Another Time topic, or is it?

As some to most of us know, space (time, for those who forget that they are the same) is expanding. Now, we are given the Hubble constant, which is based on a trend line that is fit between the distance between earth and another object and apparent velocity. (In this case velocity is measured with respect to earth) What this constant tells us is that the objects “random” velocity (i.e the velocity an object has due to everything that isn’t from the expanding universe) will cancel leaving the supposed rate at which the universe expands.

So my question, The Hubble Constant is thought to be not so constant, particularly towards the beginning part of our universe. Could we measure the Hubble constant at various times, and from that create an adequate Hubble constant v time equation. A model like that would be able to interpret the nature of an early universe, no?

Granted, if the graph were to approach a constant, say 42, we would probably measure numbers like 41.9999996, 41.9999997, etc, which calls for extreme precision when acquiring data to get the graph…

Thoughts?

-Guy

welcome back

Read a cosmology book!? because im too bored to write anything. Hubbles constant isn’t really a constant. Its contant in space but not in time.

H = (da/dt)/a

where a is the expansion coefficient. Roughly speaking H goes as 1/the age of the universe. But it all depends on lots of stuff like if the universe is matter, radiation or vacuum energy dominated.

I’m not sure if we can measure the hubble constant in the past. Not sure how. But yeah read a book on cosmology its all about hubbles constant and the start of the universe bla blah blah.