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Some troubling assumptions of SR
In article ,
"George Dishman" wrote: "Mitchell Jones" wrote in message ... In article .com, "George Dishman" wrote: On 20 Mar, 21:21, Mitchell Jones wrote: In article , "George Dishman" wrote: "Mitchell Jones" wrote in message ... ... ***{Let's get concrete. Suppose we start with three identical digital clocks, all set to keep standard time here on Earth. Call them A, B, and C. Clock A remains on Earth, and clocks B and C are transported into a gravitational environment where, if the "gravitational time dilation equation" is correct, they will advance half as fast as the clock on Earth. Clock C then has a microchip implanted which doubles the rate at which it advances, causing it to advance at the same pace as clocks on Earth, and twice as fast as clock B. I say that the speed of light on Earth, measured using clock A, is 186,000 miles/sec. I say that the speed of light at the location of clocks B and C is 186,000 miles/sec when clock B is used, and 93,000 miles/sec when clock C is used. I say further that, since clock C has been calibrated to run at the same rate as standard time on Earth, it is correct, and clock B is incorrect. The implication: the speed of light at the location of clocks B and C is, in fact, 93,000 miles/sec. Do you agree or disagree? If you disagree, please insert a detailed explanation of your reasons after the sentence, above, which you believe to be incorrect. What you say above is ok, here's the problem. Accelerate an electron in a CRT using a potential of 1000V (checked with a voltmeter) and measure its speed next to clock A. You get some value. Now take the same kit and repeat the experiment next to clock B. You get the same answer. Now repeat but measuring the electron's speed using clock C. The speed of the electron is now half the previous value. Are you going to redefine the volt or the metre or the kilogram or the charge/mass ratio for an electron or what? ***{Why would we want to redefine anything? Because you can calculate the speed from the potential difference and the charge to mass ratio of the electron. Since neither has changed, the calculated speed must be the same Mitchell, I'm going to snip the majority of what you said, sorry. I'm not interested in your philosophical rambles, the experimental evidence is what matters to me though I'll correct a few other points in passing. ... , but your using clock C means the measured value differs. ... Nothing at all, but the kinetic energy of the electron when it hits the phosphor on your crt is unchanged so slowing it down isn't a viable explanation. ***{The duration coefficient is D = 2 in our hypothetical situation. That means clocks will have to be doubled in that situation, to make them keep standard time. Result: the electron will take twice as long to travel from the electron gun to the phosphor, and its average velocity over that interval will, in fact, be half what it would have been if the same CRT were operating on Earth. Exactly. However, the kinetic energy is 1/2 m v^2 and when that is measured, it is unchanged. The only explanation if you redefine clocks so that the speed is reduced ***{I'm not redefining anything. Calibrating all clocks to advance at the same rate--i.e., using Newtonian absolute time--is mandatory in the real world, because it is the only way to get things to work. They even do it with GPS. The reason is that you cannot coordinate actions if the people or devices that are supposed to cooperate are using clocks that run at different rates. Therefore I do not have to "redefine clocks so that the speed is reduced." The fact is that according to the clocks that are used whenever things need to actually get done, the speed of light is not a constant. That is simply a fact. Nobody uses Einstein's uncalibrated local clocks in the real world George! So please stop accusing me of redefining clocks. Nobody but a few sheltered nitwits in the academic world is enamored with Einstein's clocks, and the only purpose they use them for is to cover up the fact that, when real clocks are used, relativity falls apart. --MJ}*** would be that either the mass was increased or the law for kinetic energy was wrong and that's what I said to start with. ***{The possibility you steadfastly ignore is (a) that the mass decreased due to the loss of binding energy, (b) that the law for kinetic energy is correct, and (c) that the calculated answer near the event horizon of a black hole is not the same as the calculated answer here on Earth, due to the enormous difference in circumstances. What law of physics says we always have to come up with the same answers, George? --MJ}*** This is not an explanation; it is a statement of the plain results of measurement, when clocks calibrated to keep standard time are used. Clocks _are_ calibrated Mitchell, don't waste your time pretending they aren't. ***{In the workaday world they are, because they