Speed of Light: A universal Constant?
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From: bz on 2 May 2005 18:56 H@..(Henri Wilson) wrote in news:v7ad71pae4docs5vg9o8h93cokkdvt5i1a(a)4ax.com: > S__p->__c-----------------------------------------A > > A source S sends a pulse of light towards Andromeda. > Connected to the source is a long rod with a clock on the end. > > The clock registers a time when the pulse passes by. > You didn't ask me, but I will answer. > are you one of those people who believes the clock > will register an infinite number of readings so as to accommodate the > nonsensical SRian claim that the pulse is moving at the same speed wrt > every object in Andromeda? If there is a rigid rod, then the clock at the end must be at rest wrt the source. Are we to assume the clock is sync'd with the clock at the source? If so, the clock clock can only register 1 time and that is going to be the time it takes light to travel the length of the rod at c. The observers in andromeda will each observe the pulse (assuming it spreads wide enough) as traveling at c. Each will measure the photon energy of the pulse as what would be appropriate considering their relative velocity wrt the source. -- bz please pardon my infinite ignorance, the set-of-things-I-do-not-know is an infinite set. bz+sp(a)ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap
From: Henri Wilson on 2 May 2005 20:08 On Mon, 2 May 2005 13:36:36 +0000 (UTC), bz <bz+sp(a)ch100-5.chem.lsu.edu> wrote: >H@..(Henri Wilson) wrote in >news:6lqb71ld557n8oeh66j8tchl5mnqam7a89(a)4ax.com: > >> Maybe my diagram didn't come out properly. >> I have fixed it (above). >> >> At 1km, the laser beam will diverge sufficiently to encompass both >> mirrors. > >Agreed. > >> >> It is then reflected back at c+2v and c-2v from both sides. >> >> Get it now? > >I understand the reflections now. > >>>> As the speed of the rotation is increased, any difference in travel >>>> time should be observable. >>> >>>I don't understand how the timing is going to be determined. >>>How is the time or the speed of the photons determined? >> >> The BaT predicts that the two reflected pulses will arrive back at the >> source observer 'O', at slightly different times. As te rotation is >> increased, the gap between hte pulses should widen, as seen on a CRO. > >I think that we need to look at how the reflected beams will travel during >the time that the mirrors are almost correctly aligned. > >It still isn't clear to me that the difference in arrival times of the two >beams is going to give us any information about the speed of the light. I hate to agree with Bilgey but the actual speed is irrelevant. All you want to do is show there can be a difference. > >.... >>>>>Again, each needs to be able to respond consistently. Neither needs to >>>>>be able to resolve the small difference in time between the light >>>>>hitting detector 1 and the light hitting detector 2. >>>> >>>> Then there is no point in having two detectors. >>> >>>The point is to measure the time it takes light to go from detector 1 to >>>detector 2. >> >> No you are introducing unnecessary complications. You only need one >> detector. > >You can use two rotating mirrors, one detector. >I will use two fixed detectors, no rotating mirrors? >OK No, it wont work as Bilgey explained. (once again I hate to agree with anything he says..but I said it first..he actually got the idea from me) > >>>We must have two detectors or play games with bouncing the light back to >>>the same detector from another mirror and THAT would require a very fast >>>detector and very stable optics. >> >> Correct...although there are no complicated optics....just a singe lens. >> >> The signals are likely to be only about 10^-10 secs apart. Maximizing >> the distance is an obvious requirement...but as distance is increased, >> for a particular rotation speed, the intensity of the spot decreases by >> the cube of the distance. >> Can you see why? > >Our response is based on photons per detector area. > >The area of a sphere increases as the square of the radius. This is why >light, etc decrease as the square of the distance. > >The intensity of the spot should follow inverse square law. The spot also flashes past at a speed proportional to the radius...so the energy PER FLASH impinging on a detector of constant size decreases by the cube of radius. Get it? > >If we were filling space with the energy and measuring the photons per unit >volume, the decrease would go as the volume of the sphere, which is cubic. That's true..read what I said. > >> >>> >>>My experiment does away with many of those problems. >> >> You are trying to measure the time taken for the c+v pulse to travel >> between the two detectors then in a separate experiment, measure the >> time for the c-v pulse to do the same. >> You cannot hope to achieve mirror speeds of more than about 3000 m/sec >> or 10^-5c. >> If the distance between your detectors is say 3000 metres, the travel >> time at 'c' is 10^-5 secs. >> So you are trying to measure a difference of 2 parts in 10^5 between two >> time intervals of approximately 10^-5 seconds. > >That is 10 microseconds. Measuring such things is easy. > >> >> that is a pretty hopeless task. > >Here is some CHEAP data collection hardware/software: > >http://www.picotech.com/picoscope-3000.pdf > >10 Giga Samples per second sampling rate >for the 800 POUNDS STERLING version. > >> In my single detector version, all that you have to do is synched the >> CRO trace with the rotation frequency and look for two blips on it >> rather than one. They should separate as the frequency increases. > >They are separated by time due to angular displacement which is dependent >on angular rotation velocity, mirror alignment, and perhaps the c+v, c-v. I >am not 100 percent sure that will work. > >The G forces and how they act on the mirrors will serve to confuse things. >I am not sure that there is any way to make sure