Antlion larvae catch prey by digging conical pits in sand. The steep walls of the trap are near the angle of repose, the largest angle a granular material can maintain Keep reading
Tag: granular material
The Strangeness of Sand
Sand and other granular materials can flow, jam, and transmit forces in counterintuitive ways. This Lutetium Project video gives a nice overview of some of these bizarre properties. Many of Keep reading
Granular Fingers
Finger-like shapes often form on fluids injected between glass plates, but what happens when that injected fluid contains particles? That’s the situation in this recent study, where researchers sandwiched a Keep reading
Landings Beyond Earth
With planning for manned and unmanned missions to the Moon, Mars, and many asteroids underway, engineers are using numerical simulations to understand how spacecraft thrusters interact with planetary surfaces. Most Keep reading
Testing Granular Gas Theory
When excited, a group of particles can behave much like a gas. These granular gases exhibit many similarities to molecular gases but contain one vital difference: without a constant input Keep reading
Shear in Shaken Sands
The dynamics inside a shaken granular material, like sand, are fascinatingly complex. In this study, researchers used x-ray radiograms to peer inside a horizontally-shaken container of sand. They found that Keep reading
Digging Droplets
A droplet on a surface much hotter than its boiling point will skate on a layer of its own vapor, thanks to the Leidenfrost effect. But if that surface is, Keep reading
Scaling High-Speed Impacts
The impact of a solid object into a bed of grains is a major topic in many fields from ballistics to astronomy. Researchers study these impacts experimentally using photoelastic disks, Keep reading
Colorful Tides
This false-color satellite image — the recent winner of NASA Earth Observatory’s Tournament Earth 2020 — shows sands and seaweed off the coast of the Bahamas. Ocean currents and tides Keep reading
Unifying Sediment Transport Theory
On windy days, streaks of snowflakes snake in the air above a mountaintop snowfield. And when snorkeling in the surf, you can watch the inbound waves sculpt underwater ripples in Keep reading