1. Regulus (about 75 light years distant) is part of a 4-star system, with a close companion double star visible to its lower left.
Leo I (about 800,000 light years away) is a dwarf galaxy thought to be the most distant of several known small satellite galaxies orbiting our Milky Way Galaxy.

2. Why are you taking this class?
Why does the University consider it important for non-science majors to take a course in the physical sciences?

3. Science attempts to systemized knowledge through:
observing
questioning
hypothesizing
testing
Using critical & creative thinking.
Scientific thinking has applications to all fields of human endeavors, not just science.

4. Patterns are discovered.
OBSERVING:
Patterns are discovered.
QUESTIONING:
What causes these patterns?

5. Question everything, including things you “know”
Examine your assumptions: Be aware that your thinking is influenced and structured by your previous life experiences, i.e., they are biased.
Be creative, but critical, in your thinking!

6. Our goal is to teach you to be creative, critical thinkers that question authority, not to groom you to take exams!

7. Let’s begin now …

10. What happens next?

12. In some cases we need to revisit things that we “know”
Our “knowledge” can be based upon misinformation or errant assumptions consistent with our previous expereinces.
Never get too wedded to your own “knowledge”, question it as well.

13. DISTANCE SCALE

14. SCIENTIFIC NOTATION
Expressing large and small numbers:
10n = 1 followed by n zeros
e.g., 3.2 x 109 = 3.2 x 1,000,000,000
= 3,200,000,000
10-n = 1 / 10n
e.g., 5 x 10-5 = 5 / 105 =

15. Common prefixes in numbers:
Symbol
factor
tera T
1012
1,000,000,000,000
giga G
109
1,000,000,000
mega M
106
1,000,000
kilo k
103
1,000
hecto h
102
100 1
centi c
10-2
0.01
milli m
10-3
0.001
micro μ
10-6
nano n
10-9

16. Units of Distance in Astronomy
Meter: ~ 10% larger than 1 yard
Astronomical Unit (AU): Earth – Sun distance, ~ 15 x 106 kilometers ~ 9.3 x 106 miles)
Light Year (LY): distance light travels in one year, ~ 9.46 x 1012 km
Parsec (pc): ~ 3.26 light years

17. DISTANCE SCALE
Seeing the past

18. The universe is approximately 14 billion years old
Earth is 0.04 light seconds (8000 miles) in diameter
Moon is 1.3 light seconds (250,000 miles) from Earth
Sun is 8 light minutes (1 AU) distant
Next nearest star is 4.3 light years (LY) distant
Center of the Milky Way Galaxy is ~ 26,000 LY distant
Andromeda galaxy is 2.5 x 106 LY distant
We see galaxies greater than 109 LY away

19. “The Cosmic Connection”
A video interlude…
“The Cosmic Connection”

21. Edwin Hubble was the first to observe that, with the exception of very nearby galaxies, all galaxies move away from Milky Way.
He also found that the velocity with which galaxies recede from the Milky Way is proportional to distance! The more distant a galaxy is, the faster it is moving away from us.
This is a direct prediction of a uniformly expanding universe.
BIG BANG – Universe approx x 109 years old

22. Big Bang (~ 13.7 x 109 yrs ago) T i m e
Expansion & Cooling
Initially only Hydrogen & Helium
Growth of structures (gravity)
Stars and Galaxies form
Nucleosynthesis - “star stuff”
Planets possible - “heavier” elements
Solar System forms (4.6 x 109 yrs ago)

23. Which of the following best describes what we mean by the “universe”?
(red) A vast collection of stars that number as many as the grains of sand on all the beaches on Earth.
(blue) All the galaxies in all the superclusters.
(yellow) The universe is another name for our Milky Way Galaxy
(green) The sum total of all matter and energy.

24. Which of the following best describes what we mean by the “universe”?
(red) A vast collection of stars that number as many as the grains of sand on all the beaches on Earth.
(blue) All the galaxies in all the superclusters.
(orange) The universe is another name for our Milky Way Galaxy
(green) The sum total of all matter and energy.

25. Which of the following has your "cosmic address" in the correct order?
You, Earth, solar system, Milky Way Galaxy, Local Group, Local Supercluster, universe
You, Earth, Local Group, Local Supercluster, solar system, Milky Way Galaxy, universe
You, Earth, solar system, Local Group, Local Supercluster, Milky Way Galaxy, universe
You, Earth, solar system, Local Group, Milky Way Galaxy, Local Supercluster, universe

26. Which of the following has your "cosmic address" in the correct order?
You, Earth, solar system, Milky Way Galaxy, Local Group, Local Supercluster, universe
You, Earth, Local Group, Local Supercluster, solar system, Milky Way Galaxy, universe
You, Earth, solar system, Local Group, Local Supercluster, Milky Way Galaxy, universe
You, Earth, solar system, Local Group, Milky Way Galaxy, Local Supercluster, universe

27. Looking for patterns

28. questioning: why do these patterns exist? hypothesizing testing
observing: look for patterns
questioning: why do these patterns exist?
hypothesizing
testing