I'm doing some research about space and astronomy, and I'd like to find an answer to a question that has bugged me for ages now. For the longest time I had no idea where to look for answers, but since I accidentally stumbled across the Bad Astronomer's page recently and spent many hours hence glued to the screen while perusing his site I believe I may finally have found a good place to start. At first I wanted to write to the BA himself, but when I noticed a piece of text on the site that said it could take him up to a month or more to reply to emails due to the amount of mail he receives, I decided to check out the forum instead and was happy to find a thriving community filled with people whose passion for the cosmos is equally great. So I hope I will find my answers here [img]/phpBB/images/smiles/icon_smile.gif[/img]
My question in itself is actually quite simple, but it's a little hard to explain it properly. Essentially I'd like to know whether there is a great difference between how we see cosmic vistas such as nebulae through sophisticated telescopes and how we would see them with our own eyes from certain points in space. I realize this is still pretty vague, so let me try to clarify a bit with a picture:
None can deny the inherent beauty of such images, and I'm sure many here, like myself, have spent many an hour gazing at the pictures the HST has made since its launch. What I always wondered about though is how these vistas would be seen by us humans. In the above pic for instance, we see in the top left hand corner the supergiant Antares. Around it are several more stars (the blue on on the right is Rho Ophiuchi, I don't know the names of the other ones), each illuminating great clouds of material around them with their light. But while I love to see pix like these, I can't help but doubt that such things can actually be seen without the magnifying effect of a powerful telescope. The stars in the picture for instance almost appear to be right next to each other, while I'm sure that, like with any other stars, quite a few lightyears lie between them. This would mean that if you were to find yourself within the Antares system, the other stars in this picture would probably look no different from the way we see stars from within our own system; merely as tiny specks of light and nothing more. Another example I'll bring up is something I suppose everyone is familiar with: the closing scenes of The Empire Strikes Back. There we see Luke Skywalker, Princess Leia and the robots standing in front of a large window on a frigate, staring into space. What they see is a great galaxy (I think it was a galaxy at least; it's been a while since I last saw the movie), rotating slowly. A similar scene is to be seen near the end of the movie 'Contact'. Now I wonder how realistic such scenes are; can one really see a galaxy in that way from certain points in space, spread out before one's feet like a giant, rotating wheel of stars? The more I think about it the more implausible it seems. The reason I put this as an example is because Contact has been reviewed on the Bad Astronomy site, and nothing was said about it; perhaps it was only an oversight, but I reckon that if such a scene is truly impossible, then the Bad Astronomer would probably have mentioned it in his review. He didn't however, so again I'm in doubt. The same train of thought can be used when it comes to nebulae; can one really look through the window of a spaceship, or look up at the sky from the surface of a hypothetical planet, moon or asteroid, and see massive, colourful nebulae that are lightyears across, like one might see in a fantasy/sci-fi painting, or are such things confined only to the minds and works of the artists who make them? I also wonder how it would be to actually be inside a nebula; would you actually notice, like it was depicted in the PC game Freespace II? If not, what would it be like in reality? In the picture of Antares, too, there are large clouds of gas or dust to be seen around the stars, but would you see them with your own eyes if you were to be in orbit around any of them, or would things look fairly similar to our own solar system, and are the clouds we see merely visible due to the greater sensitivity (when compared to the sensitivity of the human eye) of the telescope that was used to photograph them?
I hope my inquiries are clear; as I said I'm having kind of a hard time describing exactly what I mean. Also I realize that since man has only waded a few steps in the galactic waters (and has therefore not had the opportunity - yet - to see for himself what the naked eye may or may not perceive from any given point in space), it's likely these issues are debatable. I'll say here and now that I know very little of such matters myself, and while I try to learn everything I can about the universe around me my knowledge is no doubt far surpassed by the majority of the people on this forum (judging by what I've seen while perusing these boards for a few minutes). If you choose to answer my post however, I beg you to keep the math down to a minimum should you feel the need to use it, since I'm afraid it and myself can never be anything else then sworn enemies [img]/phpBB/images/smiles/icon_wink.gif[/img]