 Actual samples from spacespace  Particle accelerators  Telescopes ◦ All wavelengths of light

 Energy  Electromagnetic wave ◦ Can travel without a medium (matter) ◦ Transverse waves

 Electromagnetic spectrum ◦ All travel at the speed of light (3x10 8 m/s) ◦ Vary in wavelength and frequency

 Which set of “hills” takes more energy to run?  High energy ◦ Short wavelength ◦ High frequency ◦ Large amplitude

Really Muscular Idiots Ultra X-treme Grannies Visualize

 Used for:  Standard form to scientific notation ◦ 45,000,000,000,000,000,000,000,000,000,000 ◦  Scientific notation to standard form ◦ x ◦ 2.11 x 10 -6

7. Describe two different ways that all forms of light are similar. 8. Draw a transverse wave and label a crest, trough, wavelength and amplitude. 9. Draw a wave with a very high amount of energy. 10. What makes electromagnetic waves unique?

 Radio  Microwave  Infrared  Visible  Ultraviolet  X-ray  Gamma

What do you think of when you look at the night sky?

 Greeks ◦ Rotating spheres ◦ Earth centered

 Galileo  Copernicus  Kepler  Newton  Mathematical laws about movement of planets  First telescope  Calculation of gravity  Sun centered universe

 Einstein ◦ Calculations ◦ Universe changing size ◦ Disbelieved  Added a constant to his equations  Results = static universe  Friedmann ◦ Russian ◦ Removed Einstein’s constant ◦ Universe changing shape ◦ Won Einstein’s approval

 Lemaitre ◦ Priest and physicist ◦ Universe began as a single point ◦ Expanded since that time  Hubble ◦ Astronomer ◦ Published around same time ◦ Provided evidence from observing spectra

 All objects emit light  Pure light from a source ◦ Continuous spectrum  If light passes through gas or dust ◦ Light absorbed ◦ Excites/heats atoms ◦ Emit own light ◦ Makes an emission spectrum /~jbattat/a35/cont_abs_em. html

 Each chemical/atom has a unique spectrum ◦ Like a fingerprint

 Determine chemical composition  Can also determine movement of object

 Draw the lines that you see ◦ Make sure the # of lines, color of the lines and order is accurate  Write a conclusion – based on your observations what can you conclude about the different materials and light you see the material produce

11. How is an emission spectrum created? 12. What can we learn from emission spectra? 13. Who is credited with having discovered the Big Bang theory and what is the Big Bang theory? 14. If you were Einstein, would have made the same decision about changing his equations to fit his personal belief? Why or why not?

 Change in emission spectrum ◦ Same pattern ◦ Shifted from where it should be

 Doppler effecteffect  Object moving past a stationary objectobject  Waves get shortened in front ◦ Higher pitch  Waves get longer in back ◦ Lower pitch  Inside the source – no change

 Blue-shift ◦ Wavelength shortens ◦ Moving towards us  Red-shift ◦ Wavelength lengthens ◦ Moving away from us ◦ Bigger the shift the further away it has come from ◦ Hubble only saw red- shifted spectra

 Universe moving away from us  Things further away are moving away faster  Expansion rate has since beginning

 Further evidence of the big bang  Picture = ◦ Universe all same temp ◦ Very cold ◦ Not what we actually see  Where else could the microwaves come from? ◦ Extreme red-shift  From a high energy wave ◦ Travel long distances ◦ Oldest light we observe ◦ Time when universe was all the same temp.  The Big Bang

 Used by scientists and all but 3 countries  Based on 10….so much easier