Friday, December 17, 2004

Our Place

Despite the humanocentric view of the Universe that most of humanities religions espouse, the Universe does not care about the existence of Humanity.

That humans exist at all is only the result of a long string of events. Changing nearly any of them would result in our not being here. The Universe is a very dangerous place. Earth could be devistated by an asteroid impact that would affect all life on the planet. A supernova could explode a little too close to Earth. Looking into the history of the Solar System, the passage of a star too close to the sun could have disrupted the orbits of the planets. Imagine if the asteroid or comet that impacted 65 million years ago and ended the reign of the dinosaurs had been perturbed by another asteroid 4 billion years earlier and instead of hitting Earth, passed harmlessly past Earth just outside of the atmosphere? What if a dinosaur species developed the intelligence and ability to build telescopes and spacecraft and had been able to deflect that asteroid or comet before it hit? In either case, the dinosaurs would likely still be walking the planet and the line of creatures that led to you and I might not have been able to thrive in the post-Cretaceous to result in the hominid line that includes us.

Imagine if Jupiter had not formed in the early Solar System. The amount of debris in the inner solar system would have remained significantly higher than it did - Jupiter literally cleared the planet crossing debris out of the early solar system and if it had not, the impact rate of asteroids and comets could be 10 or 100 times or more higher than it is today so instead of civilization threatening impacts happening a few times per million years and extinction level events happening every 100 million years or so, they might happen at rates that might prevent higher life forms from being able to easily develope and certainly too frequently for civilizations like ours to thrive for very long.

Well, we're here now. And provided we don't do something foolish to destroy our civilization, I am optimistic that humans will be able to overcome most threats, particularly the threat of civilization or extinction level impact events. Our present asteroid surveys are quickly finding those asteroids that are dangerous to life and civilization and if we should find an asteroid that will hit us at least a few decades from now or longer, I am convinced that we can devise a scheme to deflect that asteroid. While Earth has provided the birthplace of humanity, if we and our descendent species are to survive, we will have to become a spacefaring species, not only to protect ourselves from asteroids and comets, but also to provide insurance against the accidental destruction of ourselves or even by any of a billion potentially deadly events that can happen to Earth or in the vicinity of our solar system that could make Earth uninhabitable and end everything that humanity has become or might be.