Uncertainty principle - light beam

[Dav333]

In regards to watching this video:


If the distance between the light source & board which the light is being displayed on was far apart like 100m. & you were the only person around observing the results right near the display. Then would the beam still be spread out?

Confused with this, thanks.

 

[jtbell]

Human consciousness has nothing to do with the uncertainty principle.

 

[gravimotion]

What about the fact that the edges of the slit are vertical, and their imperfection (not smooth but ragged) becomes more and more important with respect to the width of the slot?

Why would not this “physicist” decrease the height of the slot too while the width diminishes?

My point is that in the case of a large slot the beam goes through undisturbed (round projection) and projected as a round.

With the unsymmetrical "type" of reduction of the slot (that is in the vertical direction only) horizontal distortion occurs due to the edges of the slot but not to the vertical direction (because no interaction occurs there).