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I was surprised to find that there is a lot of theoretical justification for possible mechanisms of cold fusion, and a lot of experimental evidence that must ei

I was surprised to find that there is a lot of theoretical justification for possible mechanisms of cold fusion, and a lot of experimental evidence that must either be suggestive of something interesting, or indicative of bold-faced and widespread fraud. It was also interesting the discover that the original experiment was dismissed because other experimenters failed to replicate the Fleischmann and Pons result ... despite not actually trying to replicate the Fleischmann and Pons experimental setup accurately. For example, not meeting the same level of hydrogen loading in the metal matrix. It could all absolutely be BS, but I was surprised that it wasn’t actually proven to be BS; it was just not proven to not be BS, and was then made “embarrassing”.

simonh 6y ago
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.
- phkahler 6y ago
  >> 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. And here we are 30 years later with it unsettled.
  - gus_massa 6y ago
    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 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.
    - phkahler 6y ago
      >> 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.
      - gus_massa 6y ago
        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 https://en.wikipedia.org/wiki/Wu_experiment
        6y ago
- aqme28 6y ago
  Fusors aren't room temperature. 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.
  - garmaine 6y ago
    Fusors are room temperature. It’s the electrical gradient which produces the reaction, not temperature.
    - ben_w 6y ago
      The ions thermalise very quickly even in a fusor; if they fused on the first collision rather than bouncing this whole thing would be much easier. https://en.wikipedia.org/wiki/Fusor#Thermalization_of_the_ion_velocities https://en.wikipedia.org/wiki/Fusor#Thermalization_of_the_io... 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.
- DennisP 6y ago
  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.
  - simonh 6y ago
    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.
  - willis936 6y ago
    Muon-catalyzed fusion is well understood and F&P are well known frauds. There isn’t something interesting here.
  - kergonath 6y ago
    > 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.
  - prox 6y ago
    The most exiting phrase in Science is not “Eureka!” but “That’s funny...”
- japanuspus 6y ago
  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]. [0]: https://fusor.net/ https://fusor.net/
lumost 6y ago
Digging into the research here, there are a lot of results which indicate some form of LENR should be feasible in suitably complex environments. As an example, calculating the exact screening effect of a metal lattice from theory has not been performed to anyones satisfaction, particularly if you account for hydrogen moving within the lattice, or the lattice undergoing some deformation. The experimenters researching this clearly don't have a great way to control for other factors in an experimental setting either. As an example, there are multiple reports of transmutations being observed following a hydride doping experiment... however these are all done by gas spectrometer. It's unclear from the experiments whether there happened to be random impurities in the hydride prior to doping. Similarly heat/neutron measurements are really difficult to get right and be convincing.
- kergonath 6y ago
  As a materials physicist, I have no idea what you mean by this: > As an example, calculating the exact screening effect of a metal lattice from theory has not been performed to anyones satisfaction, particularly if you account for hydrogen moving within the lattice, or the lattice undergoing some deformation. Screening effect from what? There is nothing surprising in the way hydrogen behaves in a metal. We can simulate that with great accuracy, in fact we do it all the time as hydrogen embrittlement is an important issue in metallurgy. This type of cold fusion would require two nuclei overcoming humongous energy barriers to get close enough to each other. No form of motion within a crystal lattice or no amount of deformation is going to provide that. The energies involved are about 6 orders of magnitude short. Heat is trivial to measure, we’ve been doing that since the 19th century. Neutrons are not particularly difficult either, we’ve been doing that since the 1940s.
  - drran 6y ago
    The idea of LENR is not to move hydrogen protons in a lattice, but to make it jump over imperfections, with hope that it will land into nuclei.
    - kergonath 6y ago
zamalek 6y ago
I don't think LENR is possible, but I'd love to be wrong and I do think that some money and energy should be spent investigating it. What I find interesting is some phenomena that was clearly present in some of these demonstrations - even if it wasn't LENR. The anomalous results are worth investigating because there may be unknown physics lurking there, but anything related to CF is scientifically taboo.
- fsh 6y ago
  Fleischmann and Pons had a lab sponsored by IMRA (the research division of Toyota) where they were supposed to repeat their experiment. They spent 12 million dollars without getting any believable results. The idea that their research was somehow suppressed is laughably wrong.
jostmey 6y ago
If cold fusion exists that produces more energy than it consumes, it would take some extreme conditions. If cold fusion could appear under normal-ish conditions, we would have already observed it and tapped into it
- kosievdmerwe 6y ago
  Given that we only discovered and built dead downwind faster than the wind vehicles in the 2000s I wouldn't be so sure. And for being relatively simple classical physics it was very controversial, with even some physics professors denying it was possible.
  - roflc0ptic 6y ago
    We did that? That sounds awesome. Source?
    - deleted 6y ago
      [deleted]
    - kosievdmerwe 6y ago
      Some sources: https://www.lockhaven.edu/~dsimanek/museum/ddwfttw.htm https://www.lockhaven.edu/~dsimanek/museum/ddwfttw.htm https://en.wikipedia.org/wiki/Blackbird_%28land_yacht%29 https://en.wikipedia.org/wiki/Blackbird_%28land_yacht%29 The search term to use is "DDWFTTW" It's a bit confusing, but some important points are: * It only works if you're on land, you can't have a flying device that does this. * Boats can sail faster than the wind speed, but have do so at an angle to the wind. (Just to convince yourself that this isn't completely strange). * The wheels rotation on the ground is what drives the propeller, not the other way around.
  - ratsforhorses 6y ago
