#marangonieffect — Public Fediverse posts

Vanishing Spirits: Cognac

Years ago, photographer Ernie Button discovered an intriguing stain left behind in his whiskey glass after the last drops evaporated. That discovery led both to beautiful images and an entire scientific paper analyzing how the alcohol, surfactants, and polymers in the whiskey combined to leave such a uniform stain. Over the years, Button continued investigating liquor stains, looking at gin, rice whisky, and aging effects. Here, he’s turned his lens to cognac, producing stains that look like oil slicks, aerial landscapes, and even cartoonish faces! (Image and submission credit: E. Button)

Vanishing Spirits: Cognac

Years ago, photographer Ernie Button discovered an intriguing stain left behind in his whiskey glass after the last drops evaporated. That discovery led both to beautiful images and an entire scientific paper analyzing how the alcohol, surfactants, and polymers in the whiskey combined to leave such a uniform stain. Over the years, Button continued investigating liquor stains, looking at gin, rice whisky, and aging effects. Here, he’s turned his lens to cognac, producing stains that look like oil slicks, aerial landscapes, and even cartoonish faces! (Image and submission credit: E. Button)

Vanishing Spirits: Cognac

Years ago, photographer Ernie Button discovered an intriguing stain left behind in his whiskey glass after the last drops evaporated. That discovery led both to beautiful images and an entire scientific paper analyzing how the alcohol, surfactants, and polymers in the whiskey combined to leave such a uniform stain. Over the years, Button continued investigating liquor stains, looking at gin, rice whisky, and aging effects. Here, he’s turned his lens to cognac, producing stains that look like oil slicks, aerial landscapes, and even cartoonish faces! (Image and submission credit: E. Button)

Vanishing Spirits: Cognac

Years ago, photographer Ernie Button discovered an intriguing stain left behind in his whiskey glass after the last drops evaporated. That discovery led both to beautiful images and an entire scientific paper analyzing how the alcohol, surfactants, and polymers in the whiskey combined to leave such a uniform stain. Over the years, Button continued investigating liquor stains, looking at gin, rice whisky, and aging effects. Here, he’s turned his lens to cognac, producing stains that look like oil slicks, aerial landscapes, and even cartoonish faces! (Image and submission credit: E. Button)

Vanishing Spirits: Cognac

Years ago, photographer Ernie Button discovered an intriguing stain left behind in his whiskey glass after the last drops evaporated. That discovery led both to beautiful images and an entire scientific paper analyzing how the alcohol, surfactants, and polymers in the whiskey combined to leave such a uniform stain. Over the years, Button continued investigating liquor stains, looking at gin, rice whisky, and aging effects. Here, he’s turned his lens to cognac, producing stains that look like oil slicks, aerial landscapes, and even cartoonish faces! (Image and submission credit: E. Button)

Marangoni Effect in Biology

For decades, biologists have focused on genetics as the key determiner for biological processes, but genetic signals alone do not explain every process. Instead, researchers are beginning to see an interplay between genetics and mechanics as key to what goes on in living bodies.

For example, scientists have long tried to unravel how an undifferentiated blob of cells develops a clear head-to-tail axis that then defines the growing organism. Researchers have found that, rather than being guided purely by genetic signals, this stage relies on mechanical forces–specifically, the Marangoni effect.

The image above shows a mouse gastruloid, a bundle of stem cells that mimic embryo growth. As they develop, cells flow up the sides of the gastruloid, with a returning downward flow down the center. This is the same flow that happens in a droplet with higher surface tension in one region; the Marangoni effect pulls fluid from the lower surface tension region to the higher one, with a returning flow that completes the recirculation circuit.

The same thing, it turns out, happens in the gastruloid. Genes in the cells trigger a higher concentration of proteins in one region of the bundle, creating a lower surface tension that causes tissue to flow away, helping define the head-to-tail axis. (Image credit: S. Tlili/CNRS; research credit: S. Gsell et al.; via Wired)

Dancing Metal Droplets

Droplets of a gallium alloy are liquid at room temperature. When spiked with aluminum grains and immersed in a solution of NaOH, the droplets change shape and move in a random fashion. This video delves into the phenomenon, describing how a chemical reaction with the aluminum grains changes the local surface tension and creates Marangoni flows that make the droplets move. To get the droplet motion, you need to have the aluminum concentration just right. With too little, there’s not enough Marangoni flow. With too much, the hydrogen gas produced in the chemical reaction disrupts the droplet motion. (Video and image credit: N. Kim)

https://www.youtube.com/watch?v=XYRj0Ty9udo

#2024gofm #chemistry #droplets #fluidDynamics #marangoniEffect #physics #science #surfaceTension