Maybe a stupid question but... Telescopes such as the hubble telescope take pictures of distance objects such as galaxies. Some of these pictures show the galaxies to be of spiral shape. These spiral galaxies are many light years apart, in length and width. When a telescope such as hubble takes pictures of these galaxies it is taking a picture of photons that have travelled through space. But as the galaxies are light years apart the light particles that hubble sees are potentially from different parts of time. So if we see a spiral galaxy shape from hubble Nasa picture of the day, spiral galaxy example we are not seeing the picture from one time but various so are spiral galaxies really spirally?
I'm not too sure of the answer, but this is where a discussion of Spacetime would be of use. Since no matter how big or small something is there will still be a time difference with data you receive. For instance you look down a corridor and you can see all the walls on either side right down to the bottom. If the only light to that corridor was at the very end, you would be seeing light rebound from each wall at different time incriments. Although it wouldn't seem noticable to the naked eye. As another post pointed out, Cambridge University (UK) intends to develop a supercomputer containing a universe model (Possibly to see how they would create it, or to map the real one. The options are potentially limitless) One of the many things that will be placed within the model will be Spiral Galaxies, and much of what you have said will have to be accounted for. Perhaps in a few years time there will be some 3 dimensional models for you to see as a result of the supercomputer.
Spiral galaxies are perceived as spiral because the spiral arms are regions of star formation. Hot blue and blue white stars make these regions more prominent in the visible light spectrum. Older stars whose spectrum is concentrated at longer wavelengths are dominated by these newer formed stars. javascript:launch('morph_ic/sw.html','morph',275,245)