have to be. As noted above, activities cannot be coordinated, if the various factors involved use clocks that run at different rates. What that means is that people use clocks that, to extremely high accuracy, run at the rest-frame rate of T--that's big T, upper-case T-- in GR's "time dilation" equation: t = T[1 - 2GM/rc^2]^.5 Nobody uses clocks that run at t--i.e., little t, lower-case t--except a few pointy-headed academics, and even they only use them when they feel the need to bamboozle some sucker into believing that "all the experimental evidence supports the constancy of the speed of light in vacuo," or some similar piece of nonsense from the overflowing sewers of post-Humian irrationalism. --Mitchell Jones}*** The question is why, when relativists were confronted with the fact that the theory of relativity was falsified by measurement, did they respond by attempting to change the method of measurement? Nonsense, SR was published long before gravitational slowing of clocks was measured. ***{Yup, but Einstein could hardly have failed to notice that the SR "time dilation" equation only supported the constancy of the velocity of light when uncalibrated local clocks were used. After all, inside a space ship at, say .8c, the ratio t/T comes out as follows: t/T = [1 - (.8c)^2/c^2]^.5 = .6 That means one of Einstein's uncalibrated local clocks will advance .6 sec for every 1 sec advanced by a clock calibrated to keep standard time, and light in that locality will slow by exactly the same amount. Result: in .6 sec as measured by the uncalibrated local clock, light will advance (.6)(186,000) = 111,600 miles, and its speed according to that clock will be 111600/.6 = 186,000 miles/sec. According to the clock calibrated to keep standard time, however, the speed of the light will be 111,000 miles/sec. In other words, the kind of clocks used in the workaday world say the speed of light is not constant! You don't think Einstein noticed this? You don't think his awareness of it had just a teeny-weeny bit to do with his amazing postulate that only uncalibrated local clocks could be used to evaluate his theory? --Mitchell Jones}*** (In the world at large, of course, standard time has continued to be used, Nope, in the world at large time is measured by atomic clocks which run the usual way. Leap seconds are used to keep civil time in step with the slightly variable rotation of the planet. ***{You say "Nope," but then, oddly, you confirm what I have been saying--to wit: all clocks in the workaday world are calibrated to keep pace with standard time. The fact that standard time nowadays is defined by cesium atomic clocks that are occasionally adjusted to keep them in sync with Earth's orbital and rotational characteristics does not alter that key fact in the slightest. The practice of calibrating all clocks to keep pace with standard time is what is at issue here. That is the practice which cannot be followed, if the speed of light is to be deemed constant. I proved that, for the umpteenth time, just above. That's why Einstein stipulated that only uncalibrated local clocks could be used to evaluate his theory. --MJ}*** Frankly, that sort of an attitude just leaves me open mouthed with amazement. You are amazed that I assume the laws of physics are universal? ***{That remark was not directed at you in particular, but at the generalized class of people who behave in that way. (Whether you will ultimately fall into that category is yet to be determined. :-) What I intended to say was that I am amazed when I encounter inveterate refusal to accept the plain results of measurement. You are the only one doing that. Experiments including Sagnac's, the MMX, stellar aberration and so on ruled out all the aether theories other than an extended ***{You didn't do very well when you attempted to defend those claims, yet you remain unconvinced that they are wrong. Well, I'm not surprised. What that means is that it's time to agree to disagree, and draw this discussion to a close. --MJ}*** version of that proposed by Lorentz which preserves Lorentz invariance, and that means time must be defined a certain way if the laws of physics are to be universal. ***{Time is already defined by the requirements of the workaday world. We cannot coordinate our activities unless we calibrate all of our clocks to advance at the same rate, so that's what we do, and that procedure means it is T as measured in a rest frame, and not t, which is the proper measure of the speed of light, in situations where the "time dilation" equations apply. Result: the speed of light, unarguably, is a variable, not a constant. That's just the way it is. All measurements using clocks that have been calibrated to advance at the same rate support that conclusion. Period. End of story. --MJ}*** I accept the results of the measurements, you are trying to avoid those that rule out a dragged aether. ***{I am open to any arguments anyone wishes to toss at me in that regard, just