We're all familiar with the various kinds of screams we humans can emit, from the squeals of a child in those "boo!" moments, to the shrieking of scream queens on the big screen. But there is a primal scream that lurks within all of us, awaiting the proper moment to burst forth in all of its primordial glory. I uttered one of these Monday night, or rather, very early Tuesday morning, on my way home from the office.

While tooling along the interstate just above the 65-mph speed limit, quite alone in the dark, listening attentively to a spooky audio book, I suddenly saw a large, glistening form materialize immediately in front of my car. I screamed.

It started in my colon, rumbled upward into my stomach, hurtled through the esophageal sphincter in my diaphragm, gushed into the esophagus and up into my throat, where it was met with the full force of all the air in my lungs, and finally, under tremendous pressure, burst out of my mouth in the loudest, hoarsest, most blood-curdling scream I have ever heard, followed a millisecond later by a crash and cacophony of twisting metal and crumpling plastic.

My hapless victim, literally the proverbial deer caught in the headlights, vanished as quickly as it had appeared. In a foggy daze, I mindlessly proceeded along my course, every neuron firing incoherently as I tried to get a grip on what had just happened. In my frazzled stupor, seemingly unhindered in my course and direction, I removed my right hand from the shift knob and reached up to turn off the car stereo. I remember wondering how my car could still be running after such an impact. I also remember thinking that maybe the damage wasn't too bad.

Coming to my senses, I realized that the car, though still running, was slowing down. So I tried to accelerate. As the motor revved, the tachometer needle made its typical clockwise movement, but the speedometer did not. It was then that I realized the car was in neutral. I concluded that, in my panicked state, I must have tried to brace myself by pushing against the steering wheel with my left hand and against the shifter with my right, setting it to the neutral position.

I then put the shifter back to drive, depressed the accelerator and started speeding up again. As I exited the freeway, I surveyed what I could see of the front of my car. The hood was clearly damaged, having been twisted and bent several inches above its normal situation. But I still had at least one headlight, and could see the road with no trouble.

•

I began to think about the deer. Countless stories of collisions of motorists with deer finish with, "And it just ran off, like nothing happened." Surely, the same was true in this case.

Whenever I see a deer carcass on the road, I always assume it was an 18-wheeler or a cement-mixer truck that was responsible for the carnage. Mass, multiplied by velocity, equals momentum. Whatever a cement-mixer might lack in velocity, it certainly makes up for in mass. So I concluded that my little Chevy Cavalier probably could not have inflicted much damage to one of those impervious venison denizens of darkness.

When I arrived home, not 10 minutes later, I pulled my car into the garage, turned off the ignition and got out to take a look. It was a horrible, nauseating sight. The bumper was cracked down the middle. The right headlight was gone, probably still on the freeway in shattered bits. And the entire hood was a wrinkled, concave shape, a sheet of silver paper that had been crumpled into a ball and then smoothed out unsuccessfully.

When I saw deer fur stuck all over the hood, a sickening feeling came over me, exacerbated no doubt by the lingering effects of the adrenalin that had been surging through me just moments before.

It took me more than an hour to get to sleep, the muscles of my chest and abdomen still burning as if I'd had a late-night work-out and my throat feeling as if I had been at a concert, shouting at the top of my lungs for hours; both, of course, the result of that volcanic scream that had filled my head and my car with unprecedented volume.

•

Tuesday morning, I went into the garage, took another assessment of the damage, got into the car and drove off to begin the new day's responsibilities.

Retracing the previous night's route in reverse, I looked along the shoulder of the oncoming lanes to see what, if anything, had been left behind. Much to my surprise, I caught a glimpse of a lifeless fur-covered heap of animal against a concrete barrier on the far side of the highway. Apparently, what my compact Chevy lacked in mass, it more than made up for in velocity. Mass, multiplied by velocity, equals momentum.

Adding to my surprise, after I saw my victim lying there, a throbbing pain began in my right palm and wrist, apparently the result of bracing myself so violently at the moment of impact. It was as if seeing a creature I had killed spotlighted some fateful organic connection between us, having shared the same physical space, the same millisecond of terror, and undoubtedly, in one brief, chance moment, the same primal scream.

• In physics, P stands for momentum, m for mass and v for velocity. P = mv

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