author photo by Jen Siska

I DECIDED to run a little experiment of my own while reading Grunt: The Curious Science of Humans at War, Mary Roach's latest monolexically titled popular-science essay collection. I put a checkmark in the margins whenever I came across something interesting: a new anecdote to tell at parties, a sharply observed detail, or even just a particularly well-turned phrase I might try to steal someday. I made more than 400 marks over 253 pages (not including the three chapters I read on the bus). There's a reason for this: Grunt isn't a textbook masquerading as creative nonfiction, but a legitimately enjoyable romp through the back alleys of military science.

And back alleys they are. Do not go into Grunt expecting the kinetic energy of tank shells or the fire rate of assault rifles. As Roach notes in the introduction, the guns that most interest her are the kind that shoot frozen chickens at airplane windscreens, not the kind that shoot bullets (though the traumatic effects of the latter are explored in detail). Which is to say about half the chapters cover squicky medical stuff, like "a salute to genital transplants" and the fight against "military diarrhea." When it comes to other areas of inquiry, Roach casts a wider net, getting into the history of deployable malodorants (stink bombs) and how best to escape a sinking submarine (carefully).

Roach has an inarguable gift for description. Naval trainees are so young "the pimples on their backs still outnumber the tattoos." A crash-test dummy flops around like an "elderly, arthritic man [trying] to follow along in a Zumba class." There's a certain coarse poetry to Roach's style that you'll find either delightful or horrifying, depending on your sensibilities. I was in the former camp for most of Grunt, though I will admit that the image of arctic explorers walking on their own sloughed-off flesh "like Dr. Scholl's cushioning inserts," and a medical cadaver's severed penis held up like "a baby's sweater" have done my dreamlife no favors.

Indeed, the study and treatment of penis-specific trauma occupies two successive chapters early on in the book ("Below the Belt" and "It Might Get Weird"), an organizational choice that may cause squeamish readers to swear off the rest of the material. Which would be a shame, since nestled in between all the blood and guts (and spit and sweat and semen and poo) are plenty of drier but no less fascinating topics. And then nestled within THOSE are compelling sidetracks into how polar bears respond to used tampons (positively) or how military amputees can interact sexually with their partners (creatively). Like any (obnoxious) person who has ever complained about the track order of an album, I did sense that some thematic turbulence could have been avoided with a less scattershot structure.

Roach probably isn't going to be your jam if you require a high degree of reverence when discussing these subjects. She's not an academic lecturer or military-industrial boffin. Roach is your buddy in the bar bathroom of military science, cheerily explaining how some guys in the '80s literally exploded from explosive decompression, and what a cutie that penis surgeon is. Maybe this isn't how science is "supposed" to read, but I have about 400 reasons why it works for me.