    Just thought I'd add a relevant link as the phrase "dead downwind" caught my eye https://en.m.wikipedia.org/wiki/Blackbird_(land_yacht)#:~:text=On%20July%202%2C%202010%2C%20Blackbird,the%20speed%20of%20the%20wind https://en.m.wikipedia.org/wiki/Blackbird_(land_yacht)#:~:te....
jeffreyrogers 6y ago
Yeah, I always heard it was complete BS, but when you look into it there have been some weird phenomena reported. Unfortunately no one seems to be able to reliably produce them.
- sdenton4 6y ago
  Weird phenomena are a great way to justify a large investment of time and effort for yourself... But what the world wants is BORING phenomena.
  - AnimalMuppet 6y ago
    I would say the science world wants weird phenomena, boringly reproducible.
- Robotbeat 6y ago
  One thing that is an indispensable lesson of graduate research: actually trying to make a cutting edge measurement and pick signal from noise is INCREDIBLY hard. It's easy to underestimate just how noisy frakking everything is. Every thing looks complex and uncertain and it's only through extremely hard work and careful measurement that you can know ANYTHING. So complexity is actually the norm. The irreducible complexity of noise.
  - jdkee 6y ago
    The weak SNR ratio would lead one to believe that the results are bullshit, no?
    - Robotbeat 6y ago
      Yup.
    - XorNot 6y ago
      The real tell tale is when the effect starts diminishing as SNR improves. The giveaway that the EM drive is junk is that the effect has gotten smaller everytime the apparatus has removed a source of error. Nothing is ever conclusive, but it points to something which should violate the known laws of physics really just being a pile of systematic error.
mxcrossb 6y ago
> despite not actually trying to replicate the Fleischmann and Pons experimental setup accurately I’ve been seeing this claim in another field: about hydroxychloquinine. Every time a study comes out which doesn’t show a benefit, people rush in saying “that’s because they forgot X, didn’t dose the right amount of Y, etc” I’m actually not sure what to make of this phenomenon in general. I will say though that when you’re trying to test a hypothesis, completely replicating another experiment isn’t necessary. You should test it under a variety of conditions. That makes it easier to avoid the same hidden mistakes that the original experiment might have included.
- andrewflnr 6y ago
  You should definitely also try the exact original conditions. Think about reducing a tricky bug: you start with the exact input and code that first caused the problem, then try removing constraints to see what preserves the bug. Ed; I should clarify: you start with whatever big nasty test scenario you need to make sure you can reproduce the effect at all, and only then can you start changing the conditions and be confident you're still measuring the same thing.
  - mxcrossb 6y ago
    Yes but science and computer programming are fundamentally different activities. The programmer tries to reproduce the bug because his main fear is that he can’t see its effect. But the scientist’s main fear is that the experimental setup does not robustly test the underlying hypothesis. If you reproduce exactly the conditions (and remember you will always be criticized for missing X), the best you can learn is whether the previous result was not completely fabricated (or statistical noise). It’s much more productive to subject a result to a wide battery of tests.
    - andrewflnr 6y ago
      If you're dealing with an unknown, confusing phenomenon, you don't know what the underlying hypothesis is. You don't know yet what constitutes rigorous testing and what is just wandering off into the weeds. So you need to start with seeing if the thing happens at all. You do in fact need to know whether the previous result was garbage before it can be productive to do a wide battery of tests. And "wide" depends on how sensitive to conditions your effect is, which you also don't know yet. Your closest thing to an anchor is the initial claimed setup, so start there.
kergonath 6y ago
> despite not actually trying to replicate the Fleischmann and Pons experimental setup accurately They (Fleischmann & Pons) did not prove anything in the first place, so after that the “not the true experiment” thing is a fallacy. There will always be too much of something or not enough of anything. You can never replicate exactly an experiment, but this does not prevent all of science from progressing and reproducing results. Physics does not care about who operates the experiment. So if something works only when specific people try it, it does not give any confidence in the results. In other words, it does set the bullshit alarm ringing. There is no theoretical foundation for cold fusion, and no known mechanism for it to work. So even if it does exist, their stance of “just trust us, and let us move the goalposts about replicability” is just voodoo and, yes, bullshit.
lenkite 6y ago
I thought Japanese researchers had already replicated the "anomalous heat generation" in LENR. https://asiatimes.com/2019/11/cold-fusion-japan-takes-the-lead/ https://asiatimes.com/2019/11/cold-fusion-japan-takes-the-le... Why is this still considered BS if independent research teams have reproduced this ?
- simonh 6y ago
  It's important to distinguish between current actual results from labs working very carefully and methodically and turning up interesting anomalous results, and the original claims made by F&P. Yes there is interesting physics here and there's a lot we don't know about the behaviour of hydrogen and deuterium in dense metallic crystal lattices. Who knows, that behaviour might even have something to do with fusion. That's separate from what F&P were claiming 30 years ago. They claimed to have produced 'tremendous heat' and to have detected evidence of fusion (gamma rays and fusion products). They couldn't replicate the heat measurements, there were experimental errors that mean we can't know if they had generated excess heat at all, and they were simply mistaken that the evidence they had gathered indicated fusion. Two things can both be true at the same time. These new experiments might indicate heat generation and might indicate fusion, and the F&P experiments demonstrated none of those things. Those are not contradictory statements. Heck, F&P might even have stimulated fusion in their experiments. It's impossible to prove a negative. The point is they didn't demonstrate that at all.
deepstack 6y ago
This is interesting development. Back then when Pons and Fleischmann first came out with this in 89, they were heavily ridiculed ( or smeared) by main stream academics like MIT. It also turns out MIT has received a lot of money to do hot fusion research. Wouldn't be the first time that interests of funding interfered with science.

