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Old 22-11-2007, 01:25 PM
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higginsdj
A Lazy Astronomer

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Join Date: Mar 2006
Location: Canberra
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Quote:
Originally Posted by Paddy View Post
Hi Ken,

This might be a simple-minded response to be superseded by one from a more knowledgeable contributor, but "wearing out" is not the only option for light to cease being visible light. There is red shifting as has already been pointed out, but also absorption. Photons will run into things and be absorbed. So light not wearing out or running out would not necessarily imply that the universe will continue to get brighter.
That's not a correct assumption. Yes light is absorbed BUT it is re-radiated, perhaps in another wavelength (ie Light is absorbed by Dust but immediately re-radiated in IR). This is also part of Olbers Paradox (it was interesting working this out mathematically as part of my Cosmology final exam - thanks to info on the web - but it is simple math thankfully.

Cheers
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