Tuesday, December 2, 2008

Cool (or at least cooler than we thought)

We are stardust
We are golden
And we've got to get ourselves
Back to the garden

Joni Mitchell

And yet, except for us,
The total past felt nothing when destroyed.

Wallace Stevens, from "Esthetique du Mal"

The New York Times has a mind-bending article today about new theories of the early Earth. Some geologists are thinking that our planet cooled down rather faster than was previously thought, meaning that life may have gotten started, not as soon as conditions allowed, but perhaps only after a few hundred million years beyond that point.

Based on apparently abstruse calculations, it is also thought that soon after the Earth coalesced 4.5 billions years ago it was struck by a Mars-sized object (not Mars, but something roughly the size of Mars)--much of the extruded vaporized material came together as...the moon. In the several hundred million years after that cataclysm, the Earth is thought to have been struck, perhaps on four different occasions, by objects more than 200 miles in diameter; the energy released by each collision would have evaporated the oceans. How cool is that? What a show that would have been. It's probably a guy thing.

This morning I came upon a line in the book I'm reading (2666): "The scarred moon still shone in the sky." It is easy to forget that the Earth's surface has been ravaged even more than the moon's, but we have had the benefit of the extreme makeovers of plate tectonics. Planetary plastic surgery; the moon is a crone, the Earth remains a debutante.

Oh, there was also an article about doctors behaving badly (mostly surgeons of course). It took 4.5 billion years to produce...what?

1 comment:

xlbrl said...

The Goldilocks rules for intelligent life support--

Planet not to close, not to far from star

Gravity not to small too hold atmosphere, not too great for golf

Must have satellite for axis stability

Must have water, but also land.

If covered by water and without a satelitte, must be struck by Mars-sized object to blow off water and create a moon.

Must wait for satellite to recede from daily earthquake-tidal wave distance of 16,000 miles at rate of 31mm a year.

Final touch after five billion years: close the isthmus at Panama, changing the underwater currents and creating the Ice-Ages 2.5 million years ago. Change we can believe in--selection through adaptability.