Speed of Light: A universal Constant?
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From: bz on 30 Jun 2005 08:25 H@..(Henri Wilson) wrote in news:s7e7c1pu2p6dhipa07l6upr7oru6msuoft(a)4ax.com: > On Thu, 30 Jun 2005 02:35:37 +0000 (UTC), bz > <bz+sp(a)ch100-5.chem.lsu.edu> wrote: > >>H@..(Henri Wilson) wrote in >>news:iua6c192htva42b8dkla55und6pg6991ok(a)4ax.com: >> > ..... >>I disagree. By BaT, slower photons and more rapid photons are arriving >>at the same time. This is what makes the star look brighter. > Nah! > Below the critical distance no light overtakes any other. > Light from certain parts of the orbit bunches together. Light from other > parts becomes more dispersed. Then Algol can not be used as an example of a c' variable as it is a spectroscopic binary. >>These photons will have different doppler shifts. >>They will be arriving at the same time. >>This will broaden the lines. > > No you are wrong on that one Bob. Run the 'wavefront' section of my now > improved program and you will see. > >> >>> One must also remember that all the stars we are considering are in >>> orbit around something else and that something may or may not be cool >>> and dark. So two distinct doppler patterns may be observed. That is >>> the case for the star HD 81075 that Andersen keeps harping on. It is a >>> binary pair of roughly equal size and in near circular orbit. >> >>If the 2nd body is cool & dark, there should NOT be signs of >>spectroscopic binarys. No doubling of spectral lines. Cepheid don't >>usually show doubling of spectral lines. Of course cepheids may also be >>part of a spectroscopic or even optical binary system. In those cases >>you should see double lines. >> >>Of course, if the stars are different types, you will see the lines >>characteristic of each type of star, showing doppler shift, but not >>doubling, unless the lines represent lines found in both types of star. > > My theory is that most variables stars are either rotating around dark > partners OR the partner is of such different size that its velocity is > very different and it is way below the critical distance to the > observer. > > The two members of a binary pair don't share the same critical distance. You need to develope a 'critical distance' formula, so that the term can be rigorously defined. Is this correct: beyond the critical distance, a star no longer displays the effects of BaT? Or is this correct: below the critical distance, BaT effects can not be observed? ..... >>> In any practical experiment, path lengths of millions of kms are >>> required to compare OWLS from differently moving sources. >>> There is not much chance of finding them in a lab. >> >>Practical experiment and path length of millions of kms do not go >>together. >> >>We do NOT need OWLS to establish c'=c+v. >>All we need is a rapidly moving source that we can control the speed of >>and TOFLS. > > Bob, do the sums please. You keep asking ME to do the same. I did, and shewed them later in this article. ..... >>>>But, before c+v/c-v light is acceptable, it MUST be demonstrable in >>>>the laboratory or someone is going to have to come up with a very good >>>>explanation of why it is NOT observable. Henri has NOT come up with >>>>such an explanation. >>> >>> But you simpy cannot perform an experiment of this nature on Earth. >>> Even if you did it on the tops of two high mountains 30 kms apart, the >>> biggest travel time differences are going to be too small to detect. >> >>It could be done with a good scope. We don't need 30 km. 3 would do >>fine. >> >>2,500 mph, 3700 ft/s is 3.72 ppm of c. >>We should be able to measure a change of 3 ppm in the speed of light, >>shouldn't we? >> >>A 10 cm radius disk spinning at 106,722 rpm would give you that kind of >>speed at the edge. Ultra centrifuges spin that fast. >> >>So, we have to run in a vacuum. Spin both ways, you have 7.44 ppm. >>Light travels 3000 meters in 10 microseconds. >>If we used a 3 km path, we could expect to see changes equivalent to 1.1 >>cm change in path length. > > light takes about 3E-11 to move that far. 3.7e-11 seconds. That is 37 pico seconds. In the age of femto second laser pulses, that is an eternity. TDRs can see discontinuities 1.5 mm apart on a transmission line. http://www.picosecond.com/objects/4020_high_res_TDR.pdf So it is certainly possible to capture and display our data with sufficient time resolution. And we only need to see how much it CHANGES when we change the speed of the source. >>Short term stability is all that is needed. We just need long enough to >>spun up and