We all know that we humans have five senses only. We uses our five senses to observe the world and we call that the physical world and declare arrogantly that non-physical beings don't exist at all. That's similiar to a earthworm that's blind to declare that light do not exist. Our senses are present to let us observe the world. If we have less sense(s), we would observe a less real world. But if we have more senses we would observe a more real world. But even if we do not have the sense(s) to observe something that we call it 'non-physical', we can observe it indirectly through it interaction with 'physical beings'. These 'non-physical beings' are beings that can't be observe by our five senses. For example: gravity, God, spirits, nothingness and infinty. Lastly, even though the physical world that we observe is not the complete real world, it is still part of the picture of the real world.