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Friday. sound. The Doppler Effect. Tone Generator. Frog on a moving lily pad. the doppler effect. The Doppler Effect. Video: The Doppler Effect (1:56). The Doppler Effect. What does the Doppler effect have to do with stars?. wavelength in nanometres. 700. 650. 600. 550. 500. 400.
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The Doppler Effect Tone Generator
The Doppler Effect Video: The Doppler Effect (1:56)
The Doppler Effect What does the Doppler effect have to do with stars?
wavelength in nanometres 700 650 600 550 500 400 red orange yellow green blue indigo violet color & wavelength
emission spectra white light hydrogen helium neon
laboratory spectrum of sodium red shift blue shift red-shift blue shift RED BLUE
Explore questions… http://curious.astro.cornell.edu/cosmology.php
The Big Bang Theory Warmup: Explain the spectrum: Today Discussion & Video: “Back to the Beginning”
Doppler Shift blue-shifted object –moving towards red-shifted object moving away
Three important observations • The expansion of the Universe. • Hubble: galaxies are receding. 1st evidence • 2. The abundance of light elements (H, He, Li) • B.Bang theory predicts these elements should have been fused from protons and neutrons in the first few minutes after the Big Bang. 3. Cosmic Microwave Background (CMB) Radiation • The early universe should have been very hot. The CMB radiation is the remnant heat leftover from the Big Bang.
Big Bang Timeline We are here
Common Misconceptions • The Big Bang was an explosion. • The universe began as a point. • The universe is expanding into “something” and we are at the center of the expansion. • Galaxies are “flying away” in space.
Predictions of a Big Bang Universe I: Hubble’s Law • Every point is receding away from every other point. Every point seems to be at the center of an expanding universe. • The farther away something is, the faster it is receding (unlike an explosion). • Farther away looks redder (Doppler effect) • Relationship is linear: twice as far receding twice as fast.
Big Bang websites • For 2 students (& others?) • http://www.astro.ucla.edu/~wright/doppler.htm • http://science.howstuffworks.com/big-bang-theory.htm • “print” button -- this and next few pages • http://map.gsfc.nasa.gov/universe/bb_concepts.html • http://map.gsfc.nasa.gov/universe/WMAP_Universe.pdf • http://cosmology.berkeley.edu/Education/IUP/Big_Bang_Primer.html • http://curious.astro.cornell.edu/cosmology.php • Have students spend ~30 minutes reading through the questions. Write (1) new understandings (2) new questions • http://www.amtp.cam.ac.uk/user/gr/public/bb_home.html • http://curious.astro.cornell.edu/cosmology.php • http://www.umich.edu/~gs265/bigbang.htm