BELLWORK: A scientist observes that each eruption of a volcano is preceded by a series of small earthquakes. The scientist then makes the following statement: Earthquakes cause volcanic eruptions. Is the scientist’s statement a hypothesis or a theory? Why?

Question: describe the DOPPLER EFFECT in your own words, or draw a picture.

The Big Bang Theory

Objectives:

• Distinguish between a hypothesis, a theory, and a scientific law

• Describe the Doppler Effect

• Summarize the Big Bang Theory

• List evidence of the B-B-T

• A scientist devises a hypothesis and then tests it– “I think the boat will float.”

• To a scientist a theory explains existing facts and predicts new ones– The Big Bang Theory

• A scientific law is ruled by nature– The Law of Gravity

The visible light ROY G. BIV

Each color in the spectrum has a different wavelength:

Each element gives off a bright-line spectrum when heated

1. Of the 3 elements shown, which produces the fewest spectral lines?

2. Which element produces the spectrum with the largest range of wavelengths?

3. How would these spectra change if the heat source was removed?

The Doppler Effect causes the Red Shift of stars moving away from the Earth

• How is the Doppler effect on light waves the same as the apparent change in pitch of a passing siren on a police car?

The final part of the puzzle

• In the 1960’s using radio telescopes, Edwin Hubble found Background radiation evenly distributed throughout the universe

• Just as predicted in the late 1800’s