In the video above, sound waves passing around and through a drop of mercury set it oscillating. But the physics of the system — determined by things like the speed of sound in mercury and the strength of its surface tension — allow some sound waves to excite special vibrations in the drop. In other words, the mercury drop has resonances with the sound at specific frequencies.
These are called the resonant modes of the drop. When the frequency of the sound waves matches the frequency of the drop’s resonant modes, highly organized patterns of pulsation are triggered. You know you’ve hit strong resonances when something like a multiple-armed, star-shaped pattern emerges.
It’s a remarkable reminder of the hidden architectures embedded in the world around us.
That moment that ketchup transitions from a solid, high up in the ketchup bottle, to a liquid that squirts all over your fries – that moment is a big physics moment. Why? Ketchup is a non-Newtonian fluid(like oobleck, peanut butter, custard, toothpaste, paint, blood, or quicksand) that can switch between a solid and liquid state, and ketchup is non-Newtonian in two different ways…
In that transition moment, ketchup may be responding to a strong, quick force, suddenly making it thinner, or if you’re patient and apply just a wee bit of force, it may start flowing given some time and gravity. Grab a ketchup bottle and get the details in this TED Ed lesson by George Zaidan, with animation by TOGETHER.
Generate your own electricity with some wire, a magnetic field, and the relative movement between the two of them: Alom Shaha explainselectromagnetic induction using this hand-powered – or perhaps more accurately, bacon-sandwich-powered – generator.
Related watching: magnetic fields, probably one of the more awe-inducing subjects on this blog.
When this flight paths of starlings video by artist and professor Dennis Hlynsky went viral, it sparked a lot of questions for us: How did he make the visualizations? How do the starlings move quickly as a flock? What makes other groups of animals move the way they do?
In Micromigrationsfrom The Atlantic, Hlynsky discusses his own questions as we observe the water striders, ants, starlings, vultures, crows, and little white flying bugs that continue to inspire his curiosity and his work.
Watch the flight paths of starlings as they make computer-assisted trails across the sky above the Seekonk Speedway in Massachusetts. Artist Dennis Hlynsky filmed them (and others) with a Lumix GH2 and then used After Effects to make their paths more visible from their own visually-echoed image. A time-lapse of sorts…