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Photons projected towards corner, What next ? ( Uncertainty principle in bound region )

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There are series of events that led to the query - First what I was wondering is what happens when light falls in the "corner" of a perfect ( reflecting ) substance like the corner of a cube.

Then I was watching a video on Heisenberg's, where it said about spreading out of photons due to uncertainty as the slit is narrowed down. I wondered if it was not the opening but the whole passage is narrowed down so that the photons are not allowed to spread out, but uncertainty principle would still prevail, but how?

Thirdly, I related it with my light in corner question, there too the passage for light becomes narrower and narrower, so Heisenberg comes to play, but not allowed to spread out to "express" uncertainty in momentum. How is it going ?

Additional query - In a infinite potential well, an electron cannot tunnel. So now, I decrease the width of the tunnel ( keeping the barrier potential infinite ) to shorten the space for electron. So, again Heisenberg comes to play after a certain shortening. But again the electron is not allowed to escape the region to demonstrate uncertainty in momentum even if the width is reduced to JUST contain the electron, thus defining its position. How is these all going ? I feel I am missing something - please help me out ! So can in such circumstance the electron tunnel the infinite barrier ?

asked Feb 22 in Theoretical Physics by soumin.bhattacharjee (-10 points) [ revision history ]
edited Feb 22 by soumin.bhattacharjee
Most voted comments show all comments

A particle can never tunnel through an infinitely high barrier, no matter how narrow it is. 

That's it - read my question ! That's what I asked, how is uncertainty in momentum displayed ? Read my last paragraph carefully - the question lies in there...

Your contribution is too vague to know what to reply, except for the very last question, which I answered. 

Why you just don't shut up and calculate?

See, I know Uncertainty expression that comes is valid in a well, I know the calculations. MY QUESTION IS IF BY SHORTENING THE SIZE OF THE WELL, IF I MAKE IT TO THE RADIUS OF THE ELECTRON NOT LETTING IT TO MOVE ANYMORE OF IF YOU CONSIDER IT TO BE A POINT PARTICLE THEN REDUCE THE WIDTH OF WELL TO ZERO, THEN FROM WHERE THE UNCERTAINTY COME FROM ?? DOES IT COME FROM SHUTTING UP AND CALCULATING ? AND DOES THE QUESTION OF WHAT HAPPENS TO LIGHT WHEN IT IS PROJECTED INTO CORNER CAN BE ANSWERED JUST BY SHUTTING UP AND CALCULATING ?? 

In question I have not doubted uncertainty in a well. I said if I shorten the well to the size of the electron ( or the particle in the well ) so that it prevents the electron to actually form the waves with its nodes at the walls. See, electron being a point particle is actually not true, the concept of a dimensionless electron contrasts to experimental observations in Penning traps which point to finite non-zero radius of the electron. So now I place an electron in a inf well and narrow its width to the diameter of the electron. Thus the position gets defined as it cannot cross the walls. Also the velocity is also defined as it turns out to be zero. And as it is not made of any smaller particles, it cannot break up too. At this situation, what happens to the uncertainty ?

And my question of what happens when photons are projected to the corner of a substance has just been neglected by you all. And so you have no right to tell me " just shut up and calculate". And if you know the calculations that show what happens to electrons in such a case, and what happens to light ( or photons ) when projected towards corner, please show them to me, I don't know.

Please ask where you have doubt in the question - and if you feel its wrong please point it out clearly so that I may clarify. Please do it.

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