Better double slit depiction

[IM Egdall]

In a recent blog (Here's that cat again), Swansont gave a link to a visualization of the double slit experiment. He pointed out that "the depiction of electrons in classical trajectories detracts from" the depiction. I agree.

 

The best depiction I have seen is in the link below (Quantum Wave Interference):

 

http://phet.colorado.edu/en/simulation/quantum-wave-interference

 

It shows the electron (or photon or atom, etc.) as a wave (wave function) passing through both slits, producing two waves which interfere with each other, and then the detection of a single particle on the detector screen. Each time the simulation is run, the single particle shows up at another random location on the screen, the probability of its location determined by the wave function (squared). Over time, the individual particles at the detector screen build up to form an interference pattern.

 

It is a little more complicated that the depiction criticized by Swansont in his blog, but I think it is a much better aid in understanding quantum mechanics.

Edited October 26, 2014 by IM Egdall

[Enthalpy]

It's a help to understand, but this experiment and its description also bear the risk of introducing incorrect comprehension of QM.

 

For instance, the wave function is not only a means to compute a probability of single events. In atomic force microscopes, or at the interaction of two atoms, the same electrons interact all the time, and over the full extension of the wave function. The sole example of the two-slit experiment may let readers get that inaccurately.

 

Readers may also misunderstand that the interaction with the slotted screen is of a different nature than the one with the detector pixels, or that an absorption must be local.

 

So while the double-slit experiment is useful, it must not be the only basis to understand QM.

[Chriss]

What do they use to observe a particle ?

[Strange]

What do they use to observe a particle ?

 

http://www.scienceforums.net/topic/86284-particle-detectors/

[michel123456]

In a recent blog (Here's that cat again), Swansont gave a link to a visualization of the double slit experiment. He pointed out that "the depiction of electrons in classical trajectories detracts from" the depiction. I agree.

 

The best depiction I have seen is in the link below (Quantum Wave Interference):

 

http://phet.colorado.edu/en/simulation/quantum-wave-interference

 

It shows the electron (or photon or atom, etc.) as a wave (wave function) passing through both slits, producing two waves which interfere with each other, and then the detection of a single particle on the detector screen. Each time the simulation is run, the single particle shows up at another random location on the screen, the probability of its location determined by the wave function (squared). Over time, the individual particles at the detector screen build up to form an interference pattern.

 

It is a little more complicated that the depiction criticized by Swansont in his blog, but I think it is a much better aid in understanding quantum mechanics

I cannot see the depiction on my computer here. Am I missing some instructions?

[davidivad]

good old double slit...

its just the result of splitting a full wave up. of course you will get a left over...

you are literally seeing the makeup of the particle. a piece of it which is not the full particle.

we all know particles have a wave function and this experiment puts your nose in your butt for lack of better terms.

it will run you in circles.

 

if you are not looking in increments of a whole particle or wave function, then you get the left overs as they are (not a full particle measurement).

it can seem that the particles in question can bypass time but this is just a consequence of causality.

while we have a chioce in our decisions in life the whole does have direction.

in other words a particle only seems to choose because the outcome happens to be true. there is noone doing the experiment the opther way.

if there was, you would get a different result.

in other words the experiment validates that while our futures can be vaguly forcast, they cannot be known with certainty.

i call this the noise problem of predetermination.

Edited November 23, 2014 by davidivad

[derek w]

If you have a single slit and an arc shape detector centered around the slit,a water wave would expand out from the slit and hit all parts of the detector simultaneously.

photons would not do this,so how can the analogy of waves creating an interference pattern work?

[Strange]

its just the result of splitting a full wave up. of course you will get a left over...

you are literally seeing the makeup of the particle. a piece of it which is not the full particle.

 

In the classical case, it is the result of splitting up the wavefront.

 

But photons and electrons do not have a "makeup"; they cannot be split; their is no "piece which is not the full particle". Because they are quantized. (A word you should be familiar with )

If you have a single slit and an arc shape detector centered around the slit,a water wave would expand out from the slit and hit all parts of the detector simultaneously.

photons would not do this,so how can the analogy of waves creating an interference pattern work?

 

I don't understand. Why would photons behave any differently? Obviously, any one photon can only hit one point on the detector. But a number of photons would be evenly distributed across the detector in the same way that a wave is (and they would all take the same time from slit to detector).

[davidivad]

strange,

if you are going to follow me around, i suggest you start using references because this is how im going to handle you.

this is partially my fault as i have failed everyone by not supporting my ideas without references.

now i will give a ral explanationas to why i am wrong and support my claim with references.

 

ready?

 

if the test is set up with enough precision then you get the banding along with courseness in the pattern as if both are taking place. this is not consistent with my original idea.

or at the very least, it does not explain in any detail why the interference pattern shows coarseness.

here is a reference just foryou strange from a source i though you would definitely appreciate... a laymens view.

http://blogs.scientificamerican.com/guest-blog/2011/06/07/what-does-the-new-double-slit-experiment-actually-show/

hey, wait...

[Strange]

Sorry, davidivad, I'm not sure what you are trying to say. My fault I'm sure.

[Eise]

The best depiction I have seen is in the link below (Quantum Wave Interference):

 

http://phet.colorado.edu/en/simulation/quantum-wave-interference

 

It's a great site. So many simulations! Exactly right for the dark days...