# Double-slit experiment questions

v6WR5Pfk6Jm4
I recently been reading up quantum physics including the double-slit experiments and I got two basic questions:

1# Why does the electron not act like a wave when there is only one slit? Shouldn't a single slit still result in a wave like pattern?

2# 'Measuring' the wave seems to turn it into a particle. Even if this is done after the slits. Yet some scientist are calling this potential time travel. How do they know its not simple a wave that instantly turns into a particle at the point of 'measurement' without any 'time travel'?

Staff Emeritus
I recently been reading up quantum physics including the double-slit experiments and I got two basic questions:

1# Why does the electron not act like a wave when there is only one slit? Shouldn't a single slit still result in a wave like pattern?

It does. If you map out the pattern from thousands of electrons on the detector, you will find that it matches that of a wave passing through a single slit. See here: http://physics.bgsu.edu/~stoner/P202/quantum2/sld012.htm

The pattern matches that of light that passes through a single slit as well.

2# 'Measuring' the wave seems to turn it into a particle. Even if this is done after the slits. Yet some scientist are calling this potential time travel. How do they know its not simple a wave that instantly turns into a particle at the point of 'measurement' without any 'time travel'?

First, let me clarify that when we detect any particle, we are detecting it as a particle. It is only when we look at the combined pattern of many many particles do we see the wave-like effects such as interference. As for time travel, I don't see it that way.

v6WR5Pfk6Jm4
First, let me clarify that when we detect any particle, we are detecting it as a particle. It is only when we look at the combined pattern of many many particles do we see the wave-like effects such as interference. As for time travel, I don't see it that way.

But that still leaves me with the same question... What if we 'measure' every single one these electrons/photons before during or after the slits, we wouldn't see interface in any of these situations right?. So why isn't the conclusion that the measures are simple 'converting' it into particles?