accereration 101

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>[mechanic]
The term "infinite acceleration" can be used by an abstract mathemetician but should not be part of the vocabulary of a physisist. If it is, then that physisist is indeed very confused.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>
Mathematics is an indispensible tool for the Physicist. So of necessity the Physicist's vocabulary must include the vocabulary of the Mathematician.

Some of the <b>very useful</b> things a Physicist can do with math have counterparts in the real world, and <b>some don't</b>. Being a Physicist means learning the difference.

But before you can learn the difference, you have to understand that there is a difference. And that it matters. Until then you will in fact be very confused. Perhaps even to the point of believing that non-physical results from Mathematics should be avoided by Physicists.

Regards,
LB

From Larry

But before you can learn the difference, you have to understand that there is a difference. And that it matters. Until then you will in fact be very confused. Perhaps even to the point of believing that non-physical results from Mathematics should be avoided by Physicists.

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Larry, if you can say something productive please do so. You are not being productive here. Your statements don't make sense. You contradict yourself. You don't make any sense. Read your own words carefully:

"Perhaps even to the point of believing that non-physical results from Mathematics should be avoided by Physicists"

Don't you think if something is non-physical it should be avoided by those studying the physical? If you don't you're simply mixing the physical and the non-physical. If you doing so, you'll indeed get very confused at some point down the road. Your statement proves you are.

Listen Larry; Jim had a specific question which I tried to answer and contribute to the discussion in a productive way. You seem to wanna play with words. That's not fair to anyone here. Physics is about observations Larry. Observe an infinite acceleration, mesure it and then join the discussion. That's why in real physiscs, not message board physics, people rely on observations.

Time to fix some cars. Down under a Bronco a few seconds.

[... continued]

Are you familliar with the concept of an "ideal" component from the world of Engineering? Ideal resistors and ideal springs don't and can't exist in the real world, but Engineers use them all the time in analysing the machines they think about. The <b>non-physical</b> nature of ideal components does not make them useless.

But the Engineer <b>knows</b> that when it comes time to do the detailed design of his toy he <b>cannot</b> use ideal components. At least not if he wants the real gizmo to work.

And guess what? Sometimes a preliminary design (where the analysis is usually done with ideal components) can't be <b>successfully</b> translated into a real product because of the differences between real components and ideal components. Part of what makes experienced Engineers more valuable than new graduates is that they have seen this before and can factor it in at an earlier and therefore less expensive stage of the design process.

Perhaps when Physicsts use non-physical doohickeys from Mathematics we should refer to them as "ideal [whatever]"? The Mathematician's impulse or step function would become the Physicist's ideal impulse function or ideal step function.

Getting everybody to go along with something like this would be hard. Why should they change just for the benefit of a few students that are struggling?

Regards,
LB

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>[mechanic]
Don't you think if something is non-physical it should be avoided by those studying the physical? <hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>No. But it should be avoided by those who do not <b>yet</b> understand the difference.
<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>[mechanic]
Listen Larry; Jim had a specific question which I tried to answer and contribute to the discussion in a productive way. You seem to wanna play with words. That's not fair to anyone here. Physics is about observations Larry. Observe an infinite acceleration, mesure it and then join the discussion. That's why in real physiscs, not message board physics, people rely on observations.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>I'm sorry this is still confusing for you. I'm probably not doing as well as I need to be doing in the explanation department. But I realy am trying. And I really am not just playing with words. These are important parts of a Physics education.

You say "in real Physics people rely on observations", and this is true. It is also true that in real Physics people rely on logic and analysis and analogy and ANYTHING ELSE that can help them understand, and (perhaps even more important) help them <b>convey</b> that understanding to others. So now you have some obvservational data and you want to analyse it - you want to figure out what it means - you want to understand what is going on in the real universe. How do you do these things?

It helps to be familliar with the history of this sort of inquiry, so you don't waste a lot of time thinking about things that have already been done. Such familliarity also makes it easier for you to recognize when a new result actually supports returning to an older idea. Or moving to a new one.

It also helps to be familliar with Mathematics (and with its history). Even though much of math is non-physical it is still a very useful tool for the Physicst. The Physicist <b>KNOWS</b> that an infinite acceleration cannot occur in the real world. But for certain analysis purposes he can pretend, just like the Mathematician. And it is <b>useful</b> to do so, as long as you actually understand the difference.

It also helps to be familliar with... Hell, it helps to be familliar with <b>everything</b>. This isn't possible in the real world either, so we make do with what we have and try to get more. Always try to learn more. And always keep in mind the possiblilty that something you know is wrong.

[continued...]

From Larry

The Physicist KNOWS that an infinite acceleration cannot occur in the real world. But for certain analysis purposes he can pretend, just like the Mathematician. And it is useful to do so, as long as you actually understand the difference.

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I don't like people who pretend Larry, for any reason.

From Larry

Are you familliar with the concept of an "ideal" component from the world of Engineering? Ideal resistors and ideal springs don't and can't exist in the real world, but Engineers use them all the time in analysing the machines they think about. The non-physical nature of ideal components does not make them useless.

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Larry, you are a very confused person. An ideal resistor is one obeying stricly V=iR. An ideal resistor doesn't allow one to claim infinite resistance exists. This is not a good example of yours. You are very much confused. Ideal components are used by engineers because to get approximate solutions. When accuracy is required one must take in account the inductunce and capacitance effects present in every real wire and engineers can also do that as well. No engineer or physicist will confuse "ideal" components with mathematical results such as a zero voltage drop resulting from an infinite resistance. You do however.

You proving you are very confused. Your confusion keeps mounting further because a confused individual will get even more confused as his confusing thoughts perplex his own mind. As a result, you now confuse ideal components used in the modelling of real systems to getting approximate solutions needed in real world problem with mathmematical abstractions such as zero and infinity.

Everyone has zero of everything Larry and nothing of infinity. Everyone has zero yatchs, zero limousines, zero villas, zero submarines, zero offices at the White House. Find me a piece of wire with a zero, absolutelly zero, resistance or one with an infinite resistance I'll give you a penny. Even superconductors have some resistance.

I don't like people who pretend

I don't like people who confuse others to convey their own distorted vies of reality.

I suggest to all who think in such terms to get their sleeves up and try to fix something to get an idea of how reality works.

I don't like arm chair scientists

Better review your distorted perception of physics and engineering Larry.

Time to fix some cars, so at least get up to some acceleration

Fascinating ...

I rest my case.

Regards,
LB