Reasons for the Seasons

In our science class we did a very interesting lab that has clarified me a few things about the season creation on Earth. In our lab, we used a styrofoam ball as a model of the Earth, and we used a flashlight to light our model Earth (who's axis was tilted about 20 degrees) and we have observed what is happening in many different cases. After the lab, we were supposed to answer these questions. So here they are:

1. When it is winter in the Northern Hemisphere, which areas on Earth get the most concentrated light? Which areas get the most concentrated light when it is summer in the Northern Hemisphere?
When it is winter in the Northern Hemisphere, the most concentrated light is in the Southern Hemisphere, and when it is summer in the Northern Hemisphere, then it gets the most concentrated light (at that moment, it is winter in the southern hemisphere).

2. Compare your observations of how the light hits the area halfway between the equator and the North Pole during winter and during summer.
During the experiment, we observed that during winter, light doesn't hit that middle area very much. Light hits the areas closest to the equator-because of the shape of the Earth. When we did our experiment with the acetate grid, we saw that the squares from the acetate grid on the northern hemisphere looked like rectangles. while when they were closest to the equator they were perfect squares. This means that the light was less concentrated at the poles than the areas close to the equator.

3. If the squares projected on the ball from the acetate become larger, what can you infer about the amount of heat distributed in each square?
When the projected squares become larger, it means that less heat is found in each square because the light energy is spreading out through a bigger surface area.

4. According to your observations, which areas on Earth are consistently coolest? Which areas are consistently warmest? Why?
The consistently coolest areas are the North and the South Poles, because only small amounts of sunlight come in those areas, and we can say that they are never directly illuminated. The warmest area is in the equator because it is in the middle of the Earth and it is always directly exposed to the sun.

5. What time of year will the toothpick's shadow be longest? When will the shadow be shortest?
The toothpick’s shadow will be longest during summer, because it is closer to the sun and the light is directly shining on it. But, in the winter, the shadow is shortest because there is a bigger angle of the light that hits it.

6. How are the amounts of heat and light received in a square related to the angle of the sun's rays?
The amounts of heat and light received in a square are biggest when the light directly hits the surface, so this angle is almost zero while when this angle increases, (because of the tilt of the Earth and Earth’s round shape) the square becomes rectangular and this light energy is spread through these rectangles.

7. Use your observations of an Earth-sun model to write an explanation of what causes the seasons.
The seasons on Earth are caused by the Earth’s round shape and the tilt of Earth’s axis from the normal position, to the line connecting the sun and the Earth. This tilt influences the way that sunlight hits the Earth’s surface- the more direct the sunlight hits the Earth, the warmer it will be. While when there is a bigger angle of sunlight toward the surface, it will be cooler.