The Last Word On Nothing

Our mother died on August 7, 2010, quite a while ago now. Our father had already died way back in 1978. Last Monday, I noticed the date, thought it was probably their wedding anniversary, and then thought, “Oh, Mom will be sad today.” Then I thought, “No, she’s dead too.” Everybody does this, deaths never quite go away, do they. This first ran on August 17, 2011.

My mother was an old lady, she’d lived a good and useful life, and she died a year and ten days ago.  I hadn’t been keeping track of her death’s anniversary but I didn’t need to; I only had to figure out why I was walking around feeling, for no good reason, sad.  One of my cousins wrote to me, “I’m sorry you are sad, Annie. Thursday my new couch was delivered. I cried as my old one left – apparently I had an undiscovered attachment to it.”  My cousin recently moved to a new house with a new love; the old couch was from her old life, years ago, when her husband had died.  Sad in early August?  Crying over couches? Really? Science, as it often does, has a nice metaphor: resonance.

When I was a kid, I’d open the piano lid and tap a string and it would hum; and then like magic, all on its own, another string hummed too.  I thought the strings were malfunctioning and quit thinking about it.  Obviously I was a young English major; a young physicist would have tapped some more strings and then looked it all up and found the strings hummed because they were vibrating, oscillating; and that each string had its own native note, its natural frequency of oscillation, its resonant frequency. And if one string hums at that particular frequency, then as if in sympathy the other hums too.

In fact, everything – atoms, molecules, crystals, desks, skyscrapers — has its own resonant frequency at which, depending on its mass and stiffness, it most wants to oscillate.  So resonance is a response; it’s when two things are linked in some way or somehow touching, and then one taps or vibrates or oscillates and the other responds at that same frequency.   

If you’re an army crossing a suspension bridge, for instance, you shouldn’t march in cadence in case your cadence happens to match the bridge’s resonant frequency and the bridge jumps in step with you.  If you rock a rocking chair too fast or slow, the rocker will just sit there; rock at the resonant frequency and the baby falls asleep.  If you pump a swing too fast or slow, nothing much happens; pump at the resonant frequency, it’s almost like flight.  If you’re in a building and the earth quakes at the building’s resonant frequency, get out fast.

Resonance is actually more complicated than this.  Resonances can be forced or driven, all the way to disaster.  Pump the swing harder and harder at that right frequency and you risk breaking your neck.  Sing loudly at a wineglass at the right frequency and it’ll shatter.  Google a video of the resonating Tacoma Narrows bridge, nicknamed Galloping Gertie, before it fell into the river.  The genius inventor, Nicola Tesla, supposedly said that if he could figure out the resonant frequency of the earth, he could split it to pieces.  An aside: don’t google Tesla, who attracts enthusiasts, unless your bullshit detectors are robust, hair-trigger, and highly-informed (though you should read this novel; it’s charming).

But disaster isn’t part of this metaphor.  The metaphor is simple resonance — like the sympathetic piano strings, like the resonance you notice when you first meet someone and know you’re going to get along.  We use the metaphor all the time:  we’re in tune, we’re on the same wavelength, we’re in synch.   Death set up a resonance with early August, with a couch; another early August, a different couch, and there like magic is death.

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Photo credits:  couch – bartek.langer; swing – John Garghan