simonh 6y ago

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.

phkahler 6y ago
>> 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. And here we are 30 years later with it unsettled.
- gus_massa 6y ago
  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 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.
  - phkahler 6y ago
    >> 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.
    - gus_massa 6y ago
      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 https://en.wikipedia.org/wiki/Wu_experiment
      - 6y ago
aqme28 6y ago
Fusors aren't room temperature. 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.
- garmaine 6y ago
  Fusors are room temperature. It’s the electrical gradient which produces the reaction, not temperature.
  - ben_w 6y ago
    The ions thermalise very quickly even in a fusor; if they fused on the first collision rather than bouncing this whole thing would be much easier. https://en.wikipedia.org/wiki/Fusor#Thermalization_of_the_ion_velocities https://en.wikipedia.org/wiki/Fusor#Thermalization_of_the_io... 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.
DennisP 6y ago
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.
- simonh 6y ago
  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.
- willis936 6y ago
  Muon-catalyzed fusion is well understood and F&P are well known frauds. There isn’t something interesting here.
- kergonath 6y ago
  > 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.
- prox 6y ago
  The most exiting phrase in Science is not “Eureka!” but “That’s funny...”
japanuspus 6y ago
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]. [0]: https://fusor.net/ https://fusor.net/

lumost 6y ago

Digging into the research here, there are a lot of results which indicate some form of LENR should be feasible in suitably complex environments. As an example, calculating the exact screening effect of a metal lattice from theory has not been performed to anyones satisfaction, particularly if you account for hydrogen moving within the lattice, or the lattice undergoing some deformation. The experimenters researching this clearly don't have a great way to control for other factors in an experimental setting either. As an example, there are multiple reports of transmutations being observed following a hydride doping experiment... however these are all done by gas spectrometer. It's unclear from the experiments whether there happened to be random impurities in the hydride prior to doping. Similarly heat/neutron measurements are really difficult to get right and be convincing.

