Would be fun to see if it’s possible to set up the experiment as a double slit.
Would humans sense an interference pattern? Is the back of an eye a sufficient observer? :)
Would humans sense an interference pattern? Is the back of an eye a sufficient observer? :)
It definitely is. The retina "measures" photon positions, which is why you see images. Observation is just interaction, no need to consider whether A can observe B. If they interact, some kind of observation takes place.
Does that process also count as an "interaction", or is that different to what happens when the photon hits the retina?
Don't forget that the interference pattern is a statistical one, you need to average over a number of photons to "see" it emerge.
And now you understand why "quantum gravity" is such a big question in physics right now! We don't understand it all. I actually don't know anything about how EM fields affect superposition, perhaps someone else can chime in.
https://physics.stackexchange.com/questions/34993/reversing-...
The important thing is by how much, and what sort of interference patterns can this produce.
As it turns out, interference is quite hard to produce randomly because two fields only produce wavering patterns when their frequency and other parameters are almost equal.
So yes, the ball you just threw to your friend is actually spread out over a whole region, that spread is about 10^-34 m so it impact is not visible at all.