PDA

View Full Version : More Evidence for the Big Bang



Fraser
2006-Oct-16, 02:51 PM
Last week's episode started out with a bang... a Big Bang. This week we continue our discussion into the beginning of everything. We present three additional lines of evidence that have led astronomers to the conclusion that our Universe started out as a singularity 13.7 billion years ago, and has been expanding ever since. ...

Read the full blog entry (http://www.astronomycast.com/extragalactic/more-evidence-for-the-big-bang/)

WaxRubiks
2006-Oct-16, 03:08 PM
singularity, shmingularity.....

Blob
2006-Oct-16, 07:56 PM
Hum,
about time too.

Les_m_h
2006-Oct-17, 01:11 PM
I'm sorry, but this question is bugging me. "If space is infinite, and it expanded from a singularity, then at what point did it become infinite? Was the singularity infinite?"
If this is a daft question, then it probably shows I don't really understand the Big Bang.
I love the show - can't wait for the journey home tonight so that I can listen to the latest episode in the car. "Pamela Gay for President of The Universe", I say!

jim.blanchard
2006-Oct-21, 03:26 AM
Ok, so I've been listening with enormous interest to the Big Bang episodes and I have two questions. First, the CMB and it's variations. What is the best way to visualize the nature of the variations in the CMB? In my head, I'm seeing it as a sort of topological map of energy levels where some areas in the volume of the universe have higher levels then others. Measuring our own local energy level seems easy enough. How do we 'see' into other volumes? Is a thermodynamic/fluid model totally wrong?

Second, on the matter of measuring deuterium in stars and comparing them to the expected values from the Big Bang. If stars rapidly consume deuterium and covert it to helium, how is there any deuterium in a star to measure?

bethkatz17582
2006-Oct-25, 11:57 PM
I really liked this episode because you used good examples and ways of thinking about the Big Bang. I especially liked the visualization of time and distance by pushing the reset button and considering how long it would take for us to see light from various objects. I knew that already, but the example made it more concrete. Thank you.

suitti
2006-Nov-20, 06:20 PM
We hear talk of the Visible part of the Universe. Past that, the expansion of the Universe moves objects (with respect to us) faster than light - so that objects farther than that are red shifted to nothing. What is the minimum size that the entire Universe must be? Will the CMB eventually be red shifted past the edge of the Visible Universe? If so, when?

sbharrat
2006-Nov-26, 12:42 AM
The notion that we can't actually "see" to the other end of
universe because not enough time has elapsed was recently
raised. I can't quite get a handle on this. Does this mean
that during the (inflationary) period the universe would have
been expanding at faster than the speed of light? If no, can
you explain why the light from the other side wouldn't have
already reached us. If yes, what "loophole" allows this without
violating special relativity?