This surrealistic timelapse doesn’t show an ocean in the sky. These are undulatus asperatus clouds rolling over Lincoln, Nebraska. Also known simply as asperatus, this cloud formation has been proposed as but not yet recognized as a distinctive cloud type. Their speed is much slower than shown in the animation, but the wave-like motion is accurate and is the source of the cloud’s name, which comes from the Latin word aspero, meaning to make rough. Though they appear stormy, asperatus clouds do not usually produce storms. They form under conditions similar to those of mammatus clouds, but wind shear at the cloud level causes the undulations to form. (Maybe some Kelvin-Helmholtz instabilities going on there?) You can check many more images of asperatus clouds at the Cloud Appreciation Society’s gallery. (Image credit: A. Schueth, source video; submitted by leftcoastjunkies)
Ethereal forms shift and swirl in photographer Thomas Herbich’s series “Smoke”. The cigarette smoke in the images is a buoyant plume. As it rises, the smoke is sheared and shaped by its passage through the ambient air. What begins as a laminar plume is quickly disturbed, rolling up into vortices shaped like the scroll on the end of a violin. The vortices are a precursor to the turbulence that follows, mixing the smoke and ambient air so effectively that the smoke diffuses into invisibility. To see the full series, see Herbich’s website. (Image credits: T. Herbich; via Colossal; submitted by @jchawner, @__pj, and Larry B)
P.S. - FYFD now has a page listing all entries by topic, which should make it easier for everyone to find specific topics of interest. Check it out!
A Leidenfrost droplet impregnated with hydrophilic beads hovers on a thin film of its own vapor. The Leidenfrost effect occurs when a liquid touches a solid surface much, much hotter than its boiling point. Instead of boiling entirely away, part of the liquid vaporizes and the remaining liquid survives for extended periods while the vapor layer insulates it from the hot surface. Hydrophilic beads inserted into Leidenfrost water droplets initially sink and are completely enveloped by the liquid. But, as the drop evaporates, the beads self-organize, forming a monolayer that coats the surface of the drop. The outer surface of the beads drys out, trapping the beads and causing the evaporation rate to slow because less liquid is exposed. (Photo credit: L. Maquet et al.; research paper - pdf)
Hank shares the week in science news, including the top 10 new species discovered in 2014, and the start of construction of the first fusion reactor. It’s gonna be big!
Complete Top 10: http://www.esf.edu/Top10/
The Search for Antimatter
If you don’t have any idea what antimatter is, you don’t have to feel bad - the brightest minds in the world have only recently begun to understand what it is and how it works. Hank gives us the run down on what we know about antimatter, and what we’re still trying to figure out.
Is There Gravity in Space?
In a word, “yes” - space is packed with gravity. Hank explains how Isaac Newton described how gravity works, and why even though it seems that things are floating in space, they’re still effected by gravity. Every object in the universe is constantly attracting every other object in the universe.
Richard Feynman, The Great Explainer
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Aside from being a great scientist and teacher, Richard Feynman was a kooky and curious guy who played the bongos, painted, and did math in strip clubs. Hank shares his Feynman love fest with us in this episode of SciShow: Great Minds.
Fun With Potatoes & Physics! A SciShow Experiment
Hank uses a favorite subject of the YouTube community - the potato gun - to teach us about the principles of pneumatics, which use the potential energy of compressed gas to do work in lots of useful machines every day.
SciShow: Dark Matter
Physicists estimate that dark matter accounts for about twenty three percent of the known universe - the only problem is that no one really knows what it is…