Galaxy Structure Quotes

The earth is not in the centre of the Sun's orbit nor at the centre of the universe

My favorite galaxy of all is called the Sombrero, NGC 4594. It's an amazing galaxy that is really two galaxies in one.

Maybe dark matter is denser than we usually assume, kind of like the Milky Way plane.

Out Milky Way is the dwelling; the nebulae are the city.

Recent results from astronomers who study the occasional gravitational lensing of unknown worlds by intervening stars suggest that orphan planets could be at least as numerous as the stars. In other words, there could be hundreds of billions of orphan worlds shuffling through our galaxy.

The great spirals... apparently lie outside our stellar system.

The conclusion is inescapable that non-luminous matter exists beyond the optical galaxy.

The large-scale homogeneity of the universe makes it very difficult to believe that the structure of the universe is determined by anything so peripheral as some complicated molecular structure on a minor planet orbiting a very average star in the outer suburbs of a fairly typical galaxy.

Were the succession of stars endless, then the background of the sky would present us an uniform luminosity, like that displayed by the Galaxy-since there could be absolutely no point, in all that background, at which would not exist a star. The only mode, therefore, in which, under such a state of affairs, we could comprehend the voids which our telescopes find in innumerable directions, would be by supposing the distance of the invisible background so immense that no ray from it has yet been able to reach us at all.

In this way, Edwin Hubble worked out the distances to nine different galaxies. We now know that our galaxy is only one of some hundred thousand million that can be seen using modern telescopes, each galaxy itself containing some hundred thousand million stars.

The near side of a galaxy is tens of thousands of light-years closer to us than the far side; thus we see the front as it was tens of thousands of years before the back. But typical events in galactic dynamics occupy tens of millions of years, so the error in thinking of an image of a galaxy as frozen in one moment of time is small.

I am undecided whether or not the Milky Way is but one of countless others all of which form an entire system. Perhaps the light from these infinitely distant galaxies is so faint that we cannot see them.