What the Heck?

Abstract

![Figure][1] CREDIT: NASA, ESA, M. ROBBERTO (STSCI/ESA) ET AL. “Hella,” Northern Californian slang for “very” or “extremely,” is gaining tongue-in-cheek support as a new metric prefix denoting 1027. Austin Sendek, an undergraduate physics major at the University of California, Davis, first proposed hella earlier this year on his blog as a joke. But the hella Facebook fan page has 60,000 members and counting. And scientists do work on scales greater than 1024, the largest number with an official prefix, yotta. “I do believe that [metric prefixes] should not stop at yotta,” says Roger Blandford, director of the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University in Palo Alto, California. “The Hubble length [the greatest distance light could have traveled since the beginning of the universe] is about 1026 meters,” he notes, “and the Planck mass [the mass of the tiniest hypothetical black hole] is 1028 eV.” George Smoot, a University of California, Berkeley, astrophysicist and 2006 Nobel laureate, likes the word's local flavor. “Hella could also be short for the Greek word for Greek ( Hellas ),” the source language of the other prefixes, he adds. But hella's chances of official adoption are hella slim for a couple of reasons, says Kumar Sharma, a nuclear physicist at the University of Manitoba in Winnipeg, Canada, and former chair of the commission responsible for units at the International Union of Pure and Applied Physics. For one, “it derives from a slang word that refers to another slang word [helluva],” he says. And for another, “popular use alone just doesn't cut it.” [1]: pending:yes