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