Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Underwater Explosions
Underwater explosions are incredibly dangerous and destructive, and this animation shows you why. What you see here are three balloons, each half-filled with water and half with air. A small explosive has been set off next to them in a pool. In air, the immense energy of an explosion actually doesn’t propagate all that far…
Going With The Flow
Going with the flow Guys, I’m in Science! WHHHAAAAT?
Fluttering Feathers
Birds do not always vocalize in order to make their songs. The male African broadbill, shown in the top video above, makes a very distinctive brreeeet in its flight displays, but as newly published research shows, the sound comes from its wings, not its voice. During the display, the broadbill spreads its primary feathers and sound…
Bumblebees in Turbulence
Bumblebees are small all-weather foragers, capable of flying despite tough conditions. Given the trouble that micro air vehicles have when flying in gusty winds, bumblebees can help engineers to understand how nature successfully deals with turbulence. Under smooth laminar conditions like those shown in the animation above, bumblebees stay aloft by beating their wings forward…
Blowing Through a Straw
As kids, most of us got in trouble at some point for blowing through a straw into our nearly-empty drinks. What you see here is a consequence of such misbehavior, though in this case the fluid is silicone oil and the straw is a metal needle (not shown) through which helium is continuously injected beneath…
Drawing With Microfluidic Tweezers
One of the challenges of dealing with objects at the microscale is finding ways to manipulate them. This is what techniques like optical tweezers or magnetic traps are used for. The downside to these methods is that they often require complex experimental set-ups or place restrictions on the kinds of particles that can be manipulated. Recently,…
Mushrooms Make Their Own Breeze
Plants and other non-motile organisms have developed some clever methods to disperse their seeds and spores for reproduction. Some plants use vortex rings for dispersal; others make their seeds aerodynamic. Low ground-dwellers like mushrooms must contend with a lack of wind to lift their spores and carry them away. Instead, they use evaporative cooling to…
Hovering Hummingbirds
Hummingbirds are incredible flyers, especially when it comes to hovering. To hover stationary and stable enough to feed, the hummingbird’s flapping pattern not only has to generate enough lift, or vertical force, to counteract their weight, but the bird must balance any forward or backward forces generated during flapping. As you can see in the animations…
Coffee-Making in Space
In this video, Kjell Lindgren demonstrates his technique for making coffee aboard the Space Station. Astronauts usually drink coffee reconstituted from powder, or, on special occasions, enjoy a beverage from their special espresso machine. But Lindgren uses a pour-over method by attaching a pod of coffee grounds to the underside of a Capillary Beverage Experiment…
Eulerian vs. Lagrangian
When I first studied fluid dynamics, one of the concepts I struggled with was that of Eulerian and Lagrangian reference frames. Essentially, these are just two different perspectives you can view the fluid from. Physics is the same in both, but mathematically, you approach them differently. In the Eulerian perspective one sits at a location…