Wednesday, April 24, 2013

This Is Why There's Algebra.

No, I haven't dropped off the face of the earth. Just been really, really busy. Being the executor/trustee of your parents' estate can do that to a person. (Mother just faded away at age 91 back in December.)

Which reminds me. I don't care how old (or young) you are. Do your heirs a favor, and thin out your stuff NOW. If you can't figure out why that's a good thing, ask me about filling the biggest dumpster Waste Management will deliver, and still having trash left over. Not to mention so many trips to Goodwill, the guy at the donation station knows us by name.

Oh, and does anybody want to buy a 2000+ square foot house on an acre in Carmel Valley? A million in cash and it's yours.

None of which explains the algebra.

For reasons I'm too tired to explain right now, amongst my various other endeavors I am experimenting with creating handmade flutes. And before I (pun warning!) branch out into wood, bamboo and other such materials, PVC pipe is a good place to start.

Yep. Good ol' PVC pipe from Home Depot, at less than 2 bucks for 10 feet of the stuff.

Anybody can just start drilling holes in a tube, but if you want the thing to play in something resembling "tune" (what is this "tune" thing I speak of?) you have to do some math.

Well. Anybody who has known me for any length of time knows that Algebra 2 was one of the worst experiences of my life, and I quickly and purposely forgot it all once I had passed the class and moved on with my education. Where and when, I often asked, was I ever going to use this knowledge again?

Fast forward to yesterday, and a few useful websites. One of those sites offers the following text:

If I want a pipe that plays an A-440 (that is, the note at 440 Hz, which happens to be an A), sound waves have to go around it once in 1/440 second. So, (2 x (length of pipe in m)) / (345 m / s) = (1 / 440) s. We can solve this equation algebraically to find that the length of pipe must be .392 m (39.2 cm).

Algebra? Heaven help me.

Heaven came in the form of yet another nifty website. (They've got practically everything on the net these days, don't they.) Somehow I managed to actually use those instructions to draft my own equation and plug it in, once I had figured out the part about sound waves traveling at 345 meters per second. And I found that for a pipe to play a D at 293.66 Hz, it needed to be 0.58741402 meters long, or about 23 1/8 inches for us English speakers. And lo and behold, when I cut the PVC pipe to that length and blew into it, aiming at a nifty tuner app, I got a D.

I then used the Flutomat to calculate the distances and hole sizes for a D-minor scale, drilled out the holes, and now I've got my first homemade flute.

Fine-grit sandpaper takes off the black printing as well as the shiny surface, so it looks just a little less like PVC at a distance, although the cap at the end kind of gives it away....

Silly me, I should have offset the G hole a bit. Yes, it is rather awkward to play. But it has an interesting sound.

Bonus feature. If you drop it on the floor, or even step on it, it won't break!



Want to hear what it sounds like?


1 comments:

Jeff D said...

We hired someone to haul all of my brother's clutter away. Over 30 years of accumulation in one day. What a relief!

 
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