There could be real things that we can never perceive and never measure. It may be that we can never measure certain physical entities around the time of the Big Bang, or in distant galaxies, but they exist all the same. If I’m in a perfect simulation, I may never be able to perceive the world outside the simulation, but it’s real all the same. There are also some things we can perceive and measure that aren’t real. We can measure the intensity of a mirage, for example, but this doesn’t mean the mirage really exists.
maybe not in this universe
