Transcript:

Observation is done after the slit has—the photon has passed the slit—which means it's retroactive. You're doing something and affecting something that has already happened. It's bizarre. And when the slit becomes quantum, this whole wave pattern collapse to a particle interpretation from Copenhagen—it's called the Copenhagen interpretation—it goes out of the window. You don't need it because David Bohm—David Bohm worked it out. So he worked out a causal deterministic answer for this double slit experiment, which does not involve this spooky hand-waving thing of collapsing of wave function. It's pretty elegant.

However, David Bohm's interpretation, and he worked out the math later—even though the math is worked out, even though this, the math is worked out—the Copenhagen interpretation is the only one that is taught in the physics textbooks. It is the most bizarre thing. Even in the world of physics, where things are quantifiable and mathematically provable, opinions and legacy thinking dominates. It's really sad.