Age of Universe: Dist. to Big Bang vs New Star

In summary, when astronomers discover a new star that is 15 billion light years away, they relate this distance to the age of the universe because of the finite speed of light. This means that the further away we look, the older the image we see. Since the Big Bang, which is considered the beginning of the universe, occurred 13.7 billion years ago, nothing in the universe can be older than that. This also means that we cannot see anything further than 13.7 billion light years away because the light from objects further than that has not reached us yet.
  • #1
Gonçalo
8
0
Question

When astronomers find a new star, say 15 billion light years away, why do they immediately relate that distance with the age of the Universe (the distance to the Big Bang point)?

--->cause if the Universe were like a balloon, and the Earth and the star were in the the surface of that ballon, their distance could be much bigger than the distance of the Earth to the Big Bang point!...
 
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  • #2
Originally posted by Gonçalo
Question

When astronomers find a new star, say 15 billion light years away, why do they immediately relate that distance with the age of the Universe (the distance to the Big Bang point)?

--->cause if the Universe were like a balloon, and the Earth and the star were in the the surface of that ballon, their distance could be much bigger than the distance of the Earth to the Big Bang point!...
if the big bang were let's say around 20 billion years (im considering a time frame which is longer than the star's life span) (which is not but for the sake of the argument it is) old then the distance between the Earth and the big bang would be bigger than the 15 year old star.
 
  • #3


Originally posted by loop quantum gravity
if the big bang were let's say around 20 billion years (im considering a time frame which is longer than the star's life span) (which is not but for the sake of the argument it is) old then the distance between the Earth and the big bang would be bigger than the 15 year old star.

If the 15 year old star was, oh, let's say markoolio, would that make any difference?

Will he burn stronger than any other star?
 
  • #4
sorry it's should be 15 billion year old star.
 
  • #5
Actually the whole universe is only about 13.2 billion years old so no star is that old.
 
  • #6
There is no distance in space "to the Big Bang point". The Big Bang occurred simultaneously at every point in the universe. It was not an explosion of stuff into the void, it was (in part) the creation & rapid expansion of space itself.

When astronomers see a distant object (e.g., billions of light years away) they relate it to the age of the universe (currently calculated to be 13.7 billion years plus or minus a bit) because the speed of light is finite, and as such, the further away we look, the older the image we see. Since the Big Bang occurred 13.7 billion years ago, we cannot see anything further than 13.7 billion light years away because light from parts of the universe more distant than that has not reached us yet.

And since the Big Bang was the beginning of the entire universe, nothing in the universe can be older than that. (at least, the "visible universe"..i.e., the stuff within our 13.7 billion mile viewing range)

For more info, post questions to the regular forum...
https://www.physicsforums.com/forumdisplay.php?s=&daysprune=&forumid=71
 

1. How old is the universe?

The current estimated age of the universe is approximately 13.8 billion years old. This age is based on observations of the cosmic microwave background radiation and the expansion rate of the universe.

2. What is the distance to the Big Bang?

It is not possible to determine the exact distance to the Big Bang, as it occurred at a single point in time and space. However, the observable universe is estimated to be about 93 billion light years in diameter, which is the distance light can travel since the Big Bang.

3. How is the distance to the Big Bang measured?

The distance to the Big Bang is not measured directly, but rather inferred from the expansion rate of the universe. Scientists use the Hubble constant, which is a measure of how fast the universe is expanding, to calculate the distance to the Big Bang.

4. What is the relationship between the age of the universe and the formation of new stars?

The age of the universe and the formation of new stars are closely related. As the universe has aged, gravity has allowed matter to clump together and form stars, which are essential for the creation of galaxies. The first stars are estimated to have formed about 13.6 billion years ago, just a few hundred million years after the Big Bang.

5. How do we know the age of the universe?

The age of the universe is determined through a combination of observations and theoretical models. Scientists use data from the cosmic microwave background radiation, the expansion rate of the universe, and the abundance of light elements to estimate the age. Additionally, the age of the oldest stars and galaxies can also provide valuable clues about the age of the universe.

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