>>718953You have to start all the way at the beginning. Imagine the universe with no matter in it at all. Nothing. Just empty space. Now imagine the only think in the whole universe is the spaceship that you're sitting in. There's nothing else beyond your spaceship, just black.
Now consider the phrase "everything is relative". Imagine you push the accelerator and do a short rocket burn. You're pressed against the back of you seat. You can feel the acceleration of the craft. The you turn the button off. Acceleration stops, and you keep floating. ***But are you moving???*** NO.
NO, you aren't moving, because movement is relative. You have to be moving relative to something. So you could accelerate as long as you want, with the most powerful engine you could design, and you spaceship wouldn't move a millimeter, because there is nothing else in the universe for it to move relative to. (Ignore that reaction engine expel matter in order to accelerate. It's besides the point)
Now, imagine you undock a 2nd spaceship you have sitting in your storage bay, and put your copilot in the other spaceship. Now you accelerate away from him. His ship gets smaller and smaller. You're moving!
Okay, now do a similar thought experiment to the meaning of distance, of space, in a matter-less universe.
Okay, now do a similar thought experiment about time with no matter, distance, or space.
Eventually, you'll develop an intuitive sense that all of these thing ARE in fact only exist relative to one and other, and are otherwise vacuous concepts when conceived independent of one and other (that's the meaning of 'relative').
