Ya don’t look good, Joe.
Artist Fabian Oefner captures these colorful portraits of fluid instability by dripping acrylic paints onto a metal rod, which is connected to a drill. When the drill is switched on, paint is flung away from the rod, creating these snapshots of centripetal force and surface tension. Note how droplets gather at the ends of the spiral arms like in a Plateau-Rayleigh or a rimming instability. For more, check out Oefner’s webpage, which includes a video showing how the images are made, or his previously featured work, “Millefiori”. (Photo credit: F. Oefner; submitted by Stephen D.)
This happened 11 billion years ago. (Our sun by comparison, is a little over 4 billion years old) Yay Novastars!
Surface tension creates a glassy, smooth layer of water over U.S. swimmer Tyler Clary the instant before he surfaces as he competes in the backstroke. Surface tension arises from intermolecular forces between water molecules. In the bulk of the liquid, any given water molecule is being pulled on in every direction by the surrounding molecules, which results in zero net force. At the surface, however, molecules only experience forces from those to the side and below them. As a result, these molecules are pulled inwards, forcing the liquid to take on a form with minimal area. (Photo credit: Getty Images; submitted by drhawkins)
Bastard Hogberry: Bioinspired Fibers Change Color When Stretched |
A team of materials scientists at Harvard University and the University of Exeter, UK, have invented a new fiber that changes color when stretched. Inspired by nature, the researchers identified and replicated the unique structural elements that create the bright iridescent blue color of a tropical plant’s fruit.
The multilayered fiber, described January 28 in the journal Advanced Materials, could lend itself to the creation of smart fabrics that visibly react to heat or pressure.
“Our new fiber is based on a structure we found in nature, and through clever engineering we’ve taken its capabilities a step further,” says lead author Mathias Kolle, a postdoctoral fellow at the Harvard School of Engineering and Applied Sciences (SEAS). “The plant, of course, cannot change color. By combining its structure with an elastic material, however, we’ve created an artificial version that passes through a full rainbow of colors as it’s stretched.”
Since the evolution of the first eye on Earth more than 500 million years ago, the success of many organisms has relied upon the way they interact with light and color, making them useful models for the creation of new materials. For seeds and fruit in particular, bright color is thought to have evolved to attract the agents of seed dispersal, especially birds.
The fruit of the South American tropical plant, Margaritaria nobilis, commonly called “bastard hogberry,” is an intriguing example of this adaptation. The ultra-bright blue fruit, which is low in nutritious content, mimics a more fleshy and nutritious competitor. Deceived birds eat the fruit and ultimately release its seeds over a wide geographic area.
I swear I only want to hear about you, to know what you’ve been doing. It’s a hundred years since we’ve met―it may be another hundred before we meet again.
Edith Wharton, The Age of Innocence (via bookmania)