Are we moving through space, is the universe just expanding, or both? Does everything rotate the same way, galaxies, planets, anything? How do we know if we’re moving through space?

Question

Edit: Also, if we are moving through space, does everything move the same direction? (For instance all moving away from one point or towards one point)

I was thinking about this tonight and started getting really confused.

Can you clarify if, as far as we know, was the big bang an explosion or just the focal point for all of our existence?

Are we moving through space, or is the universe just expanding so it appears we are moving through space? Like a dot on a balloon that is being blown up. It appears to be moving, but really isn’t.

And does everything rotate the same direction?

In: Physics

Answer 1

Not an astrophysicist, but I did take a course in it, and here is my take on it. I may be wrong on some/all things.

Space can be considered ‘where there isn’t stuff’ like planets, stars, etc. It’s also not completely empty, just mostly. The Big Bang is where all the matter in the universe came from, so it’s the focal point of the matter in the universe. I would say that ‘outside’ the universe (where no matter has reached yet) is still the same space, but with less in it (cosmic background radiation forms the Big Bang I have no idea if it extends past the outer reaches of what we would call the universe). The universe is expanding (the matter in it is moving apart from other matter) and we are also moving within the confines of the universe.

As far as I am aware, things rotate in whatever direction based on the circumstances of its formation (stars, solar systems, planets, etc). Planets in a solar system seem to tend to rotate the same way due to having formed from the same gas cloud, as their circumstances are similar.

Movement really only has meaning in relation to other things- but in relation to other solar systems, we are moving through space. If there was nothing but our solar system it would appear like we don’t move at all (but if there is anything outside the solar system that we can detect like any kind of particle, radiation , etc that we see moving in a singular direction in relation to us we could use that to know we are moving). Though on second thought, not sure on that last bit – maybe our atmosphere drags a little behind and could be detected.