Showing 26 posts tagged elements

From “science on a budget” YouTuber Nick Moore, watch this drop of mercury being vibrated from ~120Hz down to ~10hz. We’ve seen resonance demonstrated before in Chladni Pattern videos: sound frequencies become visualized as patterns via the vibrations. Higher frequencies = more complex shapes and patterns. Adam Frank explains in more detail at NPR:

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.

In the archives: sculpting in solid mercury, with liquid nitrogen and videos about the elements.

This information-packed video from It’s Okay to Be Smart explains How The Elements Got Their Names in rhyme! It’s a great introduction for looking further into the periodic table’s rich history and etymology, from Actinium (Greek for “ray”) to Zirconium (Persian “zargun” or “gold-colored”).

For a deeper dive, definitely get Theodore Gray’s kid (and adult) friendly book The Elements: A Visual Exploration of Every Known Atom in the Universe, and watch Gray introduce his massive collection in this video.

More: They Might Be Giants’ Meet the Elements and Tom Lehrer performs The Elements live — a must for any kid.

Via jtotheizzoe.

There are quite a few neodymium magnets falling through copper pipes on the internet, but we can still understand why this demonstration video is making the rounds: it’s just so cool looking! We’ve covered the phenomenon of magnetic damping before:

When a magnetic field moves through a conductor a current called an Eddy current is induced in the conductor due to the magnetic field’s movement. The flow of electrons in the conductor creates an opposing magnetic field to the magnet which results in damping of the magnet and causes heating inside of the conductor similar to heat buildup inside of power cords. The loss of energy used to heat up the conductor is equal to the loss of kinetic energy by the magnet.

And a note of caution if you decide to try this, these magnets are not for unsupervised children. In fact, everyone should be careful: 

Neodymium magnets larger than a half inch are very strong and should be handled with extreme care since they can be dangerous. It is best to stick with neodymium magnets of quarter inch diameter or less.

Want to know more? Look up Lenz’s Law and watch Veritasium’s Derek Muller demonstrate how this phenomenon is related to English scientist Michael Faraday and the first electric generator, created with a magnet and a coil of wire in 1831:

Physics! Another must-watch magnet-doing-magic-like-things-video comes from the Ri Channel: Levitating Superconductor on a Möbius strip

What’s happening when a match is lit? From Answers.com

Matches contain sulfur, glass powder, and an oxidizing agent as the components in the match head. When you strike a match, the friction due to the particles of glass powder rubbing together generates enough heat to convert some of the red phosphorous to white phosphorous, which burns in the presence of oxygen gas. The heat from the friction also causes the oxidizing agent to produce oxygen gas, igniting the small amount of white phosphorous. Once ignited, the oxygen gas fuels the flame while the rest of the sulfur catches on fire. Of course, this entire process happens in a fraction of a second.

…unless, of course, someone films it at 4000 frames per second, and then you really get to spend time with all of the macro, slow-motion details. Fascinating to watch, and a great conversation starter about fire prevention and safety tips, and using matches as tools.

Related watching: Why do hot things glow?, firefighter helmet cam, and Smokey and The Little Boy.

Thanks, @_thp.

Above, watch molten gold transform into gold leaf as it is beaten into thinner and thinner pieces while cold. This clip is from PBS’ six-part miniseries The Ring of Truth: An Inquiry Into How We Know What We Know - Atoms (1987). 

"It was the craftsmen who mastered the remarkable properties that go with specific materials. They were the first to journey towards the atom. The goldsmiths slowly refined their craft to take advantage of what gold alone could do…”

MIT astrophysicist and Institute Professor Philip Morrison narrated the series, which he co-wrote with his wife, noted art and science educator Phylis Morrison. Philip Morrison also narrated and wrote the script for Charles and Ray Eames’ Powers of Ten, a must-watch video for all ages.

via Emily Lakdawalla.