by {???} on Fri Jun 26, 2009 7:14 pm
"Everyday, unless you happen to be an astronomer, you probably think little of our universe in general. You are not to blame for this; during the day, a star of absurd -27 stellar magnitude lights and heats our planet, and in doing so blinds us of the many other stars quite a bit further out. During night, however, everything becomes visible. Perhaps not everything, and perhaps not visible, at least to the naked eye. That star of -27 magnitude is denoted Sol, and is the closest star to us in the universe; it is but a mere 150 million kilometers from us on average. But Sol, or the Sun, as it is more commonly named, is an exception to the other stars of the universe; to those other nearby stars, our ordinary measures of distance fail us. We must instead avail ourselves of the light year. It is the distance light travels in a year, nearly ten trillion kilometers. It measures not time, but enormous distances. To the second nearest star, we would appear 4.3 light years away. That would mean that, by the time the light rays from that star--better known to the astronomers as Proxima Centauri--reach our telescopes here on earth, we would see the star as it was 4.3 years ago. Were it to supernova--a term referencing the colossal explosion that marks the death of a star--we would not know about it for 4.3 years. To the nearest galaxy, known to the astronomers as M31 and to the population as the Andromeda Galaxy, we are two million light years away. When the arriving light rays from that galaxy first departed, humans were not around to observe it; yet while in transit, we evolved from the apes and even managed to construct devices that could detect that faint light. And a light ray travelling from one end of the universe to the other would have traversed an unfathomable 13.7 billion light years. If an alien race 13.7 billion light years away sent us a message of eternal alliance, and we received it, they would have sent it to a race that had not yet evolved, on a planet that had not coalesced, orbiting a sun that had not begun to shine in a galaxy that had not yet taken flight. It is now that we begin to understand the universe's true vastness. Across the farthest reaches of the cosmos, there are a hundred billion galaxies, and a billion trillion stars. We are, for the moment, one feeble voice in the cosmic fugue."
--by {???} @ (B)Entity on the Universe