4 ms·

You're referring to the 'Gamow window' right? From what I understand, the Gamow window only refers to the energy levels of the particles, rather than temperatur

You're referring to the 'Gamow window' right? From what I understand, the Gamow window only refers to the energy levels of the particles, rather than temperature per se. I'm guessing that's why approaches like Muon-catalysed fusion can work at lower temperatures. https://en.m.wikipedia.org/wiki/Muon-catalyzed_fusion https://en.m.wikipedia.org/wiki/Muon-catalyzed_fusion

lmm 11y ago
Muon-catalysed fusion reduces the width of the barrier - the muon is ~200 times closer to the nucleus (since it's that much heavier) and so the coulomb barrier is that much narrower - and the reaction rate is exponential in that.
- ZenoArrow 11y ago
  Sure, it makes sense that it affects the Coulomb barrier (or the Gamow factor/window https://en.m.wikipedia.org/wiki/Gamow_window https://en.m.wikipedia.org/wiki/Gamow_window ), but doesn't muon-catalysed fusion kind of prove that cold fusion could exist? The Wikipedia article suggests that the reactions can take place at room temperature, with the main issue being the reliability of the required reactions. In other words, we already have one proven method for reducing the Coulomb barrier, why is that the only one that's possible?
  - XorNot 11y ago
    It probably isn't. In fact it almost definitely isn't (there was some work which showed palladium matrices should accelerate beta-decay processes a little). But there's no model which supports any of the proposed mechanisms for cold fusion currently put forward as possibly workable devices - i.e. it's not theoretically possible, and there's no solid path to show that it might be.
  - lmm 11y ago
    The standard model is very solidly established, and it tells us what fundamental particles there are. The muon is the most stable negatively charged particle other than the electron; the Xi is about 10000x shorter-lived, and the tau 1000x shorter than that - and even muons aren't stable enough to be practical. More importantly, these things are physics rather than chemistry. No amount of chemistry will produce muons from ordinary chemicals, you have to use high-energy radiation. (Admittedly molecular bonds distort electron orbitals a little bit, but nothing like the factor of 200 you get from switching them for muons). If someone had a way to catalyse any kind of nuclear process with chemistry (something as simple as making a radioactive element decay faster) that would be a major breakthrough. To jump straight to the single most useful one would be too much to hope for.
    - pdonis 11y ago
      > these things are physics rather than chemistry The atoms of palladium in the cold fusion experiments don't know that they're supposed to be doing "chemistry" rather than "physics". That division is only in our theories, not in reality. > (Admittedly molecular bonds distort electron orbitals a little bit, but nothing like the factor of 200 you get from switching them for muons) This is a valid concern, but as I understand it, the suggestion is that strong electric or magnetic fields have to be applied in order to induce cold fusion, so we're not just talking about the distortion of orbitals from molecular bonds, we're talking about the distortion due to strong externally applied fields, which can be much larger.

lmm 11y ago

Muon-catalysed fusion reduces the width of the barrier - the muon is ~200 times closer to the nucleus (since it's that much heavier) and so the coulomb barrier is that much narrower - and the reaction rate is exponential in that.

ZenoArrow 11y ago
Sure, it makes sense that it affects the Coulomb barrier (or the Gamow factor/window https://en.m.wikipedia.org/wiki/Gamow_window https://en.m.wikipedia.org/wiki/Gamow_window ), but doesn't muon-catalysed fusion kind of prove that cold fusion could exist? The Wikipedia article suggests that the reactions can take place at room temperature, with the main issue being the reliability of the required reactions. In other words, we already have one proven method for reducing the Coulomb barrier, why is that the only one that's possible?
- XorNot 11y ago
  It probably isn't. In fact it almost definitely isn't (there was some work which showed palladium matrices should accelerate beta-decay processes a little). But there's no model which supports any of the proposed mechanisms for cold fusion currently put forward as possibly workable devices - i.e. it's not theoretically possible, and there's no solid path to show that it might be.
- lmm 11y ago
  The standard model is very solidly established, and it tells us what fundamental particles there are. The muon is the most stable negatively charged particle other than the electron; the Xi is about 10000x shorter-lived, and the tau 1000x shorter than that - and even muons aren't stable enough to be practical. More importantly, these things are physics rather than chemistry. No amount of chemistry will produce muons from ordinary chemicals, you have to use high-energy radiation. (Admittedly molecular bonds distort electron orbitals a little bit, but nothing like the factor of 200 you get from switching them for muons). If someone had a way to catalyse any kind of nuclear process with chemistry (something as simple as making a radioactive element decay faster) that would be a major breakthrough. To jump straight to the single most useful one would be too much to hope for.
  - pdonis 11y ago
    > these things are physics rather than chemistry The atoms of palladium in the cold fusion experiments don't know that they're supposed to be doing "chemistry" rather than "physics". That division is only in our theories, not in reality. > (Admittedly molecular bonds distort electron orbitals a little bit, but nothing like the factor of 200 you get from switching them for muons) This is a valid concern, but as I understand it, the suggestion is that strong electric or magnetic fields have to be applied in order to induce cold fusion, so we're not just talking about the distortion of orbitals from molecular bonds, we're talking about the distortion due to strong externally applied fields, which can be much larger.