I know I’m just setting myself up for bad jokes but I’d like to find a practical method of measuring the air pressure in my mouth when I’m sucking on something.
The SD column on how a piece of spaghetti gets sucked into your mouth is still unresolved (or at least a highly a contentious issue). You can find it here. I’ve decided it’s time to take things into my own hands (insert bad joke here) and see what kind of force the air pressure alone should put on a spaghetti strand.
I’d think it’d depend more on the outside air pressure. You can’t have any less than a vacuum in your mouth. Outside air pressure is 1 atmosphere. Too bad I don’t remember how many PSI that is…
Say you already had the spaghetti in your mouth. Could you blow it out?
Vaccuum strength would be most easily measured as differential in air pressure. You will need a U shaped tube, open at one end, and sealed to a tube at the other. You suck on the tube, and cause the water to rise in the sealed end of the tube. I recommend that you make the tube some round numbered ratio of the U tube in area, such as one tenth, or one twentieth. Then figure the difference in the height of the column of water in the two legs of the tube, and the weight of the water, and compute the pressure difference necessary to lift that weight.
<P ALIGN=“CENTER”>Tris</P>
Never express yourself more clearly than you think.
–Neils Bohr
“To do her justice, I can’t see that she could have found anything nastier to say if she’d thought it out with both hands for a fortnight.”
Dorothy L. Sayers Busman’s Honeymoon
The “SLURP” at the end of the spaghetti tells it all.
A liquid in a straw isn’t really that different from a strand of spag.
Why are we still talking about this.
Peace,
mangeorge
I only know two things;
I know what I need to know
And
I know what I want to know
Mangeorge, 2000
Thanks a lot, Konrad. I never worried about noodle dynamics until you brought it up.
At first, the whole thing seemed very obvious. I mean that the force exerted on the noodle is just a function of the cross-sectional noodle-area and the pressure differential on either side of the “suck plane”.
It was even easy for me to explain (to myself) how it’s possible for air pressure to “push” something as limp and wobbley as a noodle, by examining the static conditions that exist during any particular moment, during the wobble.
Using a model where air pressure exerts equal force, on, and perpendicular to all points on the surface of the noodle, all forces are canceled by an equal and opposing force, except for total forces equal to, and perpendicular to, the aforementioned “suck plane”.(as established by the mean contact area of the lips)
Even though the entire noodle is not perpendicular to the suck-plane, angled components of the forces that are perpendicular to the noodle (at any point on the wobble) will be pependicular to the suck-plane. The opposing force components, parallel to an axis that’s pependicular to the suck-plane, will at any moment, during the wobble, reflect the difference shown by (square inches of the suck plane) multiplied by (delta PSI on either side of the suck-plane).
(What Seattle Tom was talking about in the other thread)
It seemed simple enough… until someone mentioned that two people could suck opposite ends of the same noodle.
Well that made my brain hurt, so I quit on the noodle.
…but I couldn’t help but start thinking about how suction exerts a force on a solid object that’s fixed on one end, and how that would seem to deny the model of that difference in affected areas.
Of course, the first example of a fixed-on-one-end-sucked object that came to mind was a breast (tittie).
How is it, that if you suck on one, that it stretches and moves through the suck-plane, without any apparent way for air pressure to be “pushing” it from behind?
Now I can’t get my mind off it … can’t sleep … can’t concentrate on anything but testing… and my research partner can’t quit squirming.
…and It’s all your fault … you just couldn’t leave it alone …
However, just to show you that there are no hard feelings, I’ll try to provide you with a simple method of measuring mouth-suction… just as soon as I can establish the K-value of a nipple.
Find a long tube or hose, stick the bottom end in a jar of water, and see how high you can suck it up. If the pressure in the mouth were the same as outside pressure (1 atmosphere), of course, the water in the tube wouldn’t rise. If it were a perfect vacuum, the water in the hose would rise about 30 feet. Just do the math from there. Doesn’t matter if the tube is not straight or not vertical - just measure the height (vertical distance only) of the top of the column of water relative to the water surface of the jar of water on the bottom.
Konrad, (for all the hell I know about it)
I think your reasoning is pretty sound on the first two.
The air pressure is for sure a factor. I also think that the sauce/air/noodle friction could also be a major factor, depending on the viscosity of the sauce, the surface texture of the noodle and the general noodle-sucking technique.
(air velocity, effectiveness of the seal, suck-turbulence, etc…)
…however, I don’t think that the third one (noodle expansion) would really affect the noodle acceleration very much. (especially if the suck-technique sacrifices seal effectiveness for additional sauce friction)… although I think you might be on to something there, as far as tittie dynamics go.
I guess the only way to tell for sure is to test it.
A vacuum gauge? I am not the leather-wearing hose-monster you read about in your pornographic Hot Latex Nuns on Harleys magazines. The suction I produce when eating spaghetti won’t register on a gauge that is used for… well whatever those gauges are used for… probably something that really sucks.
Right? Right? Why are you looking at me like that?
Vacuum gauges, like pressure gauges, come a varity of ranges.
You can get gauges with a full range display of anywhere from a few inches water column (typically used to measure the draft in a flue, or the suction casued by a dirty filter in an HVAC system) to full vacuum (approx -15 psig or 0 psia).
For reference, 28 inches water column is about equal to 1 psi, so a 3" or 4" water column gauge (fairly common in HVAC) is not much pressure.
In the more than you care to know department, the low range gauges are typically U-Tube manometers (or some variation on a U-tube) or a bellows activated mechanism instead of the bourdon (?sp)tube used on higher range gauges.
“You folks are kidding, right? You’ve never heard of a vacuum gauge?”
We would never kid about sucking noodles …or titties either, for that matter.
This is really serious stuF.
It’s just that sucking on things is more of an art than a science.
(It’s the human element of expressing your individuality through your own unique sucking technique that makes it so)
Should we compromise art for the sake of steENking science and mass-produced, mechanical contrivances?
Oops, seems I have stumbled upon and intruded into a particularly virulent strain of scientific investigation. I will now quietly fade into the background. But I am a card-carrying instrumentation technician in the petro-chemical industry, see, and I know about such things…ah well, no use, I can see that now…ttfn
“I’d rather have a bottle in front of me that a frontal lobotomy!” - W. Nelson
So where can I get me one of these so-called “vacuum gagues”? Would they sell them in hardware stores or would I have to look in er… “specialty” magazines… winkwinknudgenudge
Hope that works. If it doesn’t, search on Dwyer gauge (Dwyer is the manufacturer of a well known series of low pressure and differential prossure gauges and switches).