QM and String

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Main Question or Discussion Point

I keep seeing references to the observer effect in the double -slit experiment where the a
of observing the photon or electron going through the slits causes a collapse of the wave function. so, instead of getting a cool interference pattern, you get the pattern expected if the light was acting as a particle.

Has this actually been tested experimentally?

If so, I have not been able to find it anywhere.

If anyone can post a citation from a peer-reviewed physics journal where this phenomenon is reported, I would appreciate it.

thanks,

Dr. Todd
Hello, I am new in this forum and I am not a scientist
Can someone help me to understand the following question: does this String theory confute and negate the Observer Effect and that there is a subjective reality? Or it confirms it
Thank you so much
Rossella
 

Answers and Replies

Can Any One Answer My Question?

Dear Scientists
Is there anyone who can answer to the following?
Are you familiar with String theory?
Does this theory negate or contradict the previous quantum mechanic theory of observation? (Copenhagen Interpretation and Observer's effect) , does observation still have a big roll in giving properties to Strings?
Thank you so much
Rossella



I keep seeing references to the observer effect in the double -slit experiment where the a
of observing the photon or electron going through the slits causes a collapse of the wave function. so, instead of getting a cool interference pattern, you get the pattern expected if the light was acting as a particle.

Has this actually been tested experimentally?

If so, I have not been able to find it anywhere.

If anyone can post a citation from a peer-reviewed physics journal where this phenomenon is reported, I would appreciate it.

thanks,

Dr. Todd
 
ZapperZ
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These posts have been moved from a thread in the QM forum to this forum, where I think it might get more attention from people who have the expertise to answer it.

Zz.
 
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Presumably quantum string theory (when it ever becomes a physical theory) will still lie within the broader domain of standard quantum mechanics and as such will not change the prediction of which you speak.

I would also make some qualifications in how you describe this effect.
Let me emphasize that when we speak of "observation" in QM we necessarily mean physically interacting with the system. Most confusion about QM predictions arise when one makes assumptions about what is beyond what is physically observed.

When the wave function collapses we must understand the wave function as a mathematical object similar to a classical probability distribution. It's collapse is no different in principle from the collapse of the expectation values of lottery tickets once the drawing occurs. The assertion that new knowledge of a specific type is obtained about the system changes the distribution of possible subsequent behavior. Nothing physically "collapses".

Also "behaves like a particle" isn't quite right as you may still see single slit interference effects. Remember also that you never see the interference pattern of one particle. The pattern emerges when you repeat the experiment for many particles with the same setup. In all cases the particle "behaves like a particle" in the sense that you put one in and you get one out and it lands at a certain point on your film or whatever you use to detect it.
 

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