Saturday, April 09, 2011

After the Great Quake, Living with Earth's Uncertainty

The Japanese earthquake and tsunami remind us that we exist in geologic time and in a world where catastrophic events beyond our predicting may occur. These events — and the growing specter of climate change — show how precariously we exist on the surface of a volatile planet.

by Verlyn Klinkenborg

In my layman’s cosmology, the anthropic principle says this: our existence implies that the universe must take the shape it does or we wouldn’t be here to perceive it. A universe with even minutely different physical laws wouldn’t include us (which isn’t to say that such universes don’t exist).

An anthropic principle of sorts is also at work in geologic time — the 4.5 billion or so years this planet has existed. For the vast majority of Earth’s history, conditions were unsuitable for the evolution of mammals. (Nor were humans even remotely certain to evolve from those earliest mammals.) We’ve come to exist in the window of time in which we could have come to exist. Or rather, we’ve survived in the window of time in which we can survive. We call a portion of that window “historic time” — not the entire history of our species, but the history that’s part of our cultural record in one form or another, reaching back only several thousand years.
Historic time overlaps with geologic time the way a whale louse overlaps with the blue whale it infests, though the scale of that comparison is too small by several orders of magnitude. And yet it’s all too easy to believe, with the self-importance of a whale louse, that we exist apart from or outside of geologic time. That’s what our experience tells us. The last 10,000 years or so have been relatively uneventful, geologically speaking. Given the overall length of geologic time, it’s likely that any span of 10,000 years or so would be relatively uneventful.

But the Tohoku earthquake and tsunami remind us there’s no guarantee that historic time must be geologically uneventful. They remind us — forcibly, tragically — that, despite vast differences in extent, historic time and geologic time always converge in the present. Read More

Radioactivity in the Ocean: Diluted, But Far from Harmless With contaminated water from Japan’s crippled Fukushima nuclear complex continuing to pour into the Pacific, scientists are concerned about how that radioactivity might affect marine life. Although the ocean’s capacity to dilute radiation is huge, signs are that nuclear isotopes are already moving up the local food chain...