Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Slow Mo Pulse Jet Engine
Pulse jet engines rely on their shape to maintain combustion without moving parts. The pressure waves that travel through the engine pump fresh oxygen into the combustion chamber and then ignite it with exhaust remaining from the last cycle. In this Slow Mo Guys video, we get to see that process in action. It’s a…
“Mist and Water”
Years ago, I drove through the Blue Ridge Mountains on a wet and misty New Year’s Day. The fog that clung to the dark trees made the whole world quiet and surreal. And although Mike Olbinski’s “Mist and Water” takes place on the opposite side of the country in Oregon, that’s what the video reminds…
Dual Structure of Water
Water is so ubiquitous in our lives that we rarely recognize just how strange it is. For example, when pure liquid water is supercooled well below its freezing temperature, it takes on not one but two molecular arrangements, one of which is high-density and one of which is low-density. Theory had posited this configuration for…
Eyes on the Sun
Though it may look like the Eye of Sauron, this image is actually one of our best-ever glimpses of a sunspot. Captured by the Daniel K. Inouye Solar Telescope, this sunspot is larger than our entire planet, yet we can see details as small as 20km across. The dark central region of the image is…
Seismic Events Reveal Ocean Temperatures
Decades ago, researchers proposed sending sound waves through the ocean to measure its temperature. Although the technique worked, it ran into noise pollution issues, but now it’s back, using naturally-occurring seismic events as the sound source. When fault lines shift, they generate seismic waves that travel through the ocean as sound. When they reach a…
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 sand’s odd characteristics come from the way forces move through grains that touch. Around 5:20 there’s a demo of one of these effects: the Janssen…
The Best of FYFD 2020
2020 was certainly a strange year, and I confess that I mostly want to congratulate all of us for making it through and then look forward to a better, happier, healthier 2021. But for tradition and posterity’s sake, here were your top FYFD posts of 2020: Juvenile catfish collectively convect for protection Gliding birds get…
Vanishing Spirits: Aging
The necessary ingredients for scotch whisky’s evaporation patterns are alcohol, surfactants, and polymers; some of those components are absorbed during the spirit’s aging in oak casks. Photographer Ernie Button explored how long it takes for whisky to absorb enough of these chemicals by photographing the stains left by samples aged between 1 and 5 weeks…
Vanishing Spirits: Rice-Based Whisky
In yesterday’s post, photographer Ernie Button showed us that barrel-aged gin can leave behind an evaporation pattern remarkably similar to scotch whisky. But even among whiskys not every spirit uses the same grains. Here we see patterns left behind by a 10-year-aged, rice-based whisky. The stains are entirely different than those of (barley-based) scotch. The…
Vanishing Spirits: Gin
Photographer Ernie Button has spent years exploring the patterns left by evaporating scotch. A team of researchers found that the uniformity of scotch whisky’s stain requires three ingredients: alcohol to drive concentration gradients, surfactants to pull particulates away from the drop’s edge, and polymers to help stick particles to the glass. Button wondered whether other…