Cochineal, a parasitic insect native to Mexico, is the source of a vibrant red dye called carmine, which Spain’s Conquistadors encountered for the first time in 1519. We talk with Amy Butler Greenfield, author of A Perfect Red: Empire, Espionage, and the Quest for the Color of Desire, about the history of this highly sought-after commodity that eluded pirates, scientists, and kings. Plus: When restoring priceless works of art, conservators often want to know the origins of the paint. Chemist Kristen Wustholz (College of William & Mary) works with art curators to trace the molecular “fingerprints” of rare paint pigments and has produced a technique that allows precise chemical analysis from a single near-microscopic particle excised from the painting. And: Nuclear physicist Gail Dodge (Old Dominion University) has taken a leading role in atom-smashing experiments. Dodge, who won an Outstanding Faculty Award from the State Council of Higher Education for Virginia, is also devoted to growing the number of women in a field that is still dominated by men.

Later in the show: In 2009, fewer than 2% of physical science degrees—like physics and chemistry—went to African-Americans. Considering African-Americans make up 12% of the U.S. population, these numbers are shockingly low. And they’re getting even lower. In the second episode of our ongoing series about STEM education, we ask: what does a scientist look like? Short, tall, black, brown, male or female? We talk to four young scientists about their outreach project at William and Mary’s Virginia Institute of Marine Science. We also hear about what might be keeping American girls out of laboratories, and Laura Puaca (Christopher Newport University) explains the WWII history of Edna the Engineer.