Reality is determined on what we know on our own homeworld of earth.
Science and physics itself is theoretical.
Everyday we make new discoveries that surprises us and puts a hole in our logic.
There a article where there a football shape planet, a planet soft than cotton cotton candy and so forth in space.
Once again we based reality on what we know on our homeworld.
There was a time back in the 1800s where cars were considered fiction and even further back when electricity was fiction or "Witchcraft" in the pilgrims era.