What’s a mind bending science theory that most people haven’t heard of?

the double slit experiment is the most compelling evidence that we live in a simulated world. With the fact that observing the electrons changes thier behaviour from a wave to a particle. Essentially ‘rendering’ and ‘processing’ the results when observed, and acting in a basic background process when ignored. That way the universe can be simulated without infinite computing power. Essentially only render what is being observed.