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

Yet another question about the double slits

  1. Jun 7, 2009 #1
    Apparatus: Electron source + double slit + screen + lamp.

    If the lamp is left turned on but the physicist leaves the room for an hour, does he see an interference pattern when he returns?

    (Sorry if this simple question has been done before)
  2. jcsd
  3. Jun 7, 2009 #2


    User Avatar
    Homework Helper
    Gold Member

    The result of the experiment has nothing to do with whether the physicist is in the room or not.
  4. Jun 7, 2009 #3
    I see. So the photons simply destroy the superposition state, which is equivalent to an observation, collapsing the wavefunction.

  5. Jun 7, 2009 #4


    User Avatar
    Homework Helper

    Is this double-slit experiment done with photons or electrons?
  6. Jun 7, 2009 #5
    So after reading about quantum theory awhile ago, I inevitably came across the infamous double slit experiment, and I understand the concept, how the act of "observation" collapses the wave function of that which is fired through the slits, but what I did not understand fully, is what constitutes an "observer" or "observation" exactly? I know measuring where an electron is while going through the slits collapses the wave function, but what else would?
  7. Jun 8, 2009 #6
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook