Hot spots, impacts, magnetic-field reversals, and sudden isolated events have troubled what was becoming the placid surface of geodynamics. So many unstable, intermittent phenomena come together in this new way of looking at things, which elsewhere bears the name “deterministic chaos.” “System Earth” is revealing itself to us in its profound unity. The Earth’s rotation, the turbulence in its liquid core, disruptions in its mantle, volcanism and the climate, and finally the life of species, all these dynamic manifestations may be subtly linked. Over what time scale do these links have the most decisive effects? To what variations is the climate most sensitive? The tens to hundreds of millennia of the orbital Milankovic cycles? The centuries or decades of volcanic eruptions and human activity? The seconds of an impact? In the long history of evolution that has led to the world as we know it, the role of chance seems just as definitive as that of necessity. No doubt the party will go on. And many secrets remain to be brought to light.
“What the hell’s a Milankovic cycle?” Rhonda asked.
“In general,” I explained, “it’s the long-term changes
of the Earth’s orbit and axis, the astrophysics.
In particular, it’s how Jupiter and Saturn
cause a subtle change to the ellipse of Earth’s orbit
on a scale of something like four hundred thousand years.
So, you know, a pop song only lasts three minutes but
a jazz arrangement lasts a Milankovic cycle.”
Then we talked about Hamlet’s Mill the whole afternoon.
“Do you really believe,” Rhonda asked, “that humans knew
about changes to the stars that happened at that scale?
I mean, in the past? Before telescopes, computers?”
“Metronomes are in our genes,” I said. “Sometimes the click
is allegro. Sometimes the click is adagio.
Sometimes, you know, it’s very, very adagio.”
This new way of looking at things. I like slow music.
Even before turbulence from the Earth’s core began
pushing up though fractures in the Gulf of Mexico
I enjoyed playing guitar slowly to a click-track
more in time with, well, folklore than a comet crashing.
“I think,” Rhonda said, “that kind of music is extinct.”
“I am still here,” I said. Then I played Molly Malone
on an electronic keyboard that generated
real-time accompaniment at whatever tempo
the fingers of my left hand shifted from chord to chord.
The digital signal processors kept time with me.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Milankovic cycle at Wikipedia
Hamlet’s Mill at Wikipedia
Endings And Beginnings
Cookies And High Heels In A Clean Kitchen
Sheldrake: Orchestras To Planetary Systems
All The Sunlight Is For Laughing