down in both directions. > > You do it Bob. I wonder how many BaT enthusiasts there are in the world? If there are 1000 and we can get each to kick in 500 bucks, we can do it. We rent the equipment for 30 days and run the experiment. >>> The maximum practical source velocity is never going to be much larger >>> than about 0.0000002c. (Remember you must be able to determine its >>> exact position). You will be trying to detect time differences of >>> around 10^11 seconds. >> >>You are talking about 1e-5 ppm. I am talking about 6 ppm. >>You are talking about 134 mph. I am talking about 2500 mph. >>You are talking about 5721 rpm. I am talking about 100,000 rpm. > > You are talking about measuring the light travel time, NOT the > diffference in two travel times. I am talking about the time for light to travel between two detectors. Recording that time for several different source speeds. > Your '6ppm' is what you need to measure OWLS to one significant figure. I don't need to know the absolute speed of light, just compare it as the source speed is changed. >>Of course, if you want higher speeds, rifles have muzzle velocities of >>over 5000 fps. Fire a mirror or laser like a bullet. > > You have to know exactly where it is when it reflects/emits the light. That is easy to determine, you just have it 'break' a beam of light. You used two such beams to measure the bullets velocity. You bounce pulses off of the front surface continuously. If you build a laser into the projectile, you have it emitting pulses continuously. >>> It's just not on....even today. >>We can get much higher than 134 mph. > > Sorry I was a factor of ten out there. 0.000002c. > > That involves spinning a one metre circumference (1ft diam) wheel at > about 300 rps) or 18000 rpm. 1 metre is 3.281 feet. :) I would rather spin a smaller wheel at a higher speed. We get more pulses. And the technology is already there in the laboratory ultra centrifuge. Regardless, it is possible to do. > So the time differences you want to resolve are around E-10. Maintaining > a constant distance might be the biggest problem. > We can measure the distance with another laser beam from a stationary source right next to the rotating source [and securely mounted to the same baseplate that the spinning source is mounted on.] ..... >>I look forward to seeing the improved version. > > It's up there now. ..... >>I try to treat everyone with respect. >>I enjoy communicating with people that treat others with respect. > > So do I. > These groups are a lot of fun as well as being contructive. I agree. -- 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: bz on 30 Jun 2005 10:19 H@..(Henri Wilson) wrote in news:hp01c1lh3je73ctsvk8ltttsih401i30q9(a)4ax.com: > On Mon, 27 Jun 2005 00:11:03 +0000 (UTC), bz > <bz+sp(a)ch100-5.chem.lsu.edu> wrote: > >>H@..(Henri Wilson) wrote in >>news:t0eub1hpcakkobuqmr4es4skmjtjlt2957(a)4ax.com: >> >>> On Sun, 26 Jun 2005 16:23:07 +0000 (UTC), bz >>> <bz+sp(a)ch100-5.chem.lsu.edu> wrote: >>> >>>>H@..(Henri Wilson) wrote in >>>>news:sv6tb1p8jmhh8n2lmi2eb044igt0s1kqki(a)4ax.com: >>>> >>> >>>>>>> >>>>>>> "Delta Cep is one of the few easily-visible variables, its >>>>>>> magnitude changing from 3.5 to 4.3 and back over an amazingly >>>>>>> regular period of 5 days 8 hours 47 minutes and 32 seconds, the >>>>>>> star acting like a natural clock. " >>>>>>> >>>>>> >>>>>>The data would seem to indicate that the author of the phrase quoted >>>>>>might have waxed a bit too much about the regularity of the waining >>>>>>of Delta Cep. >>>>> >>>>> He wouldn't say it acted like a clock if it wasn't pretty stable. >>>>> You can look at any long term pixel curve on the britastro site and >>>>> see that most star curves appear dead constant over many years. >>>> >>>>The degree of regularity seems to have been over emphasized. >>>>Dead constant over many years seems to mean that when the data is >>>>collected and averaged over many years the fit is not TOO bad. >>>>However the degree of fit should have been reported. >>> >>> Here is another reference: >>> http://weblore.com/richard/ru_cam_ex_cepheid_star.htm >>> >>> "Cepheids are known for their precise variability which can be >>> measured to a fraction of a second." >> >>'can be measured to a fraction of a second' does not necessarily mean >>'is constant to a fraction of a second'. >> >>There is no question that some cepheids are 'regular' for some period of >>time. There is also no question that most, if not all cepheids show some >>variations. > Weren't you the one who recently accused ME of moving the