kergonath 6y ago
As a materials physicist, I have no idea what you mean by this: > As an example, calculating the exact screening effect of a metal lattice from theory has not been performed to anyones satisfaction, particularly if you account for hydrogen moving within the lattice, or the lattice undergoing some deformation. Screening effect from what? There is nothing surprising in the way hydrogen behaves in a metal. We can simulate that with great accuracy, in fact we do it all the time as hydrogen embrittlement is an important issue in metallurgy. This type of cold fusion would require two nuclei overcoming humongous energy barriers to get close enough to each other. No form of motion within a crystal lattice or no amount of deformation is going to provide that. The energies involved are about 6 orders of magnitude short. Heat is trivial to measure, we’ve been doing that since the 19th century. Neutrons are not particularly difficult either, we’ve been doing that since the 1940s.
- drran 6y ago
  The idea of LENR is not to move hydrogen protons in a lattice, but to make it jump over imperfections, with hope that it will land into nuclei.
  - kergonath 6y ago

zamalek 6y ago

I don't think LENR is possible, but I'd love to be wrong and I do think that some money and energy should be spent investigating it. What I find interesting is some phenomena that was clearly present in some of these demonstrations - even if it wasn't LENR. The anomalous results are worth investigating because there may be unknown physics lurking there, but anything related to CF is scientifically taboo.

fsh 6y ago
Fleischmann and Pons had a lab sponsored by IMRA (the research division of Toyota) where they were supposed to repeat their experiment. They spent 12 million dollars without getting any believable results. The idea that their research was somehow suppressed is laughably wrong.

jostmey 6y ago

If cold fusion exists that produces more energy than it consumes, it would take some extreme conditions. If cold fusion could appear under normal-ish conditions, we would have already observed it and tapped into it

kosievdmerwe 6y ago
Given that we only discovered and built dead downwind faster than the wind vehicles in the 2000s I wouldn't be so sure. And for being relatively simple classical physics it was very controversial, with even some physics professors denying it was possible.
- roflc0ptic 6y ago
  We did that? That sounds awesome. Source?
  - deleted 6y ago
    [deleted]
  - kosievdmerwe 6y ago
    Some sources: https://www.lockhaven.edu/~dsimanek/museum/ddwfttw.htm https://www.lockhaven.edu/~dsimanek/museum/ddwfttw.htm https://en.wikipedia.org/wiki/Blackbird_%28land_yacht%29 https://en.wikipedia.org/wiki/Blackbird_%28land_yacht%29 The search term to use is "DDWFTTW" It's a bit confusing, but some important points are: * It only works if you're on land, you can't have a flying device that does this. * Boats can sail faster than the wind speed, but have do so at an angle to the wind. (Just to convince yourself that this isn't completely strange). * The wheels rotation on the ground is what drives the propeller, not the other way around.
- ratsforhorses 6y ago
  Just thought I'd add a relevant link as the phrase "dead downwind" caught my eye https://en.m.wikipedia.org/wiki/Blackbird_(land_yacht)#:~:text=On%20July%202%2C%202010%2C%20Blackbird,the%20speed%20of%20the%20wind https://en.m.wikipedia.org/wiki/Blackbird_(land_yacht)#:~:te....

jeffreyrogers 6y ago

Yeah, I always heard it was complete BS, but when you look into it there have been some weird phenomena reported. Unfortunately no one seems to be able to reliably produce them.

sdenton4 6y ago
Weird phenomena are a great way to justify a large investment of time and effort for yourself... But what the world wants is BORING phenomena.
- AnimalMuppet 6y ago
  I would say the science world wants weird phenomena, boringly reproducible.
Robotbeat 6y ago
One thing that is an indispensable lesson of graduate research: actually trying to make a cutting edge measurement and pick signal from noise is INCREDIBLY hard. It's easy to underestimate just how noisy frakking everything is. Every thing looks complex and uncertain and it's only through extremely hard work and careful measurement that you can know ANYTHING. So complexity is actually the norm. The irreducible complexity of noise.
- jdkee 6y ago
  The weak SNR ratio would lead one to believe that the results are bullshit, no?
  - Robotbeat 6y ago
    Yup.
  - XorNot 6y ago
    The real tell tale is when the effect starts diminishing as SNR improves. The giveaway that the EM drive is junk is that the effect has gotten smaller everytime the apparatus has removed a source of error. Nothing is ever conclusive, but it points to something which should violate the known laws of physics really just being a pile of systematic error.

