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#69164 - 04/12/04 02:32 PM Formula
D. Caveny Offline
Ruler of the Roost

Registered: 07/16/02
Posts: 1102
Loc: Arizona
Are any of you familiar with this formula:

Pn + T (1/r + 1r') = P

P = internal fluid pressure
Pn = external pressure
r and r' = radii of curvature
T = tension of the envelope

It is the little known formula for egg shape and probably of no practical value since egg shape is highly heritable and can be changed rather easily by selection within most populations with normal variation between round and elongated.

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#69165 - 04/12/04 03:50 PM Re: Formula
Anonymous
Unregistered


This formula is similar to the formula for the pressure inside a water droplet suspended in air. The internal and external pressures are different largely because of the surface tension.

In fact the equation shows that, as the droplet gets smaller (1/r goes to infinity) the internal pressure grows without bound, which causes the droplet to evaporate more rapidly. This is exactly why fog is thermodynamically unstable.

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#69166 - 04/13/04 09:13 AM Re: Formula
Anonymous
Unregistered


Sorry I'm such a dummy, but I have to ask (I'm pretty sure I won't find it in past posts! LOL), What would be the practical use of the formula to us eveyday chicken lovers? (This is not a sarcastic question - I AM truly interested in most things scientific from a purely cerebral point of view. I love to learn something new.)

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#69167 - 04/13/04 09:23 PM Re: Formula
Sally Offline
Coop Keeper

Registered: 08/15/03
Posts: 686
Loc: Florida
ok, I know it's late and I should go to bed but I have to answer the question posted....I believe, with all my worldly knowledge, that the shape, pressure etc. has everything to do with the ability to "poke a hole ineach ends and blow that sucker out!!!!!" (sorry...couldn't help it, it was hearing about all Leees roosters earlier. eek laugh I'll NEVER be the same LOL
Sally
_________________________
sallyDIABLO

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#69168 - 04/14/04 05:30 AM Re: Formula
Anonymous
Unregistered


So, THAT'S IT!!!??

I figured somebody out there finally figured it out, whew! Too many sleepless nights, "darn it, there MUST be some some formula for this odd shaped thing...?"

Now that you've really got me wondering... Did someone actually measure a hundred or so eggs, average the size, calculate the curvature, the elongation, etc., to arrive at this? Or is another one of those things a computer figured out 'cause kid needed an "A" for his/her science project? How does one arrive at this kind of stuff - getting a mathimatical formula for an odd shaped physical object?

(The answer, no doubt, will be used to impress the wife and kids...)

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#69169 - 04/14/04 07:59 AM Re: Formula
D. Caveny Offline
Ruler of the Roost

Registered: 07/16/02
Posts: 1102
Loc: Arizona
If one were to tell you all the ideas that are investigated during ones graduate tenure you would wonder how many of these ideas originated let alone came to light. The important thing to know is that if one only thinks within a box of known items or thoughts that new ideas would never be developed. I suspect that the world would still think the sun rotates around the earth and other illogical ideas would still be present. I currently wonder how so many folks believe various disinformation often now popularized as "urban legends" which are so blatently stupid that one has to question whether or not the believers have even a second grade education let alone anything higher. When I brought up the formula I too was wondering why anyone would spend time concerning the shape of an egg unless it had something to do with strength and ability to withstand rough handling in the process of traveling from hen to consumer. In light of Lee's comment, I now wonder if this might also account for the variability of conductance during the incubation process and may have application as to how to incubate eggs to increase percentage of hatch by batching eggs according to size and then adjusting the microclimate within various zones of the incubator cabinet. Then again maybe I'm nuts for having such a thought. Incidently, the formula predates computers so it involved manual mathematical calculations and certainly a number of measurements to have a statistical accuracy which some mathematician would be much better qualified to comment on than I am or will be anytime in the future.

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