goalposts? Which goalposts did I move? I have been trying to show you that the 'constancy of the cepheid' is overblown. >>There is a question as to whether some people seem to have exaggerated >>the regularity of cepheids. > The BaT would predict that the periods of most cepheids should steadily > increase or decrease by varying degrees due to 'time compression'. So, eventually the period reaches infinity or zero? >>He specializes in positional astronomy. >>http://weblore.com/richard/ >> >>> >>> You cannot run away from the truth forever, Bob. >>I am searching for truth, Henri. > The speed of all starlight is not miraculously adjusted so that it > leaves its source at c wrt little planet Earth. And AE says quite clearly that the earth is not unique. Every FoR throughout the universe sees the same miracle. > Why don't you retaliate with this theory: > Light leaves stars at an infinite range of speeds. WE on Earth can only > detect that which is moving at c wrt us. It would require an infinite amount of energy to run my flashlight. > That should make you think. It might not be as silly as it sounds. It is only viable if you throw away the principles of conservation of mass and energy. >>>>Each theory has its consequences. >>>>Double stars such as you describe are known to exist but they exhibit >>>>characteristics quite different from cepheids. >>> I am pretty certain the above type of star in elliptical orbit and in >>> tidal lock would exhibit a cepheid like brightness variation. >>Cepheids show some distinctive characteristics, such as rapid cyclic >>shifts in stellar type. > That is related to observed brightness and 'estimated' size. > I would expect variations in estimated luminosity. That is relative to the shape of emission spectrum and the absorption lines in the spectrum after doppler shift is correct for. It is related to the size and temperature of the star. BaT should not cause changes in the type of star. Only changes in the atmospheric chemistry of the star can do that. -- 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 -- 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 1 Jul 2005 04:14 On Thu, 30 Jun 2005 12:25:49 +0000 (UTC), bz <bz+sp(a)ch100-5.chem.lsu.edu> wrote: >H@..(Henri Wilson) wrote in >news:s7e7c1pu2p6dhipa07l6upr7oru6msuoft(a)4ax.com: > >> Nah! >> Below the critical distance no light overtakes any other. >> Light from certain parts of the orbit bunches together. Light from other >> parts becomes more dispersed. > >Then Algol can not be used as an example of a c' variable as it is a >spectroscopic binary. Stars that are regarded as eclipsing binaries may not be. The same curve is produced by the BaT, using only one star. As I pointed out elsewhere, the companion star can eiethr be 'cool0 or its velocity may be such that it is well away from the distances required to affects its brightnes curve. >>>These photons will have different doppler shifts. >>>They will be arriving at the same time. >>>This will broaden the lines. >> >> No you are wrong on that one Bob. Run the 'wavefront' section of my now >> improved program and you will see. >> >>> >>>> One must also remember that all the stars we are considering are in >>>> orbit around something else and that something may or may not be cool >>>> and dark. So two distinct doppler patterns may be observed. That is >>>> the case for the star HD 81075 that Andersen keeps harping on. It is a >>>> binary pair of roughly equal size and in near circular orbit. >>> >>>If the 2nd body is cool & dark, there should NOT be signs of >>>spectroscopic binarys. No doubling of spectral lines. Cepheid don't >>>usually show doubling of spectral lines. Of course cepheids may also be >>>part of a spectroscopic or even optical binary system. In those cases >>>you should see double lines. >>> >>>Of course, if the stars are different types, you will see the lines >>>characteristic of each type of star, showing doppler shift, but not >>>doubling, unless the lines represent lines found in both types of star. >> >> My theory is that most variables stars are either rotating around dark >> partners OR the partner is of such different size that its velocity is >> very different and it is way below the critical distance to the >> observer. >> >> The two members of a binary pair don't share the same critical distance. > >You need to develope a 'critical distance' formula, so that the term can be >rigorously defined. > >Is this correct: beyond the critical distance, a star no longer displays the >effects of BaT? beyond the CD, multiple images can be