Chapters 5 and 10
(Hints of chapter 2, more later)

Learning Outcomes, Objectives, & Goals
• Appreciating science in general, and astronomy in specific.
• Understanding how knowledge is gained and be critical of what you see and hear.
• Developing a working knowledge of the scientific method and how to apply it to real world situations.
• Critically analyzing and evaluating information, scientific or otherwise
• Learn some simple astronomical nomenclature/terminology.
• Develop a sense of what scientists know about the overall universe, its constituents, and our location
• Explain how electromagnetic radiation is used to reveal the properties of stars and planets.

• Understand the major properties of light, including wave and particle properties.
• Know the 7 types of light and the order of the major wave & particle properties for these types.
• Understand how light and matter interact, in both distant and everyday objects. (Including Doppler effect.)
• Understand the nature of light properties and its relationship to the ozone hole and why this is a problem.
• Understand the nature of light properties and its relationship to global warming. Know the major manmade causes of global warming.

• Visible light = ___________________
• ___________
= ________________________
• Visible spectrum
= _______________
• White
= _________________________
_______________________
• ______________________ = ___________
• _______________________ = ________________

• _____________– see page 149
• _____________– ___________________________
– units are: _____________________________________
• Speed = how fast _________________________
– ____________________
– ___________________________________________
• __________________________________________

1. ______________. We’ll discuss 2 ways later.
2. __________________
3. ________________________________
4. __________________(___________things)
5. _______________________(______things)
See figures 5.2 & 5.3 on pages 151-152.
Why is the sky blue? _____________! See pages
304-305 (not on your test)

0
0
0
0
0
1. Emission
2. Absorption
3. Transmission (Passing through)
4. Reflection
5. Scatters
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0
0
0
0
0
1. Scatter
2. Reflect
3. Emit
4. Absorb
5. Transmit
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0
0
Which happens to light when it hits my shirt?
1. Scatter
2. Reflect
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0
0
Which happens to light when it hits the
Moon?
1. Scatter
2. Reflect
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0
0
What color does a green shirt ABSORB?
1. Absorb all except green light
2. Absorb green light
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Calif. Elementary School Science Standards for energy & seasons
• From California Science Standards, grade 3:
– Students know energy comes from the Sun to Earth in the form of light
.
• And from grade 6:
– Students know solar energy reaches Earth through radiation, mostly in the form of visible light
.
• And from grade 7:
– Students know visible light is a small band within a very broad electromagnetic spectrum
.

Calif. Science Standards for light
• From California Science Standards, grade 3:
– Students know the color of light striking an object affects the way the object is seen
.
– Students know an object is seen when light traveling from the object enters the eye
.
• And from grade 7:
– Students know that for an object to be seen
, light emitted by or scattered from it must be detected by the eye
.
– Students know light travels in straight lines if the medium it travels through does not change.
– Students know that white light is a mixture of many wavelengths (colors)
…
– Students know light can be reflected, refracted, transmitted, and absorbed by matter
.

Depends on two things:
1. ______________________________________
2. ______________________________________

_______________types of ____________(see page ____).
_______________________! See percentages below.
(__________________________________________)
1. _______________________
2. _______________________
3. _______________________
4. _______________________
5. _______________________
6. _______________________
7. _______________________
(__________________________________________)
_____________________________________________________________________
_____________________________________________________________________

X-ray
IR
UV
Microwave
Visible
Radio

• Your eyes see ___________ light.
• When ________ light lands on your skin, skin gets warmer.
• When ________ light lands on your skin, skin is damaged.
• When ________ light lands on your skin, you get radiation poisoning. (two answers)
• When ________ light lands on your skin, nothing changes unless a LOT lands on you. (two answers)
• Digital cameras see visible AND infrared light. Remote controls often use IR light. Look: cell phone + remote
• Blacklights emit UV light.
– Take a look – Moon lights, portable UV lights.

• Which type of photon carries the most energy?
• Which kind is most dangerous?
• Least dangerous?

• ___________________________
• _________also _________________.
• Light _____________________….
• What are the 7 types of light?
• They differ in ______________, ___________, and _________________________.

1. ____________________
– Which kind of light does the Sun shine most?
– Objects _______________cool mostly by _________
_____________________. (See page 168 – Wien’s law)
– Colder objects also ________________________
(Stefan’s law, p. 168)
2. Other cooling methods inside planets
– Similarly, can ignore these again
For the rest of this course, we’ll focus on:
– ___________________________________
For OUR solar system, that means focusing on:
– _______________________________. Why _________light?
– Which other type of light should we focus on?

