236 views

### Variation of Hubble constant in cosmological timescales [duplicate]

Although the Hubble constant appears to be a constant, it is not really a constant. Is the Hubble constant decreasing over cosmological timescales?
86 views

### If Hubble parameter varies with time how much it differs for low distances (present) and deep space (past)? [duplicate]

If deep space is shown as it was in the past how can we calculate this time lagging regarding the Hubble parameter which is a variable of time?
85 views

### Expansion rate in matter dominated era [duplicate]

Do physicists know what the expansion rate of the Universe was at the beginning of the matter dominated era?
78 views

6k views

### How can the universe expand if there is gravitation?

We live in an expanding universe - so I'm told. But how can that be possible? Everything imaginable is attracted by a bigger thing. So, why can't gravitation stop the expansion of the universe? I know ...
15k views

### Hubble time, the age of the Universe and expansion rate

The Hubble time is about 14 billion years. The estimated current age of the Universe is about 13.7 billion years. Is the reason these two time are so close (a) a coincidence, or (b) a reflection that ...
6k views

### Value of the Hubble parameter over time

There is something I don't understand about the Hubble parameter $H$, as it seems to clump two concepts together that I can't quite unify in my head. On the one side, we have $$V = D H$$ which means ...
774 views

### What was the density of the universe when it was only the size of our solar system?

What was the density of the universe when it was only the size of our solar system? Did it approach neutron star density? Is it physically correct to even ask such a question?
1k views