1. The effects of the Earth’s Axial Tilt on life on Earth
Seasons
The effects of the Earth’s Axial Tilt on life on Earth

2. What are “Seasons?”
The seasons we speak of here are changes in temperature, which in turn lead to changes in weather.

3. In the “Tropics,” located between the Tropics of Cancer and Capricorn on Earth, the Sun is nearly always overhead.
Seasons do not occur. Instead they have “Wet” and “Dry” Seasons.

4. The Reasons for Seasons
It is the axial tilt of the Earth that causes the seasons, NOT the shape of Earth’s orbit.
The Earth’s orbit is an ellipse, but the differences in distance to the Sun are NOT great enough to cause the seasons.

5. It’s the Earth’s tilt that makes the day is longer during the summer.
The tilt does NOT create enough of a difference in total solar energy delivered to cause the seasons.

6. The true cause of the Seasons is the angle in which light from the Sun strikes the ground.

7. In summer the Sun is more nearly overhead
In summer the Sun is more nearly overhead. Its rays are spread out over a smaller area of the Earth’s surface than in winter, when they come in at a low angle.

8. This means that in summer there is more light from the Sun per square foot…making the weather warmer.

9. Predicting the Season
Without a calendar, how would you know when to plant your crops?
Weather can be inconsistent from year-to-year, so it’s not a reliable planting guide.

10. If you can keep track of the Sun relative to the Zodiac constellations, you will know when the seasons are coming!
This way, even without a written calendar, you’ll plant your crops at the right time, they won’t die and you won’t starve.

11. For this reason ancient people all over the world have built astronomical structures from Stonehenge to the Mayan Observatories.

12. Those (usually priests) who knew how to use them wielded great power over their people.