Can you describe to me how CMBR was first detected?

Answer 1

Hi. When telephones were connected over vast distances there was always a hiss. The engineers tried to find out why and discovered the background radiation was the cause. http://en.wikipedia.org/wiki/Cosmic_microwave_background_radiation

From the web: "It was first observed inadvertently in 1965 by Arno Penzias and Robert Wilson at the Bell Telephone Laboratories in Murray Hill, New Jersey. The radiation was acting as a source of excess noise in a radio receiver they were building."

Answer 2

Penzias and Wilson were using a microwave detector, and no matter which way they pointed it, they always got a signal. They thought it was being interfered with somehow and even tried cleaning all the pigeon poop out of the detector. It later became an important piece of evidence that supports the Big Bang theory. Link below describes their difficulties with pigeons...

http://www.nasm.si.edu/exhibitions/gal111/universe/etu_a_cmbr.htm

The background radiation is thought to be the light/heat from the Big Bang that has been Doppler-shifted so much, it's now down in the microwave region. CMBR is often referred to as the "Echo" of the Big Bang. After very careful measurements of the strength of this field, some very small variations were found, and are thought to have been caused by quantum effects in the early expanding universe. This link has good stuff on that:

http://www.physicscentral.com/action/2001/microwave-cosmic.html