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From: PD on 23 Sep 2005 09:29 TomGee wrote: > PD wrote: > > TomGee has made a couple of logical and semantical errors, not the > > result of being stupid or recalcitrant, but because of incorrect > > preconceptions that he has not yet abandoned. > > > > > Um, PD? It ain't cool to talk to someone as if they ain't there. What > you learned folk call "in the 3rd person". I get that a lot from some > who just made a foolish statement that I could not let go unchallenged. > It means they have a fear of me and so they respond to others who are > there and respond to what I said as if I weren't there. I used to > think only the white folks did that, but ignorance has no ethnic > boundaries and it does not matter where they're from. This being a public forum, read by many, one occasionally makes a public observation. Believe me, fear has nothing to do with it. > > I have tried responding in kind, hoping they would take the hint, but > to no avail. So all I can do is ignore their little ignorant tactic of > conversation rather than to waste time telling them they have no reason > to fear me or the truth, as the pain that comes from learning the truth > will soon go away. That's an interesting statement from you, since you have said that teachers should avoid pointing out their students' mistakes, because it makes them feel stupid. You're right: the pain that comes from learning the truth will soon go away. But you seem to have a hard time accepting that for yourself. > By the time people do that to me, it is because > they're on the run from the verbal whipping I have administered to them > as punishment for misbehaving in our discussions. I see you take science to be a martial art. > Most of that is > behavior which shows they run from the truth and not necessarily from > me, so I understand their pain and I accept their "3rd-person > responses" not as cowardly behavior but the kind that makes us keep > coming back for more of the pain that comes from learning the truth > about what's reality and what's bullshit. > > > > > > TomGee has failed to recognize that, in logic, the statement "If A, > > then B" is completely equivalent to the statement "If not B, then not > > A". Their being equivalent means that both do not need to be explicitly > > stated. For example, "All female mammals feed their young from mammary > > glands," is completely equivalent to the statement, "If an animal does > > not feed its young from mammary glands, then it is not a female > > mammal." > > > > > Okay. That's tautologous, therefore redundant. It's not a tautology. (Look up "tautology" in Encarta.) But I'm glad you agree. > > > > > > In a similar vein, the statement "If a net force is impressed > > on a body, then the body accelerates," is completely, logically > > equivalent to "If a body is not accelerating, then there is no net > > force impressed on the body." TomGee feels the first can be true and > > the second one not necessarily be true, not realizing that the two > > statements are logically identical. And I suppose you agree with the above as well. > > > > TomGee also fails to recognize that the incompleteness of a statement > > does not affect its truth. For example, the statement "Some mammals > > ambulate on four limbs" is a true statement, even though it is also > > true that "Some mammals ambulate on two limbs, some mammals ambulate on > > two fins and a pair of flukes, some mammals ambulate on two limbs and > > two wings." Omitting the latter statements does not make the former > > statement untrue. > > > > > Wrong. I absolutely recognize and agree with your examples above. > > > > > > In the same way, the statement "A body only slows > > down as the result of a force acting on it" is true even though it is > > also true that "A body only speeds up as the result of a force acting > > on it" and "A body only changes direction as a result of a force acting > > on it." Omitting the latter two statements does not make the former > > statement false. > > > > > Maybe that's correct in the village you come from, PD, but that is > incorrect in the King's English. Your claim that the two statements > are equivalent is false because when you include the adverb "only", you > set a condition to indicate the one thing or person that solely or > exclusively happens or is involved in a situation. Thus your 2nd and > 3rd statements must stand alone individually and unrelated to each > other because the word "only" excludes any other thing or person from > each of the situations. You are partially correct. The relationship is sometimes called by logicians "into" as opposed to "onto". Here is one way to think about it. Effect: Body slows down Cause: Force acting on it Implication of "only": Effect requires presence of the cause. Note that the converse is *not* true. One cannot imply that the Cause implies the presence of the Effect. Why? Because a single cause can produce different effects (due to initial conditions). The relationship is not a one-to-one correspondence, nor is one required in a cause-effect relationship. In this case, the presence of the Cause can imply the Effect that the body slows down OR (in other circumstances) the Effect that the body speeds up OR (in other circumstances) the Effect that the body changes direction without change in speed. In this way, the presence of any one of the Effects implies the presence of the Cause, and the presence of the Cause implies the presence of *one* of its effects, though obviously not all of them simultaneously. Thus, all three of the following statements are correct: A body only slows down as a result of a force acting on it. A body only speeds up as a result of a force acting on it. A body only changes direction (with or without change in speed) as a result of a force acting on it. > > If your primary language is not English, PD, you are forgiven for not > knowing the many intricacies of the English language. Otherwise, you > missed too many classes in high school and that explains your poor > grammar. Well, I suppose this is one of those preconceptions that you have the option of working on. PD
