Um.....ERrrr....."Subspace"?
Interesting....We have sure come a long way since space was a simple vacuum. I recall scientists were puzzled by speed variations in our explorer craft that had left the solar system and were still transmitting data. Something besides gravity was affecting them.
We may be getting closer to figuring out gravity....At least I hope so.
I have alway thought that dark matter was connected somehow. I'm saving up for my anti-grav suit.:-)(bad knees and hip)
We don't even understand why matter has mass.
We don't understand exactly what the force fields are (em, strong, weak, gravity), and why they interact with certain matter at a distance.
Think about, we call it a field, because it is a region in which some force exists that can apply a force to matetr without actually being matter itself.
Those fields have no mass, no matter, are invisible (foreget photons for now)...yet they have the power to "move mountains" of matter.
We know like charges repel, but we don't know why. etc etc