Seeking clarification on singularity at "genesis"


by acesuv
Tags: clarification, genesis, seeking, singularity
acesuv
acesuv is offline
#1
Apr28-13, 04:09 PM
P: 45
In Stephen Hawking's book, I read that there was no singularity in the beginning of the universe. However, practically every other source I come across seems to be under the impression that there was indeed a singularity before the big bang. I would really appreciate some clarification.

Thx
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mfb
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#2
Apr28-13, 05:43 PM
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It is unknown. If you just extrapolate the current evolution in the past, you get some singularity, but this is considered as unphysical by many physicists. Some other theories do not have a singularity, or do not consider the very first "moment" of the evolution of the universe at all.
acesuv
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#3
Apr28-13, 06:31 PM
P: 45
Quote Quote by mfb View Post
It is unknown. If you just extrapolate the current evolution in the past, you get some singularity, but this is considered as unphysical by many physicists. Some other theories do not have a singularity, or do not consider the very first "moment" of the evolution of the universe at all.
Thank you very much for your reply. I have some follow-up questions which I will post below, but please do not feel obligated to respond at all if you don't want - these could be answered by anyone.

Is the singularity before the big bang analogous to the singularity beyond the event horizon of a black hole, or are they two different things? I've been under the impression that they're virtually the same thing, both being "infinitely" dense. I'm also under the impression that nothing can really be infinitely dense, and that there is a problem with our understanding and that it yields an infinite mass.
I'm very suspicious that I'm waist deep in misconceptions.

mfb
mfb is offline
#4
Apr29-13, 01:04 PM
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P: 10,767

Seeking clarification on singularity at "genesis"


They share the problem that our current theories of physics cannot describe them properly.
acesuv
acesuv is offline
#5
Apr30-13, 02:52 PM
P: 45
Quote Quote by mfb View Post
They share the problem that our current theories of physics cannot describe them properly.
Is it appropriate to say that a singularity has infinite mass?
mikeph
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#6
Apr30-13, 03:01 PM
P: 1,197
Infinite density does not imply infinite mass.
acesuv
acesuv is offline
#7
Apr30-13, 09:45 PM
P: 45
Quote Quote by MikeyW View Post
Infinite density does not imply infinite mass.
Uh huh. So you're saying it would be appropriate to say a singularity is infinitely dense? Is this what we actually think is going on in a singularity, or is that just what our theories predict?

Thank you


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