1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Schrödinger's Cat: How to.

  1. Mar 17, 2010 #1
    Hey, new member here, was wondering if anyone knew how to write this up as a Prac/experiment for science ( aka have a title, aim, hypothesis, discussion ect) and explain how i could do it at home/make it up? help would be much appreciated, thanks in advance!
     
    Last edited: Mar 17, 2010
  2. jcsd
  3. Mar 17, 2010 #2

    CompuChip

    User Avatar
    Science Advisor
    Homework Helper

    You could put 100 cats in boxes in the setup of the Schrödinger experiment and see how many of them eventually die, but I would not recommend doing that at home (or in a lab, for that matter).

    If you want to demonstrate the concept that the thought experiment introduces, you might want to look at the two slit experiment. You probably cannot do it at home, but any reasonably equipped school lab should have the necessary materials.
     
  4. Mar 17, 2010 #3
    Basically Schrodinger's cat experiment was a thought experiment created by physicist Erwin Schrodinger, who was trying to come up with a logical analogy in real life as to why matter (more specifically particles with very little mass like an electron or proton) behave with a particle-wave duality inherent in them. He wanted to come up with an analogy showing how absurd and wrong the Copenhagen interpretation of quantum mechanics was at the time, because it could not be applied to everyday objects that we see with our own eyes or can be logically explained by our own reasoning.

    The traditional Copenhagen interpretation of Quantum physics assumed that the wave function of mass particles and light collapsed into a specific state, but the theory presented no mechanism for when or how this collapse takes place. Schrodinger had a problem with this and invented his "Cat in a Box" analogy to show why. He found the mathematics used to describe quantum states as well as the bizarre nature of quantum mechanics itself to be troublesome.
     
    Last edited: Mar 17, 2010
  5. Mar 17, 2010 #4

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    Welcome to PF!

    Hi aaron12! Welcome to PF! :smile:
    I don't get it. :redface:

    The whole point of Schrodinger's cat is that you aren't allowed to say what the position was before you measured it.

    Since the only issue is what was the position before the first measurement, how can you have an experiment that measures it?
     
  6. Mar 17, 2010 #5
    Re: Welcome to PF!


    The whole issue was the general principle of how to go about explaining quantum physics to begin with. Schrodinger was merely trying to point out the absurdity with which Einstein, Rosen and Podolsky were trying to "reason" quantum super positions in scientific terms.

    To Schrodinger, it didn't make sense that something could be "everywhere" before you observe it and it only then can "collapse" into one spot when you observe it. To some degree I can see where he is coming from.

    It's like saying that technically, the moon is located "everywhere" as long as I am NOT observing it or looking at it directly, but as soon as I look up in the sky as see it, it's there in one spot only.
     
  7. Mar 17, 2010 #6

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    So how do you have an experiment that measures it?
     
  8. Mar 17, 2010 #7
    According to Heisenberg's "Uncertainty" Principle you cannot accurately measure most sub atomic particles in their natural state. This is the reason we still use probability wave functions to begin with.

    There are certain things that are linked together in physics in a cause and effect sort of way.....so if you try to measure one accurately, you will screw over or alter the true measurement of the other.

    In this case, it happens to be between the position and momentum of a subatomic particle.

    If you try really hard to accurately measure the exact position of a particle at any given time, the more it is that you will disturb that same particle's momentum because you will be adding velocity to it. Nature itself won't allow for you to EVER know exactly certain measurements and calculations of many sub atomic particles up to a certain degree!

    (This last sentence i just wrote is a scientist's worst nightmare by the way.)
     
  9. Mar 18, 2010 #8

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    Yes, but that's the Uncertainty Principle, and the experiment is to be about Schrodinger's cat.

    The Uncertainty Principle is about the impossibility of (accurately) making two measurements.

    Schrodinger's cat is about the impossibility of making any measurement at all (whether accurately or not) …

    so how do you have an experiment that measures it? :smile:
     
  10. Mar 18, 2010 #9

    CompuChip

    User Avatar
    Science Advisor
    Homework Helper

    And maybe, before we get too carried away, we should wait for some comment by the original TS.
     
  11. Mar 18, 2010 #10

    This is actually a very good question you ask in the case of quantum mechanics. The only I answer I know for certain, according to the Uncertainty Principle (again), is that YOU CAN'T MEASURE IT. If you try to measure a wave function it basically collapses the second the measurement is made.

    Once again, it's a cause and effect. That's what Quantum Mechanics and experimental research has shown us.

    As far as the cat experiment goes, you just open the box and look at the cat.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook