- Profile
Solar Coronal Heating
Our Sun‘s visible surface, the photosphere, is about 5800 Kelvin, but the temperature of the wispy corona is far hotter, reaching a million Kelvin in some places. Why the corona is so hot remains something of a mystery. Scientists have theorized multiple culprits for the extreme temperatures found in the corona, but the full details…
Fog in the Blue Ridge Mountains
Fog blankets the forest of the Blue Ridge Mountains in this photo by Tihomir Trichkov. It gives the photo the quality of an Impressionist painting. Rain from the day before left lots of moisture in the air and soil, contributing to the ethereal condensation lit by the sunrise. (Image credit: T. Trichkov; via Gizmodo)
Predicting Heat Waves
The United States, Europe, and Russia have all seen deadly, record-breaking heat waves in recent years, largely in areas that are ill-equipped for sustained high temperatures. A new paper presents a theory that predicts how hot these heat waves can get and what mechanism ultimately breaks the hot streak. Heat waves start when an area…
Polymers and Fluid Sheets
Even adding a small amount of polymers to a fluid can drastically change its behavior. Often polymer-doped fluids act more like soft solids, able to hold their shape like your toothpaste does when squeezed onto your toothpaste. Under a little stress, though, the fluids still flow; that’s why your toothpaste gets less viscous as you…
Bending in the Stream
Nature is full of cilia, hairs, and similar flexible structures. Unsurprisingly, flows interact with these structures very differently than with smooth surfaces. Here, researchers investigate flow in a channel lined with flexible, hair-like plates. Initially, the channel is filled with oil and dark particles that help visualize the flow. Then, they pump water into the…
Why We Can’t Control Rivers
Rivers are systems in a constant state of change, balancing flow speeds, path length, sediment deposition, and erosion, as seen in this previous Practical Engineering video. The next video in this mini-series considers what human interventions do to rivers. As convenient as it is for humanity to force a river into a straight and constant…
“Water in Dripping”
Zheng Lu’s stainless steel sculptures capture elaborate splashes in action. In some of the pieces, thousands of Chinese characters cover the sculpture’s surface; these are quotes from historical texts and poems, an homage to early Chinese philosophers who studied the principles of the natural world. See more examples of the artist’s work here. (Image credit:…
Hawaiian Magma Complex
Few volcanoes are as well-studied as those of the Big Island of Hawai’i. With a host of seismic monitors and frequent eruptions, scientists know the near-surface region of Hawai’i well. But a recent study looked at nearly 200,000 seismic events after the 2018 collapse of Kilauea’s crater and found hints of what goes on much…
Finding the Red in the Red Tide
Blooms of the algae Karenia brevis — known as a red tide — bring havoc to Gulf Coast shores. The algae can kill fish and other marine life, and it causes skin irritation and even respiratory problems for humans. But in spite of the moniker, these algae can be hard to spot; they can add…
Hunting By Whisker
Seals and sea lions often hunt fish in waters too dark or turbid to rely on eyesight. Instead, they follow their whiskers, using the turbulence generated by a fish’s wake. The vortices shed by the fish cause the seal’s whiskers to vibrate, giving them sensory information. To better understand what a seal can derive from…