man story lines are trying unlike FF, I feel, where it's "let's whip up something new amazing before breakfast and then never do anything with it", while Tony Stark grapples with the issues of commercializing his inventions all the time, and often has to deal with fallout from it.

Even if nothing comes from LENR, there were other interesting (probably not nuclear) things going on that have since been ignored because of the scientific taboo. The quintessential electrolysis experiment wasn't entirely inert, supposedly, even if nothing nuclear was happening.

Google could stumble into something very profitable.

I know you are joking, but unlike Google, Tesla at least tries to finish whatever they start and actually deliver stuff, while google quickly jumps the ship if the thing does not work out and abandoned all their customers

Please don't call willing experiment participants customers.

The problem with Tesla is when they take your money promising to deliver something, when they can't. Full self-driving capability is never, ever coming to the current-gen Teslas, no matter what Elon says - the sensory capability just isn't there. Google at least says "we can't support this profitably, so we won't" while Tesla engages in fraud.

Never? Even when we've already seen it working?

You've been told you've seen it working. You have not seen full self-driving.

You have? Care to share with the rest of us?

Alphabet doesn't seem to abandon moonshots as easily as it does consumer SaaS products like Reader.

They still have massive, on-going investments in anti-aging and self-driving vehicles. I don't know of any moonshots they've killed yet.

> I don't know of any moonshots they've killed yet.

Project Ara?

> I don't know of any moonshots they've killed yet.

Google fiber is mostly dead.

That one seems more like a fault of legal battles and rent-seekers.

Let's be fair, Google does usually deliver a working product, even if they take it away just as everyone starts using and liking it.

>I know you are joking, but unlike Google, Tesla at least tries to finish whatever they start and actually deliver stuff, while google quickly jumps the ship if the thing does not work out and abandoned all their customers

I'm envisioning the Mr. Fusion in Back To The Future as a Google product. Surely it would fail the second it left that narrow 5-10 year window of support. Error: 403, Forbidden; the user is not authorized for trans-time operation.

Sorry for the pedantry, but you're confused. Mr. Fusion had little to do with time travel: it was a commercial device which Doc got in the future, and which simply generated power from whatever you wanted to pour into it. Doc's flux capacitor is what allowed time-travel, and it needed a lot of power. So before, he had to either use uranium or lightning, but after installing Mr. Fusion he didn't need either of those hard-to-get things.

So, if Mr. Fusion was a Google product, as soon as McFly transported the DeLorean to the future (outside Google's window of support) and the onboard computer synced the time over-the-air and the Mr. Fusion updated its clock, McFly would be stuck in the future, though presumably in that time he should be able to find some competitor to Mr. Fusion which he could replace it with (with Doc's help; McFly never seemed to be very good with technical things).

TIL, turn off autoupdates and clock sync when doing any sort of time traveling.

I was simply remembering the end of the first movie where Doc drops a beer can, a banana peel and so on into the Mr. Fusion so he can take Marty and his girlfriend into the future and joking when Doc ended up in 198-whatever Mr. Fusion would refuse to work because it was out of support. I think you're interleaving the timelines of later movies?

As a Tesla owner, I have to say that I'm really looking forward to them delivering the Full Self Driving option that I paid for 18 months ago when I bought my car.

The worst part is, it doesn't seem like they'll be able to. I'm curious what happens if they ultimate need additional / different sensors to make it happen. Do they replace those parts for free?

I also wonder whether the choice of sensor technology they already (pre-)SOLD informs Tesla's opinion of what sensor technology is NEEDED for Full Self Driving (Their view that LIDAR is not necessary seems to be an outlier in the industry; are we sure that view is not influenced by the sizable outlay they'd face for upgrading their previously sold FSD option cars if they changed their mind?)

My understanding is that FSD will at least require a new computer module, which they are supposed to replace for free for those of us who have purchased FSD.

However, it is an open question whether or not it will require additional / different sensors (like lidar).

A hypothetical:

You are driving your car and see that the pickup truck in front of you has an empty cardboard box in it (you can tell its empty by the way its floating around in bed of truck). Suddenly a gust of win picks up the box and it lands directly in front of your car. Its not very big, about 12 inches tall. Do you: (a) Slam on breaks? (b) Roll over it?

Now what will the "AI" in your car do?

Self-driving cars are not coming anytime soon. They are a whole slew of problems that you can intuit solutions to fairly easily, that are still beyond the ability of current tech.

I'm returning your argument. Imagine your are driving your car on the highway, but you suddenly have a heart attack and become unable to remain conscious. Do you: (a) Die? (b) Die?

Manned vehicles are not coming anytime soon. They are a whole slew of problems etc. -- you got my point.

I think focusing too much on pesky details is very much a fallacy in this case - you do not want an "AI" to react like a human in all situations, you only want it to drive in a way that is conservative enough not to endanger people too much. And we clearly aren't that far from this goal right now.

