Ballistic Theory, Progress report...Suitable for 5yo Kids
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From: Jeff Root on 24 Aug 2005 07:42 Jim Greenfield replied to Jeff Root: > > Henri Wilson replied to Jeff Root: > > > >> >> Jim has every right to assume that most contributors to this > >> >> NG have some kind of intelligence which enables them to > >> >> occasionally apply their own deductive powers in cases when > >> >> every minute detail is not spelled out as though for a 2yo > >> >> kid.. > >> > > >> > Sure. But it still isn't clear what he meant by "two clocks", > >> > or how those two clocks are connected to the axle. George > >> > guessed that each of the two clocks has its own motor or other > >> > mechanism to make it run, since that is what makes them clocks. > >> > I, on the other hand, guess that Jim was talking about clock > >> > hands at each end of the axle, being driven by the rotation > >> > of the axle, which is, in turn, driven at its bottom end. > >> > > >> > George's guess may be right, or mine, or maybe both are wrong > >> > and Jim's concept is something else. Only Jim can say. > >> > >> If you have been following my discussion with George Dishman, you > >> would know what Jim and I mean. > >> > >> The rotation of the shaft itself can be used as a fixed time > >> duration reference. > > > > That was my guess of what Jim was trying to say. The rotating > > shaft, or axle, serves as a clock. However, when I suggested > > that to him, he replied that there are definitely two clocks: > > one at the bottom of the axle and one at the top. So it isn't > > clear what he really meant. > > > >> Its period doesn't need to be measured by any clocks. It can > >> be assigned the value of ONE time unit. If each of its ends is > >> connected to a rotating 'hand', the two hands must always be > >> rotating at the same angular speed and will both remain in > >> absolute synch. > > > > I agree, given certain restrictions on exactly what > > you mean by "angular speed" and "synch". The simplest way to > > do it would be for the 'hands' to just be marks on the side of > > the rotating axle-- or just a stripe running up and down the > > side of the axle. An ideal observer at the bottom would see > > the stripe twisted slightly by the time delay of the light > > from more distant parts of the axle taking longer to reach him, > > as Jim pointed out to me, but of course that twist is constant > > when the axle is rotating at constant speed, and it is only a > > simple illusion, not an actual twist in the axle. It isn't > > the effect you and Jim are interested in. > > > > Given that situation, the stripe will actually always be > > exactly straight up and down. The top end of the stripe will > > always be directly above the bottom end. Although an observer > > at the bottom will see the top end lagging behind slightly, > > and an observer at the top end will see the bottom lagging > > behind slightly. An observer at the middle will see both ends > > lagging behind slightly. > > Question: If I asked these observers what was the TRUE nature > of the line, should they not ALL use their "knowledge", and > agree that the line is straight and vertical? Of course. If they are aware that it takes some time for the light to reach them, they would realize that the curved appearence of the stripe is an illusion, and that it is really straight and vertical. The fact that the appearance of the stripe changes as the axle is brought up to speed, or as they move up and down the axle, would tell them that it takes some time for the light to reach them, if they didn't already know from prior experience. > ie, observers can be MISTAKEN in what they see, and draw WRONG > conclusions. Actually you just said the exact opposite of that. You suggested that the observers would NOT be mistaken, and I agree. They would certainly NOT be mistaken. It would be quite obvious to them what the reality is, and would NOT draw wrong conclusions. > Apart from that, you misunderstand; I say if time is passing > at a different rate, the twist will INCREASE if GR is correct. What do you mean by "time is passing at a different rate"? There was no mention of that in the thought experiment you quoted above. (Refined by Henri and myself.) If you want to introduce a new variable into the thought experiment, you need to say explicitly what it is, and how it relates to the rest of the thought experiment. If you want to fundamentally change the thought experiment, that is fine-- but you need to say what you have in mind. I can't guess. > ie a constant force must be acting to slow one end. That might be, but I don't know what you are talking about because you haven't