The Cosmic Microwave Background Radiation



A detailed view of the Cosmic Microwave Background from WMAP, compared to the original view from the COBE satellite.
Click on image for full size (86K JPG)
NASA/WMAP Science Team
In the 1960's, a pair of scientists noticed some annoying static (like you hear on the radio) when trying to use a special radio antenna. The strange thing about the noise was that it was coming from every direction and never got stronger or weaker. If the static were from something on our world, like radio transmissions from a nearby airport control tower, it would only come from one direction, not everywhere. The scientists soon realized they had discovered the cosmic microwave background radiation.

This radiation is a form of energy, like the microwaves which microwave ovens produce to cook food. It fills the entire Universe, and is believed to be a clue to the Universe's brilliant beginning, known as the Big Bang. Astronomers believe that this energy, which was trapped by electrons in the early, hot universe, escaped when the universe cooled enough for hydrogen atoms to form.

More recently, the Wilkinson Microwave Anisotropy Probe (WMAP) team has made a more detailed full-sky map of this oldest light in the universe. The WMAP image brings the COBE picture into sharp focus, and provides firm answers to age-old questions. WMAP resolves slight temperature fluctuations, which vary by only a few millionths of a degree. These new data support and strengthen the Big Bang and Inflation Theories.

The Current Universe

Following in COBE's footsteps - the MAP mission

A Matter of Scale - interactive showing the sizes of things, from very tiny to huge - from NSF

The Cosmic Microwave Background Radiation



A detailed view of the Cosmic Microwave Background from WMAP, compared to the original view from the COBE satellite.
Click on image for full size (86K JPG)
NASA/WMAP Science Team
In the 1960's a startling discovery was made by accident. A pair of scientists at Bell Laboratories detected some annoying background noise using a special low noise antenna. The strange thing about the noise was that it was coming from every direction and did not seem to vary in intensity at all. They had discovered the Cosmic Microwave Background Radiation.

This radiation fills the entire Universe and is no stronger or weaker in any direction. It has only tiny fluctuations that were only detected by the very sensitive space craft the Cosmic Background Explorer, COBE. This radiation is believed to be a clue to the Universe's brilliant beginning, known as the Big Bang.

More recently, the Wilkinson Microwave Anisotropy Probe (WMAP) team has made a more detailed full-sky map of this oldest light in the universe. The WMAP image brings the COBE picture into sharp focus, and provides firm answers to age-old questions. WMAP resolves slight temperature fluctuations, which vary by only a few millionths of a degree. These new data support and strengthen the Big Bang and Inflation Theories.

The Current Universe

Following in COBE's footsteps - the MAP mission

A Matter of Scale - interactive showing the sizes of things, from very tiny to huge - from NSF

The Cosmic Microwave Background Radiation



A detailed view of the Cosmic Microwave Background from WMAP, compared to the original view from the COBE satellite.
Click on image for full size (86K JPG)
NASA/WMAP Science Team
In the 1960's another startling discovery was made quite by accident. A pair of scientists at Bell Laboratories detected some annoying background noise using a special low noise antenna. The strange thing about the noise was that it was coming from every direction and did not seem to vary in intensity at all. They had discovered the Cosmic Microwave Background Radiation.

This radiation permeates the entire Universe and is no stronger or weaker in any direction. It has a perfect blackbody spectrum, meaning it behaves like radiation from an object that absorbs and emits all radiation that falls upon it. Its temperature is 2.7 degrees Kelvin (-454.81 degrees Farenheit). It has only minute fluctuations that were only detectable by the very sensitive space craft the Cosmic Background Explorer, COBE. This radiation is believed to be the remanant of the Universe's brilliant beginning, known as the Big Bang.

More recently, the Wilkinson Microwave Anisotropy Probe (WMAP) team has made a more detailed full-sky map of this oldest light in the universe. The WMAP image brings the COBE picture into sharp focus, and provides firm answers to age-old questions. WMAP resolves slight temperature fluctuations, which vary by only a few millionths of a degree. These new data support and strengthen the Big Bang and Inflation Theories.

The Current Universe

Following in COBE's footsteps - the MAP mission

A Matter of Scale - interactive showing the sizes of things, from very tiny to huge - from NSF


Last modified April 29, 2005 by Travis Metcalfe.
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