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John Fields John Fields is offline
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Default Momentum timer (From "re OT Sail downwind faster than the wind! on seb)

On Fri, 20 Aug 2010 08:34:12 -0700, John Larkin
wrote:

On Fri, 20 Aug 2010 06:01:25 -0500, John Fields
wrote:

On Thu, 19 Aug 2010 18:15:25 -0700, John Larkin
wrote:


Do the math and see how close it comes to the measurements.
Of course, you already know my guess *and* the experimental results.

Sure, do the math and post it.


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I've already done the math and found the 150 µs incongruous.



Yikes. My 10-second guess is better than doing the math.


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No. your guess was just that, a guess.

In the end, in order to understand the system and account for all the
incongruities, the math will have to be done.
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A lot less work, too.


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Of course.

And, from your point of view, since it's something NIH and you can't
get credit for it, the less time spent on it the better.
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The invitation was extended to you in order to see whether you'd
independently arrive at the same conclusions I did and, possibly,
either explain the incongruity or guess at the reason for it, so I'll
not post my work, yet.

The ball's in your court, so you can either hit it back or walk away.

As for me, this has gotten beyond tedious so I'm ready to quit any
time.


Hey, it's you project, all that woodwork and wiring and stuff. It's
not something I'd care to spend a lot of time on.


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Perhaps that's part of the difference between us; I'm willing to spend
money and use up some of my life in order to build an apparatus to
determine the validity of a hypothesis, while you'd rather go skiing.

To each his own.
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When the balls hit, there's a small initial contact area that squishes
down and becomes bigger with time, until the relative motion stops and
reverses. During that time, a complex shock wave progressively forms
as the contact footprint changes; it moves through the sphere, and
eventually arrives at the other side and does sort of the reverse
action on the next ball. That's absurdly complex, not something I'd
attack voluntarily.



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I think _you've_ made it absurdly complex.

Consider this:

The mass of the balls equates to inductance, their springiness to
capacitance, and the area of their contact to resistance, which bears
a pretty close resemblance to your example of charge sloshing back and
forth between inductances, through a capacitance, from an earlier
thread which you've obviously forgotten.
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You could crudely model the rocket or the three ball system in Spice
maybe, using transmission lines and diodes and such.


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Thrust hits the rocket from the rear and a shock wave propagates to
the front and then reflects back to the source of the thrust for the
source to push against?

How does that equate to the three ball problem?
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As a local redneck geezer likes to say, that's an exercize for the students.


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Indeed.

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JF