expressed your ideas completely. > >> The shaft's period can be assigned the value ONE at both top > >> and bottom. > > > > Again I agree, with certain restrictions. The restrictions > > happen to be crucial to understanding what is going on, but > > I'm going to put off discussing them until we are sure we > > agree on the more basic aspects. > > > >> If a clock is sent from the bottom to the top and emits a > >> different number of ticks per shaft rotation at each location, > >> then the clock has obviously suffered some kind of physical > >> change as a consequence of being moved. The shaft period > >> certainly didn't change just because a clock was sent from one > >> end to the other. > > > > Okay. Your version of the thought experiment has two separate > > 'clocks': one is the huge, rotating axle, turning at a constant > > rate; the other is portable, ticking at a constant rate. > > > > I agree that moving a clock or an observer from one place to > > another has no effect on the period of the rotating axle. > > It seems awfully silly to say that it does. Sometimes when > > people say things that sound silly, or ridiculous, it is > > because they are speaking in their own dialect, and not yours. > > You might both think you are speaking the same language, and > > not even realize that you are using two different dialects, > > each with its own set of meanings. So what someone says in > > his own dialect can make perfect sense in that dialect, and > > sound like nonsense in the other. > > > > I'm attempting to communicate with you in your dialect. > > > > I agree that moving from place to place has no effect on the > > axle. That isn't much, but it is something we can agree on. > > > > Moving the portable clock also has no effect on the period of > > that clock. It continues to keep perfect time. It is an ideal > > clock, made by Santa Claus under God's direct supervision, so > > it keeps perfect time nomatter what happens to it or what kind > > of environment it is in. Heat and cold, electric fields, > > magnetic fields, high g forces-- nothing affects the perfect > > accuracy of this clock. > > OK; You say two clocks, connected top and bottom are really only ONE, I did NOT say that! I said the rotating axle can serve as a clock, and it can be read at both top and bottom. That is one clock. Using more clocks is fine, but I never said two clocks are one! > so I will ignore the top one, as it always reads the same as the > bottom. Now let's look at the atomic clock floating about near > the top one! What will it read after a lapse?? Later than it did before the lapse. You obviously still left something out of your question. You need to think through what you want to say, write it out carefully, then read it carefully to be sure it conveys what you mean. I suggest that you start from the beginning and describe the whole thought experiment, ending with the questions you want to pose. that way there will be less chance that you will inadvertantly leave something out or introduce ambiguities. > (attn George) > Once the axle is spinning, let it rotate on frictionless bearings, > with very energy efficient clocks (or one with hands at each end > of the axle, if you prefer). No motors now driving- why a twisting? There is no need to posit energy efficient clocks if the axle is spinning on frictionless bearings without motors. A tall, vertical, solid axle, rotating without friction at constant speed, will not become twisted. There is no reason for it to become twisted. Further, there are no forces on it which might tend to twist it. Also, notice that I didn't need to mention clocks or clock hands in that answer. They were irrelevant to the question. > > Actually, the best real clocks come very, very close to that > > ideal. They are tested under all kinds of extreme conditions, > > and if any variation is detected, the design is changed so the > > condition no longer causes any variation. The testing never > > stops, either. The clocks continue to be carefully tested > > years after they've been made. They are used every day for > > all kinds of precision measurements, positioning, and finding > > exact locations of things, often to within a few inches, all > > around the world. So it is very important that they be both > > accurate and precise, to do the jobs they're used for. > > Not worth a pinch of rocking horse manure! Atomic clocks keep time as precisely as claimed: to better than one part in 10^15, or less than 0.0000000001 second variation in 12 hours. They are depended on by millions of people every day to keep aircraft from colliding in flight, to measure the movement of tectonic plates at less than a centimeter per year, to