Is left-handedness the key to the universe?

Well, Chris McManus thinks so. In his new book Left Hand, Right Hand, he argues that asymmetry is the key to understanding virtually every mystery of the universe — from sub-atomic behavior (the lefthanded spin of neutrinos) to psychology (why most cultures regard “right” as more normal and correct than “left”) to human physiology: Ever wonder what it means that almost everyone’s heart is on the left side of our bodies? (Unless you’re one of the rare people McManus locates who have a heart on their right side; or unless you’re a Time Lord and you have two.)

Most mindblowingly, McManus argues that our preference for right-handedness is a direct result of interstellar lifeforms brought to Earth by crashing meteors about a jillion years ago. I am not making this up. There’s an excellent piece about the book in last weekend’s Ideas section of the Boston Globe, written by my gal Emily Nussbaum, who also writes the Summary Judgment column for Slate:

According to McManus, all life forms possess some variation on handedness, from the molecular level on up. Neutrinos are lefties, DNA twists to the right, and conch shells spin both ways. Mechanical objects from spiral staircases to corkscrews are notable for their asymmetrical swirls, while the human brain’s right and left hemispheres famously work together in a peculiarly lopsided vaudeville act. McManus further suggests that the asymmetry of molecules may trigger asymmetry all the way up the evolutionary ladder. Indeed, the seemingly symmetrical human body is in fact a Rube Goldberg machine of asymmetry, with tiny clockwise swirling cilia triggering the development of our typically left-sided heart, and the heart likewise knocking the rest of the internal organs into their efficient, unbalanced tangle of tubes and sacks. The left testicle, for instance, droops lower not because (as the ancient Greeks suspected) it is heavier, but because the snarl of inner tubes dictated by the heart simply makes that position more efficient.


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I'm Clive Thompson, the author of Smarter Than You Think: How Technology is Changing Our Minds for the Better (Penguin Press). You can order the book now at Amazon, Barnes and Noble, Powells, Indiebound, or through your local bookstore! I'm also a contributing writer for the New York Times Magazine and a columnist for Wired magazine. Email is here or ping me via the antiquated form of AOL IM (pomeranian99).

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