The existence of the sun is pretty well established. The existence of a deity associated with the sun has quite a bit less scientific backing.

> The egyptians only seemed to have mischaracterized the nature of the sun perhaps, but not its effects on the planet or its role in life. Which is interesting.

I find ancient mythology interesting, but it's not surprising that ancient Egyptians knew that the sun gave life. You don't need to understand the mechanism to see that plants need sunlight to thrive and herbivores eat plants for energy and so on.