Access Planetary | Information on planets and the universe

What does the correlation between velocity and distance for galaxies tell us about the universe?

A.The Earth is located at the center of the universe.
B.The universe is expanding.

C.The universe is 100 billion years old.
D.The total extent of the universe is about 1 million light years across.

Is it B?

B!!! is the most obvious answer. it’s b

A. The greater the mass of the universe, the more gravitationally bound the universe will be.
B. The greater the mass of the universe, the more stars it will form over time, therefore lasting longer.
C. The greater the mass of the universe, the more massive stars it will contain, and the faster it will evolve.
D. The greater the mass of the universe, the more black holes will form, which will favour surrounding material more quickly.

A.
Because if omega>1, then the universe will have lots of mass, and the universe would be curved inward. More mass = more gravity, which means the universe can collapse on itself…aka Gnab Gib, or the Big Crunch.

The other answers aren’t relevant to deciding the fate of the universe. B is wrong because mass has nothing to do with the number of stars formed.
C is wrong because the mass of the universe does not depend on the mass of the stars, nor vice versa.
D is wrong because black holes only form from massive stars >20 solar masses. Mass of the universe does not mean stars become more massive, nor does it correlate with how many stars there are.

Hubble and Humason observed the red shifting of galaxies racing away from us and this is accepted as evidence today for the expanding universe. But how are the two correlated? If the universe were static would galaxies hold fixed positions?

They would not hold fixed positions, but they would not behave the way we observe them, i.e. all but a few of them are receding away from us, in all directions. The farther out we look, the faster they are receding. If we were on the surface of an expanding balloon with spots representing galaxies, that is what we would see. All the spots would be moving away, and the farthest spots would recede faster than the ones near by.

If the expansion were not occurring, I would expect the distant galaxies to be moving in a somewhat random fashion, with closer objects being attracted to each other gravitationally. Eventually, gravity would prevail, if the universe were indeed static in size and shape.

I really like astronomy and wonder a lot about the universe like how the universe would look like and if there was be a galaxy that contained a solar system just like us. And if there was other universe. I’d just like some answers and facts that are interesting. Add anything that has to do with time and space/ astronomy. Like time traveling. Thanks!!

Yea man I think about it alot too haha. But there is only one universe b/c the universe is everything and I think the theory is that it is infinite, that it is always growing and getting bigger. Yea I think theres got to be other people or aliens or somethin somewhere b/c that would be alot of wasted space don’t you think. No one knows what happens when you go in a black hole but they think that it could take you to a different dimension or time or anything, oh and I heard on some tv show that if somebody actually did go in a black hole there body would get stretched out really far, b/c it stretches everything even light.