Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Who Killed the Colorado River?
From its source high in the snowy Rocky Mountains, the Colorado River runs through two countries and five states on its way to the Gulf of California. Or at least it used to. The river hasn’t met the sea in decades. All that water disappeared into a complicated web of poor management, short-sighted policies, and…
“Chemical Somnia”
Under a macro lens, even a petri dish worth of fluids comes vividly to life. Here, artist Scott Portingale explores crystallization, Marangoni effects, and other phenomena alongside a haunting soundtrack from musician Gorkem Sen. Enjoy! (Image and video credit: S. Portingale et al.)
Hello, STEVE
A purple glow arcs across the night sky. Just another aurora, or is it? First described in 2018, this is a STEVE — Strong Thermal Emission Velocity Enhancement. (Yes, the name “Steve” came first and the acronym came later.) Scientists still aren’t entirely sure how to classify this glowing phenomenon. Although it looks similar to…
Sea Ice Swirls
Fragments of sea ice tumble and swirl in this satellite image of Greenland’s east coast. In spring, Arctic sea ice journeys down the Fram Strait between Greenland and Svalbard. Along the way, large ice floes break — and melt — into smaller pieces. Large pieces of sea ice are visible closer to the coastline, but…
Blocking Bubbles
Many industrial processes, including those producing aluminum and “green” hydrogen, use electrodes to speed up chemical reactions. Unfortunately, bubbles that form on the electrode reduce its efficiency anywhere from 10 to 25 percent by blocking parts of the electrode. The assumption has been that any area shadowed by bubbles is blocked, but a recent study…
A Comet’s Two Tails
The bright tail of a comet doesn’t actually stream out behind it. Instead, the tail points away from the sun, showing off all the ice, dust, and gas blown off the comet by the solar wind. Because the tail is tied to the sun’s direction and not the comet’s trajectory, comets sometimes have a second…
Erie Algal Bloom
Blue-green algae bloom in Lake Erie’s summer conditions. Unfortunately for those looking to spend summer on the water, the dominant organism in this bloom produces a toxin that “can cause liver damage, numbness, dizziness, and vomiting.” Bloom season can last from late June into October, depending on the how many nutrients get washed into the…
Eerie Aurora
This surreal image comes from an aurora on Halloween 2013. Photographer Ole C. Salomonsen captured it in Norway during one of the best auroral displays that year. The shimmering green and purple hues are the glow of oxygen and nitrogen in the upper atmosphere reacting to high-energy particles streaming in from the solar wind. These…
Marangoni Blossoms
When surface tension varies along an interface, fluids move from regions of low surface tension to higher surface tension, a behavior known as the Marangoni effect. Here, a drop of (dyed) water is placed on glycerol. The two fluids are miscible, but water has much a lower viscosity and density yet a higher surface tension.…
The Great Red Spot’s Cycle
First spotted by humanity in 1664, Jupiter‘s Great Red Spot is a seemingly endless storm. Strictly speaking, there is debate as to whether observations prior to 1831 were of the same storm, but there’s no denying that the storm has raged unabated since regular observations began in the first half of the nineteenth century. Despite…