So I'm standing on the top of this hill near my house wondering about thankfulness. I needed to take a walk after getting double-teamed by news about the aftermath of Typhoon Haiyan and a NY Times article about the coming crisis in food production due to climate change. Thanksgiving was just a week away and it was hard to square my own manifold blessings with a world full of difficulty and suffering.
And then I remembered time.
One of the strangest aspects of being an astronomer is your vision of time. Everyday it's more a billion years of this and million years of that. Vast, mind-numbing stretches of pseudo-eternity are pretty much par for the course. If you are not careful you can lose sight of what those numbers really mean.
Every now and then the reality of those 0's piling up behind a 1 step forward and force you to pay attention. The day before I found myself on that hilltop I was running through a calculation for the collapse of light-years wide cloud of gas under its own weight. A little algebra, a little multiplication and — boom — there was the answer: 1.73 million years.
It would have been easy to move on to the next step in the calculation I was working on. But something stopped me in my tracks.
Just think about 1.73 million years. That's 17,300 centuries. Since I can kind of wrap my mind around a century I began to roll them out, moving backwards. Ten centuries takes us back to 1,000 A.D. and the Middle Ages. One hundred centuries takes us back to the dawn of human civilization via agriculture 10,000 years ago.
The more I pushed backwards the more I could feel myself getting lost in the endless changes: glaciers coming and going, forests turning to desert turning back to forests. It was staggering, a kind of temporal vertigo, and it was all contained in that one number from that one calculation. At the moment it seemed like too much and I had take a break.
But standing on that hill with a late-fall chill in the air, weighing all the worlds' suffering, I had that vision of time return to me.
This time it was a comfort.
From my hill I could see what those glaciers had wrought in a crumpled landscape of rolling hills stretching out to the horizon. What had been abstract in my office a few days before was made real in geology and topology. This land before me had been reshaped across millions of centuries in ways I could see and in ways that were hidden beneath the ground.
Our suffering and our joy is not just our own. The planet has been rolling around the sun for so very long. Through out much of that history there has been life here, be they fishes of the Silurian, dinosaurs of the Cretaceous or mammals of the Miocene. That life has known good days and bad, times of peace and times of upheaval. Standing there on that hill, for a moment, I could feel my place in that long line of creation and destruction.
"It just this moment," I thought. "Like so many moments before and yet completely different from all that has come before."
To be present for that moment, on that hill as the planet turned towards yet another night: what else could I feel but gratitude?