Black Bull Friday, Deep Time

How do we understand Deep Time? The numbers are so big: Earth was formed 4.5 billion years ago, life began a billion years later, life colonized land 450 million years ago… but how big is a billion, or a million? To get a feel for these questions, I planned a Walk Through Time on Black Friday, the day after Thanksgiving in the US.

I prepared for the event months in advance. Translating distance to time at a scale of one foot per million years, I walked up and down my road with a clipboard to write down the landmarks: Life begins at Woody Hills Lane. Photosynthesis begins just past the tobacco barn. The Great Dying of the Permian is at this cluster of mailboxes. I researched multiple resources to get my dates right, checked and rechecked the math. I tried it out with a few friends. Finally, I promoted the event and got enough RSVPs for a lively time.

On the day of the event, things were looking good. The weather forecast still held up. I cleared off the studio table to serve tea after the walk and started tidying up. I looked at my list one more time. “When does the Cambrian start again? Oh yeah, second path in the meadow. Right.” I was feeling pretty good about the whole thing until I had to go run a last-minute errand down the road. Until I saw Clyde.

Black Angus bull just like Clyde. Thanks Bernd.K for photo.

There he was, standing territorially, beefily, on the OUTSIDE of the fence. Munching grass at the edge of the road where we’d be walking. In fact, right at the point where we’d be pausing to talk about the emergence of Eukaryotes. I often have hostess panic in the last hour before an event but it’s usually because I can’t find enough cloth napkins, not because people might DIE.

I tried to cheer myself up with the idea that maybe bulls aren’t that dangerous, really. (I’m still a city girl at heart.) So I Googled “are bulls dangerous” and found articles like “Never Never Trust a Bull,” multiple references to “the most dangerous of domestic animals” and gory descriptions of people being trampled to death. The scene played out in my mind: AS IF Center visitors getting chased down the road, injuries, lawsuits, et cetera. It was now less than an hour before my event. I hastily blasted out emails and texts to anyone who could get in touch with the farmer. I started composing my embarrassing regrets announcement to participants: “Heh, heh, sometimes science gets thwarted by a lot of bull…” But the farmer showed up, got Clyde back in, and repaired the fence, just as the first Time Walkers started to arrive.

We walked eight-tenths of a mile down the road to the formation of the Earth, and paused about 20 times along the way to talk about the Great Oxygenation, the Great Dying, and other key events. It gave us a great perspective. After walking nearly a mile, we passed through long stretches of nothing but bacterial life, didn’t reach the dinosaurs until toward the end, and all of human history was about the size of a flea. Want to go on a Deep Time Walk? Contact me if you’d like me to set up one for your group. No bull.

Why are these people smiling? Because sex! We just passed through the marker for 1.2 billion years ago, in the Proterozoic era, at the beginning of sexual reproduction.