Microgravity mandolin

[B. T. Walker]

A few years ago, I participated with a team of teachers from my school in a NASA program to integrate space sciences across the curriculum. #It was very successful, so when the education department at the Johnson Space Center got some slots to do experiments in microgravity this year in NASA's C-9 Weightless Wonder, we got the call again.

The experiment that the team I was on involved Newton's Cradles, AKA executive playthings or those clicky balls on strings. #We ran one platform with just the regular fishing line strings, and another platform with the strings held rigid by polymer string tauteners (AKA soda straws). #We dropped the balls in varying degrees of gravity and filmed the results. #We simulated Martian gravity, lunar gravity, and near zero g.

The whole experiment didn't take the entire fifty parabolas, so we were encouraged to do outreach activities like tossing frisbees and tennis balls, turning somersaults and so on, but I submitted taking my Mix A4 to see how gravity affected the tuning. #No on seemed to know what would happen. #Some thought it would go sharp, some no change, and one said it would go flat. #What do you cafe types think happened? #I'll tell you what I observed later.

Anyway, here are some pics from my week at NASA. #This first one is me getting fitted for a mask to use in an altitude chamber. #I had to shave off my mustache and goatee so the mask would seal properly, so I think I look stranger than usual in these photos. #They simulated 25,000 feet, then made us take off our masks for five minutes so we could feel what it was like to become hypoxic. #I did okay, a bit light-headed and fingertips blue, but I've been buzzed worse by a six-pack.

[B. T. Walker]

Here is the aft stair into the C-9. First time I've ever gotten onto an airplane this way.

[B. T. Walker]

Flight suit with NASA name tag. Got to keep the tag, had to give the suit back.

[B. T. Walker]

When the Newton's Cradle experiment had run it's course, there was still time to do the tuning study. #Peterson Tuners donated a StroboFlip to the cause -- deep bow of thanks to them. #The doctor on the flight took these pics after I made my observations, and I took the opportunity to float around. #Sorry for all the crotch shots; it's the way it happened. #I started out with one foot under a velcro strap, but kicked it loose to float freely.

[B. T. Walker]

Floating away!

[B. T. Walker]

Somebody pushed me away from the ceiling, and I'm headed for the deck.

[B. T. Walker]

Coming in for a landing.

[B. T. Walker]

Back on the deck pulling 2 g's.

[B. T. Walker]

A tour of the robotics lab provided this shot of Spidernaut. It is a prototype Martian rover, not a fancy automatic mando tuner.

I posted a couple of the shots in Post a Picture of Yourself. There will be much more on NASA's website in about a week. Sorry I can't link directly to the pics. Check NASA (http://zerog.jsc.nasa.gov) and follow the links to 2007 NASA Explorer Schools. There are altitude chamber photos already posted.

It was COOL!

[mythicfish]

I get it! You don't need a strap.

Curt

[B. T. Walker]

A mandolin strap would have been helpful. #The mandolin kept trying to float away when I was picking, and it was very difficult to keep it one place to play.

BTW, no one on my flight experienced motion sickness badly enough to puke. #We were a "no kill" flight thanks to good NASA medicine.

Here is a link to an article in the San Antonio Express-News: #NASA Gives SA Teachers the Ride of Their Lives (http://www.mysanantonio.com/news/education/stories/MYSA81107.01B.spaceteacher.3832be1.html)

[John Flynn]

Thanks for posting this. I got a nostalgia rush from my days as a Naval Aviator.

So what did you play? "Flying Indian?" "Ship in the Clouds?" http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

[B. T. Walker]

I'm an Army vet. I played "Soldier's Joy", or rather tried to.

[Steve Cantrell]

Mandolin in low-gravity. It did have to happen. These are great pictures.

[Brian T]

What was the effect on the tuning?

You win the prize for quirkiest mandolin post ever.

Of course, if I were designing microgravity experiments they would probably have to do with a woman. I've always wondered what that would be like...

[atetone]

I think you have probably voided the warrantee.

