Speed of Light: A universal Constant?
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From: dralexgreen on 3 May 2005 06:32 Curiously it would not really affect SR if the speed of light were not equal to the constant in the Minkowski metric. It would just mean that light had some properties that are unknown at the present. In the early days of SR even de Broglie thought that photons might be 'atoms of light' with a definite mass. See: http://en.wikipedia.org/wiki/Special_relativity_for_beginners
From: bz on 3 May 2005 06:38 "G" <gehan(a)dialog.lk> wrote in news:1115110488.882759.129790 @f14g2000cwb.googlegroups.com: > Good luck with the rotating thing. A diagram would be nice. My proposed experiment: rotating disk beam splitter >> ---------------\---------->----------| << | detector 2 - detector 1 The beam splitter would be a shiny piece of metal with holes in it to allow most of the beam to pass through. It would not be a half silvered mirror. The rotating disk would be high strength carbon fiber with some fiber optics fibers going from the center to the edge and then along the edge for a short distance to launch the laser beam tangential to the edge. The laser would be mounted above the center of the disk, directed toward the center of the disk, optically coupled into the fiber. We may want to run another experiment with another fiber from center to edge, launching the light perpendicular to the edge, to look for doppler shift due to G forces and/or transverse doppler shift. Multiple fibers in each configuration could be used to improve signal to noise ratios. -- 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 3 May 2005 17:52 On 3 May 2005 01:54:48 -0700, "G" <gehan(a)dialog.lk> wrote: >Henri > > Not to defend SR-Ians too much but I think this is how the theory >goes: >I have been analysing it and will hopefully add to my diagram soon. > >"Simple analysis will show that the light pulse is catching up to the >spaceship >at c-v. " > >About this and the light pulse towards Andromeda: > > Not to defend SR-Ians too much but I think this is how the theory >goes: > >In the reference frame of the asteroid, the rod, the clock >(all are in one inertial reference >fame, not moving wrt each other) the speed of the sapcship >is measured as v, and the speed of light is measured as c, >that is, take the time it takes for the light to travel from >the asteroid to the point on the pole with the clock and it > will show the speed of light as c. > >The problem is with observers moving in Andromeda and also >those on the spaceship. They will measure the light speed as c, > that is they also place their rods with a clock on the end, >and measure the time it takes from the time the light passes >the clock to the time it reaches the bottom of the pole. >In their reference frame, and the since c is a constant, >what will they find? That the speed of light is exactly c. That is precisely what SR claims. It is basically the old aether concept..but without the aether. SR says everyone has his own personal aether. It is a purely unproven postulate. What is more, it has no bearing on the point I have made. Light moves from the source to Andromeda with ONLY ONE speed, not an infinite number. That is why light curves from varying binaries follow the predictions of the BaT. > >At least that is how the theory goes. Group am I correct? > >If the Andromedans had a long enough rod to reach the source, >they will find that the time for the journey makes for a value > of c. What about the person on the source ? Will they measure >the same light speed WRT to the rod? Yes because for them, the rod has >contracted and so the speed works out to c in that case as well at >least I think that is the theory. > >This is why we need experiments: cephid variables should settle it : >hope to have a look By and large, their brightness curves are just as the BaT predicts. > >In fact, maybe we should make a list of already done experiments >and published results and if they support or contradict SRT. > >Good luck with the rotating thing. A diagram would be nice. I hope bz can make the arrangements. > >G 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 3 May 2005 17:53 On Tue, 3 May 2005 10:38:57 +0000 (UTC), bz <bz+sp(a)ch100-5.chem.lsu.edu> wrote: >"G" <gehan(a)dialog.lk> wrote in news:1115110488.882759.129790 >@f14g2000cwb.googlegroups.com: > >> Good luck with the rotating thing. A diagram would be nice. > >My proposed experiment: > >rotating disk beam splitter > >> ---------------\---------->----------| > << | detector 2 > - > detector 1 > >The beam splitter would be a shiny piece of metal with holes in it to allow >most of the beam to pass through. It would not be a half silvered mirror. > >The rotating disk would be high strength carbon fiber with some fiber >optics fibers going from the center to the edge and then along the edge for >a short distance to launch the laser beam tangential to the edge. > >The laser would be mounted above the center of the disk, directed toward >the center of the disk, optically coupled into the fiber. > >We may want to run another experiment with another fiber from center to >edge, launching the light perpendicular to the edge, to look for doppler >shift due to G forces and/or transverse doppler shift. > >Multiple fibers in each configuration could be used to improve signal to >noise ratios. Forget this one. 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 3 May 2005 18:15
