The banks of rivers are in constant flux, a pattern most easily captured from above. This satellite image shows a section of the Ivalo River in Finland, swollen with snowmelt Keep reading
Category: Phenomena
Slow Motion Speech
Sneezing, coughing, and speaking all produce a spray of droplets capable of spreading COVID-19 and other respiratory illnesses. This Slow Mo Guys video is the latest demonstration in a long Keep reading
Hudson Bay Watercolors
Rivers sweep fresh water and sediment into the Hudson Bay in this satellite image. Dark brown plumes mark the mouths of several coastal rivers as they add to the cyclonic Keep reading
Hydrodynamic Bearings
If you twirl a glass syringe, it spins quite nicely, lubricated on a micron-thin layer of air. This is an example of a hydrodynamic bearing, a device where the viscosity Keep reading
Colorful Kelvin-Helmholtz Clouds
Like breaking waves at the beach, these wavy clouds curl but only for a moment. The photo was captured near sunset on a late August evening in Arlington, MA. This Keep reading
Spinning Bubbles
Fluid dynamics is largely about figuring out the relationship between forces. For a soap bubble sitting still, that’s primarily the effect of gravity, which makes the fluid in the soap film drain downward, and Keep reading
Freshwater Mussels
Freshwater bivalves like these California floater mussels are critical species for the health of our waters. And although we don’t think of mussels as being very mobile, they’re actually quite Keep reading
Green Swirls and Dark Streaks
Green phytoplankton blooms swirl through the currents of the Baltic Sea in this satellite image. Individual phytoplankton are microscopic, which makes them excellent tracer particles in the flow; together, they Keep reading
Chaos in the Lagoon Nebula
Even on the scale of light-years, fluid dynamics plays a role in our universe. This photograph shows the Lagoon Nebula, where stars, gas, and dust are battling for supremacy. Jets Keep reading
Rings of Ice
Heavy rains followed by a sudden freeze can produce icy puddles like this one. Because the pool was shallow to begin with, it likely froze rapidly. As the temperature continued Keep reading