"Imagine your are driving your car on the highway, but you suddenly have a heart attack and become unable to remain conscious"

Humans who drive cautiously may go for a million miles without an accident. The best self-driving cars (i.e. Waymo) disengage on average every 11,000 miles.[1] It seems to me that a disengagement is equivalent to becoming unconscious without warning, and presumably we both agree that a given human does not have a heart attack while driving every year.

Humans, even with all the people who drive drunk, or texting, or falling asleep, average about 80 million miles between fatalities. Going 11,000 miles between events of total loss of control is nearly four orders of magnitude worse.

[1]https://www.forbes.com/sites/alanohnsman/2019/02/13/waymo-to...

It is an interesting metric, thank you for pointing it out. Until now I kept in mind the amount of miles between accidents, but surely both should be considered.

However, I think this metric could be irrelevant in the case of a home/work commute. The 11,000 miles average appears to have been obtained basically by randomly driving Waymo cars on Californian roads. But a usual commute is much less than 11,000 miles, and if your self-driving can do it by itself once then probably it can do it twice. As the article puts it:

"The value of the data is limited, however, as the figures don’t factor in the complexity of environments in which vehicles are tested–dense urban settings, versus low-speed suburbs or less complex highway driving–nor do they show conditions including weather, light or speed."

Nevertheless, you seem to have missed my point : I was arguing that coming up with a specific use-case example that may (or may not, actually) go wrong is an argument that goes both ways.

I've experienced much more soft debris fall from a vehicle in front of me on the road than I've had heart attacks at the wheel.

That is a fallacious argument.

If we pick a hypothetical where a human fails and an AI doesn't, does that mean self-driving cars are ready?

Do you think human drivers are faultless drivers?

Is their a fair cost-benefit analysis for not wasting enormous amounts of collective time driving? (Driving is a very unproductive activity).

I'm pretty sure I remember a pretty large "this technology does not currently exist, may not be feasible, and may not be available based on local regulations" disclaimer on their sales pages, right? I thought they were explicitly selling the sensors that would be required if the self-driving feature was implemented.

Has Tesla started delivering repair manuals and replacement parts? I keep hearing about Tesla vehicles at the body shop for several months.

I am excited. Worth looking into. Even if it violates (current) physical laws. Potential payoff to big.

But I have also seen google projects that did not look scientific sound to me. Measuring blood glucose with contact lenses? How? Lag time is around one hour for eye liquid. Your are dead and the sensor does not know it yet. Your need to be below 10 min lag time.

An idea that violates physical laws is just wishful thinking, no matter how big the potential payoff.

You should study the scientific method. Nothing is set in stone, science is an evolutionary process. Even the scientific method itself.

If experiments violate CURRENT laws of physics, the laws have to be revised. Guess how we came to our current atomic model from the plum pudding atom model?

this is absolutely true, but, what drives experiments are hypotheses, not just wishful thinking.

a hypothesis is "a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation."

it's arguable whether "is cold fusion possible?" is a valid hypothesis, because currently there is no accepted reason, evidence, observation, or starting point for that investigation. only the hope, the wish: "what if it was..."

Well, trust me, what drives most experiments is not hypotheses but "this is strange" results.

"it's arguable whether "is cold fusion possible?" is a valid hypothesis, because currently there is no accepted reason,"

I am not a nuclear physicist, but my chemistry is good enough to know that it should not be possible.

But take into consideration that Fleischmann was a pretty good chemist. Possible he fucked up. Looking backwards likely. But discussion is possible only based on date. Not believes what should or should not be possible.

https://en.wikipedia.org/wiki/Fleischmann%E2%80%93Pons_exper...

Exactly! I think people forget that physical "laws" are mental models, working hypotheses that need to be constantly questioned, tested against reality and revised.

>Measuring blood glucose with contact lenses? How? Lag time is around one hour for eye liquid. Your are dead and the sensor does not know it yet. Your need to be below 10 min lag time.

Why? What if you don't care about having your blood glucose data that quickly, and just want to see the overall trend, even if it is delayed an hour? This won't help people who really need to be able to see what their glucose level is right this second, but for others it's a lot more convenient than having to prick yourself every morning.

If the lag is one hour, you still need to prick.

If you want to see "overall trend" and don't care about any "lag time", just measure in Urine.

There is an enormous difference between ease of use of a contact lens sensor that you presumably wear most of your awake time and that gives you constant stream of measurements with 1h lag and urine test kit that you carry with you and with luck remember to use every few hours.

Yeah. As a non lens wearer sounds pretty comfortable to me.

But if you have money I can offer you a non-invasive glucose measurement start-up with peer reviewed publications.

I wear contact lenses. If I could instead wear lenses that continuously monitored my glucose level and it didn't cost me anything extra, and they still gave me the visual acuity of my normal lenses, why wouldn't I use that? I already wear them every day so for me, it requires zero effort.

Having to get urine samples regularly, or worse, blood samples, is a LOT more work on my part (not to mention painful for the blood samples), so it's not something I'm as likely to want to bother with.

"it didn't cost me anything extra" Good luck with that.

How about people walking abound 24/7 with an anal plug?

