double slit coherent wave interference patterns

Taster of the upcoming physics demonstration toolkit. See www.whylearnthat.co.uk

Category:

Education

Tags:

• interference pattern
• diffraction
• double slit experiment
• light interference
• wave interference

[ariana29x]

could the measuring device be causing some "magnetic" interference thus affecting the patterns

[grallator9]

@ariana29x By measuring which slit a photon goes through you do interact with the system and this destroys the patterns. When you measure at the screen (not the slit) you haven't interacted with the photon in flight and it can apparently go through both slits at the same time and interfere with itself!

[austpom333]

So when i conduct a double slit experiment - i am also conducting a double slit experiment in another close time and space, influencing my double slit experiment. By measuring my double slit experiment, i confine my experiment results to my spirit position experiment

[Aresthanas]

Greetings. That is interesting about photons passing through holes in walls and making patterns or supposedly sensitive when they are being observed. I was wondering if a pattern like this happens with solid things too but in a different way through slits (like a bullet,arrow,etc). Ex, if one was to throw a chair at a 'wall of water' there would be an interference pattern/outline of the chair for some time at least in slow motion of the chair we would see an image of the chair in motion.

[grallator9]

@shortliner1425 The photon does interfere with itself. As to what's actually going on, well, this is debated by many minds greater than mine and it depends on what interpretation of quantum mechanics you subscribe to! If you can figure it all out there's an appointment in Stockholm waiting for you!

[shortliner1425]

@grallator9 sounds like schrodinger`s cat all over again.....but could this be caused by quantum entanglement?so then the photon would interfer with itself?(but in a different dimension)so then the "many worlds"theory would be correct?this stuff is amazing!

[grallator9]

@shortliner1425 That's where it all falls down! As soon as you know which slit it goes through it stops behaving like a wave and starts acting like a particle and the interference pattern is lost. It only acts like a wave when you don't know which slit it goes through.

[shortliner1425]

@grallator9 yes,it`s interesting stuff! but if we put a camera in front of the slit,would we actually see the photon split up?( i wish i had the equipment,otherwise i`d go and see for myself...!)but if we don`t see it split up,and we still see the interference pattern,then either it`s a wave,or the interference pattern appears because of something else.it`s so weird!

[grallator9]

@shortliner1425 That's a great question! You can fire light through a double slit and get the interference pattern. If you turn down the intensity enough you can use a sensitive detector to see individual photos arriving at the screen. The thing is, if you turn it down enough so that one only photon goes through the experiment at a time you still get the pattern. It's as if the particle is behaving like a wave (and going through both slits). Observing quantum systems still causes arguments!

[shortliner1425]

@grallator9 but if it`s 2 things at once,how come when we observe it,light is behaving like a particle(or a wave) but never both at the same time?does that mean it slips in to another universe?or does the observer itself interfer with the light in some way?and by the way thanx for the explanation.