Science
In reply to the discussion: My God, this is beautiful! [View all]D Gary Grady
(133 posts)Extended objects such as nebulae don't look dimmer because they're farther away. There's less total light, but it's concentrated on a smaller area of the retina, and the two effects exactly cancel out. I'll try to find time to post a detailed explanation on my blog (the address is my name with .com on the end and the spaces squeezed out) by tomorrow, in case anybody cares.
From Earth, this nebula (NGC 6357) fills a piece of our sky several times as large as the full moon. There are other nebulae even larger from our point of view, and I've long lamented that we don't have lemur eyes to better appreciate them. This photograph is beautiful because it's a time exposure captured with a large-objective telescope; our scientific instruments extend our ability to appreciate nature's glorious beauty, and I don't see how that's a downer for anybody!