1. October 2, 2017
Monday

2. Science Log Semester 1 Week 6
Tuesday, October 3: What is your favorite season of the year, and why?
Update your Moon logs

3. Tape into page 36, leave 37 for Study page
Planetary Science Inv 3
Tape into page 36, leave 37 for Study page

4. 2. Quick Write page 38
What causes seasons on Earth?

5. 3. Identify seasons How do you know when it is summer?
Hotter days and longer days are indications of summer.
Heat and more hours of daylight are not just signs that summer is here; they also can help us understand the reasons why we have seasons on Earth.
We’ll start by looking at the issue of heat.

6. 4. Focus Question 3.1 bottom half of page 38
Why is it hotter in the summer?
Write down you initial thoughts

7. 5. Summer heat
Talk in your groups for 1 minutes to generate reasons for summer being hotter.
Longer daylight results in more time for the Sun’s heat (energy) to be absorbed by the land, water, and atmosphere.
Longer days can make it hotter.
However, the longest daylight in the summer in the Northern Hemisphere is in Canada and Alaska, and the hottest summer days are in the southern United States and Mexico.
There must be more to the story.

8. 6. Light on surface
I’m going to take a flashlight beam to represent a beam of light from the Sun,
observe the spot of light where the beam hits the floor.
You are going to take a flash light and draw a circle where you see the light, then turn the flashlight at an angle and draw or trace that circle.
One from 90, and 15 degrees put on page 40

9. 8. Light Energy Light is a form of energy.
This flashlight and the Sun are both sources of light energy.
We used a flashlight to shine light energy on the floor.
Your paper shows the area that the energy beam covered at two different times.

10. 8. Beam Spreading NBS8, page 41
Discuss the activity in your groups.
Work together to write answers to the first three question on your notebook sheets.
How do you explain the different shapes of the light spots?
When is the area of the spot largest?
Which spot delivers the greatest amount of energy to the floor?

11. 9. Beam Spreading
The size and shape of the light spot changes, depending on the angle of the beam
The light spot gets bigger as the angle between the beam of light and the floor gets smaller.
The amount of light energy in the beam stays the same, so both light spots deliver the same amount of energy to the paper.

12. 9. Beam Spreading Energy travels from the Sun to Earth as radiation.
Radiant energy travels in rays.
The number of rays hitting a given area is the energy concentration.
When lots of rays hit an area, energy concentration is high.
When few rays hit an area, energy concentration is low

13. 9. Beam Spreading
The flashlight puts out a steady beam of light rays that is about 5 cm across. When the light beam falls on a surface from directly above (90 degrees), the area it covers is a circle about 20 cm squared.

14. 9. Beam Spreading
When the angle that the light is coming from changes from 90 degrees to 15 degrees, what happens to the size of the area the beam falls on?
The area is oval, not round; the beam falls on a larger surface area; it’s about three times as large, about 60 cm squared.
Does the amount of light in the flashlight beam change? No

16. Solar Angle
The angle at which light strikes a surface is called solar angle.
These low solar-angle rays are hitting Earth’s surface at about 15 degrees.
These light rays shining from directly overhead have a high solar angle.
They are hitting Earth’s surface at 90 degrees
The incoming rays of light are equally spaced in both beams, but because of the difference in the angle of the Sun, three times as many rays are falling on a particular patch of Earth when the light comes from a high solar angle.
The concertation of energy is greatest when light shines on a surface at a 90 degree angle.

17. Solar Angle
The way a light beam covers a larger area when it hits a surface at an angle is called beam spreading.
Think about this.
When you take a spoonful of jam and put it on a piece of bread, it’s all concentrated in one area.
If you took a bite of that area, you’d get a lot of jam!
When you spread the jam around evenly, it is still the same total amount of jam.
If you took one bite of the bread, the jam would be a lot less concentrated.

18. Record Vocabulary page 39 Also put in index
Solar Angle: the angle at which light passes through the atmosphere; measured from Earth’s surface
Beam Spreading: the way a light beam covers a larger area when it hits a surface at an angle

19. 11. Answer the penny question
Answer questions 4-6 on the Beam Spreading
The solar angle determines the energy concentration—the amount of energy per unit of surface area.
Since the surface area of a penny does not change, the amount of energy hitting it varies with the solar angle.
The greater the solar angle, the more energy the penny will receive.
That means that the penny would get hottest with a heat lamp at a high solar angle.
For the same reason, high solar angles result in more surface heating by the sunlight on the surface of Earth.