Known Universe
The Helix Nebula - a gaseous envelope expelled by a dying star.
We have a sufficiently difficult problem to encompass in our imagination the universe known to us. Let us try for a moment to look at that from a far-off point of vantage, with eyes that telescope distances, and with a mind freed, if possible, from the prejudice of every-day dimensions. We see from that seat of the Gods great spaces in which bright bodies are moving in black space in apparent disorder. They seem to be subject to the complex influences of currents, swirls and eddies like bubbles in churning waters. Many of these millions of celestial bodies glow by their own light. Many of them are not self-luminous, but shine by light borrowed from a nearby glowing gem of great brilliancy. These occasionally pass into shadow and become faint ghosts illuminated by distant stars. But there are no great shadows as we conceive the night sky to be as viewed from the Earth. Everywhere celestial space is velvety dark and upon this black background we are seeing the gems of the universe from the far-off viewpoint that we have assumed in our imagination.
Looking back at the region where Earth is, an insignificant part of the whole, we see this solar system which also is a very minor part. It consists of a few bodies among millions. On close observation we see this planetary system - a number of planets revolving about the Sun which is just a mediocre star. Some of these planets have satellites attending them. Our eyes range over the universe and we see thousands of nebulae twisting themselves into balls, of course, infinitely slowly as measured by our ideas of time. Here and there bushy-tailed comets dash along in apparent independence. Star-clusters as viewed from the Earth spread out over great spaces as seen from this imagined point of view.
The millions of bright gems in this dark void differ greatly in size, shape, brightness, velocity, and direction of motion. The first glimpse gives the impression of chaos. Observations of a year or two reveal systematic motion here and there, such as in the rotations of bodies and the revolutions of their satellites. A century might include more than one complete journey of some comets over their eccentric pathways. It would reveal orderliness in our solar system and in some other places. A thousand years might show enough to make it seem safe to predict that all bodies were obeying certain laws which bound them in their paths and cemented their relationships. A thousand years of observation might change our impression of chaos into one of cosmos. But this period would be too short to detect progress in nebulae toward the spherical form that they seem to desire. If we could rid ourselves of the prejudice imposed by our experience as Earth-beings in time as well as in distance, we would then be ready to view the universe as a whole in our imagination.
