Why do slanted rays from the sun feel weaker than direct rays from the sun?

The suns rays hit the earth more or less straight on centered at the Equator. As you travel further away from the equator the sun has to hit you at a more shallow angle. As the earth curves away from the sun, the rays have to travel through thicker and thicker atmosphere as it does. The particles that float in the atmosphere block the suns heat and light more and more.

The same process occurs in the morning, day and evening anywhere with daylight on the planet. The sun has to pass through thicker, then thinner, then thicker atmosphere.
Because the same amount of radiation is spread over more area.

You can see this very easily. Take a small flashlight and a piece of white

notebook paper into a dim room. From a foot or two away, shine the

flashlight on the paper, first directly, then slant the paper and watch the

spot of light get bigger.