Was General Relativity really a hard idea to come up with

Yes.

Except I think the learning barrier to anything (properly) geometrical is smaller than to derived functors etc.

>the natural course
wat

>A matter of time

Holy fuck. He did say general though. That's the gravity one

IS means an equality of two substances, or in some cases for one element to pass through another so as to become part of another for an infinite amount of time.

So if that's the case and is IS actually IT'S, then answer the fucking question.

If gravity could potentially be blocked just like we can block light, would such device be detrimental or instrumental in the innovation of antigravity?

This. Is this a question on predestination? Was Einstein an anomaly against a predetermined course of the universe? Is a certain scientific discovery required before another can happen?

A derived stack is geometrical.
ncatlab.org/nlab/show/derived algebraic geometry