Smallest ruler
- Who
- National Research Council of Canada.
- When
- 1994
A ruler used for measuring very small lengths in an electron microscope was developed in 1994 by John McCaffrey and Jean-Marc Baribeau of the Institute for Microstructural Sciences at the National Research Council of Canada. The smallest division on the ruler is 18 atoms thick and individual atoms are visible. It is so small that ten of the rulers stacked end to end would equal the diameter of a human hair.