How we smell has been a bit of a mystery to scientists. Other senses are easier to understand: For example, it’s possible to predict what a color will look like based on its wavelength. But predicting what a new molecule will smell like is more difficult. Our sense of smell can be quite complex. Take the delicious smell of morning coffee—that aroma is made up of more than 800 individual molecules. How does our brain keep track of the millions of scents that we sniff? To find out, a group of scientists gave mice different molecules to smell, and tracked what patterns were formed in their brains. Their results were recently published in the journal Nature. Neurobiologist Robert Datta, one of the authors on that study, joins Ira to discuss how our brains make patterns every time we sniff, and how wine aficionados train their noses to decode the different scents in wine. To understand variation in living things, scientists often compare specimens, recording the details. This kind of scientific investigation has long been practiced: Charles Darwin, for example, made sketches of everything from finch beaks to barnacles shells in his field notebooks. Today, natural history museums store these catalogues in shelves and drawers of preserved specimens. But scientists can also draw from less likely forums. Recently, one team of researchers—an art historian and a plant biologist—documented the different plant species represented in historical paintings and sculptures. Their results were published in the journal Trends in Plant Science. Plant biologist Ive de Smet and art historian David Vergauwen discuss what a 17th century painting by Giovanni Stanchi can reveal about watermelon evolution, as well as other trends in strawberries, potatoes, and other plants spotted in works of art. Have you ever met a friend for dinner at a restaurant, only to have trouble hearing each other talk over the din of other diners? And as we get older, this phenomenon only gets worse and can be compounded by age-related hearing loss and conditions like tinnitus. Unfortunately there is no silver bullet for tinnitus or other forms of hearing loss, and researchers don’t even understand all the ways in which the auditory system can go awry. But we now have more sophisticated technology to help us cope with it.  Nowadays, there are over-the-counter hearing aids and assistive listening devices that connect with your smartphone. Certain tech allows you to amplify softer sounds and cancel out the noise of a crowded room—it can even focus on the sound waves created by the person you’re speaking with.  Ira chats with David Owen, New Yorker staff writer and author of the new book Volume Control: Hearing in a Deafening World about the industry that’s helping millions of Americans cope with hearing loss.