Ann Arbor inventor Mike Gould describes his Lunchbox Laser Shows as a portable laser light show. Key to its operation is a wobbulator, which turns coherent straight-line light coming out of the lasers into a swirl of ever-changing patterns and colors.

Plans for building such a lunch box are online, including the precise way to make your own wobbulator.

I saw Gould at yesterday's a2b3 lunch, which is a lunch group that I have been organizing every week for five years. As a part of the lunch effort I asked people to think about thing that wobble, and here's a summary of sorts of that lunch based on descriptions of other things that wobble.

The earth wobbles on its axis

The earth wobbles on its axis. These wobbles can be measured, and they have consequences for climate.

The Earth Orientation Centre in Paris, France tracks the detailed wobbling of the earth's orbit, producing a daily record of how long the day is and where the pole is. It's part of the international earth science community that will do things like make a recommendation for a leap second day.

Link: Earth Orientation Centre, Paris.

Ohio State wobbles in its shoes

The song "I want to go back to Ohio State" includes this stanza:

And when we win the game, we'll buy a keg of booze!
And we'll drink to old Ohio, 'Til we wobble in our shoes!

which is originally from the California Drinking Song.

During Prohibition, the line was changed to

And when we win the game, I'll tell you what we'll do
We will yell for old Ohio, Til' we wobble in our shoes!

Link:I Want To Go Back To Ohio State
Link:I Want To Go Back To Michigan
Link: California Drinking Song
Link: Talk of the Town: Hail to the Victors - a borrowed song?, James Dickson, AnnArbor.com, November 2009

Your wobbly old turntable, vinyl wow!

Audio turntables spin vinyl or shellac records, with a needle or stylus picking up signals cut into the grooves and turning them into sweet, sweet music.

Several kinds of audio distortion are characteristic of the wobbles that can be heard if the turntable or the record is not perfectly flat, if the vinyl disc is not perfectly centered on the table, or if the motor does not maintain a perfectly even 33 1/3 rpm or 45 rpm or 78 rpm speed.

Similar effects happen on audio cassette tapes, which are subject both to stretching of the tape medium itself or motor problems.

The word "wow" is used to describe a frequency variation under 4 kHz, which would be picked up by the woofer of your big old speaker and make the music sound muddy. "Flutter," on the other hand, comes from sounds above 4 kHz and is characteristic of pitch distortion in the tweeter, which make piano notes sound cracked.

Link: WCBN 88.3 FM, University of Michigan student radio, with a vinyl collection that will wow you, with free-form deejays that can play all of it if you ask them nicely.
Link: Underwater sound propogration in the Straits of Florida, a 1967 report of sonar research done at the University of Michigan's Cooley Electronics Laboratory: "A primary consideration in using analog tape recording in processing real data is the problem of compensation for wow, flutter, and slew in recording."

Wobbulators as precision electrical components

It's clear to me that there are a number of precision bits of equipment which could be described as wobbulators. From the heavy slug that keeps a Weebles toy wobbling but not falling down to the computer-controlled variable frequency oscillator in your communications gear, wobbles are everywhere in real world systems, even when you would think there are straight-line ways to get from here to there.

As described by an entry in the Museum of Broadcasting:

"A wobbulator is basically a sweep generator so that
I.F. transformers can be "flat-topped" rather than peaked.
This alignment technique was called for with the "high
fidelity" sets that sported broad-band I.F. strips. (Whether
this provided for a better listening experience might be a
topic for debate.) A plain wobbulator is a device that
would be hooked up to a scope in conjunction with an R.F.
(really an I.F.) signal generator. The Oscillograph-Wobbulator
is a scope with a built in wobbulator."

Link: Wobbulator, Museum of Broadcasting
Link: Triumph Model 830 Oscillograph-Wobbulator (1943), from Phil's Old Radios, Copyright Philip I. Nelson 1995-2010.
Link: Museum of Broadcasting, St Louis Minnesota

Wobbulators as public safety devices

This wobbulator makes a good front end for a siren; this video gives you some sense for what the Wobbulator VS-4 sounds like and how it's controlled.

Edward Vielmetti wobbles for AnnArbor.com but he doesn't fall down. Contact him at edwardvielmetti@annarbor.com.