• Objects can ______________________________:
1. Because ______________________
– These _________________________, but _______________________.
– Examples: the __________, ___________________________
– Which kind given off most by _________? ______________?
• ___________light indicates ____________________.
2. Because they are _________________________
– These give off ______________ (we’ll see)
• Called “________________” or “_____________________”
– Example: fluorescent gas tubes we’ll see
– Useful to astronomers because __________
___________________________________
– Show animation: Composition of Mystery Gas [4 th row from bottom]

• Now that you understand the basics of light properties, let’s examine two issues related to humans and the Earth.

•
Ozone is a form of molecular ________________________.
•
Occurs naturally ( if the atmosphere already has O
2
) in the _______
___________________in small quantities (parts per trillion).
• _______________________________________________very efficiently (90-99% of them).
•
Without it, _____________________________________________
________________________________________________________
________________________________________________________
•
Chloro-Fluoro-Carbons (_____) produced by humans are nearly inert molecules that get into the upper atmosphere.
• CFCs attack the ozone molecules. Each _____molecule destroys
____________ozone molecules over its several year lifetime before the _______molecule is finally destroyed. (No convection in upper atmosphere. See pages 305, 324-325.)

The worst damage, by far, occurs over ____________.
Fortunately ________________!
There are also precious few
_________________there. How lucky!
Equally fortunate is that we found this problem and its cause in time! Here is a more recent map of the ozone layer. It’s not as good as we’d hoped.

Production of ______were banned worldwide in _____. Look at the chart after
_____. _________are dropping! Predictions were that the worst damage to the ozone layer would occur by 2000, and then it would start “healing”. BUT: in
2007, the hole got bigger. Hopefully the healing will (re-?)start soon!
EXPECTED TO BE BACK TO NORMAL LEVELS IN ______________
Important point: international effort was necessary and seems to be working.

Human influences & economics
• Until recently, people assumed we couldn’t affect the atmosphere.
• Then we started measuring it.
• Ozone hole showed up. Nobody expected it.
• It cost a LOT of money to stop damaging the ozone layer.
• It was money we HAD to spend to keep life alive.

Human influences & economics
• People didn’t believe the ozone hole was caused by humans. They claimed:
– FIRST: It’s not happening
– SECOND: It might be natural; Earth goes through cycles.
• We’re not making enough stuff to cause the damage.
– NOW:
• We don’t know enough (it’s too early) to make any major changes
• It might naturally fix itself; life has been on Earth for billions of years. It’ll adapt and solve this problem.
• The economy would suffer if we force ourselves to change our ways
• Same argument used for cigarettes & lung cancer , seat belts, airbags, car catalytic converters, and sulfur dioxide emissions (that cause acid rain).
Using same argument now to prevent increasing fuel economy. History shows these economic arguments were often wrong.
• These EXACT same arguments are now being used when discussing global warming.

What would happen if we wrapped the
Earth in an ___________________
_____________________?
Talk to your neighbor. I’ll solicit answers from you.

0
0
0
What would happen IN THE LONG TERM if we wrapped the Earth in an ___________________
__________________?
1. Earth would cool down
2. Earth would get hotter
3. Earth would stay same
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• The fundamental idea about global warming and the potential dangers deals with the
_______________________ portion of Earth’s
___________________________.

• Did we use the infrared camera?
• Did we see people wearing glasses on the infrared camera?
• What did that mean?
• What happens when you surround Earth with an IR blocking gas?
• This is called the Greenhouse effect.
• Two key ideas:
– Visible light from Sun comes in, warming Earth up
– Infrared light from Earth gets blocked by some
Greenhouse agent, so Earth can’t cool as easily

• Some ____________are __________________
– ____________________________________________
– ________________________________(methane is 23x better!)
– _________________. But lots of it in Earth’s atmosphere, which causes most of our Greenhouse Effect.
• Greenhouse atmosphere _________________________.
• Earth would be _________________than it is without G.E.!
– Water would _____________! (Avg temp: 3 ˚F or -16 ˚C)
• Which planet do you think should be hottest?
– Why?
• Does Venus have an atmosphere?
• Why is ______________________________?

From James Hansen’s PowerPoint downloaded from his NASA –Goddard web page. The next slide’s graphs are from an article he wrote a few years ago. This graph was SET to zero for a specific year. The century-long change is the important idea here.

The temperature of the Earth is _______
______________(___________graph).
We see: average temperature of Earth has increased about ________________
_____________. This is much faster than scientists can explain without human influence.
Coincides with huge increase in CO
2 from burning fossil fuels. Levels now higher than any level seen in past
400,000 years and rising.
(Was 280 ppm in
1850; in 2009 it’s 387 & rising 2.4/yr. In 1980’s rose
1.4 ppm/yr, <1ppm/yr before then)
Other changes: sea level has risen, carbonation in the oceans increased (i.e. oceans are storing much of our CO
2
).

•
People make lots of _______________________________________
•
Both of these gases cause the ___________________________.
•
Most from the ________________burning fossil fuels. _______CO
2 emitters. (But China has 4x the US population! Use LOTS of coal!)
• Cutting down/burning trees (deforestation) is also a major factor.
•
Do we understand EVERYTHING about the temp increase?
• Of course not. Atmosphere = complicated. New data every day.
Your book gives an objective summary on pages 328-330.
NOTE: While humans account for 2 percent of the world’s carbon dioxide emissions. That’s enough to tip the balance, though.
__________________________________________________________.

You’ve probably heard about the “controversy” surrounding global warming.
Here are facts:
1._____________who understands the data _____
_________________________________. ____% of scientists agree the temperature is rising in the
__________term (over _________________).
2.The only “controversy” ___________________the temperature to rise.

o ______(___% of) scientists who study the Earth’s
LONG-term atmosphere believe manmade _____
_____________________________ o Even 90% of ALL 3,146 earth scientists surveyed agreed temperatures are rising, and 82% said
“human activity [has] been a significant factor…” o However, some deniers say that we don’t know enough yet to say what’s going on.
o Mostly petroleum geologists & meteorologists o Meteorologists study SHORT-term effects.
o Source: http://www.cnn.com/2009/WORLD/americas/01/19/eco.globalwarmingsurvey/index.html

Intergovernmental Panel on Climate Change
• IPCC = group of ~2000 atmospheric scientists
• IPCC’s 4th report (2007):
• Greenhouse gas emission rate has increased 70% since
1970.
• “Warming of the climate system is unequivocal.”
• 90% likelihood that human activity is affecting the climate.
• Under current policies, emission will continue to increase for decades to come.
If we continue to do what we are doing now, we are in deep trouble. - Ogunlade Davidson, IPCC

2
1. _______________
2. _____________
1. China
2. Russia
3. Russia 3. Japan
4. Japan 4. India
And my personal favorite:
5. India
But if we separate the US into states…
5. ____________
… 12. __________________
China has now (in 2008) overtaken the US in total CO
2
.

Five Biggest CO
2 emitters PER PERSON (as of
June 2008)
1. USA – 19.4 tons per year
2. Russia – 11.8 tons
3. European Union – 8.6 tons
4. China – 5.1 tons
Driving 12,000 miles releases ~6 tons CO
2
.
(average;
Prius is ~2.5 tons)
5. India – 1.8 tons
China’s rate is growing faster than the US, largely due to coal and cement plants. But they have a lot of catching up to do.

Other possible causes of global warming
• Other things may explain the temp raise during the last 100 years.
•__________________________.
(This is the _____________________________.)
•_________________(
Maunder Minimum) . ___________=
_____________. Not well understood. But _________link.
•We thought this is the strongest sunspot cycles during the last 50 years. But as of Apr 2009 we may be in the deepest solar minimum in 100 years, so this argument is less convincing. Stay tuned as we learn more.
Bottom line: Most scientists predict _____________
__________________________________________,
____________________________________.

• Retreat of glaciers (Apparently happening)
• Melting of Greenland & Antarctic ice caps. (Seen;
Greenland’s caps are melting faster than predicted)
• Melting of Arctic permafrost.
• Melting of Arctic sea ice.
• Rising sea level & flooding on coasts.
• Stronger hurricanes/storms (a bit more controversial)
• Shift of malaria farther from equator. (Seen already)
• Similar shift of wine-producing regions. (Seen)
• Similar shift of desert belt.
• Mass extinctions of wildlife.

0
0
1. Yes
2. No
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• Sound maker demo
– Close eyes & listen; describe
– 440 Hz. F#
– Match description with observation

0
0
Which kind of Doppler shift do we see for most objects in the universe?
1. Redshift
2. Blueshift
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• Interactive figure 5.22
• Why called redshift & blueshift for light.
• Doppler shift of lines [5 th row top]
• Application in your everyday (?) life:
– Speeding tickets!

Learning Outcomes, Objectives, & Goals
• Appreciating science in general, and astronomy in specific.
• Understanding how knowledge is gained and be critical of what you see and hear.
• Developing a working knowledge of the scientific method and how to apply it to real world situations.
• Critically analyzing and evaluating information, scientific or otherwise
• Learn some simple astronomical nomenclature/terminology.
• Develop a sense of what scientists know about the overall universe, its constituents, and our location
• Explain how electromagnetic radiation is used to reveal the properties of stars and planets.