Science Wednesday: You Say You Want A Revolution

Link to EPA's External Link DisclaimerLinks on this page may exit EPA.

Each week we write about the science behind environmental protection. Previous Science Wednesdays.

You say you want a revolution,” said the Beatles. Well, we have one—a scientific revolution.

Nanotechnology is a scientific revolution of the sort described by Thomas Kuhn. In Kuhn’s description, science moves along with a certain set of beliefs until anomalies occur that don’t fit in with these beliefs. As the anomalies become more evident and common, somebody or some group forms a new and totally different theory that explains what’s going on–and shifts the whole direction of science. Hence, a scientific revolution occurs, and science moves forward on this new basis.

For example, 17th Century scientists were doing their “normal science” developing equations that explained how the sun rotated around the earth. These equations got more and more complicated trying to explain what was happening. Then, Galileo came along and said the earth rotated around the sun. This shifted the current geocentric paradigm and caused a scientific revolution in astronomy.

Unfortunately, Galileo was punished by the Inquisition for his “heresy,” but science marched on.

Before being able to work at the nanoscale, we thought that you could slice and dice materials to their smallest size, and they would still retain their properties—like color, magnetism, conductivity, melting point, etc. However, an anomaly occurred at the nanoscale. Materials were changing properties in a particular very small size scale—the nanometer scale.

For example, if you take a piece of gold jewelry, it is colored gold. You would expect that by chopping it up really, really small, its color would remain gold. That is not the case, however. If a particle of gold is 10 nanometers across, it is red. You also would not expect your gold ring to be reactive; yet, at a 2-3 nm size range, gold is a good catalyst.

All this is very exciting to scientists and engineers. Maybe we could “tune” properties to get the color we want or the reactivity we want. However, as scientists and engineers at EPA, we must make sure that the environment and human health are protected while making use of these really cool materials.

To carry out this mission, I support research in both applications of nanotechnology for helping the environment and implications of nanotechnology that may cause harmful effects. Some of the research results can be found at

About the Author: Dr. Barbara Karn is a scientist in EPA’s National Center for Environmental Research where she works in nanotechnology.