Undoubtedly one of the most mind-boggling instances of fluid dynamics I’ve learned about in writing FYFD is that of sonoluminescence - an effect in which light is produced from imploding cavitation bubbles. In a laboratory, the effect is usually initiated with acoustic waves. A bubble can be forced to oscillate and collapse periodically when forced by the sound. During the collapse, the vapor inside the bubble reaches temperatures of the order of thousands of Kelvin, and light is produced. What is far more wild, though, is that the effect occurs in nature as well. Both the pistol shrimp and the mantis shrimp produce the effect. As shown in the video above, the mantis shrimp swings its club-like arm with such speed that the local pressure drops below the vapor pressure, causing a cavitation bubble to form and sonoluminescence to occur. Some real Mortal Kombat finishing move s&#% there, indeed. (Video credit: Z. Frank)
The hummingbird has long been admired for its ability to hover in flight. The key to this behavior is the bird’s capability to produce lift on both its downstroke and its upstroke. The animation above shows a simulation of hovering hummingbird. The kinematics of the bird’s flapping—the figure-8 motion and the twist of the wings through each cycle—are based on high-speed video of actual hummingbirds. These data were then used to construct a digital model of a hummingbird, about which scientists simulated airflow. About 70% of the lift each cycle is generated by the downstroke, much of it coming from the leading-edge vortex that develops on the wing. The remainder of the lift is creating during the upstroke as the bird pulls its wings back. During this part of the cycle, the flexible hummingbird twists its wings to a very high angle of attack, which is necessary to generate and maintain a leading-edge vortex on the upstroke. The full-scale animation is here. (Image credit: J. Song et al.; via Wired; submitted by averagegrdy)
A blue morpho caterpillar turning into a chrysalis.
Sand cats live in sandy, stony deserts and the only species of cat that survive without water for long period of time (couple of months). Unlike other species of cats, sand cat is poor climber and jumper but proficient digger. It digs burrows in the sand where it hides from the harsh desert sun.
Paws covered with thick fur protect the cat’s feet from the hot desert sand. This foot cushion also act like snowshoes. They prevent the cat from sinking into the sand and leaving footprints [x].
When you flip bats upside down they become exceptionally sassy dancers.
The African bullfrog is the biggest frog in Africa and very aggressive. But in spite of that, it’s a devoted father. Bullfrogs spawn in little pools around the margins of larger ponds and after mating is over one male stays to keep watch over the newly hatched tadpoles. If the pool begins to dry up the dutiful dad digs a channel to a new water source.