Mary Roach would like you to understand one very important thing about herself: She is not a scientist. "It makes me an especially irksome presence in my sources' lives," she says, adding that she asks "naive, misguided questions" and that she tends to "giggle at the wrong moments." This is not necessarily a bad thing, especially when writing a book like Spook: Science Tackles the Afterlife, which could have very easily become overrun with scientific and parapsychological mumbo-jumbo that only an advanced degree holder could begin to decipher. However, this is not the case, and the book is not only easy to read, but difficult to put down, mainly because you find yourself either with your jaw on the floor or laughing hysterically, or trying to figure out how to do both at the same time. (Answer: It's very difficult to laugh with your mouth agape--usually it just makes people on the subway think you're insane.)

Roach got a head-start from working on her last book, entitled Stiff: The Curious Lives of Human Cadavers, which was a shocking and often weirdly hilarious look at what happens to human bodies once we've left the mortal coil. Spook is, to some extent, an extension of Stiff, which was a New York Times bestseller; however, the title is a bit misleading. The phrase "the afterlife," at least for the majority of the American population, probably conjures up images of heaven (or, maybe, hell); however, Roach spends only one chapter discussing scientific research that (kinda, sorta, maybe) investigates the possibility of heaven, while the rest of the book is devoted to more paranormal sorts of post-death activities. Amusingly enough, my father, who is a Southern Baptist minister, glanced at the book title and demanded to know what sort of blasphemy I was reading--until I explained to him that Roach is more interested in determining whether ghosts actually exist than in disproving the existence of God. He calmed right down after that.

This is not to say that the book is not useful or interesting--nothing could be further from the truth. Of particular interest to me were the few chapters where Roach talks to experts who are currently in the midst of finding scientific explanations for "hauntings." For example, Roach submits herself to an experiment in which she sits inside of a sensory deprivation chamber while being bombarded with electromagnetic radiation. The point? Errant, random EM radiation is believed to cause auditory and visual hallucinations, which might explain a great number of "encounters" with ghosts and spirits. (It did work on her, by the way--she saw glimpses of faces and heard what sounded like a police siren, even though the chamber was soundproofed.) Another similar chapter investigates the effects that stray "infra-sound"--that is, sound at sub-audible frequencies--can have on the human body. Sound at certain extremely low frequencies, such as 13 Hz, which is actually the resonating frequency of the human eyeball, can cause symptoms ranging from uneasiness to actual hallucinations. So much for that beyond-the-grave encounter with Great Aunt Clara!