expected. >Or is this correct: below the critical distance, BaT effects can not be >observed? The critical distance is very dependent on radial velocity. Many stars are just too close to exhibit much variation. In the case of a pair whose masses are very different, the velocity of the larger one might be only a fraction of that of the smaller. So one star might show considerable variation in brightness while the other appears almost stable. the spectrum would still show the opposite doppler shifts of both. >>>We do NOT need OWLS to establish c'=c+v. >>>So, we have to run in a vacuum. Spin both ways, you have 7.44 ppm. >>>Light travels 3000 meters in 10 microseconds. >>>If we used a 3 km path, we could expect to see changes equivalent to 1.1 >>>cm change in path length. >> >> light takes about 3E-11 to move that far. > >3.7e-11 seconds. > >That is 37 pico seconds. >In the age of femto second laser pulses, that is an eternity. > >TDRs can see discontinuities 1.5 mm apart on a transmission line. >http://www.picosecond.com/objects/4020_high_res_TDR.pdf > >So it is certainly possible to capture and display our data with sufficient >time resolution. > >And we only need to see how much it CHANGES when we change the speed of the >source. > >>>Short term stability is all that is needed. We just need long enough to >>>spun up and down in both directions. >> >> You do it Bob. > >I wonder how many BaT enthusiasts there are in the world? >If there are 1000 and we can get each to kick in 500 bucks, we can do it. We >rent the equipment for 30 days and run the experiment. But it would have to be done on a couple of high mountains. Atmospheric effects would drown the time differences you are looking for. > >>>> The maximum practical source velocity is never going to be much larger >>>> than about 0.0000002c. (Remember you must be able to determine its >>>> exact position). You will be trying to detect time differences of >>>> around 10^11 seconds. >>> >>>You are talking about 1e-5 ppm. I am talking about 6 ppm. >>>You are talking about 134 mph. I am talking about 2500 mph. >>>You are talking about 5721 rpm. I am talking about 100,000 rpm. >> >> You are talking about measuring the light travel time, NOT the >> diffference in two travel times. > >I am talking about the time for light to travel between two detectors. > >Recording that time for several different source speeds. > >> Your '6ppm' is what you need to measure OWLS to one significant figure. > >I don't need to know the absolute speed of light, just compare it as the >source speed is changed. > >>>Of course, if you want higher speeds, rifles have muzzle velocities of >>>over 5000 fps. Fire a mirror or laser like a bullet. >> >> You have to know exactly where it is when it reflects/emits the light. > >That is easy to determine, you just have it 'break' a beam of light. >You used two such beams to measure the bullets velocity. > >You bounce pulses off of the front surface continuously. >If you build a laser into the projectile, you have it emitting pulses >continuously. > >>>> It's just not on....even today. >>>We can get much higher than 134 mph. >> >> Sorry I was a factor of ten out there. 0.000002c. >> >> That involves spinning a one metre circumference (1ft diam) wheel at >> about 300 rps) or 18000 rpm. > >1 metre is 3.281 feet. :) You didn't read properly. Overworked today, maybe.... I said 'metre circumference'. That is about 1 foot diameter. > >I would rather spin a smaller wheel at a higher speed. We get more pulses. >And the technology is already there in the laboratory ultra centrifuge. > >Regardless, it is possible to do. One foot diameter. > >> So the time differences you want to resolve are around E-10. Maintaining >> a constant distance might be the biggest problem. >> > >We can measure the distance with another laser beam from a stationary source >right next to the rotating source [and securely mounted to the same baseplate >that the spinning source is mounted on.] Best if you can use the same source and a couple of mirrors, one moving and the other not....then you can be certain that the emission times are within the required tolerance. ..... >>>I look forward to seeing the improved version. >> >> It's up there now. >.... >>>I try to treat everyone with respect. >>>I enjoy communicating with people that treat others with respect. >> >> So do I. >> These groups are a lot of fun as well as being contructive. > >I agree. 