This year at Thanksgiving tables across America, folks will sit down with family and ask themselves the time-honored question: "What am I thankful for this year?"
It's a moment that makes Thanksgiving one of the best ideas we ever came up with. But this year, I thinking of tipping that inquiry in a slightly different direction. This year, instead of asking what (or who) we're thankful for, what if we asked when we're thankful for?
Asking that question certainly sounds kind of weird — and may even be grammatically incorrect. But I think that weirdness is an important hint pointing us into the central mystery of our lives, lying hidden in plain sight — the mystery of time.
I could spend a lot of words telling you about how little we physicists really understand time. On the one hand, we have Albert Einstein's General Theory of Relativity ("GR") that seems to imply all time exists simultaneously. In GR, time and space in their totality comprise a "block-universe" consisting of all events that will ever happen. That means the lovely speech you are going to make at Thanksgiving in 2021 already happened (or it's always happening depending on how you look at it). But GR is not the whole story. For 60 years we've been trying unsuccessfully to get GR to mesh with quantum mechanics (our powerful theory of the nano-verse). All that nonsuccess has some physicists thinking it's our lack of a deeper understanding of time that's the problem.
So, yeah, I could tell you about physicists and quantum gravity and the mystery of time but, really, I don't need to go that far. We all already understand time's mystery, whether we have a Ph.D. in physics or not.
After all, it was William Shakespeare who reminded us: "We are such stuff / As dreams are made on; / and our little life / Is rounded with a sleep."
This movement from the fog of childhood to the fragility of the elderly is so short. The clock never stops spinning and we become ever more surprised to find summer is done, fall has slipped by and it's Thanksgiving already — again.
So you don't need me to remind you of time's endless movement, or its ghostly pressure pushing us through our lives. But as I get older, there's a new aspect of time that has made its appearance. For me, it makes all I love in this life more tender and more worthy of thankfulness. The best way to phrase this new appearance is in a question.
Where is time's home?
Where does time live in all its cosmic mystery of millions of years and billions of sunrises? Were does it reside? Where is it, shall we say, most comfortable?
The answer, I think, is within us. That's because we are the unfolding place for time. We are saturated with time. Right now, as you read these words, it's rolling out from you. It's filling space with your awareness of this one precious present moment. That, after all, is all the time we ever know. The past is a memory and the future an idea. But this moment, this breath, this deep sigh of relief or exhaustion, of care or concern — that, really, is all there is to time. The rest is nothing but words on a page or equations on a blackboard.
That's why this Thanksgiving I'm shooting for being thankful of when. I'm hoping this long moment which is my life will find its knife's edge at that table, filled as it will be with bounty and surrounded as it will be by love. I'll try to be aware — keenly aware — that the moment always comes unbidden and, in that way, I am always being given a great gift.
For that, I'll be truly grateful.
Adam Frank is a co-founder of the 13.7 blog, an astrophysics professor at the University of Rochester, a book author and a self-described "evangelist of science." You can keep up with more of what Adam is thinking on Facebook and Twitter: @adamfrank4