# Reason for the Seasons

Good afternoon scientists! Last night we conducted an experiment so that we could see why we have seasons instead of just the same temperature all year long.

Materials

Beach Ball (Ideally a Globe)

Small Bright Flashlight

Ruler

Black Marker (We used a washable one)

Investigation

1. First show your child the beach ball with the earth standing so that it is straight without an angle. (If you don;t have the globe on yours then talk about how the middle stays in the middle the whole time). Have your child shine the flashlight straight in front of them, and slowly turn the ball so that it goes in a circle and tell your child that this is what happens each day. When the sun faces us it is day, when the sun is on the other side of the Earth it is dark and night here. If our Earth was straight up and down then we would have the same temperature and type of weather all the time. Ask you child is this what happens? (Even here in Florida it does get cooler in the winter and hotter in the summer).
2. Next tell your child that the Earth doesn’t sit straight up and down, but instead is at an angle. Again have your child shine the flashlight straigt at te ball while you slowly turn the tilted Earth. ASk you child if they noticed any differences with how the light shined this time.
3. Take a sheet of printer paper and measure along each side in 1 inch increments, making a dot. Connect the dots across and up and down to create grid paper or download by grid
4. Hold the flashlight close to the graph paper and sign the light straight down, count the number of squares in the grid that have light.
5. Hold the flashlight close to the grid paper on an angle, count how many squares have light.
6. Which way did more of the squares get light on them?

Talking Points

In this investigation we used a flashlight to represent the sun. The Sun is the star at the center of our Solar System (sun with the planets). Earth is tilted at a 23.5 degrees. We have seasons because the Earth is titled on its axis (angled).

The Earth makes one rotation (spins once) per day. The Earth orbits or circles the sun every 365.25 days. Depending on the time of year the Northern Hemisphere (north half of Earth separated by the equator or imaginary center line) is tilted closer to the sun (summer) or farther from the sun (winter). The Southern Hemisphere (south half of Earth separated by the equator) is titled the opposite of the north half. So when the north half of Earth has summer the south half has winter.

When we held the flashlight straight over our grids the light was grouped in a small area.  There would be no seasons if the Earth was not on a axis, the world would receive the same amount of light all year, causing the temperatures to remain the same, because the amount of light would never change.

When we titled the flashlight it covered a larger area of the grid paper. This represented Earth spinning on its axis. On Earth when we have summer the our section of the Earth is titled towards the sun, causing it to be hotter. When we have winter our area of the Earth is tilted away from the sun so we get less light causing it to be colder. The flashlight that we held at an angle represents the sun shining on the titled Earth, the rays of the sun are spread out across the grid (Earth), the part of the Earth Closet to the sun represents summer and is the grids closest to the flashlight. The part of the Earth further from the sun represents winter and would be represented by the light on the grids further from the flashlight.