Is the universe rotating as opposed to expanding and how do we know for sure?

Question

I saw an answer to a similar question and it said for the universe to be spinning it would need a massive gravitational centre, yet don't two planets orbit each other around a common axis, which has no gravity in its own right?

Answer 1

I>>s the universe rotating as opposed to expanding and how do we >>know for sure?

No, it isn't rotating, it is expanding.

We know that it is expanding by the observed doppler shift in their colour.

We know that there is a dopler shift, by comparing the absorbtion lines of the  stars we believe to be dopler shifted with those of known stars.

It doesn't matter whether the star is red shifted, (moving away from us)or blue shifted, (moving towards us), the spacing of the absorbtion lines will remain unchanged, and so tell us what sort of star it is, and which direction it is moving.

>>I saw an answer to a similar question and it said for the universe to be spinning it would need a massive gravitational centre,

That is true.

>>yet don't two planets orbit each other around a common axis, which has no gravity in its own right?

Yes, and no.

The Moon, a planetary mass, orbits the Earth, a planetry mass.

They share a common center of gravity.

A center of gravity is not s source of gravity, it is a balance point, it requires no gravity of it's own.

Answer 2

What if just about everything you thought you knew was a lie?

Answer 3

If the universe is expanding at the speed they say, each of us would be growing noticeably bigger each day, not just the obese people. But you will agree that you are not getting bloated by the day without over-eating. The expansion lark is an illusion. As for spinning, it sure is. As they say, what goes around must come around, and many things seem to come around (BBC repeats), so the whole lot must be going round. QED.

Answer 4

I think the person answering above has somehow lost the point!

We are not individually expanding you muppet, we are just travelling at high speed outwards from a centre. There are billions and billions of other bodies also travelling outwards in all directions, hence the expansion.

....shakes his head.....