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- Path: sparky!uunet!stanford.edu!unixhub!slacvm!doctorj
- From: DOCTORJ@SLACVM.SLAC.STANFORD.EDU (Jon J Thaler)
- Newsgroups: sci.physics
- Subject: Re: How old is the universe?
- Message-ID: <92255.094948DOCTORJ@SLACVM.SLAC.STANFORD.EDU>
- Date: 11 Sep 92 17:49:48 GMT
- Organization: Stanford Linear Accelerator Center
- Lines: 17
-
- tolman%asylum.cs.utah.edu@cs.utah.edu (Kenneth Tolman) says:
-
- > How old is the universe in seconds?
- > How much time is left before it crunches back together?
-
- We do not know the answer to either of these questions.
-
- If by "age of the universe" you mean the time since the initial singularity
- (or some state near, but not at, the singularity), the answer depends
- on the expansion properties of the very early universe. These
- are not known. We *DO* know the time since, for example, recombination.
- This is the era one observes when one looks at the 3-degree black body
- radiation. It occurred 10-15 billion years ago (3-5 * 10**16 sec).
-
- The answer to the second question is not known for a simpler reason - we don't
- know if there is enough matter in the universe to cause it ever to crunch
- back together. This is the famous "dark matter" problem.
-