WMAP

(Ruthlessly expropriated from DISCOVERY NEWS)


WMAP has, quite literally, changed our view of the Universe. And after nine
years of mapping the slight temperature variations in the cosmic microwave
background (CMB) radiation, its job is done and NASA has commanded the probe
to fire itself into a "graveyard orbit" around the sun.

Launched in 2001, this ground-breaking spacecraft set out to unravel some of
the most fundamental questions in modern cosmology. How old is the Universe?
What happened when the Universe was born?

Findings bolster the argument that Dark Energy is the reason our universe is
expanding. Before WMAP, scientists knew the Universe was expanding, they
even had a ballpark figure of how old the Cosmos might be -- somewhere
between 8 to 20 billion years. However, the details were somewhat sketchy.

Then WMAP came along and it began its nine-year study to create a full-sky
survey of the very tiny variations in temperature of the "afterglow" of the
Big Bang.

The young Universe was very hot, so hot in fact that its heat still pervades
the entire sky. But this ancient echo of electromagnetic radiation is
extremely weak with a temperature hovering just above absolute zero -- 2.725
Kelvin.

The probe was so sensitive to this echo that it could detect very slight
variations -- or "anisotropies" -- in the CMB radiation. These variations
are the fingerprints of the birth of our Universe revealing the conditions
at the start of time, moments after the Big Bang.

As a result of this survey, a mind-bogglingly precise measurement on the age
of the Universe was found. The magic number turned out to be 13.75 billion
years (plus or minus 0.11 billion years).

But WMAP didn't stop there. Although scientists have hypothesized that the
Universe went through rapid inflation just after the Big Bang, WMAP has
managed to find even more supporting evidence that this growth spurt did
happen. Thanks to WMAP, we also know that a mysterious entity called Dark
Energy fills 72 percent of the Cosmos and Dark Matter makes up for around 23
percent. "Normal" baryonic matter makes up for a piddly 4.6 percent of the
observable universe.

WMAP has not only given us the ability to understand the nature of the
Universe in its entirety, but it has acted like a time machine, deriving the
nature of the Big Bang, early Universe and how the Cosmos evolved over 13.75
billion years of existence.






--
"I don't want to believe, I want to KNOW" - Carl Sagan