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Newbie question - about Schroedinger's Cat

  1. Jul 5, 2012 #1
    Newbie question -- about Schroedinger's Cat

    Perhaps I'm looking at this question with a conventional classical frame of mind but I just don't understand the basic principle and would like an explanation.

    Schroedinger's cat is assumed to be both alive and dead inside a box. This is because it's not being observed. The act of opening the box affixes the cat into one of these two states.

    Two questions arise from this.

    1. Even when the cat is inside the box, the environment inside the box is observing the cat. So the cat cannot be alive and dead simultaneously despite no human observation.

    2. How do the particles that mke up the cat know its being observed. This for me, is a similar argument to 'how does a massive Object know another massive abject has moved.' (prime question asked while studying Newtonian gravity). It Appers to me that both questions exist on a micro and macro level. So applying the principle of quantum mechanics to gravity. It follows that, if an object that has mass is being observed by another object with mass. It induces a gravitational force of attraction between both masses due to the resultant warping of space time fabric. So the resultant force of this observation manifests itself as gravity?

    Could anyone answer these two questions? I'm not a physicist so apologizes for the errors
     
    Last edited: Jul 5, 2012
  2. jcsd
  3. Jul 5, 2012 #2
    Re: Newbie question -- about Schroedinger's Cat

    I think you're missing some parts of the Shroedinger cat thought experiment. Youre missing the part with the bottle of poison attached to a geiger counter. You place an atom of radioactive material in the box, and if the atom decays, then geiger counter goes off, causing the bottle of poison to break open, killing the cat. Since the decay of the atom is probabalistic, until you look into the box, the cat is both dead and alive.
    The environment inside the box can't disturb the quantum state (or measure) the cat because the environment itself is also in a probabilistic quantum state. If the bottle of poison breaks then the box will be filled with noxious gas, if not it will be clean. Since the whole system is dependent upon the decaying radioactive atom, the only way to measure it is to open the box.
    I hope this answers your first question.
    Im not sure I understand what you mean by your second question, could you reword it?
     
  4. Jul 5, 2012 #3
    Re: Newbie question -- about Schroedinger's Cat

    Environment can't observe the cat unless someone conscious is there to actually observe the cat. Most people say that cat is NOT in super position because it is a macroscopic object. yet no one knows for sure!

    Nobody knows
     
  5. Jul 5, 2012 #4
  6. Jul 5, 2012 #5
    Re: Newbie question -- about Schroedinger's Cat

    Wrong. Consciousness is NOT required in Quantum mechanics.

    Wrong. The particle doesn't have to know. Observation disturbs the particle state.

    This is similar to the Wigner's friend thought experiment (you should check it out). In your case the entire inside of the box is in a superposition of states, not just the cat.

    Once again, the particle doesn't know. When you perform a measurement (observe) a particle you disturb it somehow. You always disturb it, you cannot make a measurement without it. Let's say you simply look at it. Well there was a light reflected of the particle and this reflection was enough to change it's position a little bit.
    Your thoughts about quantum gravity are best left for another discussion. They are quite far fetched actually.
     
  7. Jul 5, 2012 #6
    Re: Newbie question -- about Schroedinger's Cat

    Particles haves to know somehow that it is been observed. otherwise how does it decide whether to stay in superposition or be in a exact position??There has to be a method to know that...
     
  8. Jul 5, 2012 #7
    It doesn't have to know anything. If you observe it, you have to disturb it. When you disturb it it collapses it's wave function and it doesn't have a superposition anymore.
     
  9. Jul 6, 2012 #8
    Re: Newbie question -- about Schroedinger's Cat

    Schrodinger's experiment was not meant to reflect reality, it was meant to bring up a point of applying quantum mechanics to the visible world. Quantum physics is not largely observed in the visible world, and this experiment is what Schrodinger said would happen if it did. Obviously the cat and all of its millions of cells are capable of measurement, so it would collapse it's own probability to a single outcome anyway.
     
  10. Jul 6, 2012 #9
    Re: Newbie question -- about Schroedinger's Cat

    how this disturbance happen,what did you mean exactly by disturbing?
     
  11. Jul 6, 2012 #10
    Re: Newbie question -- about Schroedinger's Cat

    Disturbing a particle doesn't always measure it, it alters it's probability in some way, and sometimes it's enough to alter it to a single outcome, sometimes it's not and it merely restricts the degrees of freedom or increases them.
     
  12. Jul 6, 2012 #11
    To measure a particle you have to disturb it somehow. For example, if you wanted to look at it you would half to shoot a photon at it. Whenever you measure a particle you disturb it in some way.
     
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