Update: December 13, 2006

AS DEEP AS IT GETS

By Pam Eastlick for THE DEEP on line

Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.

Today, we’re going to do a little math and learn some interesting facts along the way.  But don’t put this paper down because you hate math and never learned your multiplication tables, because we’re going to do the best kind of math.  The kind that’s so big and so complex that you don’t actually have to DO it.  You just have to stare at it in awe and wonder. To start our little trip, the first thing you need to do is take a nickel out of your pocket or purse.

If you don’t happen to have one and there’s a drop ceiling over your head with little tiny holes punched in it; that will do too.  If you’ve got your nickel, hold it out at arm’s length and have a look at it.  Now, look at Thomas Jefferson’s face.  You may discover that it doesn’t look like you remembered it because they changed the portrait while you weren’t paying attention.

But that’s OK; either style will work.  Hold it out at arm’s length, look at Jefferson’s eye and fix its size in your mind.  If you’re nickelless, just have a look at one of those spots in your ceiling.  Fix its size in your mind.

OK, here comes the impossible math problem.  I want you to figure out how many holes that size it would take to cover the entire sky.  We’ve certainly progressed past the “1-2-3-many” counting system of most primitive people, but figuring out how many Jefferson’s eye-sized holes it takes to cover the whole sky enters the “1,000-2,000-3,000-many” realm for me!  Oh, and by the way, after you get your “holes to cover the entire sky” number firmly planted in your mind, multiply it by 2 to get the “holes to cover the whole sky” number since the sky is not just above you, it’s below you as well.  Are you with me so far?  Don’t forget that number, you’ll need it later.

Now a little background.  Stars like our Sun live in gigantic star cities called galaxies.  The name of our galaxy is the Milky Way (the Romans called it that because it looks like spilled milk in the sky.  It was NOT named after the candy bar!) and astronomers estimate that there are roughly 200 BILLION stars in the Milky Way.  Now the Milky Way is a chunky galaxy as star cities go and we are going to assume for the purposes of our impossible math problem that an ‘average galaxy’ contains only 100 BILLION stars.
(For a little ‘impossible math’ background, if you want to count to ONE billion, starting with one, two, three and so on; it will take you 31 YEARS and that’s only if you count non-stop and give up eating and sleeping.)

Between September 2003 and January 2004 the Hubble Space Telescope took over 800 pictures of an area of sky in the constellation Fornax the Furnace.  To find its location in the sky, go out at 7:30 p.m. tonight, face where the Sun disappeared (that’s west) and turn 90 degrees to your left.  You’ll be facing south and you’ll see a bright star.  That’s Achernar, the ninth brightest star.  Hold your arms out full length, make two fists and put one on top of the other with the thumbs pointing up.  Put the bottom of the lower fist on top of Achernar.  Fix the area of sky at the top of your fists in your eye and use your fists to measure three fist-widths to the left.  The area to the left of your fist is where the Hubble Space Telescope took the most important picture ever taken.

The 800 exposures taken by the Hubble Space Telescope amounted to about 1 million seconds or 11.3 days of viewing time.  The average exposure time was 21 minutes.  All 800 pictures were digitally combined to produce this picture.  It’s called the Hubble Ultra Deep Field.

So, you say, what’s so important about this picture?  It’s just a picture of a bunch of stars.  Well, if you look a little closer (and I admit that the resolution in the newspaper may not be the world’s best) you’ll begin to realize that most of the ‘stars’ don’t look like points of light; they’re round or elongated discs.
In this kind of ultra-long exposure, stars in our own Milky Way typically have ‘crosshair’ bars from overexposure and I count four stars in this picture.  Everything else is a galaxy, and there are (wait for it!) over TEN THOUSAND galaxies in this picture.  Well, hey, we know there are a lot of galaxies out there, probably at least 10,000, right?  So that’s not so surprising.

But now we return to our impossible math problem because the Hubble Ultra Deep Field isn’t a picture of the entire night sky, or a picture of half the night sky.  The Hubble Ultra Deep Field is a picture of an area of sky the size of Thomas Jefferson’s eye. 

Remember you figured out how many ‘Thomas Jefferson eyes’ it would take to cover the entire night sky and multiplied that number by 2?  Now, take that number and multiply it by 10,000, the number of galaxies in the HUDF.  And then take that number and multiply it by 100 BILLION, the number of stars in the ‘average galaxy’ and you begin to realize two things.  The first is why the Hubble Ultra Deep Field is the most important picture ever taken and the second is just how many stars there are.

There are so many stars out there that have so many planets that circle them that no matter what YOU personally think the aliens might be like, there have probably been aliens like that in the past, will be aliens like that in the future or are aliens like that right now.  There are that many stars!  The aliens aren’t here and have never been here for a very simple reason that will be the subject of a future column.
The universe is enormous, mind-boggling, incomprehensibly enormous.  So go outside tonight, find Fornax the Furnace and join the Hubble Space Telescope in contemplating infinity.

Cruise on over to the Deep Website at www.thedeepradioshow.com to learn more about The Hubble Ultra Deep Field and many other topics.  Peter Melyan has returned to Guam.  Welcome back Peter!  It’s good to see you looking so great!