This is another theoretical question post of mine. I read somewhere that there is a huge temperature polar opposite change in space just from shielding ie shadow vs. exposed to sun. That was because of the absence of an atmosphere or "stuff to keep the heat" So, pulling numbers from the air, it was like 300C or -200C if it was exposed to the sun or in the shadow. I was wondering if one were to build generators with spinning gates (open/close) to let in light then not let in light. Could you build generators from temperature change? There is the added benefit of no gravity or little anyway I apologize if I am missing major concepts, I failed thermodynamics after I got into the statistical portion which is not an excuse I basically temporarily lost interest in the subject and did not study. So perhaps my questions may be deemed unworthy but just for the hell of it, I'd like to ask you guys your thoughts. Also just to throw it in there How much "scrap atoms" are there in space Could you "capture them" in the void blackness of space? I'm interested in gathering oxygen molecules and such from the outside and then processing them inside for use in life support and what have you. Is there "nothing" besides dark matter/energy in space? Unless it is in a planet, nebula or galaxy?