"Can't make mirror perfect enough"
I thought a huge number of spells in D&D hinged on your will alone? All you would need to do is know of what you would need, and your will itself would make it as perfect as it needs to be, no? (Question, not argument)
Fabricate is the crafting spell, and it still requires a crafting skill check. While it's nearly instantaneous, it has problems as well. You can't claim crafting bonuses from masterworked artisan's tools, circumstance bonuses for having access to a well prepared shop, nor Aid bonuses from assistants, since they can't actually participate in the crafting.
In the end, it still comes down to a skill check, and the item is only as "perfect" as you could make it by hand.
Greater Creation can create the mirrors out of nothing at all, though they don't last, and there's still a Craft check involved for fine work.
To my mind, a parabolic mirror with a focal length of 231,000 miles qualifies as "fine work". Hell, it's overqualified if anything.
"Earth is Colossal"
Some things in D&D MUST be homebrewed, as the WotC people are not perfect, and so it is arguable that making a new size category for a planet could be considered official rule, regardless of the fact that it would vary for every group. To consider earth to be the same size category as a dragon is... No, I'm not even going to bother arguing the logic. I'll just leave it at that for everyone following this.
Most of my argument here has been that you can follow the rules of the game, or you can try to follow the laws of physics and "common sense". It's really hard to do both.
So if your solution is to "homebrew" an answer (which amounts to changing/ignoring the rules of the game) then that's your solution.
Awesome. Smaller mirror array, set at a closer distance, focusing on a "Wrath of Palor". Pristine mirrors would be best, but not a necessity in this case.
What book is that in?
It isn't. I made it up. In fact, I said as much when I wrote "...create an Artifact". And there's no reason to limit it to a smaller mirror array. You could include as many as you like.
What you need to look out for is the enemy with a mirror of his own. He'll be able to redirect your weapon to use as he will.
Side note... I thought energy could not travel in the form of heat, (since heat is just molecules with high energy) in a vacuum? Would the light energy, after it is turned partially to heat energy when contacting the mirrors, really dissipate into the vacuum behind the mirrors? How does earth, then, keep from dropping to absolute zero...?
Infra-red radiation is a form of light, radiant energy, and can travel through a vacuum. It excites molecules when it strikes them, inducing "brownian motion", meaning vibration on the molecular scale. Other wavelengths of light can do this as well, but less effectively.
These molecules can re-emit the infra-red energy, which can again radiate back into space. If that couldn't happen then you wouldn't worry about the Earth dropping to absolute zero, you'd worry about it superheating into a plasma cloud. The ultimate "greenhouse effect".
