by John Burgeson, www.burgy.50megs.com, to the Rico Bugle
Just how large is our universe? It is hard to appreciate. Let's try.
Some numbers first. These may make your eyes glaze over. It is 80,000,000,000,000,000,000,000,000,000 (80 octillion) miles to the furthermost galaxy. Twice this is the diameter of the known universe. Light from the furthermost galaxy takes 13.5 billion years to arrive on earth. There are billions of galaxies, each with billions of stars. Look at the second star down in the sword in the Orion constellation. When you look at it, you are seeing as it looked about a million years ago. You are actually seeing something that is about 6,000,000,000,000,000 (six sextillion) miles away! Didn't know you could see so far, did you?
It is 600,000,000,000,000,000 (600 quadrillion) miles to the edge of our galaxy. There are 100,000,000,000 (100 billion) stars in our galaxy, of which our sun is one (medium size, somewhere on the outskirts).
It is only (!) 25,000,000,000 (25 billion) miles to the nearest star (Alpha Centuri). When you look at it, you are seeing it as it existed about 4 years ago. Maybe it's no longer there! Four years from now you can tell for sure.
It is 4,000,000,000 (4 billion) miles to Pluto, whether or not you call it a planet. It is 93,000,000 miles to the sun (The light you see left the sun 8 minutes ago). It is "only" 250,000 miles to the moon. (The light you see left the moon 1.2 seconds ago).
the following models may help in understanding these sizes:
Picture the Earth as a softball in the middle of Glasgow just outside the Rico schoolhouse.
The moon is a ping pong ball at the side of the road.
The sun is a 36 foot balloon at the cemetery, about a mile away
Pluto is a ping pong ball in the center of Cortez
The nearest star (Alpha Centuri) is 200,000 miles away, a dirigible on the the moon.
The edge of our Milky Way galaxy is at the orbit of Jupiter.
The furthermost galaxy is still 625 trillion miles away.
Try again. Here is another model:
Think of the earth as a grain of sugar in the middle of Glasgow just outside the Rico schoolhouse.
The moon is a speck of dust a quarter inch away.
The sun is a ping pong ball, at the side of the road.
Pluto is a dust speck at the Conoco station.
The nearest star (Alpha Centauri) is an orange in El Paso, Texas, 500 miles from Rico.
The edge of our Milky Way galaxy is 2,500,000 miles away.
The furthermost galaxy is still 1,500,000,000,000 (1.5 trillion) miles away.
Now make up your own model!