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 1 Jul 2005 04:16 On Wed, 29 Jun 2005 21:07:19 -0700, "N:dlzc D:aol T:com \(dlzc\)" <N: dlzc1 D:cox T:net(a)nospam.com> wrote: >Dear bz: > >"bz" <bz+sp(a)ch100-5.chem.lsu.edu> wrote in message >news:Xns9684DBB983C2WQAHBGMXSZHVspammote(a)130.39.198.139... >... >>> But you simpy cannot perform an experiment of this >>> nature on Earth. Even if you did it on the tops of >>> two high mountains 30 kms apart, the biggest travel >>> time differences are going to be too small to detect. >> >> It could be done with a good scope. We don't need >> 30 km. 3 would do fine. >> >> 2,500 mph, 3700 ft/s is 3.72 ppm of c. >> We should be able to measure a change of 3 ppm >> in the speed of light, shouldn't we? > >"We" bounce light off of very high energy electrons to generate >TeV photons for further experimentation. There is no surprise >that total_path_length / (time_of_detection - time_of_emission) = >c. The resulting energy is boosted by as much as gamma^2, >depending on the reflection angle. How much room does this leave >for c' <> c? Wishful thinking again.... Don't sprout propaganda Smithy. > >David A. Smith > 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: bz on 1 Jul 2005 11:34
H@..(Henri Wilson) wrote in news:2st9c1h5qs4fi28oeqafls5t4pc0bqqjko(a)4ax.com: > On Thu, 30 Jun 2005 12:25:49 +0000 (UTC), bz > <bz+sp(a)ch100-5.chem.lsu.edu> wrote: > >>H@..(Henri Wilson) wrote in >>news:s7e7c1pu2p6dhipa07l6upr7oru6msuoft(a)4ax.com: >> > >>> Nah! >>> Below the critical distance no light overtakes any other. >>> Light from certain parts of the orbit bunches together. Light from >>> other parts becomes more dispersed. >> >>Then Algol can not be used as an example of a c' variable as it is a >>spectroscopic binary. > > Stars that are regarded as eclipsing binaries may not be. Of course not. Of course, you must then explain the spectroscopic data, the doppler shift data as well as the photometric data. All are consistent with an eclipsing binary. > The same curve is produced by the BaT, using only one star. > As I pointed out elsewhere, the companion star can eiethr be 'cool0 or > its velocity may be such that it is well away from the distances > required to affects its brightnes curve. All data must be consistent. Stellar type is inconsistent with BaT. >>>>These photons will have different doppler shifts. >>>>They will be arriving at the same time. >>>>This will broaden the lines. >>> >>> No you are wrong on that one Bob. Run the 'wavefront' section of my >>> now improved program and you will see. >>> >>>> >>>>> One must also remember that all the stars we are considering are in >>>>> orbit around something else and that something may or may not be >>>>> cool and dark. So two distinct doppler patterns may be observed. >>>>> That is the case for the star HD 81075 that Andersen keeps harping >>>>> on. It is a binary pair of roughly equal size and in near circular >>>>> orbit. >>>> >>>>If the 2nd body is cool & dark, there should NOT be signs of >>>>spectroscopic binarys. No doubling of spectral lines. Cepheid don't >>>>usually show doubling of spectral lines. Of course cepheids may also >>>>be part of a spectroscopic or even optical binary system. In those >>>>cases you should see double lines. >>>> >>>>Of course, if the stars are different types, you will see the lines >>>>characteristic of each type of star, showing doppler shift, but not >>>>doubling, unless the lines represent lines found in both types of >>>>star. >>> >>> My theory is that most variables stars are either rotating around dark >>> partners OR the partner is of such different size that its velocity is >>> very different and it is way below the critical distance to the >>> observer. >>> >>> The two members of a binary pair don't share the same critical >>> distance. >> >>You need to develope a 'critical distance' formula, so that the term can >>be rigorously defined. >> >>Is this correct: beyond the critical distance, a star no longer displays >>the effects of BaT? > > beyond the CD, multiple images can be expected. But you have cited critical distance as a reason to NOT to see variation in brightness, haven't you. >>Or is this correct: below the critical distance, BaT effects can not be >>observed? > > The critical distance is very dependent on radial velocity. Many stars > are just too close to exhibit much variation. They MUST be close for short variable cycles. You can't get wide separation and rapid orbiting without velocities that are inconsistent with the observed doppler shifts. > In the case of a pair > whose masses are very different, the velocity of the larger one might be > only a fraction of that of the smaller. So one