Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
How Sinkholes Form
Growing up in the Ozarks, I explored my fair share of caves and sinkholes. These geological features form when flowing groundwater erodes soil, sand, and even rock underground. The Ozark Plateau consists largely of limestone, which is water soluble, making it very prone to this internal erosion. As bedrock dissolves away, it is eventually unable…
“Stranded”
The advantage of flying a drone over a volcanic eruption is getting all of the beauty with none of the danger. No asphyxiating on sulfuric gases, no burns from intense heat, no ash or flying rocks. Just the stunning, glowing beauty of fresh earth being born. “Stranded” takes us over and around the recent Icelandic…
Stingray Eyes
With their flexible, flattened shape, rays are some of the most efficient swimmers in the ocean. But, at first glance, it seems as if their protruding eyes and mouth would interfere with that streamlining. A new study uses computational fluid dynamics to tackle the effects of these protrusions on stingray hydrodynamics. With their digital stingrays,…
Starlings Over Rome
Each winter millions of starlings migrate to Rome, where they form enormous murmurations in the sky above. The ephemeral and amorphous displays are driven by each bird responding to its neighbor’s motions. But the slight delay in individual responses gives the flock as a whole a wave-like, fluid appearance. Behaviors like this help protect the…
Twisting Free
Anyone who’s dealt with hot glue guns is familiar with the long, thin tails of glue they leave behind. 3D printers suffer from a similar problem with the nozzle pulls away from viscoelastic materials like plastics and polymers. Little tails, like the ones seen above, are left behind on the part and must be cleaned…
Really, Really Slow Mo Fluids
Fluid dynamics is a perfect subject for high-speed video. So much goes on at speeds that are far too quick for our eyes and brains to perceive. But there is such a thing as too slow – a concept explored in this Slow Mo Guys video, which takes everyday activities like turning on a faucet…
Tides and Tempests of the Coast
Photographer Rachael Talibart specializes in capturing the majestic and tumultuous power of the sea along England’s coast. Her most recent book “Tides and Tempests” looks incredible — full of turbulent crashing waves, skies of spray, and shorelines of surge and froth. I love how her photographs freeze the water in positions that seems surreal while…
Animals Lapping
Without full cheeks, cats, dogs, and many other animals cannot use suction to drink. Instead, these animals press their tongue against a fluid and lift it rapidly to draw up a column of liquid. They then close their mouth on the liquid before it breaks up and falls down. (Cats are a bit neater about…
Noctilucent Clouds
Noctilucent clouds are the “highest, driest, coldest, and rarest clouds on Earth.” Formed in the mesosphere at altitudes over 80 kilometers, these clouds typically form at polar latitudes where they can catch sunlight hours after sunset, hence their night-shining name. The clouds take shape when water vapor in cold mesospheric air layers freezes onto dust…
Why Creases Don’t Disappear
Flex your fingers and you’ll see your skin fold into well-defined creases. Many soft solids (including old apples) fold this way, and like your skin, the creases never fully disappear, even when the stress is removed. A recent study finds that surface tension and contact-line-pinning are critical to the irreversibility of these creases. The authors…