[B. T. Walker]

I'll tell you what observed about the tuning after some of you posit hypotheses. #I'll say this, what actually happened was not what I expected. #Any engineers or physicists out there? #Niles, do you have a theory?

I know it's hard on a Sunday morning, but think! #http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

Sorry, Zman, but human experimentation is not allowed. #The zero g portion only lasts twenty seconds each parabola, anyway. #If that's enough time for your experiment, you have other problems. # http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif

[JoeD]

OK - I was an English major, just inches away from earning minors in music and philosophy. So I feel myself uniquely unqualified to answer the question. With that caveat, I'm going to guess (and it is a guess) that nothing happened to the tuning. Assuming that temperature, humidity, and air pressure were relatively constant, the parabolic flight path of the plane should have had no impact on the mando's tuning.

I think it's also true that you didn't actually decrease the impact of gravity during the flight anyway, right? As I understand these "zero-gravity" trainers, the plane just goes into a steep dive so that it appears from the perspective of those in the plane that you are floating, instead of suicidally hurtling to the ground and instant death. Correct? If that's true, gravity would have remained constant. Unless there's something special that happens to a mandolin when it's dropped from 60,000 feet, I'd think that it should have stayed in tune.

[Milan Christi]

Another English major here. But I have a theory. Since strings on the mandolin are wire - and the aircraft you were flying on had about 5,000 miles of wire - if nothing happened to the 'strings' of the airplane, nothing happened to the strings on your mando. my point: the tensile strength of the twisted wire was unaffected by weightlessness.

BUT! Since aircraft are prone to have very dry, conditioned air flowing through their bodies I'd guess you went a little sharp with your tuning.

(And people wonder why I hang out here! Where else are you gonna get an education like this?!) http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif

[Philphool]

Since aircraft are prone to have very dry, conditioned air flowing through their bodies I'd guess you went a little sharp with your tuning.

=========================================
Milan,
You forgot; this is a Mix mando. Humidity-proof!!

My guess is that the strings would go SLIGHTLY flat, since they would not have the additional tension from their own weight pulling on them. My guess is that this is minimal enough that there may be no measurable change.

Am I VERY wrong??
Phil

[B. T. Walker]

All right. #I'll give you a clue. #Remember that the plane is not just diving in microgravity all the time. The plane also climbs in hypergravity. #Hmmm. #http://www.mandolincafe.net/iB_html/non-cgi/emoticons/rock.gif

Quite right, Phil. Humidity-proof.

[Bill Snyder]

I think you have probably voided the warrantee.
I bet the warranty has no provisions of any kind for antigravity. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

Not sure how the mandolin would react but the StroboFlips have a known problem with being exposed to g-forces above 1.

[Milan Christi]

My guess is that the strings would go SLIGHTLY flat, since they would not have the additional tension from their own weight pulling on them.
Aha! That's a much more scientific hypotheses than mine. I guess it shows that I majored more in 'herbology' when I was in college.

What altitude was the cabin pressurized to?
To what altitude was the cabin pressurized?
Pressurized to what altitude was the cabin?

Oh, the *&^* with it.

How many feet was the inside air?

[B. T. Walker]

I don't know the pressure. It felt like a regular airliner, and not a lot of ear popping until we landed.

[pathfinder]

Cabin air pressure should've been stable and controlled (ie: you didn't suddenly find yourself in a 'vacuum' when simulating weightlessness during the parabolic flight path).

And, as far as I can tell, fluctuating cabin temperature wasn't a factor because it should've been controlled too. #

And lastly, humidity isn't a concern for a Mix C/F.

So I'd guess the tuning and the pitch would be unaffected to anyone listening in the same aircraft fuselage. #It might be different if you went flying past me on a subway train with an open window while I was standing on a stationary subway platform. #

But that's for an Einstein relativity thread. #http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

I was under the impression the mix had an ebony fretboard and bridge, No?

[B. T. Walker]

It does have an ebony fretboard and bridge. #Pick guard, too. Strings were month-old J-74s.

