Breaking science news and multimedia, heavy on astronomy and physics (and heavy on citing). New vids, pics, articles, and the occasional research post for http://researchblogging.org/

Friday, March 9, 2012

A Trick From 1680 Revisited In All Its Beauty

------
Sand on the the surface of this table skitters in scientifically predictable patterns according to the resonant frequency.  I realised halfway through viewing this that my jaw had dropped.  It's quite a hypnotic ride. 



These patterns you see are called "Chladni figures."

These days, the technique is mostly practised with speakers and a sine wave generator. (electronic oscillator)  In this video though, the hands-on, careful rubbing to induce vibration makes the scene more personal I think.


Resonance effect shown for various input frequencies and damping coefficients.

"One of Chladni's best-known achievements was inventing a technique to show the various modes of vibration on a mechanical surface. Chladni repeated the pioneering experiments of Robert Hooke of Oxford University who, on July 8, 1680, had observed the nodal patterns associated with the vibrations of glass plates. Hooke ran a bow along the edge of a plate covered with flour, and saw the nodal patterns emerge."
-Wikipedia entry on Ernst Chladni

Found via Io9


-----Sharing via these buttons will share the current article page, unless your current url is the main page of Astronasty. Click the title of the article to go to an individual article page.
Share Spread the Love

No comments:

Post a Comment

Your Comments?

Popular Posts This Month

Follow by Email