Colonel Panic
28 May 2007, 10:15 AM
You're driving down the highway, and for whatever reason veer out of your lane slightly. Your tire starts running over those annoying grooves in the side of the road, making a loud, irritating buzzing tone which warns you to get back in your lane. (What are those things called, anyway?)
While driving through canada I had this idea. The grooves in the road are causing a tone to be generated when they are driven over, the frequency of which depends on:
1. Your speed
2. The distance between said grooves.
Now over a distance, wouldn't it be cool if the distance between them changed, so as to make music?
The most common modern tuning system, the equal temperament system, specifies this equation for determining the frequency of each note, in hertz:
(2 ^ (x/12)) * y
^ = to the power of, / = divided by, * = multiplied by
Here, x is which of the twelve notes in the chromatic scale you want to find, and y is some predetermined tone to base the whole thing on, usually "A" at 440 Hz. Double the frequency to go up an octave, halve it to go down an octave.
Now I'm going to use the metric system here, since centimeters are more accurate than inches.
A typical highway speed would be 100 km/hr, which should be about 28 meters per second. (2777 cm/second) So to find the frequency of the note you want to generate, divide 2777 by the frequency you want in hertz to find how many centimeters apart to make the gaps. (this includes the gap itself...from the start of one groove to the start of the next groove. We'll call this value x from now on, not to be confused with the x in the equation above.)
This puts x at about 6.311cm for a concert 440 "A".
A = 440Hz, x = 6.311cm;
Bb = 466Hz, x = 5.957cm;
B = 493Hz, x = 5.633cm;
C = 523Hz, x = 5.31cm;
Db = 554Hz, x = 5.013cm;
D = 587Hz, x = 4.731cm;
Eb = 622Hz, x = 4.465cm;
E = 659Hz, x = 4.214cm;
F = 698Hz, x = 3.978cm;
F# = 740Hz, x = 3.753cm;
G = 784Hz, x = 3.542cm;
G# = 831Hz, x = 3.342cm;
Those values are all theoretical and starting to look a bit small towards the top end of the spectrum. You'd probably want to double all the x values, thereby reducing the whole thing by 1 octave, if you wanted to really do this.
8.428cm, 7.084cm, 6.311cm, 8.428cm, 7.084cm, 5.957cm, 6.311cm,
8.428cm, 7.084cm, 6.311cm, 7.084cm, 8.428cm
This is smoke on the water. :)
One wouldn't have to drive over it at exactly 100km/h to hear the song, it would be the equivalent of playing a tape or vinyl record faster/slower than it's supposed to be. You'd of course have to figure out the timing of the notes too (how far to hold each one for), but I just figured this stuff out while I was bored at work. Gimme a break.
While driving through canada I had this idea. The grooves in the road are causing a tone to be generated when they are driven over, the frequency of which depends on:
1. Your speed
2. The distance between said grooves.
Now over a distance, wouldn't it be cool if the distance between them changed, so as to make music?
The most common modern tuning system, the equal temperament system, specifies this equation for determining the frequency of each note, in hertz:
(2 ^ (x/12)) * y
^ = to the power of, / = divided by, * = multiplied by
Here, x is which of the twelve notes in the chromatic scale you want to find, and y is some predetermined tone to base the whole thing on, usually "A" at 440 Hz. Double the frequency to go up an octave, halve it to go down an octave.
Now I'm going to use the metric system here, since centimeters are more accurate than inches.
A typical highway speed would be 100 km/hr, which should be about 28 meters per second. (2777 cm/second) So to find the frequency of the note you want to generate, divide 2777 by the frequency you want in hertz to find how many centimeters apart to make the gaps. (this includes the gap itself...from the start of one groove to the start of the next groove. We'll call this value x from now on, not to be confused with the x in the equation above.)
This puts x at about 6.311cm for a concert 440 "A".
A = 440Hz, x = 6.311cm;
Bb = 466Hz, x = 5.957cm;
B = 493Hz, x = 5.633cm;
C = 523Hz, x = 5.31cm;
Db = 554Hz, x = 5.013cm;
D = 587Hz, x = 4.731cm;
Eb = 622Hz, x = 4.465cm;
E = 659Hz, x = 4.214cm;
F = 698Hz, x = 3.978cm;
F# = 740Hz, x = 3.753cm;
G = 784Hz, x = 3.542cm;
G# = 831Hz, x = 3.342cm;
Those values are all theoretical and starting to look a bit small towards the top end of the spectrum. You'd probably want to double all the x values, thereby reducing the whole thing by 1 octave, if you wanted to really do this.
8.428cm, 7.084cm, 6.311cm, 8.428cm, 7.084cm, 5.957cm, 6.311cm,
8.428cm, 7.084cm, 6.311cm, 7.084cm, 8.428cm
This is smoke on the water. :)
One wouldn't have to drive over it at exactly 100km/h to hear the song, it would be the equivalent of playing a tape or vinyl record faster/slower than it's supposed to be. You'd of course have to figure out the timing of the notes too (how far to hold each one for), but I just figured this stuff out while I was bored at work. Gimme a break.