[pathfinder]

Yer spinnin' this one 'way too long. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/sleepy.gif

[B. T. Walker]

Okay. #I give. #Had to go to the grocery store and fix some supper, so sorry if it took too long.

I expected that the mandolin would go flat since it was no longer under the strain of gravity.

I tuned the mandolin using the StroboFlip until the strobe stood perfectly still. #Sounded great. #I put it in the case and boarded the C-9 (didn't have to check it), putting the mando in the overhead storage of the seats located in the rear of the cabin. #When the real research was over and it was time for the outreach activities, I clamped the tuner to a camera pole and ran it through the Mix's onboard Schertler.

At zero g I hit the E string and ... nothing. #Perfectly in tune. #But when we came out of the dive and pulled 1.83 g, the E string went a whole tone sharp to F#. #The effect was not as noticable as I went up from treble to bass, but it was there. #When we nosed over again into zero g, it went back into tune. It did it again fairly consistently the few parabolas I had to check.

Here's my theory, and I'm no physicist. #Think of the mando as a bow that is strung and resting with the handle on the ground and the string above it. #When more strain is exerted on the bow (mando), the string becomes more taut. #It goes sharp. #I could have easily tested this by repeating the process with the strings held down or with the mando held vertically, but I didn't think to do it and there was no second chance. #Next time, right?

Big thanks to many folks at NASA, but especially to the Reduced Gravity Office for the C-9 ride and the lifetime opportunity to almost be an astronaut. #The tax money spent to do this is well worth the investment. #It was a facinating experience.

[Chris Baird]

"The tax money spent to do this is well worth the investment."


That's easy for you to say. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif

[David Hanson]

It's in danger of becoming boring now, so just tell us what happened.

Dave H

[F5G WIZ]

Did you play a little "I'll Fly Away" ? http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

[Hambonepicker]

For many years, the C9 belonging to NASA at Ellington Field in Houston has been in plain view.

People in these parts call it the "vomit comet."

Yippeee!

Hambonepicker

[Keith Erickson]

Brian,

Going where no mandolin has gone before!!!! You truly are a pioneer http://www.mandolincafe.net/iB_html/non-cgi/emoticons/mandosmiley.gif

Thank you for sharing and I'm glad you made it back okay from the "vomit comet".

Cheers http://www.mandolincafe.net/iB_html/non-cgi/emoticons/coffee.gif

[B. T. Walker]

Thanks Keith. #Thanks to those who played along with their own theories, especially the English majors (who were as right as anyone). #

The inpiration was Scott's April Fools' story. I had just gotten my Mix when the opportunity popped up; how could I not try? I actually had to propose it as a science thing and make a presentation to a review committee, or they would have simply said no.

It was especially cool that all those teachers were doing their thing at the same time Barbara Morgan and teachers returned to space on Endeavor and STS-118. #A nice touch for me since I work at Christa McAuliffe Junior High.

[Celtic Saguaro]

Technically since pitch is about string tension gravity shouldn't affect the pitch. #Nor should the upward acceleration of climbing since the strings aren't very massive. It's possible with the back of the mandolin resting on you, that the lever arm of the free neck (plus possibly your own arm) resisting the upward acceleration caused the change you noticed. The air pressure in the cabin is a different matter and big changes in that might affect the pitch. Free fall isn't any more low gravity than just flying at high altitude. It's the relative speed of falling compared to the airplane diving that makes you experience a 'weightless' state.

[rohan]

If U think gravity effects the pitch of the mando then measure the pitch as you strum standing up. Then, hang from a cross bar by you knees and measure again. Lets take gravity out of the equation and hold the mando with the neck pointing straight up or down. Measure again. I don't think even a Mark IV calibrated ear could tell the difference. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/mandosmiley.gif

[shiloh]

Great story! Thanks. My husband works for NASA (Ames Research Center) so I'll pass this along to him.

BTW, I'm an airline pilot by day....aircraft cabin is usually around 8,000 feet on a C-9. Depends....

Jill

[Tom C]

I think the zero-gravity has no affect what so ever. The pitch change I would think is more of an air-displacement or air being moved just like your body does with G-forces.