Astronomical figures (with two irresistible political asides)

From Richard Panek, The 4 Percent Universe: Dark Matter, Dark Energy, and the Race to Discover the Rest of Reality, 28:

“Saying that all the billions of stars we see are part of our galaxy and that billions of galaxies lie beyond our own doesn’t do justice to the scale of the universe.  Just as our eyes didn’t need to evolve to see radio waves in order for us to survive, maybe our minds didn’t need to evolve to understand the numbers that astronomers were now trying to incorporate into their thinking.  Like cultures that count ‘One, two, three, more,’ we tend to regard the scale of the universe — to the extent that we regard it at all — as ‘Earth, planets, Sun, far.'”

To help us picture the magnitudes, Panek uses the “one Mississippi” method of counting.  (If you say “one Mississippi,” “two Mississippi,” and so forth, you’re giving each number approximately a second.)

At the “one Mississippi” rate, it would take you 11 days, 13 hours, 46 minutes, and 40 seconds to count to a million.

To count to one billion — that’s a thousand millions — it would, obviously, take you a thousand times as long as counting to a million.  That is, it would require 31 years and 8.5 months.

To reach a trillion, you would be obliged to count one thousand times to a billion — which would occupy about 32,000 years of your life.

(Try not to think, in this context, of the federal government deficit in Gree . . . er, in the United States, which, at the end of 2012, stood at roughly $16.5 trillion.  If you simply counted those dollars individually, taking a second for each, doing so would require approximately 528,000 years.  No, let’s stick with Richard Panek and astronomy.  Much less depressing.)

A light-year — the distance that light travels in twelve earthly months — comes to about six trillion miles.  To count that high would take you 6 x 31,000 or 186,000 years.

(Sorry.  I can’t resist pointing out that it would take you far less time to count the miles in a light-year than to count the number of dollars in the federal debt.  But back to the much more humble figures involved in astronomy.)

The Sun is 93 million miles from Earth.  Otherwise, the nearest star is 4.3 light-years, or 25 trillion miles.  (If you would like to count those miles, block out 800,000 years in your calendar.  Maybe you can get to it this weekend.)

Our galaxy, the Milky Way, from the edge of one of its spirals over to the edge of the one opposite, is about 100,000 light-years in diameter.  That would take you eighteen billion years of counting.  You’ll probably need to wait until retirement before tackling that number, of course, and then you face the fact that there are estimated to be at least 100,000,000,000 — one hundred billion — galaxies in the observable universe.

In other words, the thing is pretty big.

Posted from Victoria, British Columbia