It travels through the vacuum, but it doesn’t heat the vacuum, there’s nothing there to heat. The “Goldilocks spot in the atmosphere” is on the ground, that’s why we live here.
When you’re close enough to the sun it heats you enough, because at some point you’re so close you’ll burn up, and at some point you’ll freeze, so there must be a point between them that’s comfortable. (And yes that might involve spinning so you don’t cook on one side and freeze on the other.) Never said it “heats the vacuum”.
It travels through the vacuum, but it doesn’t heat the vacuum, there’s nothing there to heat. The “Goldilocks spot in the atmosphere” is on the ground, that’s why we live here.
When you’re close enough to the sun it heats you enough, because at some point you’re so close you’ll burn up, and at some point you’ll freeze, so there must be a point between them that’s comfortable. (And yes that might involve spinning so you don’t cook on one side and freeze on the other.) Never said it “heats the vacuum”.
But the theory that the space (proper outerspace space) in-between Earth and the sun has an even temperature gradient assumes that it does.
I literally never said it’s even, only that if you plot it out it would be continuous instead of piecewise.