as I was open to yours. It is my opinion that your arguments were unsound, and I believe I demonstrated that quite conclusively. In any case, I had my say and you had yours, and others will evaluate the outcome in accordance with their own concepts and preconceptions. Therefore it appears to be time to draw this to a close. --MJ}*** Relativists evidently do not like the results of measurement when clocks calibrated to standard time are used, and so they want to use uncalibrated clocks. Telling lies won't help you, scientific clocks are always calibrated to the internationally accepted standard. ***{Lies? My, my. What that tells me is that I was correct, above, in thinking I had conclusively demonstrated my conclusion, and also correct in thinking that this discussion is approaching the limits of its usefulness. Anyway, to repeat: the workaday world uses calibrated clocks of necessity. When GPS started out, for example, they tried using cesium clocks on the satellites, without calibrating them to run at the same rate as clocks on the ground. In effect, they were using Einsteinian proper time rather than Newtonian absolute time. That means the clocks on the satellites advanced at rates influenced by their lower gravitational potential and their higher speeds, while clocks on the ground kept standard time. Result: the clocks on the satellites got further and further out of sync with those on the ground, and GPS made larger and larger errors. Result: they turned on an onboard microcomputer, which began adjusting the readings of the onboard clocks, so that they advanced at the same rate as standard time on the ground, and that solved the problem. In other words, they had to use Newtonian absolute time to get GPS to work. They tried Einstein's uncalibrated local clocks, and they failed to get the job done. My point, therefore, is not that relativists advocate abandoning standard time in the workaday world. They wouldn't dare. The point, instead, is that relativists insist on using uncalibrated local clocks WHEN ATTEMPTING TO DEFEND THE SO CALLED LAW OF CONSTANCY OF THE SPEED OF LIGHT. Hopefully that distinction is clear enough for you to grasp, because it is all you are going to get. Once a discussion deteriorates to the point where one party calls the other a liar, its useful life is pretty much over. --Mitchell Jones}*** so that it says the same potential applied to an identical electron accelerates it to a lower speed ***{If I fire a bullet through the air, and then fire another one through water, you are willing to adust the calculation in the latter case to take the resistance of the water into account. Yet if I fire an electron through low-pressure aether here on Earth, and then fire one through high-pressure aether just above the event horizon of a black hole, you insist that the speeds ought to be the same. Frankly, that makes no sense to me at all. --MJ}*** Of course not, but then I don't accept that your aether exists so our assumptions differ, and what I am pointing out is that if an aether did exist and it slowed the electron down then the elctron would hit the screen with lower energy. That doesn't happen. An electron accelerated through 1V at ground level has trhe same kinetic energy as one accelerated through the same potential at the top of a hill. ***{There are no significant differences between the bottom and the top of a hill, but there are differences. Potential energy, for example is greater at the top of the hill, and it has mass; and, other things equal, speed will be slightly greater at the top of the hill than at the bottom. The differences, of course, are negligible for practical purposes. They are not negligible, however, when values at the surface of the Earth are compared to those just above the event horizon of a black hole. --MJ}*** George ************************************************** *************** If I seem to be ignoring you, consider the possibility that you are in my killfile. --MJ |
#582
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Some troubling assumptions of SR
"Mitchell Jones" wrote in message ... In article , "George Dishman" wrote: "Mitchell Jones" wrote in message ... In article .com, "George Dishman" wrote: On 20 Mar, 21:21, Mitchell Jones wrote: In article , "George Dishman" wrote: "Mitchell Jones" wrote in message ... ... ***{Let's get concrete. Suppose we start with three identical digital clocks, all set to keep standard time here on Earth. Call them A, B, and C. Clock A remains on Earth, and clocks B and C are transported into a gravitational environment where, if the "gravitational time dilation equation" is correct, they will advance half as fast as the clock on Earth. Clock C then has a microchip implanted which doubles the rate at which it advances, causing it to advance at the same pace as clocks on Earth, and twice as fast as clock B. I say that the speed of light on Earth, measured using clock A, is 186,000 miles/sec. I say that the