How accurate is the 14 billion year age of the universe?

Question

i'd like to better understand the relation between the universe's age we get from the rate of the expansion of the universe (the rate in which galaxies become more and more separated from each other), and the age we get from how many light years away the furthest light source is.

do they complement each other in showing the universe is around 14 billion years old? (I'd imagine they must complement each other in yielding the same 14 Gy age.)

and my second question is, how likely is it that the universe is much older than 14 billion years (but light from the furthest regions of the universe just haven't reached us yet?)

Answer 1

The age is actually calculated from the expansion of space - As the expansion slowly accelerates, it's age must be around 1/H - with H being the acceleration constant of the expansion of the universe. By knowing that the expansion must have been started at 0 once, they got the estimate 13.73 billion years.

But the estimate is pretty rough. The age might vary by up to 120 million years alone when the currently used model is correct. When the model is not correct, the errors might vary by up to 1 billion years.

On the second question: the universe can be theoretically much older as 14 billion years, but there is one constant limit to our observations - the 3K background radiation. We can't look beyond this background, because this radiation marks the point where the universe became transparent for radiation after cooling down to 3000 Kelvin. Behind this veil, there can be almost anything in theory. The laws of physics we know today might not even have to apply in the same way as they do today. We don't know yet. Because of collider experiments, it is possible to research the possible laws of physics at that time, but uncertainty will remain.

Answer 2

It's accurate to within twenty minutes.

Answer 3

Current observations suggest that the time elapsed since the Big Bang is about 13.73 billion years, with an uncertainty of about 120 million years.

We can see that the universe is expanding, and using the rate of expansion (and other methods), we can extrapolate how close together the galaxies were a million years ago or 10 billion years ago. We can calculate how long ago it was that everything was in one place (Big Bang).

We cannot tell how large the entire universe is, only the part we can see. We can see almost 13.73 billion light years away in all directions, so we know that is its minimum radius. There is no reason it can’t be trillions of times larger.

Your second question: Apparently, we can view nearly the time when objects first were able to emit light at the time of a recombination, 379,000 years after the Big Bang.

Answer 4

ah... not!!

its 4.5 billion now... and they have the fossils to prove it....

light years is not time... it is the distance light travels in a year... the earth is 6 light "minutes" from the sun...

it not more than 8... too small... we have estimated the size and it comes out to no more than 8...

u could probably search more details about this on-line...

put "big bang" or "earth age" or "fossil record" into google and see what you can find...