Hot Big Bang Model

l George Gamow (1946) - First hot big bang model
l Bell Labs (1965) - First background radiation measurement
l Cosmic Background Explorer (1992) -  Ripples in background radiation

Slide 6 of 22

George Gamow (1946) - Proposed the "hot" model for creation of the universe. This hot explosion would have been expected to produce a background radiation temperature of 5°K (Kelvin is a metric scale of temperature, with absolute zero, the lowest possible temperature, at which no molecular motion occurs, equal to zero). At the time there was no known way to measure a temperature this low from earth, so there was no way to test this theory.

Bell Labs (1965) - Scientists at Bell Labs were measuring radio emission at 7 cm wavelength (where emission from galaxies was negligible) and found a 3°K excess in antenna temperature. This 3°K background temperature was found throughout the entire universe.

COBE (Cosmic Background Explorer, 1990-1992) - Demonstrated the existence of the predicted variations in background radiation (see next slide).