Quote Originally Posted by N/A View Post
As for space, if one can't explain what space is, what that empty void consists of, then how can one say it can be warped or folded?

The same with time. What is time exactly? What is time made of?

If you don't know what space or time is made of, then how can one say the two can be combined together into space-time? Is it just a fancy thought to explain what we really can't explain?

The visible effects of gravity (gravitational lensing, the fact that the sun occults stars at a slightly different time than it should and the anomalies in Mercury's observed orbit) prove that "space" can be and is "warped" by gravity.

The fact that two synchronized clocks will differ in time if one is on the ground and the other is in orbit proves that relativity exists. In fact, GPS satellites have to correct their onboard clocks to cancel this effect!

And, I think all this will ultimately lead us to figuring out how to do interstellar (i.e FTL) spaceflight.