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 5 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 over 1 year ago

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


Viewed
56170 times

More from MIT Department of Physics Technical Services Group

Hero's Engine

Hero's Engine

Added almost 4 years ago | 00:01:38 | 20772 views

MIT Physics Demo -- Microwave Interference

MIT Physics Demo -- Microwave Inter...

Added over 6 years ago | 00:02:11 | 26749 views

MIT Physics Demo -- Magnetic Deflection of a TV Image

MIT Physics Demo -- Magnetic Deflec...

Added 6 years ago | 00:01:35 | 53296 views

MIT Physics Demo -- Bicycle Wheel Gyroscope

MIT Physics Demo -- Bicycle Wheel G...

Added 6 years ago | 00:01:28 | 163863 views

Interrupted Pendulum

Interrupted Pendulum

Added almost 4 years ago | 00:01:40 | 14598 views

Bell Labs Wave Machine: Superposition

Bell Labs Wave Machine: Superposition

Added over 3 years ago | 00:00:34 | 11110 views