Another Larry Brasfield Self-Aggrandizing Put-Down Anecdote

Pulease...

When I say *puzzle*, perhaps I should have said "apparent discrepancy", or "poser", or something like that. It's not puzzling if you know the answer, of course.

Right, that's the trick with puzzlers, you lead people down the path, and they arrive someplace unexpected. Then, their job is to figure out why, or to find the flawed logic.

Just return to fundamentals when confronted by posers/shamans...

F =/= ma, except for CONSTANT mass

F = d/dt(mv)

Sir Isaac Newton first presented his three laws of motion in the "Principia Mathematica Philosophiae Naturalis" in 1686. His second law defines a force to be equal to the differential change in MOMENTUM per unit time as described by the calculus of mathematics, which Newton also developed.

...Jim Thompson

No, that is a consequence of doing the computation with a fixed mass rocket. If you let the mass of the rocket vary, then the rocket can achieve any velocity. My old physics book claims the final velocity is related by

Mf/Mo = exp(-vf/Vt)

where vf is the final velocity, Mf is the final mass, Mo is the initial mass, and Vt is the velocity of the thrust with respect to the rocket. Thus,

vf = Vt * ln(Mo/Mf)

Since Mf can get as small as you want, the final velocity can get as large as you want. Clearly, the more Vt you can get, the better off the situation is.

There is no reading between the lines required. *ALL* of your little anecdotes are the same: 1) Larry Brasfield is brilliant, 2) Larry Brasfield discovers associate who is not brilliant, 3) Larry Brasfield poses puzzle to associate, 4) associate collapses in wonderment at Larry Brasfield's brilliance, and 5) his/her/its life changed forever. This is all quite explicit and does not involve any inference-and your narration style also betrays a profound lack of intelligence on your part in the way you assume everything needs to be spelled out with no allowance for subtlety.

It seems that quite a few people have been misconstruing what you have said lately, Larry- maybe you need to get a clue, instead of insisting on the same tired old model of Larry educating the inferior world.

He is dropping posts left and right now. After shooting his mouth off in his usual vague and non-informational way in the "How to Verify the Correction of the Optical Encoder on Motor" thread, and then asked by the OP to clarify- he never responded. It doesn't take much to backlog that windbag.

Interesting little problem- let's solve it. Note that it is understood that Vt is relative to rocket V so that thrust exhaust products have velocity V-Vt. Then the total differential of momentum in time interval dt must sum to zero and this is -(V-Vt)*(dM/dt)*dt + (M+(dM/dt)*t)*(dV/dt)*dt + V*(dM/dt)*dt , where first term is increment of exhaust mass contribution to momentum, second term is rocket acceleration contribution, third term is rocket time rate of mass change contribution, and dM/dt is fuel burn rate V=-Vt*Ln(M) + k0 where ko=Vt*Ln(M0) by simple integration, and assuming V=0 at M=M0. Then V=-Vt*Ln(M/M0)=Vt*Ln(M0/M) or V/Vt=Ln(M0/M) in agreement with your textbook equation.

Well, I measured the zero-order effect, the initial leakage. And I measured the first-order effect, the linear increase in Ic with Ie. If there are higher-order effects, I didn't have the resolution or enthusiasm to resolve them. The linear effect was clearly the biggie.

Well, the only answer you provided was that it would go down.

"First order" doesn't mean "large"; it means linear on input. Or maybe you're using a different kind of polynomial than the ones I'm used to.

John

"Fred Bloggs" wrote in message news: snipped-for-privacy@nospam.com... [Referring to my absence of a little more than a half day]

usual vague and non-informational way in the "How to

by the OP to clarify- he never responded.

That's funny, Fred. You claimed to be amused by the "fact" (your claim) that "Electronic Swear" was a troll who had sucked me in. I went through most of that entity's recent posts to determine whether there was any substance to that claim, and decided you were right. Now, you would appear to take the position that not answering a troll's followup represents some kind of laxity.

All I can say to your effort is that I do know better than to worry about your opinion.

Hmmm. Had lunch with a friend, did some work, spent a few hours in the park with my grandson, and spent a pleasant evening with my wife. Yep, some burdensome backlog had me completely occupied.