mxcrossb 6y ago

> despite not actually trying to replicate the Fleischmann and Pons experimental setup accurately I’ve been seeing this claim in another field: about hydroxychloquinine. Every time a study comes out which doesn’t show a benefit, people rush in saying “that’s because they forgot X, didn’t dose the right amount of Y, etc” I’m actually not sure what to make of this phenomenon in general. I will say though that when you’re trying to test a hypothesis, completely replicating another experiment isn’t necessary. You should test it under a variety of conditions. That makes it easier to avoid the same hidden mistakes that the original experiment might have included.

andrewflnr 6y ago
You should definitely also try the exact original conditions. Think about reducing a tricky bug: you start with the exact input and code that first caused the problem, then try removing constraints to see what preserves the bug. Ed; I should clarify: you start with whatever big nasty test scenario you need to make sure you can reproduce the effect at all, and only then can you start changing the conditions and be confident you're still measuring the same thing.
- mxcrossb 6y ago
  Yes but science and computer programming are fundamentally different activities. The programmer tries to reproduce the bug because his main fear is that he can’t see its effect. But the scientist’s main fear is that the experimental setup does not robustly test the underlying hypothesis. If you reproduce exactly the conditions (and remember you will always be criticized for missing X), the best you can learn is whether the previous result was not completely fabricated (or statistical noise). It’s much more productive to subject a result to a wide battery of tests.
  - andrewflnr 6y ago
    If you're dealing with an unknown, confusing phenomenon, you don't know what the underlying hypothesis is. You don't know yet what constitutes rigorous testing and what is just wandering off into the weeds. So you need to start with seeing if the thing happens at all. You do in fact need to know whether the previous result was garbage before it can be productive to do a wide battery of tests. And "wide" depends on how sensitive to conditions your effect is, which you also don't know yet. Your closest thing to an anchor is the initial claimed setup, so start there.

kergonath 6y ago

> despite not actually trying to replicate the Fleischmann and Pons experimental setup accurately They (Fleischmann & Pons) did not prove anything in the first place, so after that the “not the true experiment” thing is a fallacy. There will always be too much of something or not enough of anything. You can never replicate exactly an experiment, but this does not prevent all of science from progressing and reproducing results. Physics does not care about who operates the experiment. So if something works only when specific people try it, it does not give any confidence in the results. In other words, it does set the bullshit alarm ringing. There is no theoretical foundation for cold fusion, and no known mechanism for it to work. So even if it does exist, their stance of “just trust us, and let us move the goalposts about replicability” is just voodoo and, yes, bullshit.

lenkite 6y ago

I thought Japanese researchers had already replicated the "anomalous heat generation" in LENR. https://asiatimes.com/2019/11/cold-fusion-japan-takes-the-lead/ https://asiatimes.com/2019/11/cold-fusion-japan-takes-the-le... Why is this still considered BS if independent research teams have reproduced this ?

simonh 6y ago
It's important to distinguish between current actual results from labs working very carefully and methodically and turning up interesting anomalous results, and the original claims made by F&P. Yes there is interesting physics here and there's a lot we don't know about the behaviour of hydrogen and deuterium in dense metallic crystal lattices. Who knows, that behaviour might even have something to do with fusion. That's separate from what F&P were claiming 30 years ago. They claimed to have produced 'tremendous heat' and to have detected evidence of fusion (gamma rays and fusion products). They couldn't replicate the heat measurements, there were experimental errors that mean we can't know if they had generated excess heat at all, and they were simply mistaken that the evidence they had gathered indicated fusion. Two things can both be true at the same time. These new experiments might indicate heat generation and might indicate fusion, and the F&P experiments demonstrated none of those things. Those are not contradictory statements. Heck, F&P might even have stimulated fusion in their experiments. It's impossible to prove a negative. The point is they didn't demonstrate that at all.

deepstack 6y ago

This is interesting development. Back then when Pons and Fleischmann first came out with this in 89, they were heavily ridiculed ( or smeared) by main stream academics like MIT. It also turns out MIT has received a lot of money to do hot fusion research. Wouldn't be the first time that interests of funding interfered with science.