The Naked Scientists

The Naked Scientists Forum

Author Topic: Double slit experiment expanded  (Read 3353 times)

Offline Ignorant Enthusiast

  • First timers
  • *
  • Posts: 9
    • View Profile
Double slit experiment expanded
« on: 15/02/2008 09:22:20 »
<ramble>
First off let me say hi to everyone as this is my very first post on these forums. I am in no way a scientist (hence the user name), my understand of the sciences comes from a standard high school education combined with an interest in reading, well anything interesting really. Hope you guys and gals don't mind me asking what may very well be really stupid questions from an uninformed mind - don't worry though, I won't get offended if you tell me I'm an idiot  :)
</ramble>

First question, I assume everyone is pretty familiar with the Double Slit experiment that shows photons behaving as waves and or particles.
newbielink:http://en.wikipedia.org/wiki/Double-slit_experiment [nonactive]

Well I was wondering if a Triple Slit (or more) experiment had ever been tried (or theorised about)? It's well know that detecting a photon passing through one of two paths will cause the probability waveform to collapse in a double slit experiment and show that photon behaving as a particle, but what would be the effect of monitoring one possible path in a triple slit experiment? Detecting the photon passing along the monitored path would obviously(?) result in it behaving as a particle, but not detecting it would result in it having an equal probability of passing along either of the other two paths to the detector screen, would you end up with an experiment that showed a photon behaving as both a particle and a wave all in one experiment, or would the detecting device in one of the three paths result in every photon showing particle properties?


 

Offline lightarrow

  • Neilep Level Member
  • ******
  • Posts: 4586
  • Thanked: 7 times
    • View Profile
Double slit experiment expanded
« Reply #1 on: 15/02/2008 12:17:05 »

First question, I assume everyone is pretty familiar with the Double Slit experiment that shows photons behaving as waves and or particles.
http://en.wikipedia.org/wiki/Double-slit_experiment

Well I was wondering if a Triple Slit (or more) experiment had ever been tried (or theorised about)? It's well know that detecting a photon passing through one of two paths will cause the probability waveform to collapse in a double slit experiment and show that photon behaving as a particle, but what would be the effect of monitoring one possible path in a triple slit experiment? Detecting the photon passing along the monitored path would obviously(?) result in it behaving as a particle, but not detecting it would result in it having an equal probability of passing along either of the other two paths to the detector screen, would you end up with an experiment that showed a photon behaving as both a particle and a wave all in one experiment, or would the detecting device in one of the three paths result in every photon showing particle properties?


We usually talk about double slit experiment because it's simpler, but there isn't any conceptual difference with n slit (which you have in any common diffraction grating); you will have in that case an n-slit interference pattern if you don't detect the photon's positions near the slits, or an n-peaks pattern if you detect them.
http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html
Select "Light and Vision" and then "Grating" or "Interference" and "Multiple Slits".

In this applet you can edit source, frequency, speed, resolution, draw the wall, and so as many slits as you want (mouse = EditWave or EditWalls ecc.) and see what happens:
http://www.falstad.com/ripple/

It's very interesting. Enjoy it.
« Last Edit: 15/02/2008 12:24:46 by lightarrow »
 

lyner

  • Guest
Double slit experiment expanded
« Reply #2 on: 15/02/2008 13:06:37 »
Quote
It's well know that detecting a photon passing through one of two paths will cause the probability waveform to collapse in a double slit experiment and show that photon behaving as a particle
Actually, even with one slit, there still be diffraction effects (looking at the problem in wave terms) and a 'spread' of effective angles by which the photon can emerge (looking from the particle point of view).
 

The Naked Scientists Forum

Double slit experiment expanded
« Reply #2 on: 15/02/2008 13:06:37 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums