Here's why:
* Direct rays hit the Earth at a more perpendicular angle, meaning they are concentrated over a smaller area. This leads to higher energy density.
* Indirect rays hit the Earth at an angle, spreading the same amount of energy over a larger area. This results in lower energy density.
Think of it like shining a flashlight on a wall. If you hold the flashlight perpendicular to the wall, the light is concentrated in a smaller area. If you angle the flashlight, the light spreads out over a wider area.
This is why areas closer to the equator (which receive more direct sunlight) tend to be hotter than areas farther away from the equator (which receive more indirect sunlight).
