Thread: Is The Speed of Light really a Constant? How will we ever know?

I read that though the speed of light is considered and taught to be constant which is important in regards to a lot of current theories in physics, hard evidence suggests that it is not always constant.

Early reading of the speed of c (light) were 'suprisingly variable but by 1927 speed of light was thought to be 299,796 kilometres per second which was considered a very accurate reading. But from 1928 until through till 1945 the speed of light dropped all around the world by 20 kilometres per second. Suggesting perhaps cyclical rhythems in light speed. In the lates 1940's the speed of light increased again by 20 m/s.

This is where it gets a little dark, so to speak: The embarresing possibility of variations in this physical 'constant' was eliminated when the speed of light was fixed by definition. Further to that, in 1983 the unit used to measure light, was redifined, in terms of light! The metre is now defined as the length of path travelled by light in a vacum in 1/299,792.458 of a second. Further more, the second is also defined in terms of light 'the duration of 9,192,631 770 periods of vibration of the light given off by cesium 133 atoms in a particular state of excitation (the transition between two hyperfine levels of the ground state, who knew!).

So what this all means, is that from 1983 onwards, any further changes in the speed of light will be undetectable by science and it will always be considered a physical constant.

This remarkable episode is attributed to the 'psychology of meteorologist' and brushed aside as experimental error, though the readings coincided across the entire globe. Brian Petley a british meteorologist claims that 'the tendency for experiments to coincide within a given epoch has been described by the delicate phrase 'intellectual phase locking (Ba, baaaa)... More likely that either the speed of light changed, or something affecting the entire globe cause the equipment to faulty consistently by a mere 20 metres per sec speed of light variation.


I'd be interested to know more about this near 20 year fluctuation in our readings of the speed of light.

Is it a good idea that we measure the speed of light by units (metres and seconds) which are themselves defined by speed of light, meaning that should speed of light change.... we will never know.

My next interest would be why on earth these decisions were made to measure light by units defined by light itself... unbelievable!

Is that a scientific way to operate? my instincts suggest it is not.

Just thought I'd share my new finding with those of you who didn't know, and hopefully get some explainations/further knowledge from those who do understand the ins and outs of this remarkable series of facts.

Originally Posted by question for you

This is where it gets a little dark, so to speak: The embarresing possibility of variations in this physical 'constant' was eliminated when the speed of light was fixed by definition. Further to that, in 1983 the unit used to measure light, was redifined, in terms of light! The metre is now defined as the length of path travelled by light in a vacum in 1/299,792.458 of a second. Further more, the second is also defined in terms of light 'the duration of 9,192,631 770 periods of vibration of the light given off by cesium 133 atoms in a particular state of excitation (the transition between two hyperfine levels of the ground state, who knew!).

LMBO! Talk about totally misrepresenting reality, here- And by this, I mean YOU, not the definition of the constant.

Originally Posted by question for you

So what this all means, is that from 1983 onwards, any further changes in the speed of light will be undetectable by science and it will always be considered a physical constant.

Yes, the Illuminati are hard at work, maintaining the scientific illusion.

Originally Posted by question for you

Brian Patley a british meteorologist claims

Can't find any reference of this person. Can you clarify?

Originally Posted by question for you

we will never know.

Your ill-informed conclusions demonstrate a desire on your part that we believe that we can never understand the fundamentals. This is further demonstrated below and in the majority of your posts on scientific topics.

Originally Posted by question for you

unbelievable!

Is that a scientific way to operate? my instincts suggest it is not.

You seem far more intent on presenting inaccurate imagery than in learning science. Rather than learn about what you clearly do not understand, you instead, try to cast doubt on what you don't understand. As if making it appear to be wrong will somehow vindicate your ignorance.

I find your posts disgusting. Your entire attitude on the broad spectrum of science is not about holding it accountable to facts, but proving itself against your misconceptions that you flatly refuse to let go of.

You deserve neither polite answers not the wasted effort of showing you your errors. You do not care to learn about any of it- and you repeatedly demonstrate this time and time again.

The Science delusion is the belief that science already understands the nature of reality. The fundamental questions are answered leaving only details to be filled in. The scientific world view has becoma a belief system. All reality is material or physical. The World is a machine made up by dead matter. Nature is purposless. Consciousness is nothing but the physical activity of the brain. Free will is an illusion. God exists only as an idea in Human minds, imprisoned within our skulls.

Rupert Sheldrake, one of the Worlds most innovative scientists shows that science is being constricted by assumptions that have hardened into dogmas, he examines those dogmas and shows persuasively that science would be better of without them in his new book, The Science Delusion- 'Freeing the Spirit of Enquiry', (2012).

Which is wher I got the stuff about the speed of light.

Some people on here would comment on this viciously and condemn the sharing of evidence that goes against their own indoctrinated, dogmatic belief system when in truth, they have never done an experiment or probably ever heard of this before. They probably do a little cheap research and find futher dogmatic interpretations of the evidence from their favourite preists of orthodox science, then make out they have a clue what they are talking about. This is imo, the problem with the science delusion. It is ruining nearly every thread on this website and restricting the 'spirit of enquiry' which many of us posses as in our acumulation of knowledge we have learnt just how ignorant we still are.

