Or in other words which forces keep electrons in orbitals and prevent it from flying away or crashing into the nucleus according to modern understanding?

  • JWBananas@lemmy.world
    link
    fedilink
    English
    arrow-up
    3
    ·
    3 months ago

    So: Because an electron with an exactly defined position must have infinite kinetic energy

    There are an infinite number of velocities I can use to get up off the couch right now.

    That does not mean that I will get up off the couch at infinite velocity.

    • thebestaquaman@lemmy.world
      link
      fedilink
      English
      arrow-up
      5
      ·
      3 months ago

      Yes, there are an infinite number of velocities you can use, but if you look at their distribution, you’ll find that it quickly goes to zero somewhere around 1-2 m/s, so the expectation value of the velocity is convergent.

      If you have an object with a velocity taken from a distribution that doesn’t approach zero sufficiently fast as the velocity goes to infinity, the expectation value diverges. A simple example would be a person that would be half as likely to get up at a velocity of 2 m/s as 1 m/s, and half as likely to get up at 4 m/s as 2 m/s, etc.

      The more mathematical version of the same argument is to compute the energy of a particle who’s wavefunction is a delta pulse, and you’ll find that the particle has infinite energy.

    • SmoothOperator@lemmy.world
      link
      fedilink
      English
      arrow-up
      1
      ·
      3 months ago

      You choose a velocity from an infinite number of options, but the electron exists in a superposition of all those options.