On Tue, 3 May 2005 08:23:27 +0000 (UTC), bz <bz+sp(a)ch100-5.chem.lsu.edu> wrote: >H@..(Henri Wilson) wrote in >news:25vd71t3tmebj977tft966i2i7am3vok1v(a)4ax.com: > >> On Tue, 3 May 2005 02:04:20 +0000 (UTC), bz <bz+sp(a)ch100-5.chem.lsu.edu> >> wrote: >> Pretty good glue. > >An epoxy. The same thing that holds together the carbon fibers of the disk >itself. > >>>The mass of a light fiber is very low, the G forces are not going to >>>have much effect, at all. >> >> It is just as practical to glue a couple of mirrors onto it. >> Balance is critical of course. > >Any useful mirror will be much more massive that an optical fiber. Have >you ever played with fiber optics? You don't seem to have much understanding of practical physics. Your 'fibre' has to be a certain diameter or you wont get enoung light through it. The laser will melt it. A thin mirror will be much lighter. It also gives you c+2v. > >.... >>>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. >> >> Of course. That's what we are looking for. > >good, we are agreed on this. > >>>>>> 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 said the change takes place at the source ONLY. >> >> No. Wavelength, frequency and speed are all measured in the source >> frame. > >We can measure them in any frame but everything except the speed will be >different in different frames. See, you are already indoctrinated. Ther is absolutely NO proof that light speed is c in all frames. It is an old aether concept. > >.... >>>> 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? >> >> Of course you do. >> The speed of the light relative to you is increasing or decreasing so >> the 'wavecrests' pass you at different rates. >> >> But the light doesn't change in any way simply because you are looking >> at it! > >Correct. But saying 'the light doesn't change in any way' could be taken >to say 'the light will look the same in every way as it would if I were at >rest'. No it is NOT te same. Light that is traveling through space does its own thing, independent of observers. > >However when I measure the energy, it will be different. >The frequency I measure will be different. >The wavelength I measure will be different. >But the speed with still be c. That's a postulate not a fact of life. OWLS from a moving source has never been measured. >> >> That's about doppler shift due to movement. It has nothing to do with >> GR. > >I have been understanding you [or some other BaT advocates] as saying that >ALL doppler shift is due to c'=c+/-v. And I understood you as saying that >the shift all takes place at the source, none at the observer. > >Have you changed your mind or did I misapprehend you? You misunderstood completely. > >>>> 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. >> >> Aything can travel at any speed relative to anything else...if you can >> find enough energy to get it there. > >There doesn't appear to be enough energy in the universe to move anything >with rest mass at c wrt anything in the universe. 1/2mc^2 is a large quantity of KE. > >> The reason few things in the universe are moving very quickly wrt other >> objects is pure and simple. It is like a gas at 2.7K. It is very >> difficult to accelerate anything to near c wrt its original state. > >or wrt any other state. There are gas outbursts from various supernovae that appear to be traveling wrt Earth 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. >> >> There is no connection between the observer and the light as it travels. >> I am talking about an 'intrinsic' change in the light. > >And what 'intrinsic' properties does light have? >I assume'intrinsic' means a property that is NOT source or destination >dependent. > >Speed, spin (?), angular momentum, rest mass. Those are 'intrinsic' >properties. I don't know of any others. Bilgey will try to tell you that a photon is a point particle with no properties except energy. He claims all photons are identical. Just goes to show what an idiot he really is. > >.... >>>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. >> >> It doesn't even have to absorb anything. It can be a potential observer. > >Agreed. > >>>>>>>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? >> >> You will find all kinds of figures for the density of space. > >I used your figure for the first set of calculations. I used another >estimate for the second. > >There should be some the lower and upper limits for concentration of >molecules in 'clear' space. > >I showed that if the concentration is 1 molecule per cc, then the effect >on the light of traveling 1.4 million light years would be the same as >traveling through 1 meter of hydrogen at STP. You cannot assume that. > >>> >>>You can even measure the gain or loss of KE of the source/target due to >>>the radiation/absorbtion of the photon. >> >> Look, there is only one way you can make meaningful statements about >> ,eg, the H alpha line photon. > >There is more than one way to make meaningul statements but I agree with >your next line: > >> It has a certain energy and wavelength in its source frame. > >Agreed. AND I say that the photon will be found to be traveling at c wrt >any observer's frame of reference. If that frame is different from the >source frame the energy/frequency/wavelength will be different from that >observed in the source frame. The speed will NOT be different. That comes from aether theory. An observer's rods and clocks both 'contract' by exactly enough to make OWLS always measured as 'c'. Einstein merey did away with the ONE absolute aether and made OWLS constancy a postulate. I repeat, there is absolutely no proof. > >> All similar photons have the same properties in their respective source >> frames. Why would anyone want to make claims about its properties in any >> arbitrary frame. It would be totally useless. > >Not useless, it explains observed red and blue shifts. So does changing relative lightspeed. > >>>> What properties are possessed by photons then? >>> >>>Spin, angular momentum, frequency, energy, polarity, and velocity. >>> >>>Speed is always c. >> >> wrt its source. > >Wrt its source. Wrt any target. Why should you think that. > >>>Rest mass is always zero. >> >> maybe..but debatable. >> What constitutes mass. > >E = m c^2 / sqrt(1 - v^2/c^2) > >so m = (c^2 / sqrt(1 - v^2/c^2))/E The term 'gamma' is a myth based on Einstein's erroneous assumption that a vertical light beam in one frame becomes a diagonal beam in another. My demo: www.users.bigpond.com/hewn/movingframe.exe shows why. 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. |