observe radio emissions from distant galaxies with resolution far more detailed than the best optical telescopes (by long-baseline interferometry), and many more mundane applications. Considering that you referred to a "nuclear clock" when you clearly meant an atomic clock, I suspect that you know nothing at all about them or how they work. Considering that you thought the wheels in your car are connected together by a single axle, I suspect that you don't know how *anything* works. > If GR is correct, they will even vary with the moon's position, > not to mention the sun etc. It follows, that if these clocks are > NOT altering their periods, points on the earht's crust must be > changing velocity (speed). I doubt that this causes earthquakes. How about if you try to finish one thought experiment before starting another? > > You suggested above that the portable clock might tick some > > number of times per shaft rotation when at the bottom of the > > shaft, and a different number of times per shaft rotation when > > at the top of the shaft. I'm going to ask you: > > > > What makes you think that the clock might tick a different > > number of times per shaft rotation depending on where it is? > > Because Henri (devil's advocate) Wilson realises (sigh), that > IF real time is passing at a DIFFERENT rate with altitude, THAT > is absolutely required. I'll let Henri answer for himself: | Real clocks as used in the GPS system DO speed up slightly when | placed in free fall. | I am merely accepting observed facts. I hope that he'll say more specifically what "observed facts" he is referring to. As for your answer, you need to explain what you mean by your phrase, "real time is passing at a DIFFERENT rate". I can't guess at what you mean by it. -- Jeff, in Minneapolis
From: Henri Wilson on 24 Aug 2005 18:43 On Wed, 24 Aug 2005 09:55:36 +0200, "Paul B. Andersen" <paul.b.andersen(a)deletethishia.no> wrote: >Henri Wilson wrote: >> On Mon, 22 Aug 2005 10:40:34 +0200, "Paul B. Andersen" >> <paul.b.andersen(a)deletethishia.no> wrote: >> >> >>>Henri Wilson wrote: >>> >>>>The rotation of the shaft itself can be used as a fixed time duration >>>>reference. >>>>Its period doesn't need to be measured by any clocks. It can be assigned the >>>>value of ONE time unit. If each of its ends is connected to a rotating 'hand', >>>>the two hands must always be rotating at the same angular speed and will both >>>>remain in absolute synch. >>>> >>>>The shaft's period can be assigned the value ONE at both top and bottom. >>>> >>>>If a clock is sent from the bottom to the top and emits a different number of >>>>ticks per shaft rotation at each location, then the clock has obviously >>>>suffered some kind of physical change as a consequence of being moved. The >>>>shaft period certainly didn't change just because a clock was sent from one end >>>>to the other. >>> >>>Why is that obvious, Henri? >>>Why do you find it impossible that the shaft simply IS rotating >>>at a different rotational frequency at different heights? >>>It doesn't help that YOU call one rotation "one time unit", >>>if the lengths of those "time units" are different when >>>measured by local clocks, does it? >> >> >> It depends on how difficult you want life to be. >> >> You can either take the simple attitude that "the period of Jupiter represents >> a constant duration of time " or you can become quite absurd and claim that "it >> changes depending on how it is measured", ....whether you use a cesium clock or >> an egg timer.. >> >> You people seem obsessed with measurement. Don't you inderstand that the >> universe functioned perfectly well before human eyes even evolved? >> >> Time exists without human life. >> Jupiter rotated well before the Earth cooled. >> Its rotation period has occupied a fairly constant length of time ever since. >> It can be used safely as an 'absolute' time standard. >> >> So let's just define it as ONE TIME UNIT. >> >> >>>The only kind of "time" of interest in physics is the "time" >>>that have physical consequences, and determines the pace of >>>local physical processes such as clocks. >> >> >> The definition of Jupiter's period as ONE TIME UNIT has EXTREME PHYSICAL >> SIGNIFICANCE. > >To Jupiter. >But it is of no use if you want to boil your eggs. >Then you will have to use a local clock running with >the pace governed by the same laws of physics which >determine the coagulation of your egg. Do you agree that the ratio of Jupiter's rotation to Earth's rotation is constant and independent of measuring frame? > >Paul HW. www.users.bigpond.com/hewn/index.htm Sometimes I feel like a complete failure. The most useful thing I have ever done is prove Einstein wrong.
