Nicole Sharp
Nicole Sharp

Celebrating the physics of all that flows with Nicole Sharp, Ph.D.

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  • Roll Waves in Debris Flows

    When a fluid flows downslope, small disturbances in the underlying surface can trigger roll waves, seen above. Rather than moving downstream at the normal wave speed, roll waves surge forward — much like a shock wave — and gobble up every wave in their way. Such roll waves are fairly innocuous when flowing down a…

  • Recycling Water

    As regions are stressed by severe drought, communities considering how to stretch their water supply increasingly turn to the option of reclaiming wastewater. As Grady explains in this video, that idea faces both technological and psychological challenges. But neither, it turns out, is insurmountable. (Video and image credit: Practical Engineering)

  • “Sensations”

    Beautiful colors, subtle flows, and sudden fractals animate Thomas Blanchard’s “Sensations,” which, like his other short films, is entirely CGI-free. It’s a lovely exploration of droplets, liquid lenses, Marangoni effects, and fingering instabilities. (Video and image credit: T. Blanchard)

  • Uranus Emits More Than Thought

    Since Voyager 2 visited Uranus in 1986, scientists have debated the odd ice giant’s heat balance. The other giant planets of our solar system — Jupiter, Saturn, and Neptune — all emit much more heat than they absorb from the sun, indicating that they have strong internal heat sources. Voyager 2’s measurements from Uranus indicated…

  • Veil Nebula

    These glowing wisps are the visible remains of a star that went supernova about 7,000 years ago. Today the supernova remnant is known as the Veil Nebula and is visible only through telescopes. In the image, red marks hydrogen gas and blue marks oxygen. First carried by shock waves, these remains of a former star…

  • What Makes a Dune?

    Wind and water can form sandy ripples in a matter of minutes. Most will be erased, but some can grow to meter-scale and beyond. What distinguishes these two fates? Researchers used a laser scanner to measure early dune growth in the Namib Desert to see. They found that the underlying surface played a big role…

  • Understanding Acoustic Dissonance

    Dissonance — the discomfort we feel when two or more musical notes feel mismatched — is more than just a subjective measure. In this video, Henry of Minute Physics delves into some of the physics involved in dissonance, first with simple sine waves and then with musical instruments. Our ears — and our brains —…

  • A Sandy Spine

    Where sea and sand meet, Gaia’s spine rises. Photographer Satheesh Nair captured this striking image in western Australia, where wind and wave action have dragged a dune into vertebrae-like cusps. Notice how the size and shape of the curves differs between the under- and above-water sections. Those differences reflect the differing forces that shape them…

  • Seeding Clouds With Wildfire

    Raging wildfires send plumes of smoke up into the atmosphere; that smoke is made up of tiny particles that can serve as seeds — nucleation sites — where water vapor can freeze and form clouds. To understand wildfire’s effect on cloud growth, researchers sampled air from the troposphere (the atmosphere’s lowest layer) both in and…

  • The Incredible Engineering of the Alhambra

    Begun in 1238, Alhambra Palace in Grenada, Spain is a monument to Islamic architecture and clever engineering. Despite sitting far above the city, the Alhambra was fed by the river, diverted from upstream along a canal. Within the palace itself, this water was used for heated flooring, steam rooms, baths, and even a fountain that…