Parvaneh, Shelby & Marleena
Microwaves have wavelengths range from centimeters to those closer to a foot in length.
Longer are for heating food.
Shorter waves Doppler radar
Microwaves were first utilized by British the 1940s during WWII.
Sir John Randall and Dr. H. A. Boot, invented a device called a magnetron (Radar) using microwaves to detect Nazi warplanes.
1945, examining the magnetron, Percy Spencer’s candy bar melted
Product was marketed, thank goodness Percy was a chocolate lover!
1960's at scientists at Bell Laboratories detected background noise using a special “low noise” antenna.
This static noise came from every direction and did not vary in intensity.
The scientists soon realized they had discovered the cosmic microwave background radiation.
“This radiation, which fills the entire Universe, is believed to be a clue to it's beginning, something known as the Big Bang.”
Universe was once much smaller, hotter, and denser
Based off of Einstein’s theory of general relativity
Expansion of the universe – 1929
Deuterium, helium, lithium
The geometry of the universe
Whether the universe will expand or collapse
How much matter there is in the universe
Amount and nature of dark matter and energy
Expansion rate of the universe
Age of the universe
The origins of galaxies and galaxy clusters
Universe cooled as expanded – became less dense
Density variations affected temp. of photons
Dense regions = hot spots in CMB
300,000 years – cooled enough to form atoms
Photons traveled through – form relic radiation
Gravitational collapse – 1 billion years
“The cosmic microwave background radiation is a remnant of the Big Bang and the fluctuations are the imprint of density contrast in the early universe.”
COBE (November 18, 1989- 1993)
Frequent observations were made over 6 mo. periods for 4 years.