which effect is causing >the blips to shift. That has to be considered. but the initial aim is to get a positive result. >> >> Same thing. > >Not at all. You have c+2v, I have c+v. You have g forces distorting the >position of the mirrors, I avoid that problem. No you don't. The laser mountings are just as likely to be distorted. >> >> It depends on the distance. Like I said, the spot intensity decreases >> with the CUBE of the distance. > >Everything I can find shows light decreasing as the inverse of the square >of the distance. Where do you get your cubic factor? I have now told you. The time the moving flash spends over the detector also decreases linearly with distance. > >>>> Something determines the time it takes to travel from its source to >>>> other places. What is that something? >>> >>>The distance. A moving source wrt the destination produces a different >>>distance for each wave crest to travel. >> >> No, that works for sound in air and possibly for light in a medium. >> >> But there is NO medium in this situation. > >I don't see anything in the above that REQUIRES media. You are claiming that property of space between any two points determines light speed between those points. That is straight aether theory. Space has no absolute properties. > >>>When we start to talk about photons, we have to realize that the >>>distance between source and destination changed during the time that the >>>EM field was going through one oscillation. This compresses or stretches >>>the the length of the photon. >> >> How can 'eventual target movement' affect the physical distance between >> 'wavecrests' of a remote beam of light. >> >> Do you think it changes every time the target moves.... it might be a >> billion lightyears away. > >The change takes place AT THE TARGET. That's the BaT concept. Good!! You are starting to see the light. > >>> >>>When the EM field oscillates faster, it induces a stronger reaction in >>>the detector, higher energy. Blue shifted. When the EM field oscillates >>>slower, it induces a weaker reaction in the detector, lower energy. Red >>>shifted. >> >> That's just doppler theory. We know all about that. It is about the same >> for SR, LET and the BaT at low speeds. > >right. > >> Read above. How could the wavelength be affected by all the possible >> eventual targets in the universe? > >Each target sees the wavelength that is determined by its velocity wrt the >source. What a target 'sees' is not what matters. The point is, nothing physically changes because of anything an observer does. > >> >> The true physical spacing between 'wavecrests' is not affected by any >> observer. > >That is like saying that there is an absolute frame of reference or an >absolute velocity. > >The 'true physical spacing' can only be observed by observers that are at >rest wrt the absolute frame of reference of the universe. Since no such >frame exists and all observers are 'in motion' wrt other observers, >there is no 'true physical spacing between 'wavecrests'. Here's an experiment. A source sends pulses of EM in a particular direction. Detween each pulse, it also fires a rigid rod, the ends of which are adjacent to the pulses. Do you sincerely believe that these rods change length every time a different observer looks at them? > >All are relative, relating the source and the observer. Contrary to what SRians believe, physics is not just about measurement. Physics is also about the realization that the universe doesn't depend on human perception for its existence. The Earth functioned quite well, over time and space, without human observers. >>>Interstellar gases are unlikely to change density during a normal >>>exposure time and thus unlikely to blur the images. >> >> Photons are not likely to be 'absorbed and re-emitted' when there is >> only one molecule per m3 either. > >How many cubic meters must a photon transit at that density before it >probably encounters a friendly molecule? > >Lets see. 2 grams of hydrogen is one mole, occupies 22.4 ltr at 1 atm. >That is 6.023e23 moles of hydrogen. A m3 contains 1000 ltrs. That gives >about 1.349E+28 molecules in a cubic meter of Hydrogen gas at STP. > >So we line up 1.349E28 meters and our light has, in effect, just passed >through hydrogen at STP. That is 1.426e12 light years. A bit bigger than >the universe. > >Of course, the estimate I have seen is for interstellar space is one >molecule per cubic cm. A million times denser than your figure. > >THAT would bring the distance down to 1.4e6 light years. MANY stars are >further away from us. This is all speculation. >>>> Which can only be specified in relation to the speed wrt their source. >>> >>>Right. But they will be moving at c, not at c+v. >> >> They are moving at c+v wrt the target. > >We obviously disagree on that point. > >> They only have ONE speed and don't know what their eventual target will >> be. > >They don't need to know that until they hit the target. At that moment, the >energy/wavelength is clear. So you think they don't possess energy and wavelength until they hit something? What properties are possessed by photons then? 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 2 May 2005 20:09 On Mon, 02 May 2005 13:59:45 +0200, YBM <ybmess(a)nooos.fr> wrote: >Henri Wilson a ýcrit : >> On Mon, 02 May 2005 04:17:19 +0200, YBM <ybmess(a)nooos.fr> wrote: >> please contribute something intelligent or remain silent. > >I did try to teach you something about computing... It ended up >as an impossible task. My programs work and do what I want them to do. I'm not trying to get a job as a programmer. 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: YBM on 2 May 2005 21:58 Henri Wilson a ýcrit : > My programs work and do what I want them to do. You're right : when they didn't crash they illustrate how and why you don't understand SR. > I'm not trying to get a job as > a programmer. Unfortunately you could, the computer industry is full of bad programers.
