Physics Buzz

Studying physics and learning about the laws that define our universe is usually its own reward—but sometimes it's nice to have other rewards, too. That's why we're excited to share the news about Physics in Advent: an opportunity to learn physics via hands-on experiments all throughout the month of December, and also to win books, electronics, science kits—and, for one lucky American student, a trip to Europe!

Fluid dynamics often produces some of the most beautiful, albeit under-appreciated, physics images and videos. To celebrate this field's striking images, the American Physical Society's Division of Fluid Dynamics holds a contest every year for related posters and videos that best display "artistic value, scientific content, and originality." One promising entry this year features a high-speed capture of fluid jets juggling ping pong balls. It's a gorgeous video, and you can watch it below. As researchers Roberto Zenit and Enrique Soto (National Autonomous University of Mexico) explain in the video, streams of water can suspend the balls due to a Bernoulli-like effect similar to the one responsible for lift in an aircraft. To levitate the ball for long periods of time, the researchers needed two things: a balance of vertical forces (we'll call this levitation ) and horizontal forces (we'll call this stability ).