(November 27, 2013 at 12:32 pm)orogenicman Wrote: Yes it is, because there is only one observer, not two. The experiments for two-way speed of light measures the round trip speed of light between two points, hence the synchronization issue. This experiment eliminates that problem by only using one point of measurement. In other words, the starting and stopping point is at the same location, thus there is no synchronization issue. That they used mirrors to get the light back to the origin is irrelevant to the measurement because light reflecting off of a mirrored surface doesn't change velocity, only vector direction. That the entire apparatus rotates and they get the same results verifies the Michelson-Morley experiment. You should also read the last link.

The last link takes you to the same paper as the second link. The fact that the same location is used for emission and detection is irrelevant. If you shine a light onto a mirror and time how long it takes to get back to you, it is the two-way speed that is being measured. The light is going from point A (you) to point B (the mirror) and then back to A. It's a two leg journey. Adding more mirrors creates more points, not less.

The first paper is the more interesting one. It does actually test the one way speed, (which is nice) but the spinning holed discs do not remove the problem of synchronisation. It's still assuming an isotropic convention in regard to the photodiodes.

(November 27, 2013 at 8:23 pm)Optimistic Mysanthrope Wrote:

(November 27, 2013 at 12:32 pm)orogenicman Wrote: Yes it is, because there is only one observer, not two. The experiments for two-way speed of light measures the round trip speed of light between two points, hence the synchronization issue. This experiment eliminates that problem by only using one point of measurement. In other words, the starting and stopping point is at the same location, thus there is no synchronization issue. That they used mirrors to get the light back to the origin is irrelevant to the measurement because light reflecting off of a mirrored surface doesn't change velocity, only vector direction. That the entire apparatus rotates and they get the same results verifies the Michelson-Morley experiment. You should also read the last link.

The last link takes you to the same paper as the second link. The fact that the same location is used for emission and detection is irrelevant. If you shine a light onto a mirror and time how long it takes to get back to you, it is the two-way speed that is being measured. The light is going from point A (you) to point B (the mirror) and then back to A. It's a two leg journey. Adding more mirrors creates more points, not less.

The first paper is the more interesting one. It does actually test the one way speed, (which is nice) but the spinning holed discs do not remove the problem of synchronisation. It's still assuming an isotropic convention in regard to the photodiodes.

Any discussion over the one-way speed of light is not that it cannot be measured, but that some method must be used to assure that the clocks at each end of the measured path are "synchronized" The mirror discussed above is NOT point b because it isn't measuring anything. Point A and point B are the same (the origin). Thus, because the experiment uses only one clock to measure start time and end time, the measurement eliminates the problem of synchronization. But I see your point about the two overlapping because, by definition any measurement in which the light follows a closed path is considered a two-way speed measurement. Point taken.

Here are some thoughts. If the one-way speed of light and the two-way speed of light are assumed, for purposes of discussion, to be different, why then, when we conduct a two-way measurement, is the frequency the same in both directions? Why is there no shift, which there must be if the velocity had changed?

Moreover, for purposes of determining the age of the universe, why would we ever need to know the one-way speed of light? Since we are essentially always measuring the two way speed, and that velocity is verified by numerous independent research paths and theoretical calculations for well over 100 years, what's the point? How would the two-way speed of light negate the distances measured in the universe, particularly when those measurements depend ultimately on the standard candle, which is also well understood to depend entirely on the inverse square law, not the speed of light, and on the parallax of stars, which is also well understood? My point is that it doesn't, making warped one's argument that the age of the universe as determined using this measurement being wrong is superfluous. It isn't wrong. What's worse, he doesn't explain how such a "wrong measurement" could ever give us a number such as 10,000 years, or any other such fanciful number.

We need to remember the crux of Lisles idiotic "theory"

Because we can't accurately measure the one way speed of light because of the time dilation induced when you try to move your two clocks away from each other( a function BTW of velocity, not position), the only way you can measure it is with a two way measurement.

Lisle is trying to weasel his YEC bullshit into the equation by saying that you can't KNOW that the velocity in both directions is the same.

Which, admittedly you can't. But then he uses this uncertainty to try to claim that the speed away from the observer is half c while the return speed is instantaneous.

Complete bullshit of course. And disproven quite simply by measuring the one way speed of light.

Even though it won't be accurate, it WILL show a finite velocity.

In short, Lisles crap is only credible to cretinists with a zero understanding of basic physics.

(November 28, 2013 at 5:18 am)Zen Badger Wrote: We need to remember the crux of Lisles idiotic "theory"

Because we can't accurately measure the one way speed of light because of the time dilation induced when you try to move your two clocks away from each other( a function BTW of velocity, not position), the only way you can measure it is with a two way measurement.

Lisle is trying to weasel his YEC bullshit into the equation by saying that you can't KNOW that the velocity in both directions is the same.

Which, admittedly you can't. But then he uses this uncertainty to try to claim that the speed away from the observer is half c while the return speed is instantaneous.

Complete bullshit of course. And disproven quite simply by measuring the one way speed of light.

Even though it won't be accurate, it WILL show a finite velocity.

In short, Lisles crap is only credible to cretinists with a zero understanding of basic physics.

