What helps us understand space? Actual samples from space Particle accelerators Telescopes
◦All wavelengths of light
What is Light? Energy Electromagnetic wave
◦ Can travel without a medium (matter)◦ Transverse waves
Electromagnetic spectrum◦ All travel at the speed of light (3x108 m/s)◦ Vary in wavelength and frequency
Many Types of Light
Which set of “hills” takes more energy to run?
High energy◦ Short wavelength◦ High frequency◦ Large amplitude
Energy in Waves
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
◦ 0.00000000005604
Scientific notation to standard form◦ 9.807 x 1012
◦ 2.11 x 10-6
Scientific Notation
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?
Daily Review #3
Radio
Microwave
Infrared
Uses Visible
Ultraviolet
X-ray
Gamma
What do you think of when you look at the night sky?
http://www.astro.ufl.edu/~lada/ast3018/lectures/ast3018lecturestarform.pdf
How has our “picture” of the universe changed?
Greeks◦Rotating spheres
◦Earth centered
Early Scientists
GalileoCopernicusKeplerNewton
Mathematical laws about movement of planets
First telescope Calculation of
gravity Sun centered
universe
Next generation of scientists…
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
http://wouterdeheij.wordpress.com/2013/04/27/famous-innovation-quotes-from-steve-jobs-gunter-pauli-einstein-henry-ford-and-many-others/
http://en.wikipedia.org/wiki/File:Aleksandr_Fridman.png
The Big Bang Theory 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
How is a spectrum created?
If light passes through gas or dust◦ Light absorbed◦ Excites/heats atoms◦ Emit own light◦ Makes an emission
spectrum
https://www.cfa.harvard.edu/~jbattat/a35/cont_abs_em.html
What does a spectrum tell us?
Each chemical/atom has a unique spectrum◦Like a
fingerprint
http://www.umsl.edu/~physics/Lab%20Connection/Electricity%20and%20Magnetism%20Lab/12-lab13.html
How do astronomers use spectra?
Determine chemical composition Can also determine movement of object
http://www.eso.org/public/outreach/eduoff/cas/cas2004/casreports-2004/rep-236/
Spectroscopy Activity
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?
Daily Review #4
Hubble’s Evidence - Redshift Change in emission spectrum
◦ Same pattern◦ Shifted from where it should be
Same thing happens with sound… Doppler effect Object moving past a stationary object Waves get shortened in front
◦ Higher pitch Waves get longer in back
◦ Lower pitch Inside the source – no change
http://archive.ncsa.illinois.edu/Cyberia/Bima/doppler.html
Relating back to light… 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
Hubble’s Conclusions
https://www.e-education.psu.edu/astro801/book/export/html/1967
Universe moving away from us
Things further away are moving away faster
Expansion rate has
since beginning
Cosmic Microwave Background Radiation
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
Metric System