Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Quantum Tunneling in the Sun

  1. Jan 14, 2015 #1
    Hi pf,

    I'm fairly new to QM so this may seem like a trivial question. As I understand it, an electron (or any small particle) does not have a definitive position in space until it is observed which causes the quantum wave like nature of the particle to disappear (collapse of the wave function). For example, in the electron double slit experiment, the electron behaves like a wave showing an interference pattern until you try to measure which slit it goes through which causes the wave function to collapse and the pattern resembles two peaks rather than an interference pattern.

    From what I have read, the energy released by the Sun cannot be fully explained without taking into account quantum tunneling. This seems to be explained by the quantum wave like nature of particles which means since two protons can be in many places at once (due to their wave like nature) some of these places result in these particles tunneling through the electrical repulsion barrier and fusing together. This sounds silly but if you use the same logic for the effects of observation on quantum objects for the double slit experiment then what would happen if you were to simultaneously try to observe all the protons in the Sun (obviously this is impossible). If you could observe all the protons in the Sun then effectively wouldn't all their wave functions collapse and you would have no quantum tunneling and the Sun would produce less energy?
  2. jcsd
  3. Jan 14, 2015 #2


    User Avatar
    Gold Member

    You misunderstand. Quantum objects are not in two places at once, they are not in ANY place until observed. It actually makes no sense to talk about the "position" of a quantum object until it is observed and then it is in one place.
  4. Jan 14, 2015 #3
    Thanks. This video () from 40 seconds - 1min 30secs seems to say that particles have a wave like behaviour so there is a probability that such particles in the Sun can be found close enough together to fuse. But if you observe the position of all the particles in the Sun then surely they will exhibit no wave like behaviour so the quantum tunneling effects will go away?
  5. Jan 14, 2015 #4


    User Avatar
    Gold Member

    Quantum object do exhibit wave-like characteristics if that's what you measure for (and particle-like behavior if that's what you measure for), but I don't know enough to comment on whether your thesis about tunneling is sound. In practical terms, of course, it doesn't matter since it is impossible to do what you require experimentally (as you already realize).
  6. Jan 15, 2015 #5


    User Avatar
    Science Advisor

    In quantum mechanics, observe means to interact with a detector. Observation only collapses a wavefunction for the parameter which is observed, and only to the extent that it is observed. Mathematically, it is a projection operator. Heisenberg uncertainty principle puts some limits on what you can observe. In order to measure the protons of the Sun in a way you envision, you would have to capture the protons into a larger device. While they are captured by the device, the protons might have trouble fusing. But when you release the protons, their wavefunctions will spread out again and they'll start fusing again.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook