In 1827, botanist Robert Brown observed an odd jittery motion of particles as he watched grains of pollen floating in water under his microscope. He saw the random motion also Keep reading
Tag: molecular diffusion
Searching For Solar Neutrinos
An experiment in Italy has reported new findings confirming a long-standing theory of nuclear fusion in our Sun. The researchers were able to detect neutrinos released by the relatively rare Keep reading
Water Anoles Breathe Underwater
Meet the water anole, a small lizard native to the tropics of Central America. While studying these anoles, researchers discovered that they could flee underwater and remain submerged for 16 Keep reading
Ink Drops Spreading
Ink drops atop a layer of glycerol spread in a beautiful fan of blue and white. The ink’s motion is the result of two processes: molecular diffusion and the Marangoni Keep reading
Un-Mixing a Flow
This video demonstrates one of my favorite effects: the reversibility of laminar flow. Intuition tells us that un-mixing two fluids is impossible, and, under most circumstances, that is true. But Keep reading
Dye Droplet
A drop of fluorescent dye falling into quiescent water forms fantastical structures that are a mixture of vorticity, turbulence, and molecular diffusion. The horseshoe-like shape near the front of the Keep reading
Reversing a Flow
The reversibility of laminar mixing often comes as a surprise to observers accustomed to the experience of being unable to separate two fluids after they’ve been combined. As you can Keep reading
Testing Flames in Space
In microgravity, flames behave very differently than on earth due to a lack of buoyant forces. On earth, a flame can continue burning because, as the warm air around it Keep reading
Molecular Diffusion
This video explains molecular diffusion with demonstrations in gases and liquids. Molecular diffusion is an important process in all fluids and will occur in laminar, turbulent, or quiescent fluids. Diffusion Keep reading
Un-Mixing a Fluid Demo
Not only is this demonstration one of my favorites, it’s a reader favorite, too. Even though I posted it nearly a year ago, I’ve had it resubmitted over and over. Keep reading