You can’t prove a negative though, the onus was on F&S to prove their result and they couldn’t do that. They had misinterpreted some of their results (they had not detected gamma rays or fusion byproducts) and had made errors in their experimental design. Basically they were chemists, and their claims of fusion were based on misunderstandings of the physics.
A way to think about this is just to eliminate fusion from their claims. Ignore that, they didn’t have any evidence for it. The bottom line was, could they reliably generate useful heat. The answer to that was also no. So really, what are you left with?
Having said that room temperature fusion is a real thing. You can build a fusor in a garage with commonly available parts. It may well be possible to generate very low levels of fusion reactions in various ways, but generating useful energy that way may never be possible. Best of luck for these people for trying, you never know and maybe some useful insights will come from it.
What you're left with is something you don't understand. That's often been a precursor to real breakthroughs.
If you don't understand it, it's not surprising that you can't make it useful. That doesn't say much about what you'll be capable of, after you do understand it.
While it's true that the onus was on F&P to prove their results, it's also true that if someone else is claiming to replicate the experiment, the onus is on them to do it correctly.
F&P were unable to replicate their results. People have been trying for decades, with their help and the best they get is some occasional anomalies. The contention that the experiment has never been ‘properly’ replicated comes from the fact that they made some errors in their experimental design and description. How can you ‘properly’ recreate an experiment if the given design is known to be inaccurate?
If you follow the known to be inaccurate description people will complain you’re not doing what the actually did. If you do what they actually did (or seem to have done as best we can tell), people will complain you didn’t follow their published description. Meanwhile F&P still couldn’t get reliable results themselves.
> What you're left with is something you don't understand. That's often been a precursor to real breakthroughs.
Sometimes. Often, what you’re left with is unusable experimental results because you don’t have a clue. The proper way to resolve that is what they did with faster-than-light neutrinos: ask for collaboration with other labs and try to replicate the result. This whole thing is not science, it’s cargo-culting the way science is described in pop culture.
Which is when (if you do Science much) your heart sinks because you become absolutely certain that you have made (another) mistake and will now spend days/weeks/months trying to pin it down.
Just wanted to follow up on fusors, since the technology seems to be less known that it deserves to be. As parent says, it is a completely solid, in-your-garage demonstration of fusion. Lot's of information at fusor.net [0].
It looks like positive-return-on-energy fusion will almost certainly be achievable in 5-10 years, though it won't be commercializable for a lot longer than that.
I do like how incredibly simple and easy fusors are compared to the other types of fusion reactor, but sadly they are still very very hot where it counts.
>> Basically they were chemists, and their claims of fusion were based on misunderstandings of the physics.
That's an interesting interpretation. My interpretation at the time was that they are chemists and ruled out chemical reactions as the heat source. They concluded it must be physics. Physicists then said "It can't be nuclear, it must be chemical" - forgetting who was doing the experiment. They seemed really arrogant to me.
The problem of Cold Fusion is the lack of a reliable experiment.
Compare this with high temperature superconductivity. If you get a time machine and go to 1985 and try to promote high temperature superconductivity, nobody will take you seriously.
But a team discover one material and published a clear recipe to built it. Other team tried some variations, and discovered an easier recipe to build them and published it. So soon everybody and their dog was making new variants, and new variants, and new variants...
A few years ago, they gave one in the physics' lab for undergraduate students, and we made a few measurements for a month carefully because they don't tolerate humidity. Until someone put it in a glass with water and ice to measure the properties at 0°C.
Also, now you can also see the recipe in a video in YouTube by "Applied Science": https://www.youtube.com/watch?v=sLFaa6RPJIU , the guy has some advanced lab, but nothing too advanced.
The problem of Cold Fusion is the lack of a reliable experiment.
>> The problem of Cold Fusion is the lack of a reliable experiment.
That certainly seems to be the case today, but it was not the case when physicists rejected the claim outright. In other words, the rejection came before the reproducibility problems.
I can tell you exactly what the editor said after reading the first paper about high temperature superconductivity:
fake quote> Nah.
The nice thing about physics is that it doesn't matter if the community reject the idea. If you have a nice experiment that is reproducible and has clear and easy instructions, sooner or later the community will accept it, and you may get a Nobel price. If the experiment is weird and you are unlucky, it can take a few decades.
Here is another weird experiment, with another weird result, but it's reproducible and has clear and easy to follow instructions https://en.wikipedia.org/wiki/Wu_experiment
This is entirely unlike high-temperature superconductivity, though. We knew superconductivity was a thing in some materials under a give material-dependent critical temperature. Looking for compounds with higher critical temperature is not a major shift, or surprising in any way. Why would any editor say no when someone writes “look, we’ve found a crystal with a high critical temperature”?
Had they published something along the lines of “we’ve seen this cool thing; we think it works that way; could anyone replicate this?”, there wouldn’t have been any controversy. But they did not offer any insight, their results were unreliable, and their interpretation was doubtful. It’s not because you don’t understand something that fairies must be involved somehow.