star might show > considerable variation in brightness while the other appears almost > stable. the spectrum would still show the opposite doppler shifts of > both. But it will show the velocities of each. Those must be consistent with the orbital periods. In a two body system, the periods must be equal. The more massive object must move slower and in a smaller orbit >>>>We do NOT need OWLS to establish c'=c+v. > >>>>So, we have to run in a vacuum. Spin both ways, you have 7.44 ppm. >>>>Light travels 3000 meters in 10 microseconds. >>>>If we used a 3 km path, we could expect to see changes equivalent to >>>>1.1 cm change in path length. >>> >>> light takes about 3E-11 to move that far. >> >>3.7e-11 seconds. >> >>That is 37 pico seconds. >>In the age of femto second laser pulses, that is an eternity. >> >>TDRs can see discontinuities 1.5 mm apart on a transmission line. >>http://www.picosecond.com/objects/4020_high_res_TDR.pdf >> >>So it is certainly possible to capture and display our data with >>sufficient time resolution. >> >>And we only need to see how much it CHANGES when we change the speed of >>the source. >> >>>>Short term stability is all that is needed. We just need long enough >>>>to spun up and down in both directions. >>> >>> You do it Bob. >> >>I wonder how many BaT enthusiasts there are in the world? >>If there are 1000 and we can get each to kick in 500 bucks, we can do >>it. We rent the equipment for 30 days and run the experiment. > > But it would have to be done on a couple of high mountains. Atmospheric > effects would drown the time differences you are looking for. Do it in a vacuum chamber to avoid extinction. http://www.ligo.caltech.edu/LIGO_web/200002news/200002han.html >>>>> The maximum practical source velocity is never going to be much >>>>> larger than about 0.0000002c. (Remember you must be able to >>>>> determine its exact position). You will be trying to detect time >>>>> differences of around 10^11 seconds. >>>> >>>>You are talking about 1e-5 ppm. I am talking about 6 ppm. >>>>You are talking about 134 mph. I am talking about 2500 mph. >>>>You are talking about 5721 rpm. I am talking about 100,000 rpm. >>> >>> You are talking about measuring the light travel time, NOT the >>> diffference in two travel times. >> >>I am talking about the time for light to travel between two detectors. >> >>Recording that time for several different source speeds. >> >>> Your '6ppm' is what you need to measure OWLS to one significant >>> figure. >> >>I don't need to know the absolute speed of light, just compare it as the >>source speed is changed. >> >>>>Of course, if you want higher speeds, rifles have muzzle velocities of >>>>over 5000 fps. Fire a mirror or laser like a bullet. >>> >>> You have to know exactly where it is when it reflects/emits the light. >> >>That is easy to determine, you just have it 'break' a beam of light. >>You used two such beams to measure the bullets velocity. >> >>You bounce pulses off of the front surface continuously. >>If you build a laser into the projectile, you have it emitting pulses >>continuously. >> >>>>> It's just not on....even today. >>>>We can get much higher than 134 mph. >>> >>> Sorry I was a factor of ten out there. 0.000002c. >>> >>> That involves spinning a one metre circumference (1ft diam) wheel at >>> about 300 rps) or 18000 rpm. >> >>1 metre is 3.281 feet. :) > > You didn't read properly. Overworked today, maybe.... right. > I said 'metre circumference'. > That is about 1 foot diameter. very close. 1.044. interesting coincidence. >>I would rather spin a smaller wheel at a higher speed. We get more >>pulses. And the technology is already there in the laboratory ultra >>centrifuge. >> >>Regardless, it is possible to do. > > One foot diameter. ok. >>> So the time differences you want to resolve are around E-10. >>> Maintaining a constant distance might be the biggest problem. >>> >> >>We can measure the distance with another laser beam from a stationary >>source right next to the rotating source [and securely mounted to the >>same baseplate that the spinning source is mounted on.] > > Best if you can use the same source and a couple of mirrors, one moving > and the other not....then you can be certain that the emission times are > within the required tolerance. I was going to use use cw laser for the moving source. I was going to time with two detectors. I am REALLY measuring time of flight but don't care about exact time since I will be comparing times as the rotation speed is varied. -- 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 |