The double slit experiment has its bases in the wave/particle duality of subatomic particles. What makes it so amazing is that the results are among the strangest in quantum mechanics. It is the king of quantum weirdness being the strangest results in science. The original double silt experiment used photons of light, but later versions used electrons but the results are the same The double slit experiment is actually responsible for starting Quantum Physics.
Over the decades numerous explanations have been proposed to explain the results of what on the surface is a very simple experiment. However resent experiments involving quantum erasure seem to have reduced the possibilities to being the information that is collected making the difference.
What seem to be happening is the in general subatomic particles tend to exist as wave functions that represent multiple possibilities. When specific information is measured about an event those possibilities are reduced to one producing the needed information. A new wave function of multiple possibilities is then produced consistent with that one possibility.
Putting it all together suggests that what we call reality is actually immaterial at its most fundamental level. At its most fundamental level the universe seems to be composed entirely of information. This makes it more like a sophisticated computer program than a world of material objects.
It is more than just the existence of the information the affects the experiment but its ability of it to eventually be accessed by the experimenter. That experimenter is ultimately a human being that is a conscience entity. The information that makes up reality seems to be calculated as need for a conscience entity so as to produce a consistent reality. This shows that consciousness is a fundamental part of reality. This is not new age thought but what the observation of subatomic particles is actually telling us.