The double-slit experiment is a fundamental experiment in quantum mechanics that demonstrates the wave-particle duality of matter and the probabilistic nature of quantum systems. It does not directly imply that we are in a simulation or that reality is contingent upon observation.
In the double-slit experiment, particles, such as electrons or photons, are sent through two slits and then observed on a screen behind them. Surprisingly, even when particles are sent one by one, they still display an interference pattern on the screen, as if they were waves interfering with each other. This phenomenon suggests that particles can exhibit both wave-like and particle-like behavior simultaneously.
The interpretation of the double-slit experiment and its implications for reality have been the subject of intense debate among physicists and philosophers. One interpretation, known as the Copenhagen interpretation, suggests that particles exist in a superposition of all possible states until observed, at which point they "collapse" into a definite state. This interpretation does not imply that reality only exists when observed, but rather that the act of observation influences the outcome of the experiment.
Regarding your question about being in an empty room and the existence of things behind you, the interpretation of quantum mechanics is not directly applicable to macroscopic objects in everyday life. The principles observed in quantum experiments typically manifest at the microscopic scale and are not noticeable in our macroscopic world.
In our everyday experience, objects exist independently of our observation, regardless of whether we are looking at them or not. The behavior of macroscopic objects, such as furniture in a room, follows classical physics rather than quantum mechanics. Classical physics provides a reliable framework for understanding the behavior of macroscopic objects in most situations.
While the implications of quantum mechanics are fascinating and still the subject of ongoing research and debate, there is currently no conclusive evidence or consensus among scientists to support the idea that we are living in a simulated reality or that the existence of objects depends solely on observation.