A long while ago I had this idea for a plot of a story. Now I'm not so sure my logic is right. If I were to place a (perfectly) mirrored parabolic dish out near Pluto, point it at the sun and put my (tiny point-like) spaceship at the focus, how big would the parabolic dish have to be to give me an amount of sunlight equivalent to a spot in Earth's orbit? I'd originally assumed that, as long as the apparent size of the disc of the dish were equivalent to the apparent size of the disc of the sun (i.e. ~0.5 degrees), that would be enough. Say you placed your mirror 93 miles away from your spaceship and made the mirror 0.8 miles in diameter. It would appear the same size as the sun from Earth (93 million miles distance at .8 million miles diameter). Because the mirror's focus is set to 93 miles, when you looked at the mirror, you'd see a disc as bright as the sun and as large as the sun. Is my logic correct?