How old is the universe according to the big bang theory?

Answer 1

The Big Bang theory doesn't actually say all that much about how old the Earth is. Obviously, if the Universe is 13 billion years old, the Earth can't be any older than that. Less obviously, the Big Bang produced mostly hydrogen and virtually no metals ("metal" is astronomical code for "anything heavier than helium"). Heavy elements were produced later, in stars, and released by supernova explosions. Since the Earth is made mainly of elements heavier than helium, it has to have formed after there was time for stars to form, age, and go supernova, and for the gas and dust produced to coalesce into the solar system. However, this only provides a maximum age, not a minimum; as far as the Big Bang theory is concerned the Earth could have formed last Tuesday. The generally accepted age for the Earth (4-5 billion years) is based on other factors, such as radioisotope ratios in rock.
The big bang theory has nothing to do with the age of the earth. Scientists think the earth is 4.4 billion years old. That is the age of the solar system. That is the age of some meteorites that have fallen to earth. Their age is determined by the ratio of uranium to lead. Uranium is radioactive and over the years becomes a special form of lead.

The big bang theory had to do with the age of the universe. Scientists determined the age of the oldest light in the universe and put some formulas into their equations to figure out how long ago it was created. They assumed it was created by the big bang. If their equations are correct, they know the age of the universe.

Answer 2

The best available estimate of the age of the universe is 14.1 billion years.

Plus or minus.

Subject to later revision.

Really, we don't know all that much about the early state of the Universe, and no doubt some of what we think we know is wrong. That's what science DOES; it makes predictions based on theories, and improves these theories later in the light of new evidence. The Large Hadron Collider, the tool specially designed to do research on the early moments of the Universe and on fundamental physics, should be online in late 2009. Ask me then.

Answer 3

About 4.6 billion years old. Some scientists estimate this a little higher, and others a little lower - but I don't think the facts support any more precise answer at this point.

The oldest individual rocks on the Earth are known to be about 3.2 billion years old, and we know that a long period of intense volcanism occurred as the planet cooled and condensed from our planetary nebula.

Answer 4

In the neighborhood of 13.5 billion years old, perhaps a little older.

Of course, that's assuming that we have the correct analysis of the paltry data that we have on the subject. It's entirely possible that the "universe" is far older, or somewhat younger, if our understanding of the basic physics is in error. (As a scientist, one must always allow for the possibility that our understanding of the basic physical processes is incorrect.)

Answer 5

If your asking how many years, 13.3 billion years Approx.

Answer 6

The latest estimate is something around 14 billion years.

Answer 7

According to Big Bang Cosmology, my Universe began to expand approximately 13.7 billion years ago.

However, it says nothing about how long YOUR Universe began.

Answer 8

The current theories of the big bang suggest an age of any where from 13.5 Billion and 14 Billion years old.

The generally excepted figure is 13.8 Billion Years Ago.

Answer 9

Scientists calculate about 13.75 billion years old.

Answer 10

As of 2010[update], the initial conditions occurred around 13.3 to 13.9 billion years ago.