25 Jun 2006
Where we have been, where we are, where we are going. These are three of the big mysteries that nearly everyone who calls himself a human being wants to know. There is nary another species out there beside our own which tries to uncover meaning to life by investigating its past, present, and future, trying to make sense of it all.
And there are few disciplines in the sciences that can reveal to us as much as astronomy can - not that I'm biased at all. But a meaningful science should tell us more than just facts, more than just pure trivia; it should help us fill in a gap or two in that trillion piece jigsaw puzzle we call The Big Picture. And astronomy helps enormously.
This week we will look at where we have been. In my next two columns we will take a look at where we are and then where all this is headed. And, hopefully, along the way, we can discover something about ourselves, and our place in The Whole Shebang.
A century ago the scientific community was convinced that the universe was infinitely big and ageless. There was no beginning; it just always was. And the three dimensions of space and the one of time was it, the entire package.
Now, after a lot of hard work by a lot of clever men and women, we are firmly convinced that the universe - all matter and energy and space and even time - came into existence from nothing about 13.74 billion years ago in a burst of creation called the big bang.
To be sure things have changed over time - much energy became matter, matter formed stars, stars gave shape to galaxies, star remnants became planets, and space has stretched to unimaginable lengths - but the fact remains: there was a beginning.
Not everyone was all too excited at this conclusion. For many - including the renowned astronomer Fred Hoyle who derisively coined the phrase "big bang" - a beginning to everything, an actual event originating from beyond, was thoroughly repulsive.
But it gets more complex than that.
That our universe is expanding into unseen dimensions implies heavily that there is more to existence than the three dimensions of space we enjoy. There is something that transcends our life.
Let me illustrate by using the standard example we use in astronomy classes today, the blowing up of a balloon. Unimaginably tiny beings living on the surface of a balloon are only aware of that stretching two-dimensional surface. But they are unaware of what is outside and above the expanding balloon, or what's inside of it. It is not part of their "space." They can point neither to where it's all headed, nor to where it all started.
It's similar with us. We are on a stretching fabric of space, only ours is three-dimensional. But we cannot see any "place" we are headed for, not can we point to where we have been. Those are, in the fullest sense of the term, beyond us.
To take this even more "out there," string theory - the theory which tries to explain essentially everything - postulates that there are nearly a dozen dimensions of space, many more beyond the three we know and love.
Stephen Hawking made it still more nerve-racking for some when he told us that even time itself had its beginning at the beginning. Some transcendent cause and effect system got us here.
That we had a beginning, that all was created at the beginning, that there is more beyond space and time than we can possibly imagine has profound philosophical and theological implications. Who and/or what is beyond? What caused this universe to be? Was it an inexplicable accident or was it purposed?
Get together this week with some friends, open up your mind, don your philosopher's hat, and have at it.
Next time we'll look at some things astronomy has to offer concerning our present, and what that may say about our existence.
10 Jun 2006
Seeing how it's the end of the school year again, it's seems the right time for another astro quiz, one with maybe just a bit if chemistry and geology thrown in for good measure. Don't worry, I know summer is on your mind, so this quiz will be just two true-or-false statements. Ready?
1. Uranus and Neptune have atmospheres rich in methane. One well-placed match would set them on fire!!!
Methane is a tiny molecule, the simplest of the hydrocarbons, CH4. Just one carbon surrounded nicely by four well-placed hydrogens, it is a powerful little energy storage unit.
Methane is in our atmosphere in very small amounts, measured in just parts per billion. Its sources are not exactly something to talk about over dinner. Rotting vegetation gives it off. Termites do. The world's millions of cattle and sheepâ€¦ ahemâ€¦ release tons and tons of the gas into the atmosphere every year. And - cover the children's ears - you and I donate our fair share, as well.
Methane is one of our planet's greenhouse gases, helping to keep our atmosphere nice and comfy. But it can burn, too. It is the gas that heats our ovens and stoves. One little match fires up that gas and *poof* we have ourselves a flame.
Uranus and Neptune both have a load of methane in their atmosphere. It is the reason both planets are bluish-green, believe it or not. Methane absorbs the red end of the sun's spectrum of light and reflects away the blue.
So why haven't both planets just lit up like fireballs? Because there is one ingredient missing: oxygen. Fuel needs oxygen to burn. The fuel alone, even with an available spark, would just sit there.
Thankfully for those Uranians and Neptunians there is no oxygen up there to fire up their giant planets.
2. The biggest known volcano in the solar system is on a little planet we call Mars.
How can that possibly be true? We have gigantic, nasty mountains of exploding rock right here: Etna, Vesuvius, Pinatubo. Our largest is the Big Island of Hawaii, over 30,000 feet high from head to toe. Mars? Mars is just a puny little rock half our size.
Well... Earth's inner make-up and its overall size don't really allow us to have supergigantic mountains and volcanoes. Our bigger size means a greater gravity, which keeps our mountains from poking too high into the sky. They just get pulled back down and spread out like cold Silly Putty.
And potential contenders for Solar System's Biggest Mountain, like the Big Island, don't have enough time to build up much higher. The plate the islands are riding on is moving over a hot spot in the middle of the Pacific Ocean.
A hot spot below a plate can cause a leak in that plate. By the time an island builds up substantially from magma oozing up through the leak, the plate it's riding on has already passed beyond the hot spot and a new island down the line is forming from a new leak.
Moreover, the island gets weathered eventually all the way down to the sea, which is why island chains like Hawaii can only stretch out so far before their islands go submarine. Mars, in comparison, has no oceans and essentially no atmosphere to tear down any great mountains.
Olympus Mons on Mars was a big leaky hole in the crust that just kept spewing magma from one stationary place. No plate tectonics moved it away from its hot spot.
And Mars' gravity is weak enough that the volcano could build higher and higher and higher. It stands now at about 89,000 feet and covers an area the size of our neighbor, Arizona.
That is one colossal mountain and winner of Biggest in the Solar system.
How did you do? Did you at least learn something new? Good, because that is what's really important here.
Until next time, clear skies!