(Saveur) - On a recent Wednesday evening at 7 p.m., dozens of people flocked to their screens, glasses of wine in hand, for a mass Zoom call. 

But it wasn’t your usual quarantine happy hour. These attendees were gathered for a B.Y.O.B discussion of the mathematics behind “wine tears”—those gravity-defying drops of liquid that hover on the inside of a wine glass, millimeters above the wine itself, dripping back down as if quietly weeping. 

“Now, I even see someone here from the four o’clock session!” said Cindy Lawrence, CEO of the National Museum of Mathematics and event host, as participants streamed in. “They must have liked it enough, they decided to come back!”