Harold Craighead, professor of applied and engineering physics, and research assistant Rob Ilic have their research featured in the 2006 edition of "The Guinness Book of World Records."

In its Science and Technology section, the book cites the "Lightest Object Weighed:" a mass of 6.3 attograms. An attogram is one-thousandth of a femtogram, which is one-thousandth of a picogram, which is one-thousandth of a nanogram, which is a billionth of a gram. The entry is based on research reported in the Journal of Applied Physics in April 2004 (and profiled in the April 15, 2004, Cornell Chronicle), in which the researchers used changes in the vibration of a nanoscale oscillator to detect the mass of a single E-coli bacterium.

Researchers in the Craighead lab have since extended the work to detect the mass of viruses, and expect to go even smaller.