If you are so smart, why have you not learned to stick to the evidence?

You prove my point here. Your "designed" conjecture can only result from imaginary remote mind reading skill or from cherry picking one of numerous interpretations of the sentence, "My physics teacher could not resolve it, (but, to his credit, that bothered him)." Here are some questions that you cannot answer (in any rational way) by reading the anecdote: - How much time was allotted for the attempted resolution? - To how many students was the attempt addressed? - What unstated constraints applied to the attempt? - What did that attempt involve in the way of explanation? - What ability or inability did the kid have to follow same? Take careful note of the word "resolve", with its implication of getting the kid to understand. It is neutral with respect to what the teacher actually knew.

You choose, for reasons I can only surmise, to interpret the "could not resolve" as a portrayal of incompetence. To do that goes beyond the evidence. Some equally consistent interpretations are: The attempt was cut short for unstated reasons. The discussion focused on E = m v^2 / 2 and why it applies to the rocket regardless of the puzzle. The offered explanations went over the kid's head. The kid was given an approach to work out on his own time and never got around to it. None of those implicates the teacher's competence and are equally supported by my wording of the anecdote.

There is, of course, the very real possibility that the teacher was taken in by the puzzle's implicit assumptions, at least for the time that he attempted to "resolve" it. I think to call somebody incompetent for that is highly inappropriate and conflates talent with infallibility.

My personal view of that teacher is, in fact, very favorable. He prepared his lectures and demonstrations very well, had an engaging manner of presentation, encouraged questions, and could usually find alternative ways of explaining what confounded some students (including myself). In addition, he made himself available after regular classroom hours for long discussions with students who wished to do so. During those sessions, (in which I and some friends partook), he was usually able to answer our questions and go on to illuminate interesting related issues.

I consider myself indebted to that teacher, (Mr. McMurtry of Seattle's Ingraham High in 1968), not only for his extra effort and dedication, but for being a friend as well during a difficult time. He proved that by efforts that went well outside of his classroom.

Because of my high regard for the man and his talent, I would never attempt to impugn his competence as has been so vilely proclaimed by a few ill-motivated people.

My anecdote is true, insofar as I am able to accurately remember the incident 37+ years later, and I would be craven beyond words to warp his effort(s) on my behalf into the ploy John and his pal(s) have tried to portray. I deny it, unequivocally and vehemently.

I further deny that I have any desire whatsoever to impress John Fields, Fred Bloggs, or anybody else who is willing to assume or invent the worst possible interpretation of sparse facts. In my estimation, such people's "good" regard is worth a tad less than nothing.

Their insult, (which I do not take personally), is the suggestion that I would court their good opinion in any way, let alone the despicable manner they have alleged. Their imagination to that effect is completely baseless.

Conjecture, speculation, and surmise. Your forte.

Why is your speculation and conjecture true? Is that what you're asking? You do realize, I should hope, that when you build speculation upon conjecture upon surmise, the result differs little from fantasy.

(John's speculation regarding his own speculation cut.)

In general, I will not be answering your conjectures and innuendos. This is more certain when they are obviously strung together flights of fancy and self-serving conclusion.

Why do you not deal with the merits? I was misconstrued; there has been no change of position, and your conjecture about why my answer was not complete and final is silly.

I never wrote "(emphasis mine)" or "_usually_" as "quoted" below.

So, do you mean to imply that you *could* blow it off if only you wished to take the time and did not prefer your usual conjecture and innuendo? Or are you merely suggesting it might be wrong if only you could learn the relevant subject matter and decide? You are a most amusing specimen.

You could consult my answer to him if you were actually interested in an answer instead of posturing. I think, given your absence in the b-e zener discussion and lack of device physics study, you really could care less.

Unless you have something intelligent to say in response to this, any reply of yours will likely [1] go unanswered. Your posturing, games, and habitually low tactics are too insufferable for me.

usual vague and non-informational way in the "How to

by the OP to clarify- he never responded.

Right- because it should have been a no-brainer to post a quick demodulator like you pretended to know about.

That is what you say, but what you mean is that you are withdrawing.

