Formation of the Universe

The Big Bang Theory

The Big Bang

All matter & energy in the universe was compressed into a tiny volume

13.7 billion years ago, all the matter & energy began expanding outward

Evidence

Discuss with your partner:What evidence do scientists have

that supports the Big Bang Theory?

Name at least 2 things

Evidence

There are two things that scientists use as evidence:

Red Shifts

Cosmic Background Radiation

Red Shift & the Doppler Effect

Close your eyes and imagine you are standing on a street corner. An ambulance is headed towards youWhat do the sirens sound like?

Red Shift & Doppler Effect

Doppler Effect: an observed change in the frequency of a wave when the source or observer is moving.Ex: The abulance is the source, and when it moves past us, the frequency of the sound waves change.The same thing can happen with light waves.

Doppler Effect Movie Clip

http://www.youtube.com/watch?v=imoxDcn2Sgo

Hubble & Star Spectra

When the astronomer Edwin Hubble looked at the spectra of stars, he noticed a shift.What did the shift look like?The Red shift that he observed showed that the stars and galaxies were moving away.

Star Spectra-Red Shift

Evidence #2: Cosmic Background Radiation

CBR: radiation uniformly detected from every direction in space

Radiation in the form of radio waves

First detected in 1965 Formed shortly after the Big Bang

Cosmic Background Radiation

Temperature of CBR

Temperature of the radiation is VERY cold, -273°CIf the Universe was VERY HOT after the Big Bang, and takes a very long time to cool, what does this temperature indicate about the age of the universe?

Expanding Universe

Do you think the universe expands at a constant rate?Do all parts of the universe move away from each other evenly?