From: bz on 2 May 2005 22:04
H@..(Henri Wilson) wrote in news:i5cd71tp79n5atrotfacm8dm2s08jg5j48(a)4ax.com: > On Mon, 2 May 2005 13:36:36 +0000 (UTC), bz <bz+sp(a)ch100-5.chem.lsu.edu> > wrote: > >>H@..(Henri Wilson) wrote in >>news:6lqb71ld557n8oeh66j8tchl5mnqam7a89(a)4ax.com: ..... >> >>It still isn't clear to me that the difference in arrival times of the >>two beams is going to give us any information about the speed of the >>light. > > I hate to agree with Bilgey but the actual speed is irrelevant. All you > want to do is show there can be a difference. I understand that showing the time of flight light speed is constant (or that it changes) may be more difficult. ..... >>> No you are introducing unnecessary complications. You only need one >>> detector. >> >>You can use two rotating mirrors, one detector. >>I will use two fixed detectors, no rotating mirrors? >>OK > No, it wont work as Bilgey explained. (once again I hate to agree with > anything he says..but I said it first..he actually got the idea from me) Actually, he didn't say it wouldn't work. He just said it was more difficult and would require an expensive scope. >>> but as distance is increased, >>> for a particular rotation speed, the intensity of the spot decreases >>> by the cube of the distance. >>> Can you see why? >> >>Our response is based on photons per detector area. >> >>The area of a sphere increases as the square of the radius. This is why >>light, etc decrease as the square of the distance. >> >>The intensity of the spot should follow inverse square law. > > The spot also flashes past at a speed proportional to the radius...so > the energy PER FLASH impinging on a detector of constant size decreases > by the cube of radius. > > Get it? You are right. I get it. ..... >>> If the distance between your detectors is say 3000 metres, the travel >>> time at 'c' is 10^-5 secs. >>> So you are trying to measure a difference of 2 parts in 10^5 between >>> two time intervals of approximately 10^-5 seconds. >> >>That is 10 microseconds. Measuring such things is easy. >> ..... >>> In my single detector version, all that you have to do is synched the >>> CRO trace with the rotation frequency and look for two blips on it >>> rather than one. They should separate as the frequency increases. >> >>They are separated by time due to angular displacement which is >>dependent on angular rotation velocity, mirror alignment, and perhaps >>the c+v, c-v. I am not 100 percent sure that will work. >> >>The G forces and how they act on the mirrors will serve to confuse >>things. I am not sure that there is any way to make sure which effect is >>causing the blips to shift. > > That has to be considered. but the initial aim is to get a positive > result. Lets get an accurage result. BTW, if the mirror were continuous and properly balanced, I don't think the G forces would distort it significantly. Also, I saw a storage device using a light weight flywheel that spins at 100,000 rpm and has an edge velocity of 1000 m/s, so we can get higher speeds than I initially thought. .. >>Not at all. You have c+2v, I have c+v. You have g forces distorting the >>position of the mirrors, I avoid that problem. > > No you don't. The laser mountings are just as likely to be distorted. My laser is mounted at the center (it might even be mounted off of the disk entirely) and the output is guided to the edge of the disk via fiber optics. The fiber at the edge will be aligned to launch the laser beam tangential to the edge of the disk and will be firmly glued in place. The mass of a light fiber is very low, the G forces are not going to have much effect, at all. ..... >>> But there is NO medium in this situation. >> >>I don't see anything in the above that REQUIRES media. > > You are claiming that property of space between any two points > determines light speed between those points. > That is straight aether theory. > Space has no absolute properties. That is beside the point. As long as the travel time from detector 1 to detector 2 is constant and independent of source speed, BaT is invalidated. On the other hand, if travel time decreases with blue shift (approach) and increases with red shift (retreat) then SR is invalidated and BaT rules. ..... >>> Do you think it changes every time the target moves.... it might be a >>> billion lightyears away. >> >>The change takes place AT THE TARGET. > > That's the BaT concept. Good!! You are starting to see the light. I thought Bat sait the change takes place at the source ONLY. >>>>When the EM field oscillates faster, it induces a stronger reaction in >>>>the detector, higher energy. Blue shifted. When the EM field >>>>oscillates slower, it induces a weaker reaction in the detector, lower >>>>energy. Red shifted. >>> >>> That's just doppler theory. We know all about that. It is about the >>> same for SR, LET and the BaT at low speeds. >> >>right. >> >>> Read above. How could the wavelength be affected