And in which of your alternative realities did this occur?

We don't play those games around here and you are in no position to dictate the rules.

is

Couldn't tell where this thread started so I think I'll edge in here. this thread is getting too long .. and the problem as its stated is completely offtrack. Anyone whos has a basic knowledge of Physical Chemistry knows that rocket fuel consumption / energy produced and so on isn't necessarily increase linearly with time. It actually depends on the type of fuel used and the rate reaction equations. I had the badluck in life to have to do with similar problems and so here is what I get. Using conservation of momentum.

Before ejection of fuel total Momentum of car + fuel in rocket = Mv. After a mass m of fuel is ejected

Momentum of rocket = (M-m)(v+dv)

Momentum of fuel= m(v+dv/2 -u).

Velocity of fuel = initial velocity + final velocity /2 - the velocity of fuel relative to rocket

=(v + (v+dv)/2) -u So (M-m)(v+dv) + m(v+dv/2 -u) = Mv

neglecting m.dv being an infinitesimal of second order (as m =-dM) =>

m/M = dv/u

also m = -dM

so integrating

M= Mo* exp(vo-v)/u Which implies KE is not constant and varies . where Mo , vo are initial Mass and velocity of the rocket.

If you need the acceleration just differentiate with respect to time the above expression using the product rule of differentials SO dM/dt = (dv/dt) * -1/u *Mo * exp (vo-v)/u

ACCN = dv/dt from which you can easily calculate the variation of the velocity and distance with time with the opportune integrations with respect to time or distance.

"John Larkin" wrote in message news: snipped-for-privacy@4ax.com...

...

I'm hoping, with some distortion analysis, to pull some of that out, if there. I don't expect any because I do not see more than one large input, (the tunnelled carriers), and its primary or direct effect is practically zero.

The only "answer" I provided was not, strictly speaking, an answer. I suppose one would be timely, (although it can be readily inferred from what I've stated). To wit: I do not predict the sign of the effect for either transistors having relatively low b-e breakdown voltage or those having b-e breakdown in the neighborhood of 6 V. This non-prediction is due to my awareness of several indirect effects, patiently explained to me by a couple of the more knowledgable interviewees I have had the pleasure of interviewing. There is more than one sign in that set, and I have little basis upon which to guess whichs ones will predominate in their summed effect.

I agree with your point that there is such a precise meaning for the term, and that I have abused the term in that sense. There is a common and still useful (I think) meaning which relates to effects that show up indirectly, often delayed or obscured in some way. I did not invent that usage.

Maybe. Who can say? Want a polynomial shootout? (It could be the most boring technical argument of all time.)

OK, I'll grant you that!

Don't go to any trouble. I did it.

So you and the interviewees for, I think you stated, 27 years, patiently pontificated on "indirect" effects, and never actually tried it? What's the point of abstractly philosophising on a transistor effect when you can't even decide on the sign, and you can measure it in five minutes?

And, as far as I can tell, you've posted thousands of words on the subject and you *still* haven't measured it.

This is silly.

John

"John Larkin" wrote in message news: snipped-for-privacy@4ax.com...

Your experiment is such a small sample that it does not answer the question either. Do you have reason to predict the same answer for a PNP, or an RF transistor, or a cooler one?

I believe somebody has already declared the uselessness of the effect. So running out to the lab was not a priority during or after those interviews. However, I did perform a similar experiment back when the question first arose in a practical context. The answer I got was "not much", and I could not tell you the sign to save my life because it did not matter.

As for "you ... pontificated", that has not happened. There is too much to discover in too little time during an interview to be spending time on anything as silly as that.

You've gone beyond the evidence again.

Ok, I have to agree, in this context. But that question has worked very well for interview purposes. I doubt that my employer's would consider it silly or misconceived.

I don't see what question you mean is not answered. You proposed a theory and suggested a result of an experiment based on this theory. An experiment has shown that the results do not match your theory. You have, as of yet, not proposed an adjusted theory that matches the expermental data we have. Until you have said "I have a theory X that predicts the results of experment Y as being Z" there really is no need for anyone to perform the experiment to test the improved theory.