Thread: Can the big bang be dated?

There are several guesses on when the big bang was formed, but if the universe has been expanding can't you calculate the rate of the expansion and work backwards and eventually find the time the big bang had occurred.


The biggest problem i see with this is that the universe could be reaching it's furthest point, meaning it will stop expanding and either rip or contract. Thus the numbers for the expansion rate would change the results

Using the rate of expansion and other clues, the big bang is estimated to have occured about 13.7 billion years ago.

The expansion is at the moment speeding up, so the ultimate fate of the universe is unknown.

Originally Posted by Robert Blandford

There are several guesses on when the big bang was formed, but if the universe has been expanding can't you calculate the rate of the expansion and work backwards and eventually find the time the big bang had occurred.


The biggest problem i see with this is that the universe could be reaching it's furthest point, meaning it will stop expanding and either rip or contract. Thus the numbers for the expansion rate would change the results

The experts say the BBT is 13.7 billion years old.
Its expansion rate is 72 kms per second per megaparsec.
It is expanding at a 'uniform' rate.

But how do you incorporate the megaparsec?
Is it involved in the expansion of space or what?
With this puzzle, you cannot determine the size of the BB nor its age by using the current space expansion, IMO.

So the BBT is just a gigantic question mark?

Cosmo

If we have expansion at about 13.6 miles per second per million light years and allow that expansion cannot exceed light speed, we get:


Light speed = 186,282 divided by 13.6 which comes out to 13,697 (million light year) units of 13.6 miles.

So 13,697,000,000 light years.

August 23 , 13,745,367,489,243 BC

Originally Posted by Cyberia

If we have expansion at about 13.6 miles per second per million light years and allow that expansion cannot exceed light speed, we get:


Light speed = 186,282 divided by 13.6 which comes out to 13,697 (million light year) units of 13.6 miles.

So 13,697,000,000 light years.

First of all, as a scientist, use SI units as dimensions.
These are meters, seconds and etc.

The expansion rate is only 72 kms per second.
So why are you using light years.
The light years expansion is only between observers and does not apply to the expansion of space.
To be honest about it, this even confuses me. Ha ha.

Cosmo

Cosmo. I am not a scientist. I was brought up in England in a time where we used feet and miles. If someone wants to convert my distances, not hard to do.

Just saying expansion is 72 kms per second tells us nothing since you did not give a distance for said expansion. It's per megaparsec (I detest parsecs) as in over a distance of 3,260,000 light years.

I still have to be convinced on expansion. Certainly the idea of space expanding is on a level with space turning pink.

Originally Posted by Cyberia

I still have to be convinced on expansion. Certainly the idea of space expanding is on a level with space turning pink.

I don't know if this will help, but it certainly can't hurt

Originally Posted by PhoenixG

I don't know if this will help, but it certainly can't hurt

There is always this belief on any science forum that if you do not agree with an accepted subject, that means you don't know anything about that subject, since GOD himself came down and said it was infallibly true so any other opinion MUST be wrong.

Explaining inflation often ends up like explaining how many angels can dance on the head of a pin. It's wrong from the start so why compound it?

Originally Posted by Cyberia

There is always this belief on any science forum that if you do not agree with an accepted subject, that means you don't know anything about that subject, since GOD himself came down and said it was infallibly true so any other opinion MUST be wrong.

Explaining inflation often ends up like explaining how many angels can dance on the head of a pin. It's wrong from the start so why compound it?

I'm sorry?? What does this have to do with the podcast episode on inflation that I linked to in my last post?