Posted by Mike
We were in Orlando last week, driving down I-4 to one of the few Disney locations where you can get the ambiance of Disney but don’t have to spend any money if you don’t want to. The section of I-4 right before you get there is reminiscent of Vegas’ pre-Strip area: smaller motels, eating places, more than a little tawdry. Suddenly you come onto, right off I-4, this massive cathedral. There’s a sign prominently displayed to I-4 passersby, Mary Queen of the Universe.
Now for some back fill. Our solar system consists of the sun, eight major planets, and other assorted flotsam and jetsam. The earth is the third planet from the sun, only 93 million miles away. This distance is called an AU (astronomical unit). The furthest planet from the sun is Neptune, at almost 2,800 million miles. That would be about 30 AUs. The asteroid belt lies within the solar system, generally between the planet Mars and Jupiter , that’s about 2-5 AUs from the sun. The objects in the asteroid belt consist of carbon and metals, rather than the less compact icy substances found in the Kuiper belt and the Oort clouds. The Kuiper belt is a system of comets beyond the planets, 30-55 AUs from the sun, much more massive than the asteroid belt. And finally, the Oort cloud is a hypothetical band or sphere of comets, about 50,000 AUs or about a light year away from the sun, that surrounds our solar system. A light year (ly) is actually about 63,000 AUs.
The nearest star system to our own solar system is Alpha Centauri, which consists of a double star; however, it appears to us as a single star. In addition to the double star is the star that is nearest to us, which is Proxima Centauri, a red dwarf star, which is about 4.2 light years away from the sun. Alpha Centauri is, of course, within our galaxy, which is called the Milky Way Galaxy. Because Alpha Centauri is fairly close to us (astronomically speaking) its movement is more noticeable over time; it is estimated to disappear within a larger group of stars in the galaxy within 100,000 years.
Our solar system lies within one of the spiral arms of the Milky Way Galaxy. This, our galaxy, is estimated to be about 100,000 light years across and about 1000 light years thick. Thus, you can see that it would be likened to a very, very thin pancake. There are estimated to be about 200 billion stars in the Milky Way Galaxy, and possibly up to 400 billion. Associated with our galaxy are two small companions called the Magellanic Clouds.
Moving away from our galaxy, we find that there are an estimated greater than 100 billion galaxies in the observable universe. The nearest spiral galaxy to us is Andromeda. It is approximately 2.5 million light years away from us and is the only galaxy, aside from our own, that can be seen with the naked eye (at times). Galaxies appear in clusters, and Andromeda is part of a group of galaxies, including the Milky Way, that is considered the “local group.” Galaxies were not clearly identified as being separate and far beyond the stars in the Milky Way until Edwin Hubble and others made discoveries in the 1920’s. The Milky Way and Andromeda are moving toward each other at breakneck speed and might well collide in the future, perhaps around five to six billion years from now. The age of the universe is estimated at 14 billion light years and the size of the universe to be 93 billion light years.
We have a sense that the distances and times in outer space are so extensive that time is irrelevant to our consideration of the universe’s cosmogony. Part of our problem, of course, is that, regarding time, what we experience is “human time,” which is extraordinarily puny when it comes to the time and distance dimensions of outer space. The sign, Mary Queen of the Universe, started me musing on this topic. The sign seems rather grandiose and completely unrelated to the human aspects of the mother of Jesus. I would rather see the humble peasant girl, who was likely illiterate and less than 50 years old when her son was disgracefully martyred, to be honored just for who she was, without bringing queenship or the universe into it.
We are just an advanced breed of monkeys on a minor planet of a very average star. But we can understand the universe. That makes us something very special. – Stephen Hawking
I’m astounded by people who want to “know” the universe, when it’s hard enough to find your way around Chinatown. – Woody Allen