We need to repeat this iterative scale-down process of dividing the current length into 10 equal parts two more times to get to the
billionth part of our initial 100-metre unit.
Put another way, they timed events lasting no longer than ten million
billionths of a second.
"Nano" is the term used to designate a
billionth of something -- in this case, a
billionth of a meter.
Unfortunately, thermometers that can measure temperatures of a few
billionths of a degree rely on physics that doesn't apply at these extremely low temperatures.
At 7 zeptograms, or
billionths of a trillionth of a gram, this mass is comparable to that of many small proteins important in functions such as cell-to-cell signaling, Roukes notes.
Most of the studies focused on the effects of lung exposures because the particles' size--just a few
billionths of a meter in diameter--permits them to reach the most vulnerable lung tissue.
Nanotechnology is the study and manipulation of materials on atomic and molecular scales measured in
billionths of a meter.
