Twice as Long and Half as Short
Twice as Long and Half as Short
(OP)
Yesterday, at my church, I went to a "Get to Know the Pipe Organ" event (sounds kind of boring, I know, but it was actually interesting). Anyway, the handout said that pipes that are "twice as long" produce a pitch that is an octave lower, while pipes that are "half as short" produce a pitch that is an octave higher. The engineer in me thought, shouldn't that be "half as long"? And is a pipe that is "half as short" actually the same length as a pipe that is "twice as long"?
DaveAtkins





RE: Twice as Long and Half as Short
I'm with ya.
RE: Twice as Long and Half as Short
RE: Twice as Long and Half as Short
RE: Twice as Long and Half as Short
RE: Twice as Long and Half as Short
It simply means half the length.
NozzleTwister
Houston, Texas
RE: Twice as Long and Half as Short
Twice as long = two feet
Half as short = 1/2 foot
This is correct english is it not?
"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?
RE: Twice as Long and Half as Short
RE: Twice as Long and Half as Short
Yes it is correct English.
NozzleTwister
Houston, Texas
RE: Twice as Long and Half as Short
RE: Twice as Long and Half as Short
It would have been simpler and elegant to say "half as long", oh yes. But that was not the point. The point that is being made is "Longer = lower pitch" and conversely, "Shorter = higher pitch". That is the reason "short" is used in the sentence.
Try saying "half as long," and the whole point is missed. Whereas now the correct relationship will be registered in the audience's mind. Instructional design relies to an extent on psychology and pedagogy.
RE: Twice as Long and Half as Short
Twice the length or half the length would be more correct.
... and as for having a "one foot pipe" ... heh, you should be so lucky.
Helpful SW websites FAQ559-520
How to get answers to your SW questions FAQ559-1091
RE: Twice as Long and Half as Short
Ie: "200% longer produces an octave higher" (Should be 100% longer or 200% of the original length)
And 50% shorter just makes my brain hurt.
RE: Twice as Long and Half as Short
Sorry, those nits just needed picking. ;)
RE: Twice as Long and Half as Short
No such thing as a "major fifth" - because the dominant of major and minor scales is the same, the interval is called a "perfect fifth".
The "octave plus a fifth" interval you get from a 200% increase in resonator length is usually just called a "twelfth" - and against all reason is also the interval you tend to get if you overblow a cylindrical pipe (which is why most woodwind instruments are tapered).
A.
RE: Twice as Long and Half as Short
RE: Twice as Long and Half as Short
12th as first harmonic in a pipe is not against all reason. It's because the easy modes of vibration have a node at the blown (closed) end and then are open at the other end. So the pattern would be 1/2 standing wave, then 1 1/2 standing waves, then 2 1/2, etc. The jump from 1/2 to 1 1/2 is a threefold increase.
Here, these folks say it better than I do:
http://www.phys.unsw.edu.au/~jw/pipes.html
Hg
Eng-Tips policies: FAQ731-376
RE: Twice as Long and Half as Short
RE: Twice as Long and Half as Short
"200% longer produces an octave lower" (Should be 100% longer or 200% of the original length)
RE: Twice as Long and Half as Short
It only gets 321 hits on google.
RE: Twice as Long and Half as Short
So what do you call it... an imperfect fifth?
=====================================
Eng-tips forums: The best place on the web for engineering discussions.
RE: Twice as Long and Half as Short
.
RE: Twice as Long and Half as Short
Hg
Eng-Tips policies: FAQ731-376
RE: Twice as Long and Half as Short
Thx.
=====================================
Eng-tips forums: The best place on the web for engineering discussions.
RE: Twice as Long and Half as Short
Helpful SW websites FAQ559-520
How to get answers to your SW questions FAQ559-1091
RE: Twice as Long and Half as Short
=====================================
Eng-tips forums: The best place on the web for engineering discussions.
RE: Twice as Long and Half as Short
A.
RE: Twice as Long and Half as Short
In any case, Bach rules the roost in music theory and pipe organs. Do you know why he had so many children (20)?
His organ didn't have any stops.
RE: Twice as Long and Half as Short
Helpful SW websites FAQ559-520
How to get answers to your SW questions FAQ559-1091