We had an explanation of superconductivity https://en.wikipedia.org/wiki/Cooper_pair but it didn't apply to high temperature superconductivity. It took many years to get a good enough explanation of high temperature superconductivity, and IIRC there are a few details that are not understood. So it was surprising that someone made a high temperature superconductor.
As far as I know, there is no theoretical reason to discard cold fusion. There are a few "cold fusion" method that work, like using muons https://en.wikipedia.org/wiki/Muon-catalyzed_fusion but it's so expensive to create muons and they are short lived, so you expend more energy than the useful energy you can collect from the device.
So (in 1985) both phenomena were in the same class, it was not theoretically impossible, but no one had shown a good experiment were they happened.
> Had they published something along the lines of “we’ve seen this cool thing; we think it works that way; could anyone replicate this?”, there wouldn’t have been any controversy. But they did not offer any insight, their results were unreliable, and their interpretation was doubtful. It’s not because you don’t understand something that fairies must be involved somehow.
Perhaps we agree, the problem of Cold Fusion is the lack of a reliable experiment. (And too many scammers publishing bad experiments and trying to get investors.)
The concept of low-temperature fusion in itself is not absurd necessarily, but there is a whole lot of orders of magnitude to overcome. And it cannot be easy or common, or we’d have seen it already: one particle releasing ~1 MeV in a crystal leaves traces, which we can interpret very well. So the proofs need to be solid, not just hand-waving “it must be fusion, because we haven’t got the faintest idea”.
The fuzziness about how you’d have fusion reactions by just putting protons in a metal is a bit dodgy. Everything else about it was a huge red flag. Yes, HTS are a bit different than older superconductors, and yes, we don’t know everything about them. But again, it’s not a huge stretch to imagine that there could be some mechanisms that could move the critical temperature by a factor of 5 to 10. Fundamentally, it’s still an exotic form of collective behaviour. Cold fusion amounts to getting ~0.1 MeV (the order of magnitude to tunnel through electrostatic interaction to reach a nucleus) out of ~0.05 eV (the energy of a proton at room temperature). That’s about as plausible as saying that you’d reach Earth’s escape velocity by running down a mountain. Of course, you’d be more credible with a rocket strapped on your back. Cold fusion is missing that rocket.
Not every outlandish claim should garner the attention and respect from scientists. If you hide your "discovery," refuse to publish in scientific journals and be subject to peer review, if you claim "secrecy" is why no one can replicate your result, well, you'll be tossed on to the tall pile of folks claiming this or that physics breakthrough.
Physicists have to deal with this kind of crackpottery a LOT. They don't owe you their time unless you have some solid evidence and full transparency. Don't want full transparency? Be prepared to be called a fraud. That's how it goes.
> That certainly seems to be the case today, but it was not the case when physicists rejected the claim outright.
The claim was of specific results which were inconsistent with the people performing the experiment having survived it. The experimenters being alive to give press appearances was sufficient reason to reject that claim out of hand.
That something else very interesting, but unknown, might have been happening wasn't rejected until after robust reproduction attempts failed to produce any evidence of that.
The nuclear physicists were simply pointing out that the evidence F&P offered of detecting a fusion reaction, was not actually evidence of fusion. I dont really see what’s arrogant about that.
> The nuclear physicists were simply pointing out that the evidence F&P offered of detecting an [unknown] fusion reaction, was not actually evidence of [known] fusion reaction.
No I don't, even if there is something unknown going on that has none of the known characteristics of fusion, why even say it's fusion? Why attach that label to it, especially when you have no actual theory of what is happening and why?
To put it another way, why are you calling this an unknown fusion reaction? What's the basis for the claim that it was fusion of any kind?
F&P thought that the evidence they had found demonstrated fusion. That it was known evidence of fusion. They were simply wrong. Saying 'well it might be some unknown form of fusion' is post-hoc rationalisation (for which you have no evidence or theory). That's not what they were saying at the time.
It's so infuriating that 30 years later we're still fighting these fundamental misconceptions about what was going on.
Excellent thanks. That's very helpful as those analogies are very apt. The West Indies has nothing to do with India. Atoms are no unbreakable. Cold Fusion has nothing to do with fusion. I'm glad we got that straight.
> Physicists then said "It can't be nuclear, it must be chemical" - forgetting who was doing the experiment.
No, what lots of people (many of them far more prominent chemists than P&F said, not just physicists) is that, if honest, it had to be measurement error, not only based on abstract analysis of the described setup and results, but also based on robust attempts to replicate the claimed results.
A way to think about this is just to eliminate fusion from their claims. Ignore that, they didn’t have any evidence for it. The bottom line was, could they reliably generate useful heat. The answer to that was also no. So really, what are you left with?
Having said that room temperature fusion is a real thing. You can build a fusor in a garage with commonly available parts. It may well be possible to generate very low levels of fusion reactions in various ways, but generating useful energy that way may never be possible. Best of luck for these people for trying, you never know and maybe some useful insights will come from it.