Moreover, we can measure the parallax of nearby cephid variable stars and compare that measurement with the standard candle for the same stars and get very close distance measurements. This alone provides strong evidence for the validity of our near distance measurements, and also verifies the standard candle methodology which is used for more distant objects.

(November 28, 2013 at 2:59 am)orogenicman Wrote: Here are some thoughts. If the one-way speed of light and the two-way speed of light are assumed, for purposes of discussion, to be different, why then, when we conduct a two-way measurement, is the frequency the same in both directions? Why is there no shift, which there must be if the velocity had changed?

Bloody good question. I would have thought that accelerating to infinite velocity would produce an infinite doppler shift. I readily admit I'm not an expert on the matter, though.

Quote:Moreover, for purposes of determining the age of the universe, why would we ever need to know the one-way speed of light? Since we are essentially always measuring the two way speed, and that velocity is verified by numerous independent research paths and theoretical calculations for well over 100 years, what's the point? How would the two-way speed of light negate the distances measured in the universe, particularly when those measurements depend ultimately on the standard candle, which is also well understood to depend entirely on the inverse square law, not the speed of light, and on the parallax of stars, which is also well understood? My point is that it doesn't, making warped one's argument that the age of the universe as determined using this measurement being wrong is superfluous. It isn't wrong. What's worse, he doesn't explain how such a "wrong measurement" could ever give us a number such as 10,000 years, or any other such fanciful number.

You're right, we don't need to know the one way speed to work out how far away stars and galaxies are - I made the exact same point to Statler. The thing is, it's the isotropic convention that tells us how long it took the light to reach us from those stars and galaxies.

(November 28, 2013 at 5:18 am)Zen Badger Wrote: Complete bullshit of course. And disproven quite simply by measuring the one way speed of light.

Even though it won't be accurate, it WILL show a finite velocity.

Only if you assume an isotropic convention when setting up the experiment. I really don't know how I can phrase it in more simple terms than have already been used. I'm starting to think that you aren't actually reading any of the posts that explain why you're wrong.

The one way test proves the isotropic , it doesn't assume it.

The two way test assumes the isotropic.

It's other way around. If you have a way to test the one way speed with the inherent synchronisation issue then I'm all ears. That's not sarcasm by the way, I like being wrong - it means I've learned something.

(November 28, 2013 at 8:17 am)Optimistic Mysanthrope Wrote: It's other way around. If you have a way to test the one way speed with the inherent synchronisation issue then I'm all ears. That's not sarcasm by the way, I like being wrong - it means I've learned something.

I'm not even sure what you're trying to argue here.

I'm refuting Lisles claim that light travelling towards Earth does so instantly.

Therefore my point about testing the one way speed of light. It doesn't have to be perfect, it merely has to show duration.

Thereby destroying Lisles theory.

And if you actually could test the one way speed without assuming a convention, you would be right. Until you can do that, one way measurements prove precisely nothing.

You are viewing a very narrow description of the problem of assessing isotropy of speed of light. It is true we can't directly measure one way speed of light when the light is aimed directly at us without clock synchronization. But we do have overwhelming evidence that one way speed of light is isotopic when the light is shining out from a cosmic event in every direction except pointed directly at us. This comes from observation of type II supernova. In the hundreds of thousands of years before going bang the supernova's progenitor star usually shed substantial amount of its outer layers in a series of minor cataclysms. This results in a Russian doll like layered expanding spherical shells of gas surrounding the progenitor star that we can observe in the form of planetary nebula. When the star does go supernova the massive pulse of light from the supernovae would reach out from the epicenter in all directions at speed of light, and successively hit each shell, heat them, and cause them to glow intensely. We can use just our own clock to see exactly how long after the instant of supernova explosion the outward racing light from the nova hits each point in each shell surrounding the supernova. And you know what, each point on each in the cross section of the spherical shell light up at almost the same time, to within the difference fully accountable by the know minor deviation from perfect sphericality of the gas shells. The different shells light up in succession precisely according to the shell's radius and this distance from the origin of supernova light at its center. You know what, the results show the successive shells become excited by the light from supernova at precisely the times predicted if light from supernova moves out in every direction at exactly the know universal speed of light C.

So this tells us with certainty without any spectacular special pleading assumption that light emanating from cosmic sources travels isotropically at C without requiring any special, tailored synchronization between the clocks at each point on each shell. Only one master clock at the observer is necessary.

Wordork is thus stripped to his disgusting nakedness, his argument reduced to not just special pleading, but special exemptions to special pleading. Yes, light is instantaneous except when we observe its progress from supernova, but its finite isotropy in this case applies except only in just those instances where its isotropy would show the bible to be bulkshit and wordork to be a sack of shit.

All this convolution, and more, just so he can cling to the only reason he ever advanced for believing the bible, because it is "consistent".

Yet anything can be made to seem consistent special if the fool is willing to special plead on the fly to avoid each and every inconsistency. So we must conclude he does not cling to the bible because it is consistent. He clings to the bible because he is diseased, and "bible is most consistent" is just an intro to the special pleading to make himself seem, to himself only, to be less diseased.