1. planet solar system galaxy local cluster supercluster Intro to Cosmos scale Powers of 10 our place in the cosmos

2. EM Song! http://www.youtube.com/watch?v=bjOGNVH3D4Y Via Light aka ElectroMagnetic Radiation (EMR) How do we get information about the universe?

3. ALL EM Radiation is LIGHT Visible light is just one narrow band of the EMR nanometer = I billionth of a meter!

4. Animate it! VISIBLE LIGHT White light contains all the wavelengths of visible light Colors are due to differences in wavelength (λ) red = longest 700nm violet =short 400nm Mnemonic: ROY G. BIV

5. Waves of electrons (an electric current) produce a magnetic field the magnetic field produces more current the energy is carried forward in a wave Electromagnetic radiation is a WAVE Animate it!

6. Waves are described in terms of wavelength, frequency, and amplitude # wavelengths per second wave height Distance between crests or troughs Animation Motion

7. high frequency short wavelength high energy low frequency long wavelength low energy (No difference in amplitude)

8. WAVES TRANSPORT ENERGY Unlike these other types of waves, light does not require a medium to move

9.  Frequency and wavelength are inversely proportional  The product of frequency(ƒ) and wavelength(λ) is speed  Therefore, in a vacuum (space) the speed of light(c) is constant  speed does vary when light waves pass through a medium; ex: a prism affects the speed of each visible wavelength differently animation animation  mathematically: c = ƒ(λ)  c = 299,792,458 m/s OR (~3.0 x 10 8 m/s) WHAT ABOUT LIGHT SPEED?

10.  A light year (ly) is the distance light would travel in one year given a speed of 3.0 x 10 8 m/s  1 ly = 9.4607 × 10 12 km  More commonly used to measure universe-scale distances is the parsec (pc)  distance that one astronomical unit (AU) creates an angle of one second of arc (1/3600° )  approximately 3.26 light-years [SIDEBAR]

11. LIGHT is INFORMATION Planets Stars Novas Black holes Light also tells us about an objects....temperature..composition..distance..age..motion CMBR

12. Observatories detect EM waves via satellites, telescopes, dishes… Compton Gamma Ray observatory Very Large Array radio telescope

13. visible infrared radio One object in many wavelengths actual false- color

14. false-color images are generated from non-visible wavelength data Gamma raysGamma rays ‘seeing’ Gamma rays‘seeing’ Gamma rays

15. xray uv visible infrared radio

17.  Energy of the wave is carried by a photon – a packet, or quantum of light  Photons do not have mass LIGHT IS ALSO A PARTICLE MinutePhysicsinutePhysics

18. WAVEPARTICLE EVIDENCE Creates a spread of light Creates discreet points of light Short exposure photo: points of light Long exposure photo: waves of light Double slit experiment here here

19.  Light is a stream of photons, each traveling on a wave path  Radiation types are defined by the energy of the photons  Radio waves have photons with the lowest energies, gamma-rays the greatest energies  Light behavior reflects energy  Low energy light behaves as a wave, high energy light as a particle WAVEPARTICLE DUALITY Einstein Explored