As a physicist who explores ways to measure light more accurately, it should come as no surprise that I’m fascinated by even common optical phenomena that we see all around us (e.g., rainbows or oil slicks on butterfly wings).

Rainbows occur because light travels through water and air at different speeds and because different colors of light travel at different speeds through water. Oil slicks on water, opal, and butterfly wings look the way they do because of the way light waves bouncing off of different surfaces or facets interfere with one another.

Although these effects are beautiful, they also have practical aspects. For instance, the same effect that causes rainbows also allows fiber optic cables to faithfully carry information across thousands of miles.

Our understanding of light—and our ability to manipulate it—is helping us to improve our understanding of our world and how we affect it. Much of my own work focuses on ensuring that the instruments on remote sensors, such as satellites that measure Earth’s vegetation cover and land use, are working properly by comparing them against some known quantity or standard. This process is called calibration.

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