Did we really try to 'trick' the universe?

[rrw4rusty]

Hi!

 

This regards the famous experiment were photons (or other particles) were fired through two slits and the wave pattern appeared -- even when fired one at a time... and then we 'watched' to see what was actually passing through the slits and the wave pattern collapsed and we then got two lines instead of the wave pattern...

 

First, how did we 'watch'?

 

Since I do now know the answer to the above, I will assume we just aimed a special camera at one (or both) of the slits.

 

Then... (did we try to trick the universe?)

1. Did we try recording instead of watching it live and then... not watching the recording -- burning the tape!?!?

2. Did we try putting the camera there but not turning it on (or using bad film!)?

3. Did we try only 'watching' (filming) the first particle?

4. Did we try only 'watching' half of the sequence (or one forth... one eighth)

5. What if someone else put a phony/or a real camera there so even 'we' didn't know! Could we then determine if it was a phony or real camera 100% of the time?

 

How could the 'universe' know that it was being watched or that it wouldn't be?!?! Was it just the presence of the camera??? Or, was it really whether someone watched or not and... what if we watched (or didn't) after the pattern was created!!!!?????!!!

 

Sorry, this one defies even sci-fi and really makes me crazy. ;-)

 

Thanks,

Rusty

 

Edit: This issue won't let me sleep (it's 1:24 AM). It must be that if it 'could' be watched the wave collapses (that is the 'camera' is in place and it's working whether its being watched or not... or, it's being recorded, whether it's watched or not). Also, it must be that whatever part is filmed or recorded creates lines but the rest reverts to the wave pattern. Any other circumstance and this thing could predict the Lotto!

Edited October 30, 2009 by rrw4rusty

[DrP]

Whether you watch or not, the same thing happens. You can use a screen or unexposed film. If you fire them singularly they act as if there are many (BECAUSE it travels as a wave and hits as a particle).

 

Read about Thompsons double slit experiment.

 

 

The purpose is to demostrate that the ONE photon "knows" (maybe "experiences" would be a better word) that there are 2 slits because it is travelling as an electromagnetic wave. When it hits the wall/screen/film or whatever you choose to put in the way, it hits at a single pont making one flash. But always in the area where you would expect to see a light strip from the difraction pattern. Hope that is clear - if not look up Thompsons double slit experiment - it explains all this.

[swansont]

http://en.wikipedia.org/wiki/Quantum_eraser_experiment