A burning question for all you science and physics geeks

[JP-]

A burning question for all you science and physics geeks:

If I could transport a guitar to the top of Mt. Everest – and suppose I could keep the tuners untouched the entire way up – when I got to the top would the pitch of the guitar be the same?

Of course, the air would be comparatively thin. Would the strings vibrate faster since air is so scarce?

To a somewhat remote listener, would the perceived guitar volume be quieter – as the air molecules are farther apart?

I imagine that with less air friction, the sustain of the guitar would be greater?

Obviously, it is so cold at the top that my fingers would quickly freeze. Also, my steel strings would contract, thus changing the pitch. But discounting these matters – do strings vibrate faster in rarified air? And is perceived volume diminished?

[Bob Womack]

Ask the band Chicago. Their producer, Jim Guercio, created a destination studio, Caribou Ranch (Altitude 8300'), outside Nederland, Colorado, where they recorded a couple of their albums. When they traveled to Hollywood (and sea level) to rehearse the new songs for the resulting tour they discovered that they couldn't hit the high pitches they had when recording at Caribou.

Bob

[rick-slo]

No change in pitch.

[musicman1951]

The temperature can drop as low as -30 to -60. I think you might have bigger problems than tuning.

[M19]

My guess: Less volume, no change in sustain (on a % decay rate basis).

[AHill]

Assuming the tension is the same, the temperature is the same, and the wood didn't change moisture content, the pitch would be exactly the same. The volume might not be as strong due to the lower viscosity of the air, but the physics of the string vibration is the same. Air doesn't offer a measurable difference in friction for the string. It's possible that the less-dense air might totally attenuate some lower frequencies, because the body of your guitar is a resonant chamber. Less dense air has a higher speed of sound, so lower wavelengths might not have a possibility of leaving the soundhole. Think of the effect of inhaling helium and then trying to talk. The higher frequencies you hear were always there with normal density air, but the lower frequencies just didn't make it out of your vocal chamber due to the increased speed of sound in helium compared to normal density air.

All this with no math.

[Pitar]

Might saw your fretting hand on the exposed fret ends standing proud from the frozen, contracted board. I'd imagine any edge binding on the board would be broken as well. Bridge might crack grain-wise across the pin holes from contraction. Finish would craze because the wood and it would contract at different rates and extents. Braces would pop as they remain grain-wise more stable than the plates do cross-grain. The top would probably crack either side of the bridge. It's minus 60°F at that altitude so all manner of cold related structural calamities would occur. Most of the glues used in construction of a guitar fail at those temps. I think one pluck of the low E string would let loose a cascade of rapid disassembly.

[twofer]

For a harmonic oscillator, less damping increases the resonant frequency at which it will vibrate. At 29,000' there will be less air than at sea level and consequently less damping, and the string's frequency will increase. It may not be perceptible to the human ear, but it will increase.

At colder temperatures, the strings will contract and thus will get tighter. Once again, this will increase the frequency at which the strings will vibrate.

The wood will also contract, which, by itself, would decrease the frequency of the strings. But, it is not clear to me whether the wood's contraction will offset the frequency increase caused by the decreased damping and contracting strings.

JMHO

[fazool]

duplicate post

[Goat Mick]

You wouldn't be able to hear the guitar. As soon as it came out of the case it would be used to build a fire.

[Purfle Haze]

Originally Posted by AHill

Assuming the tension is the same, the temperature is the same, and the wood didn't change moisture content…

Does it have to be a wooden guitar? This looks like a job for…

Carbon Fiber!

[JeffreyAK]

This is what happens when you breathe helium and talk, https://www.livescience.com/34163-he...e-squeaky.html Basically, the quality (not the fundamental pitch) changes because the speed of sound in helium is much faster than in air.

Originally Posted by JP-

...do strings vibrate faster in rarified air? And is perceived volume diminished?

Yes, very slightly (doubt you would notice), and yes.

[Jabberwocky]

You won't hear a thing...

[Silurian]

I tried it once.
Got to the top, opened the case, brought the D18 by mistake, got back to the top with the D28. Still couldn't hear anything, the drummer was too loud.

[Mr. Jelly]

Originally Posted by JP-

If I could transport a guitar to the top of Mt. Everest – and suppose I could keep the tuners untouched the entire way up – when I got to the top would the pitch of the guitar be the same?

No. The change in humidity (effects the top) and the change in temperature (effects the strings) would effect the tuning.