speed of light at the location of clocks B and C is 186,000 miles/sec when clock B is used, and 93,000 miles/sec when clock C is used. I say further that, since clock C has been calibrated to run at the same rate as standard time on Earth, it is correct, and clock B is incorrect. The implication: the speed of light at the location of clocks B and C is, in fact, 93,000 miles/sec. Do you agree or disagree? If you disagree, please insert a detailed explanation of your reasons after the sentence, above, which you believe to be incorrect. What you say above is ok, here's the problem. Accelerate an electron in a CRT using a potential of 1000V (checked with a voltmeter) and measure its speed next to clock A. You get some value. Now take the same kit and repeat the experiment next to clock B. You get the same answer. Now repeat but measuring the electron's speed using clock C. The speed of the electron is now half the previous value. Are you going to redefine the volt or the metre or the kilogram or the charge/mass ratio for an electron or what? ***{Why would we want to redefine anything? Because you can calculate the speed from the potential difference and the charge to mass ratio of the electron. Since neither has changed, the calculated speed must be the same Mitchell, I'm going to snip the majority of what you said, sorry. I'm not interested in your philosophical rambles, the experimental evidence is what matters to me though I'll correct a few other points in passing. ... , but your using clock C means the measured value differs. ... Nothing at all, but the kinetic energy of the electron when it hits the phosphor on your crt is unchanged so slowing it down isn't a viable explanation. ***{The duration coefficient is D = 2 in our hypothetical situation. That means clocks will have to be doubled in that situation, to make them keep standard time. Result: the electron will take twice as long to travel from the electron gun to the phosphor, and its average velocity over that interval will, in fact, be half what it would have been if the same CRT were operating on Earth. Exactly. However, the kinetic energy is 1/2 m v^2 and when that is measured, it is unchanged. The only explanation if you redefine clocks so that the speed is reduced ***{I'm not redefining anything. Calibrating all clocks to advance at the same rate--i.e., using Newtonian absolute time.. That's a redefinition. The SI second is defined and scientific clocks use that definition. Civil time such as UTC is defined in a particular frame and measurements are converted where necessary. --is mandatory in the real world, because it is the only way to get things to work. They even do it with GPS. The reason is that you cannot coordinate actions if the people or devices that are supposed to cooperate are using clocks that run at different rates. Sure, but the laws of physics don't use civil time. Atoms don't care about UTC. Therefore I do not have to "redefine clocks so that the speed is reduced." The fact is that according to the clocks that are used whenever things need to actually get done, the speed of light is not a constant. That is simply a fact. Nobody uses Einstein's uncalibrated local clocks in the real world George! In the civil world, no but in science where accuracy matters they do. would be that either the mass was increased or the law for kinetic energy was wrong and that's what I said to start with. ***{The possibility you steadfastly ignore is (a) that the mass decreased due to the loss of binding energy, That would further _decrease_ the energy, and since an electron is a fundamental particle it doesn't have anything to be bound. You could suggest the mass of the electron is _increased_ so that you get the same energy for the lower speed. (b) that the law for kinetic energy is correct, and (c) that the calculated answer near the event horizon of a black hole is not the same as the calculated answer here on Earth, As far as I know, there is no "black hole" in my monitor where electrons are accelerated through several kV. due to the enormous difference in circumstances. What law of physics says we always have to come up with the same answers, George? The rule that the laws must reflect reality and accelerating an electron through 1V gives it an energy of 1eV regardless of where you do the experiment. I have only given a crude example but you asked above for me to "insert a detailed explanation of your reasons" if I disagreed. You should now understand why, it means that basic laws that work universally using the current scientific definition of time would not work. That's the problem 19th century physicists were facing and Einstein's correction of Newton's incorrect assumption that time in nature was absolute solved it. If you think you can make an aether theory work and thus regain absolute time, feel free to try but nobody has done it so far and dragged aether doesn't achieve it. George |
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