Massachusetts Institute of Technology
Sign in Create Account

Breaking Glass with Sound

Rubbing the rim of a wine glass with a wet finger will cause it to resonate at its resonant frequency. The glass is placed in front of a speaker playing a sine wave, created by the function generator, of this same frequency. When the amplitude is turned up, we can see by shining a strobe light at the glass that this resonant frequency causes it to oscillate. When the glass becomes too stressed, it will shatter, which we see very clearly on high speed video.

A few things to note: The scrolling effect seen in the strobe light footage is caused by interference between the strobe light frequency and the video camera frame rate. Also, the real oscillations of the glass are much faster than they appear in the strobe footage. Setting the frequency of the strobe light can make them appear much slower so that we can see the oscillations in real time without the help of high speed video.

We would like to thank Dr. Jim Bales of the MIT Edgerton Center for helping us with the high speed video recording, and for the use of the equipment. The high speed camera used here is a Phantom v7.1, donated by the manufacturer Vision Research, Inc.

Comments (1)

First, I would say you need a quality crystal wine glass. Next you need to determine that individual glass’s natural resonance, i.e., the freq,. that it vibrates the easiest at. An oscilloscope would help. Next you need a quality freq. generator to reproduce that exact freq. and some quality transducers (speakers) that are not going to get burnt up playing back a loud sustained freq. or sine wave., not to mention a pretty awesome amplifier. really interesting facts

Posted almost 6 years by danny4u

You need to log in, in order to post comments. If you don’t have an account yet, sign up now!

MIT Department of Physics Technical Services Group

MIT Department of Physics Technical Services Group

Category: Science | Updated almost 2 years ago

Created
May 27, 2009 11:18
Category
Tags
License
Creative Commons Attribution-NonCommercial (What is this?)
Additional Files


Viewed
59233 times

More from MIT Department of Physics Technical Services Group

Gyroscopes Made Easy

Gyroscopes Made Easy

Added 3 years ago | 00:29:09 | 5928 views

Michelson Interferometer

Michelson Interferometer

Added over 4 years ago | 00:04:06 | 20372 views

Breakdown of Air

Breakdown of Air

Added 5 years ago | 00:02:09 | 32855 views

Center of Mass Trajectory

Center of Mass Trajectory

Added almost 6 years ago | 00:01:30 | 49476 views

DC Motor

DC Motor

Added 2 years ago | 00:01:17 | 3635 views

MIT Physics Demo -- Jumping Wire

MIT Physics Demo -- Jumping Wire

Added almost 7 years ago | 00:00:37 | 35920 views