The Universe is a BIG place.

Hey folks,

If you ever follow my twitter or facebook, you know that I'm VERY excited for the new season of "How the Universe Works" on the Science channel. It's one of my favorite shows ever, and has always given me a lot of ideas for Braderwood books...it also gives me a starting place to check some of my facts.

The new season starts today, July 11th. Here's a nice little clip from last season:

http://www.youtube.com/watch?v=GmWNs4QrshY

That clip, on youtube, is about star and galaxy size. Some of the numbers are incredible. Betelgeuse, one of the stars they talk about, is so big that it's diameter would stretch all the way out to Jupiter if it was in our own solar system! That's 1,500,000,000 times bigger than our own sun!

Galaxies are even crazier. Our galaxy is believed to have 100-200 BILLION stars. That's a lot...but then, consider the other ones that are two, three...ten...fifty times the size of our own. And astronomers believe there are 200 billion galaxies out there...and that's all we know of! That number is probably changing every day as we can see further and further into the Universe. In fact, just ten years ago, astronomers only thought there were 4 billion stars in our galaxy.

Recap...100-200 billion stars in our 100,000 light-year-across galaxy.

Oh, right. That brings me to light years. Light travels at approximately 186,000 miles a second. A SECOND! That comes out to about 671 million miles an hour...or about 6 TRILLION MILES A YEAR!

Finally, let's talk a little bit about numbers. People hear numbers like million and billion all the time...but often don't appreciate just how astronomically large those numbers are. Let's do a little experiment, shall we?

Take a pen and tap it on the desk as fast as you can for ten seconds. (As the example, I did it 70 times in ten seconds. You may be a little faster, but I had to pay attention to my watch.)

You've inherited some super-powers that allow you to tap the pen at that same exact rate without experiencing fatigue, the need to sleep...to ever stop.

Here's how the numbers would crunch:
70 times in ten seconds
x6 is 420 times a minute
x60 is 25,200 times in an hour...wow! great job. You'll be there in no time.
x24 is 604,800 in a full day
x365.25 is 220,903,200 in a full year
at that rate, it would take you approximately 4.5 straight years of your life to tap it a billion times!
and a trillion? Well, a trillion is 1,000 TIMES a billion...so it would take you 4,500 years to reach a trillion!

Looking back at our numbers, if each time you tapped your pen, you were counting a star in our galaxy, it would take you about 450 - 900 years to count each one. And that's just one galaxy out of the 200 billion we know of.

And finally, light travels 6 trillion miles a year...remember, trillion is that number that would take you 4,500 years to tap out...and our galaxy is 100,000 LIGHT YEARS across...600,000 trillion miles!

So, anyway...I hope you enjoyed the lesson. The Universe is BIG. REALLY BIG. In fact, most of it is empty space between all of those huge galaxies, accumulating in what is estimated to be 3x10^23 (that's a 3 with 23 zeros after it) stars in our 92 billion light year wide OBSERVABLE universe.