From: Henri Wilson on 24 Aug 2005 18:44 On 23 Aug 2005 18:58:27 -0700, "Eric Gisse" <jowr.pi(a)gmail.com> wrote: > >Henri Wilson wrote: >> On 22 Aug 2005 16:27:40 -0700, "Jeff Root" <jeff5(a)freemars.org> wrote: > >[snip] > >> >> A perfect clock should not change its rate no matter what happens to it.. >> >> Real clocks as used in the GPS system DO speed up slightly when placed in free >> fall. > >Speeding up in proper time? No. Speeding up in observed time? Yes. > >> I am merely accepting observed facts. > >You accept only the facts that support your worldview, the rest get >handwaved away or ignored. > >Read up on one one of the test sattelites for the GPS system. You have >been arguing this for years, you know what I am talking about. I have >mentioned it dozens of times, as have others. > >> I suggest that there are several reasons for the change in GPS clocks ...and >> none involves GR. > >Just because you say it, doesn't mean it is true. For how many years >will you repeat lies? > >Remember Henri, you are irrelevant. Nothing you say or do will ever >influence any physical theory nor the implementation of one. All you >can do is blow hot air. > >How are those fabled experiments that you mentioned several months >back? Still in the planning phase? Remember, a month in the lab saves a >day in the library. > >> >> > >> > -- Jeff, in Minneapolis >> >> >> HW. >> www.users.bigpond.com/hewn/index.htm >> >> Sometimes I feel like a complete failure. >> The most useful thing I have ever done is prove Einstein wrong. ignored.... HW. www.users.bigpond.com/hewn/index.htm Sometimes I feel like a complete failure. The most useful thing I have ever done is prove Einstein wrong.
From: Henri Wilson on 24 Aug 2005 19:00 On 24 Aug 2005 04:42:39 -0700, "Jeff Root" <jeff5(a)freemars.org> wrote: >Jim Greenfield replied to Jeff Root: > >> > Henri Wilson replied to Jeff Root: > >> If GR is correct, they will even vary with the moon's position, >> not to mention the sun etc. It follows, that if these clocks are >> NOT altering their periods, points on the earht's crust must be >> changing velocity (speed). I doubt that this causes earthquakes. > >How about if you try to finish one thought experiment before >starting another? > >> > You suggested above that the portable clock might tick some >> > number of times per shaft rotation when at the bottom of the >> > shaft, and a different number of times per shaft rotation when >> > at the top of the shaft. I'm going to ask you: >> > >> > What makes you think that the clock might tick a different >> > number of times per shaft rotation depending on where it is? >> >> Because Henri (devil's advocate) Wilson realises (sigh), that >> IF real time is passing at a DIFFERENT rate with altitude, THAT >> is absolutely required. > >I'll let Henri answer for himself: > >| Real clocks as used in the GPS system DO speed up slightly when >| placed in free fall. >| I am merely accepting observed facts. > >I hope that he'll say more specifically what "observed facts" >he is referring to. Ask Paul Andersen. He will tell you all about it. :) >As for your answer, you need to explain what you mean by >your phrase, "real time is passing at a DIFFERENT rate". >I can't guess at what you mean by it. Time flow cannot have a 'rate' unless there is another time dimension. .....and there is. Time normally flows at 1second(t1) per second(t2). Maybe 'timeflow' COULD BE affected by such things as gravity fields but even if it were, that would not imply that all made made clocks should change rates by the same amounts when moved between similar gravity potentials. > > -- Jeff, in Minneapolis HW. www.users.bigpond.com/hewn/index.htm Sometimes I feel like a complete failure. The most useful thing I have ever done is prove Einstein wrong.
From: George Dishman on 25 Aug 2005 04:24
<jgreen(a)seol.net.au> wrote in message news:1124864703.213704.5830(a)g14g2000cwa.googlegroups.com... .... > (attn George) > Once the axle is spinning, let it rotate on frictionless bearings, with > very energy efficient clocks (or one with hands at each end of the > axle, if you prefer). No motors now driving- why a twisting? No motors, no twist. Jim this is really easy. Think for a moment about a horizontal shaft to take GR out of the picture. If it has frictionless bearings and you start it spinning, it will continue to spin at that rate. Attach one end to a motor that rotates once every second and the shaft will rotate with the motor. Now attach the other end to a second motor that rotates twice per second. The shaft gets twisted and the power must come from the motors. That should be trivial so far. Now let's consider the vertical shaft. Attach a motor at the bottom and place a perfect clock next to it. Adjust the motor so it that rotates once per second as measured by that motor. Now place a second identical perfect clock at the top. By that clock, the shaft takes a little more than a second to rotate. If you attach a second motor that rotates once per second according to the top clock, the shaft gets twisted and again the power simply comes from the motors. This is only surprising if you make the assumption that time is universal hence if the bottom clock reads 1s per turn so should the top clock. George |