Saturday, March 18, 2006

Science Saturday I: The Cosmic Smoking Gun

Astronomers announced this week that they've gotten the first detailed glimpse of the beginning of time.

You with me? (It took a while before the meaning of this extraordinary accomplishment insinuated itself into my brain, and I'm still not sure I get it.)

The scientists, led by Charles L. Bennett, a Johns Hopkins University prof, used a newly created map of the infant universe to suss out what was going on less than a trillionth of a second after time began.

Still with me?

The results of an analysis of this map validate a cosmic theory known as inflation that explains how matter and energy were distributed in the so-called Big Bang, the violent and nearly instant explosion of the universe from the submicrosopic to the immense.

The map was produced by the Wilkinson Microwave Anisotropy Probe (WMAP), a NASA satellite that has been circling the Earth since 2001 recording faint emanations of microwaves thought to be the remnants of the Big Bang. (Check WMAP out at this cool site.)

Microwaves bathe the entire universe in a more or less uniform way, but tiny variations at various points enabled the scientists to draw the map.

Using that map, Bennett and his team have been able to revise an earlier estimate of the time at which the first stars began to form following the cooling of the Big Bang. It is now believed that those stars appeared when the universe was about 400 million years old, which is double the old estimate of 200 million years. The universe is estimated to be 13.7 billion years old.

Said Bennett:
It amazes me that we can say anything about the universe in the first trillionth of a second. It appears that the infant universe had the kind of growth spurt that would alarm any mom or dad.
The theory of cosmic inflation was first proposed by physicist Alan Guth in 1981. Andrei Linde, a cosmologist at Stanford University and a Guth collaborator, put the WMAP team's work in perspective:
Theorists sometimes believe we are so smart—nobody can be compared to us. But these experimentalists, they can sometimes do things that look like science fiction to us.

For more on this incredible story, check out National Georgraphic here and the Washington Post here.

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