What is the empty space?

Physics. Outer space, especially the relatively empty regions of the universe outside the atmospheres of celestial bodies. Vacuum, a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. I don't see you
You're not in every window I look through
And I don't miss you
You're not in every single thing I do
I don't think we're meant to be
And you are not the missing piece
I

C. a mature ovule of a plant.

It explains why rocks appear in layers