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kg034
2005-Mar-18, 08:05 AM
"Our solution to the paradox posed by the accelerating universe," Riotto says, "relies on the so-called inflationary theory, born in 1981. [.....snip.....]
It is widely believed that during the inflationary expansion early in the history of the universe, very tiny ripples in spacetime were generated, as predicted by Einstein's theory of General Relativity.

These ripples were stretched by the expansion of the universe and extend today far beyond our cosmic horizon, that is over a region much bigger than the observable universe, a distance of about 15 billion light years.

In their current paper, the authors propose that it is the evolution of these cosmic ripples that increases the observed expansion of the universe and accounts for its acceleration.





Fermilab's Kolb called the authors' proposal the most conservative explanation for the accelerating universe. "It requires only a proper accounting of the physical effects of the ripples beyond our cosmic horizon," he said.


As pointed out somewhere else, we can see back in time about 15bil. years. But the distance to that object now is much greater than the 15bil years due to the expansion of spacetime.

edited to add link to story
here (http://www.spacedaily.com/news/cosmology-05n.html)....I really should stop posting at 1am in the morning :o

Cougar
2005-Mar-19, 10:48 PM
...the authors propose that it is the evolution of these cosmic ripples that increases the observed expansion of the universe and accounts for its acceleration.

I have great respect for Rocky Kolb, but this proposal does not seem to square with the observations. If this proposal was right, the acceleration would be seen to increase with distance, right out to the edge of our visible horizon. But this is not observed. Beyond 7 or 8 billion lightyears, the relative effect of the dark energy becomes less and less - because dark energy is directly proportional to the amount of space (and there was less and less space back then), plus everything was closer together, hence gravity had a much greater effect relative to the amount of dark energy. Matter dominated. Then around 7 or 8 billion years ago, the dark energy started to get the upper hand. [My numbers come from memory. Your mileage may vary.]