Tuesday, May 31, 2005
What causes the seasons?
Question:
What causes the seasons:
Hints:
If you had to give one reason it's because the earth is titlted 23.5 degrees relative to the ecliptic (the plane that the earth rotates around the sun in).
This causes two effects, one is that the sun is up for longer during the summer than it is in the winter. This gives the sun more time to heat the ground than in the winter. But this is not the most important reason.
The most important reason is that the sun is higher in the sky, and points down more directly. Imagine flashlight in your hand and you point it straight down to the ground. It makes a small, bright circle of light. If you tilt the flashlight it'll make a larger, duller oval of light. But the amount of energy is the same from the flashlight it's just spread over a bigger area.
Note also that the sun doesn't heat the air or the clouds (or very little) it heats the ground (or the water) and the ground heats the air.
What causes the seasons:
Hints:
- It's not because we are closer to the sun in the summer.
- There are two reasons it's warmer in the summer and both are caused by one other reason. (name all three for a bonus!)
If you had to give one reason it's because the earth is titlted 23.5 degrees relative to the ecliptic (the plane that the earth rotates around the sun in).
This causes two effects, one is that the sun is up for longer during the summer than it is in the winter. This gives the sun more time to heat the ground than in the winter. But this is not the most important reason.
The most important reason is that the sun is higher in the sky, and points down more directly. Imagine flashlight in your hand and you point it straight down to the ground. It makes a small, bright circle of light. If you tilt the flashlight it'll make a larger, duller oval of light. But the amount of energy is the same from the flashlight it's just spread over a bigger area.
Note also that the sun doesn't heat the air or the clouds (or very little) it heats the ground (or the water) and the ground heats the air.
# posted by Scott Kirkwood @ 7:07 PM 