by all the possible >>> eventual targets in the universe? >> >>Each target sees the wavelength that is determined by its velocity wrt >>the source. > > What a target 'sees' is not what matters. > The point is, nothing physically changes because of anything an observer > does. So, If I (an observer) take a space ship toward the nearest star and accelerate at a constant 1 G (I have plenty of fuel). I don't see any blue shift in the light from the stars I am approaching? I don't see any red shift in light from our sun? >>> The true physical spacing between 'wavecrests' is not affected by any >>> observer. >> >>That is like saying that there is an absolute frame of reference or an >>absolute velocity. >> >>The 'true physical spacing' can only be observed by observers that are >>at rest wrt the absolute frame of reference of the universe. Since no >>such frame exists and all observers are 'in motion' wrt other observers, >>there is no 'true physical spacing between 'wavecrests'. > > Here's an experiment. Lets try this one first. A satellite is in orbit around the earth. There are uplink and downlink frequencies used in communications with the satellite. If your contention were true, the uplink would show no doppler shift, the downlink would show doppler shift. Why, then why it necessary to compensate for doppler shift of the downlink AND the uplink frequencies? [quote from http://services.eng.uts.edu.au/ ~samr/AjThoms/crcss/articles/IAC99_Paper.pdf] ..... Frequency Tracking Requirements The maximum Doppler shifts of the signals are +662.1 kHz for the 30 GHz uplink frequency and +441.4 kHz for the 20 GHz downlink frequency. Additionally, there will be large frequency errors from the transmit and receive earth station local oscillators and from the spacecraft local oscillators. The rapidly changing Doppler shift and slowly varying oscillator drifts are accommodated by the utilisation of a frequency acquisition and tracking algorithm. [unquote] > A source sends pulses of EM in a particular direction. > Detween each pulse, it also fires a rigid rod, the ends of which are > adjacent to the pulses. I assume the rigid rods travel at the same speed as the pulses. Magic rods with no mass so they can travel at C. > > Do you sincerely believe that these rods change length every time a > different observer looks at them? Only if the different observer is at a different velocity relative to the source. >>All are relative, relating the source and the observer. > > Contrary to what SRians believe, physics is not just about measurement. > Physics is also about the realization that the universe doesn't depend > on human perception for its existence. The Earth functioned quite well, > over time and space, without human observers. when I say observer, I am not talking about something alive. It could be an atom or a molecule or a PM tube or a coat of paint. Anything that will absorb a photon. >>>>Interstellar gases are unlikely to change density during a normal >>>>exposure time and thus unlikely to blur the images. >>> >>> Photons are not likely to be 'absorbed and re-emitted' when there is >>> only one molecule per m3 either. >> >>How many cubic meters must a photon transit at that density before it >>probably encounters a friendly molecule? >> >>Lets see. 2 grams of hydrogen is one mole, occupies 22.4 ltr at 1 atm. >>That is 6.023e23 moles of hydrogen. A m3 contains 1000 ltrs. That gives >>about 1.349E+28 molecules in a cubic meter of Hydrogen gas at STP. >> >>So we line up 1.349E28 meters and our light has, in effect, just passed >>through hydrogen at STP. That is 1.426e12 light years. A bit bigger than >>the universe. >> >>Of course, the estimate I have seen is for interstellar space is one >>molecule per cubic cm. A million times denser than your figure. >> >>THAT would bring the distance down to 1.4e6 light years. MANY stars are >>further away from us. > > This is all speculation. Speculation? What is speculative about it? Do you see an error in my calculations or the reasoning behind them? ..... >>> They only have ONE speed and don't know what their eventual target >>> will be. >> >>They don't need to know that until they hit the target. At that moment, >>the energy/wavelength is clear. > > So you think they don't possess energy and wavelength until they hit > something? I think that they get some energy from the radiation frequency, add or subtract energy for the velocity of the source, and, finally add or subtract more energy for the velocity of the target. You can even measure the gain or loss of KE of the source/target due to the radiation/absorbtion of the photon. > What properties are possessed by photons then? Spin, angular momentum, frequency, energy, polarity, and velocity. Speed is always c. Rest mass is always zero. -- bz please pardon my infinite ignorance, the set-of-things-I-do-not-know is an infinite set. bz+sp(a)ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap |