In her postcard, my friend Judy Harris asks why there isn't a Grand Canyon in Middletown, New Jersey, or any other place that a river runs through.
One reason is that the Rocky Mountains create a catchment area for a lot of water that eventually has to find its way to the Pacific Ocean. The other is that much of Arizona consists of an enormous intact plateaua huge slab of land that had been uplifted gradually for millions of years, and then miraculously was not broken up by earthquakes or other tectonic activity. When the predecessor to the Colorado River materialized, it had a vast blank slate to pass over, rather than a landscape already made craggy by earlier geological processes. Grand canyons, by the way, are not formed by water gouging a deep furrow as it passes over a flat surface (that image never made sense to me). They work their way backwards from where a plateau ends in a huge cliff. Imagine the Colorado river reaching the end of its plateau and forming a Niagara Falls. Just as Niagara Falls could eat away its bed and migrate backwards, leaving behind a canyon, the Colorado River ate its way through the plateau backwards in a mouth-to-source direction.
learned all this from Canyon Dave, a geologist at a small state college
in Arizona. Canyon Dave served as our guide to the Grand Canyon one
afternoon last month during an old-fashioned family driving vacation
out west with my wife Ilavenil and her mother and stepfather. (Having
in-laws from New Zealand means that you get to see a lot of spectacular
scenerynot just because New Zealand has a lot of it, but because
they force you to see the spectacular parts of your own country when
they visit.) We began at Stanford, where Ilavenil gave a presentation
on her art to the Art, Brain, and Cognition study group at the Center
for Advanced Study. Then we drove to the Mojave National Reserve,
London Bridge (in Lake Havasu City, Arizona), the remains of Route
66, the Grand Canyon, the Painted Desert, the Glen Canyon Dam, Zion
Canyon, Mono Lake, and Yosemite, all in 8 days and 2200 miles. As
the old ad slogan said, See America First.
rest of the summer, I hope, will provide some calm before the stormbeginning
in mid-September, six weeks of touring to talk about the book, and,
given its subject matter, probably some controversy. In July and August
I'll be alternating time at MIT with time in Cape Cod, where I'll
distract myself with photography, kayaking, and tandem bicycling.
Ilavenil and I are planning to repeat our feat of last summer, when
we rode a century (a hundred miles in a day, a test of endurance much
like writing a book, but with a much sorer butt. And no, I won't take
the wireless email gadget.