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Credit: WMAP Science Team,
NASA
Explanation:
The above sky map tells us the universe is
13.7 billion years old -- but how?
At first look, one only sees the
microwave glow of gas from our
Milky Way Galaxy,
coded red, and a
spotty pattern of microwaves
emitted from the
early universe, coded in gray.
The gray cosmic microwave background is light
that used to bounce around randomly but came
directly to us when the expanding universe became
cool enough for nearly transparent atoms to form.
A close inspection of the spots reveals a slightly
preferred angular distance between them.
One expects such a pattern to be generated
by sound emanating from slightly over-dense
regions of the early universe.
Sound waves will take time to
generate such a pattern, and the present age of the
universe can then be directly
extrapolated.
The above
universe age is estimated to be
accurate to better than 0.2 billion years.
The above map was taken by the
WMAP satellite orbiting the
Sun at the
L2 point, just outside the orbit of the Earth.
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NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day
Publications with keywords: WMAP - CMB
Publications with words: WMAP - CMB
See also: