1. Electromagnetic Energy

2. Energy Energy: The ability to do work
Earth has two sources of heat energy:
External source: The energy provided by the sun
Internal source: The decay of radioactive substances and compression inside the Earth

3. Electromagnetic Energy
Electromagnetic Energy: a type of energy that is given off in the form of transverse waves from all matter not at absolute zero

5. How Animals See the World
Flowers and Bees
How Snakes See in Infared

6. ESRT page 14

7. Some Definitions
Wavelength: The distance from one crest to the next crest or the distance between any two corresponding points on two consecutive waves

8. Electromagnetic waves and us
Visible light is the only part of the spectrum that can be seen by humans
Infrared energy is often felt due to its heating effects
Ultraviolet waves causes the skin to tan or burn

9. Interactions Between Electromagnetic Energy and an Environment
Energy waves can interact with a material by:
a. Refraction: bending in the wave causing a change in direction, caused by varying density

10. b. reflection: bouncing off of the material

11. c. Transmission through the material d
c. Transmission through the material d. Absorption or taken into the material

12. Energy absorption
Dark-colored, rough surfaces absorb more sunlight (heats faster) than light-colored shiny surfaces
Dark objects are better at radiating heat energy (cool faster) than lighter objects
If 2 nearly identical cups of hot water were left outside at night, the darker one would cool faster

14. Texture
The rougher the surface is, the more energy it will absorb and the less it will reflect
Example: mirrors are smooth so they are shiny, therefore reflecting most of the incoming visible light

15. Land and water Land warms up and cools down faster than water
Good absorbers of energy are good radiators of energy (land)- that means the faster something heats up, the faster it cools down

16. Why is it cold at the poles?
Snow and ice reflect much of the insolation back into space
The sun is always low in the sky so sunlight is less concentrated
The sunlight has to travel through more of the atmosphere