20 Apr 2009
The hills are alive with the sound of... plate tectonics. OK, that was a little cheesy, but it's true! We here in Southern California are surrounded by hills and mountains and valleys, and the active crust of our state is to blame.
Most of us recall from school that our planet is not just a solid ball of rock. It has layers. Way down deep we have a solid - and very hot - inner core of nickel and iron. Surrounding that is a hot liquid layer of the same stuff. That swirling molten rock gives us our life-preserving magnetic field.
Above those two layers is our thick semi-solid layer called the mantle. But the thinnest layer of all, the lightweight "floater" layer, the scum of the earth, is the crust. It is that delicate, tenuous layer - just tens of miles at its thickest - that slides about on top of the mantle, making Earth a pretty amazing place to live.
The crust consists of about a dozen giant plates and a litter of smaller ones. When these plates crash into each other we get mountain ranges and island chains, like the Himalayas and the Andes, the Philippines and Japan. Where they separate we get oceans like the Atlantic.
Here in Southern California we live at a plate boundary, too, one between the North American Plate and the Pacific Plate. But this plate boundary is one in which the plates move by each other. Surely this "sliding by" rather than colliding or diverging should result in a smooth, featureless surface. Not really.
The plates that split California are kind of jagged on the edges. They would probably like to travel by each other gently but their friction makes that a tall order.
But that's OK! These giant plates and smaller slabs of rock trying to move by each other gradually force large amounts of rock up into the air. For example, the terrestrial fender bender taking place up near LA gives us the San Gabriel mountains on the Pacific Plate side of things and the San Bernardino mountains on the North American plate. The infamous San Andreas fault separates the two.
Add to that the millions of years of all the other earthy movements going on around here that have lifted the vast array of hills around us and we have one seemingly continuous rolling hill of a southland. People move here for scenery like that. But they hate the earthquakes.
Well, sorry. No earthquakes means no plate tectonics. No plate tectonics means no hills and mountains. That's something all us Californians have to accept - and prepare for.
The hills may not be alive with the sound of music, but they are a part of the active, ever-changing face of this amazing planet.
06 Apr 2009
Last time here we discussed the new Kepler satellite and what exactly it was looking for in the heavens above us. Now we look at little deeper into it all, and even wax philosophical.
You may recall that the Kepler satellite is on a very specialized mission - to look for earthlike planets. Only the definition of earthlike isn't too clear. When Kepler makes a find, as it is almost certain to do, will the planet be "earthlike" merely because it was a big rock found at a certain distance around its star? Will many automatically assume that the discovery must be an earth clone, with continents and oceans, mountains and valleys?
The latter, but popular, idea is ridiculously improbable - astronomically so. But what if, just for the sake of argument, it were so? What if an earth twin were found? Does it follow life must be there?
Many in the scientific community assume that since life appeared so quickly and so early here, that it must be rife in the universe. Well allow me, if you would, to play the grumpy old skeptic here and ask a few uncomfortable questions.
If one indeed thinks that life is ubiquitous throughout the universe, then it is probably relatively easy to make in the laboratory. But is it? For more than a century, the best labs all over the world run by some of the smartest people on the planet, under the most controlled, pristine conditions, cannot even build a "simple" one-celled organism. Why not? Is life maybe too complex to "just happen"?
We skeptics need evidence that life is all over the place. We have none and mere wishful thinking doesn't count. We need mechanisms that show how it might have happened. We have seen none. The origin of life is one of the Great Mysteries even in today's ultra-hightech milieu.
Let me now take off my science hat and put on my philosopher's cap. Perhaps the reasoning is flawed, the reasoning that says, "Nature is all there is. Therefore life sprang spontaneously here, naturally, all by itself. If it did here, it must have sprung up countless other places."
A fatal flaw might be in the premise that says nature is all there is. There might be more than nature. People for tens of thousands of years have believed that there is a Being beyond nature who created life. Who knows? Maybe they have been right the whole time.
When my fellow scientists carelessly toss out Life-Is-Everywhere statements, feel free to throw back the hard questions. Science will benefit by your skepticism and we can all benefit by asking the Great Questions.