Wow, that's an incredibly asinine comparison and comment. Millions of people walk around with contact lenses every day, myself included, and don't find them uncomfortable at all (or at least, much more comfortable than glasses). If they had an additional useful feature built into their lenses for no extra cost, I'm sure plenty of them would be happy to have it. If you don't like contacts, that's your issue, not mine.

FYI that project was killed last year[1]. Also, like a lot of research projects, there was a lot of auxiliary research that could end up quite useful, even if the initial idea didn’t work out. For example, figuring out how to put an antenna into a contact, how to safely store power, etc.

[1] https://en.m.wikipedia.org/wiki/Google_Contact_Lens

Which Google moonshot has paid off so far?

The "Google Brain" deep learning research has probably worked out extremely well for Google. Self-driving cars seem pretty likely to make bank within a decade.

https://x.company/projects/

A couple of them. In terms of economic success they only really need one every 10 years too succeed as every one of them might be worth tens to hundreds of billions.

It‘s also a great way to find out what ideas don‘t work without too much risk.

https://brillouinenergy.com

These guys seem to have figured it out.

Seems the problem with replicating cold fusion is that what most researchers do degrades the "lattice" that enables the reaction. So even if you do manage to get results, you won't be able to repeat it.

> "The Google team explored three experimental set-ups that have been proposed to generate cold fusion — two involving palladium and hydrogen, and one involving metallic powders and hydrogen. None found evidence of fusion. The results have been published across 12 papers over the past 2 years: 9 in peer-reviewed journals and 3 on the arXiv preprint server."

It seems obvious to me that you can't achieve fusion using a catalyst. Catalysts are great if you're doing chemistry, but nuclear fusion is a lot different. You've got to force two positively charged nuclei to merge and I just don't see how a catalyst could accomplish that. That it didn't work for them seems to vindicate my casual dismissal, but I'm left wondering why they thought it worth trying in the first place. What were they thinking of that I haven't?

> "Trevithick recruited 30 researchers who had no strong opinions on cold fusion."

Surely 'having an open mind' about cold fusion is itself a "strong opinion" about cold fusion.

>Surely 'having an open mind' about cold fusion is itself a "strong opinion" about cold fusion.

A cynical reading might be: "30 researchers whose opinions on cold fusion were not strong enough for them to speak up at the job interview and thus forfeit the job".

I think it's probably people who weren't expecting to achieve the impossible, but were willing to experiment in areas of science that aren't well understood to possibly learn something new. Maybe there is some previously unknown effect that was mistaken for fusion in the previous experiments? It could be an exciting find.

But at the same time they have to know that the most likely scenario is a big null result and no new science discovered. Unfortunate, but if you knew where the next discovery was going to be you wouldn't have to hunt for it.

It's not a chemical catalyst, but the idea of muon-catalysed cold fusion has been around since the late 50s. I think I first read about it as a child in the appendix of Arthur C Clarke's "2061" novel.

https://en.m.wikipedia.org/wiki/Muon-catalyzed_fusion

Is that an open mind or parallel thinking? It's an interesting idea anyway, but seems no way to efficiently create enough muons / u- mesons.

Muon catalysed fusion is not comparable to chemical catalysts for one thing. Secondly, although enough muons can actually be created, too many are lost for the reaction to work out.

They were thinking of quantum tunneling, which could, along with a lattice, allow protons to tunnel close enough together to fuse without having to cross the coulomb barrier. Or something. Some guy from a Berkeley LENR startup named Bloomsomething told me this tale once. Sounds vaguely plausible in a "quantum stuff is zany" way.

As far as I understand, most of the ideas concerning how fusion at low temperatures, and their relationship with eg. Pd is not because of chemical catalysis, but because it readily dissociates and dissolves hydrogen (and isotopes) into it's crystal structure.

This process brings the hydrogen atoms ( at ntp ) at least as close as hydrogen molecules at roughly 2000 atmospheres, and maybe much closer, if I punched in the correct numbers.

I believe it was (when cold fusion was, ahem, hot) speculated that the process of hydrogen solution/diffusion within the metallic matrix had somehow forced the hydrogen much closer together, while possibly creating local heating because of changes in the metallic structure at high hydrogen saturation, and that this was somehow both hot enough and close enough to create fusion.

That makes a lot more sense, thanks. But if the metallic lattice is retaining the pressure of bringing hydrogen nuclei that close together, wouldn't the whole thing tear itself apart? Is that the instability they're talking about when they say "But at high concentrations the team was unable to create stable samples." ?

>at least as close as hydrogen molecules at roughly 2000 atmospheres, and maybe much closer,

it is just a liquid hydrogen density. If any cold fusion is there i would bet that it would be some play due to huge electron cloud of Pd.

Pressure/atom distance wise - the high pressure experiments using diamond anvil compress hydrogen up to 1M+ atm . That is still well below the Jupiter core though, and so naturally no fusion, yet one can make things interesting say by zapping that pressurized hydrogen with laser. Should get NIF style results with much less power or alternatively much better results with the NIF power.

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