From: Randy Poe on 23 Sep 2005 10:17 TomGee wrote: > PD wrote: > > TomGee has made a couple of logical and semantical errors, not the > > result of being stupid or recalcitrant, but because of incorrect > > preconceptions that he has not yet abandoned. > > > > > Um, PD? It ain't cool to talk to someone as if they ain't there. What > you learned folk call "in the 3rd person". As PD points out, it's fairly common on Usenet. It isn't "talking about a person as if they weren't there". Usually people are aware that the subject is reading what they're saying, and what is said is for that person's benefit as well. > I get that a lot from some > who just made a foolish statement that I could not let go unchallenged. > It means they have a fear of me Oh, the "fear" thing. The last refuge of the desperate crackpot. Would it affect your view of this "fear" if I told you that every single crackpot, no matter what crackpot theory they were pushing, eventually said something to the effect that "you are all afraid of me" or "you're afraid of the truth". Hint: when you start claiming telepathic powers by telling people what they're feeling and thinking, it makes you look even more like very other crackpot who has ever darkened these doors. It certainly doesn't bolster a case that you've got anything rational to sell. Do I get to use this line on the crackpots when they talk about me in the third person? > ...fear me or the truth... pain... learning the truth... > ... pain More telepathy, more "you're afraid of the truth". An old song. > > TomGee has failed to recognize that, in logic, the statement "If A, > > then B" is completely equivalent to the statement "If not B, then not > > A". Their being equivalent means that both do not need to be explicitly > > stated. For example, "All female mammals feed their young from mammary > > glands," is completely equivalent to the statement, "If an animal does > > not feed its young from mammary glands, then it is not a female > > mammal." > > > Okay. That's tautologous, therefore redundant. You've missed the point of logic being addressed here. Let me try to come up with something less "tautologous". "If you take a night flight to Chicago, you cannot connect to an Indianapolis train before 11:00." is completely equivalent to "If you connected to the Indianapolis train before 11:00, you weren't on the night flight to Chicago." > > In a similar vein, the statement "If a net force is impressed > > on a body, then the body accelerates," is completely, logically > > equivalent to "If a body is not accelerating, then there is no net > > force impressed on the body." TomGee feels the first can be true and > > the second one not necessarily be true, not realizing that the two > > statements are logically identical. Do you feel this is true? > Wrong. I absolutely recognize and agree with your examples above. Really? But I thought you have said that a body with velocity, even in the absence of force, will eventually run down to zero velocity. That is called acceleration in the absence of force. > > In the same way, the statement "A body only slows > > down as the result of a force acting on it" is true even though it is > > also true that "A body only speeds up as the result of a force acting > > on it" and "A body only changes direction as a result of a force acting > > on it." Omitting the latter two statements does not make the former > > statement false. > > > Maybe that's correct in the village you come from, PD, but that is > incorrect in the King's English. Your claim that the two statements > are equivalent is false because when you include the adverb "only", I think there's a subtlety of English you're missing. The word "only" does something very odd to a logical sentence: the part followed by "only if" is really the "then" clause. It took me a while to believe this when I first learned it, but you should be able to convince yourself it's true. That is, "A only if B" is really the logical statement "if A then B". Try it. "If X is a dog, then X is a mammal." True, right? "X is a dog only if X is a mammal." Also true, right? "X is a dog if X is a mammal." False, right? Come up with your own examples. So "a body slows down only as the result of a force acting on it" is equivalent to "a body slows down only if there is a force acting on it" (agree?) which by the above rules is equivalent to "If a body slows down, there is a force acting on it." > you > set a condition to indicate the one thing or person that solely or > exclusively happens or is involved in a situation. Thus your 2nd and > 3rd statements must stand alone individually and unrelated to each > other because the word "only" excludes any other thing or person from > each of the situations. Lots of words, signifying nothing. In English and in logic, the "only" has the function I said. Don't try to make abstract pronouncements about grammar, TRY IT. Construct some if-then statements you agree with, and try the "only if" construction. > If your primary language is not English, PD, you are forgiven for not > knowing the many intricacies of the English language. There's one you missed. - Randy
From: Herman Trivilino on 23 Sep 2005 10:35 "TomGee" <lvlus(a)hotmail.com> wrote ... >> > If you think you did not say it. then just what do you mean by F=dp/dt? >> >> Wow! Don't you know the difference between a quantity and its time rate >> of >> change? >> >> We can write v=dx/dt, where v is velocity and x is position. Do you >> think >> this means that velocity and position are equal? And that we can write >> v=x?! >> > So you don't know what he means by that either, eh? Yes, I do. He's talking about a derivative, or rate of change. In this case, its a rate of change with respect to time. p is the momentum. dp/dt is the rate at which p changes with time. F is the net force. He's claiming that F=dp/dt, a valid claim. You're claiming that F=p, an invalid claim. ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =----
From: Randy Poe on 23 Sep 2005 10:41 TomGee wrote: > Randy Poe wrote: > > TomGee wrote: > > > It would be a pity if you were right, but you contradict yourself > > > immediately by saying above that force and momentum are equivalent. > > > > Where did I say that? I would have snipped more, but I wanted > > to leave all the stuff you quoted from me so you can point > > me to the passage where you think I said F = p. > > > If you think you did not say it. then just what do you mean by F=dp/dt? That force is the derivative of momentum with respect to time. For instance suppose p is a constant in time, say p = 5. The F = dp/dt = 0. Five and zero are not the same. Suppose p is increasing linearly in time, p = p_0 + b*t Then F = dp/dt = b, a constant. The constant b and the linearly increasing function p_0 + b*t are not the same. - Randy
From: Herman Trivilino on 23 Sep 2005 10:44
"TomGee" <lvlus(a)hotmail.com> wrote ... > Then, Herman, what does E=mc^2 mean to you? It means that mass is a form of energy. When you are co-moving with respect to a composite body, the mass m that you measure of the composite body consists of two parts. It is the sum of the masses of each of the objects within the composite body PLUS the total energy (divided by c?) of those objects. In other words, when we measure the mass of a composite body we find that it consists not only of the masses of the components, but also the total of their energies. Thus we see that mass is just one of the many different forms of energy. That is what it means to me. Thanks for asking. That is one of my favorite questions to answer! ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |