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Q & A: before the Big Bang?

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Most recent answer: 01/10/2016
Q:
Could dark energy and matter have existed in the area the universe currently is in before the Big Bang? Could cosmic background radiation be from matter and energy interacting with and displacing dark matter?
- Emily (age 36)
Independence, mo USA
A:

It's hard for our minds to picture, but the space of our universe simply didn't exist before the Big Bang. It's not that some stuff expanded out into pre-existing space, it's that a space with some stuff in it became larger. Our visual imagination evolved to deal with little regions of pre-existing space, so we have to grasp this picture abstractly rather than visually.

As nearly as can be told form the form of the ripples in the cosmic microwave background, the dark matter was there along with our type of matter from very near the start, in the same proportions as today. The origins of the CMB are one of the least mysterious aspects of cosmology. Anything hot gives off light, as I can see at the moment in my kitchen. Once the universe got cool enough for atoms to form it became almost transparent, so that glow from it being hot never went away. That light just got diluted and stretched to longer wavelengths as the universe expanded. It's the CMB.

Mike W.


(published on 01/10/2016)

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