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Q & A: more cosmology

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Most recent answer: 10/22/2007
Q:
What is the shape of our universe and does it have a dynamic property (expanding, contracting)
- Kelvyn Chin
Asrix Pte. Ltd., v
A:
We don't know what the shape of the universe is. We do know that it is now expanding, and has been for the last 13.7 billion years. It looks like the expansion is getting faster, and may continue forever.

Getting back to the shape, we don't even know if the universe is finite (closed back on itself, like a 3-d version of the surface of a sphere) or open (going out forever in all directions). There's even a bit of recent evidence that it may be closed but not in a simple symmetrical way but rather with special directions for folding back on itself.

The sort of evidence used to study these questions partly consists of looking to see how distant stars are receding from us. Another part consists of looking at how the background radiation leftover from the hot early days of the universe varies slightly from place to place, in ways predicted by certain types of theories for the expanding universe.

Mike W.

(published on 10/22/2007)

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