This is the difference between the ignorance of a child and the ignorance of a great mind. A great mind realises it's ignorance, a child is oblivious to it's ignorance.

I suppose Rupert Sheldrake is a great mind? Wrong. Pseudo.

Originally Posted by question for you

The Science delusion is the belief that science already understands the nature of reality.

Strawman. Science merely says "show me some evidence." You prefer to ignore evidence because you'd clearly prefer that magic be real. Science, with its unreasonable demands for evidence, spoils your fun.

The fundamental questions are answered leaving only details to be filled in. The scientific world view has becoma a belief system.

Bullpuckey. It's evidence-based. That's why science keeps evolving.

All reality is material or physical. The World is a machine made up by dead matter. Nature is purposless. Consciousness is nothing but the physical activity of the brain. Free will is an illusion. God exists only as an idea in Human minds, imprisoned within our skulls.

Science merely says, "You got some hypotheses? Let's see what the evidence says about them." We go with the evidence. What's your alternative? Guesswork? The confident utterances of fools?

No thanks. Humanity tries that enough already.

Rupert Sheldrake, one of the Worlds most innovative scientists...

Bwahahahahahaha! Pleeeeez.

shows that science is being constricted by assumptions that have hardened into dogmas, he examines those dogmas and shows persuasively that science would be better of without them in his new book, The Science Delusion- 'Freeing the Spirit of Enquiry', (2012).

Let's see now. You select, from all that is written about science, the ravings of Sheldrake. Why is that? I suspect it's because you aren't a truth-seeker at all (as is evident by your infamously thin skin; you can't handle challenges to your beliefs). Instead you seek those who agree with your view of a mysterious, magical universe where pink unicorns sing a cappella while repairing carburettors.

Which is wher I got the stuff about the speed of light.

Again, were you interested in the truth, rather than in agreement with your ill-founded beliefs, you would've delved deeper into the situation. You need to study the history of metrology to understand better the reasons for the spread in the values of c. Yes, the change in standards in 1983 does indeed mean that direct measurements of c are really measurements of length. However, there are other methods (e.g., measuring the product of permeability and permittivity, or looking at the fine structure constant) that provide an independent check.

You need to look at the error bars of the earlier measurements. It is simply not supportable to assert that there is a statistically significant periodicity (or other trend) in the value of c.

Some people on here would comment on this viciously and condemn the sharing of evidence that goes against their own indoctrinated, dogmatic belief system ...

You are talking about yourself here, but you clearly don't realize it.

when in truth, they have never done an experiment or probably ever heard of this before.

Phlogiston, heal thyself!

This is the difference between the ignorance of a child and the ignorance of a great mind. A great mind realises it's ignorance, a child is oblivious to it's ignorance.

It's = it is. You mean "its" for the possessive.

That said, your posts are full of magical thinking and breathtaking ignorance. You dislike science presumably because science keeps making these pesky demands for evidence. You'd rather live in a fantasy world. Reality intrudes on it in a most unwelcome way, and as any True Believer, you fight back with irrational emotionalism.

I mean, c'mon. Sheldrake? Really? That's your best source?

question for you, do you understand that the apparent variations in the speed of light through the early part of the century were reflections of steadily improving measurement techniques?

You seem to working to be working to an agenda that involves 'proving' conspiracies within the scientific community. I imagine that can be quite fun, but its hardly educational. I think you would ultimately get a lot more pleasure from your study of science if you were to remain grounded. What do you think?

Neverfly, frustrating as q-for-you's position is let's try to keep it civil.

Originally Posted by question for you

Further more, the second is also defined in terms of light 'the duration of 9,192,631 770 periods of vibration of the light given off by cesium 133 atoms in a particular state of excitation (the transition between two hyperfine levels of the ground state, who knew!).

a. The second is not defined in terms of "light"
b. Everyone knew.

So what this all means, is that from 1983 onwards, any further changes in the speed of light will be undetectable by science and it will always be considered a physical constant.

If the speed of light changed then it would affect all sorts of other things and would be detectable. For example, the permittivity and permeability of free space would change. This would cause electronic circuits to behave differently. Distance measured by GPS satellites would change. And on and on...

This is what makes it a fundamental constant.

I'd be interested to know more about this near 20 year fluctuation in our readings of the speed of light.

I'm pretty sure the advances in measurement technology are well documented. Even wikipedia has a reasonable high-level summary.

Originally Posted by question for you

Rupert Sheldrake, one of the Worlds most innovative scientists

I think you misspelled "deluded fantasists".

Which is wher I got the stuff about the speed of light.

Ah, that explains a lot.

Some people on here would comment on this viciously and condemn the sharing of evidence that goes against their own indoctrinated, dogmatic belief system when in truth, they have never done an experiment or probably ever heard of this before.

That is just nonsense. And slightly offensive to people who prefer solid evidence to fantasy.

Originally Posted by question for you

The Science delusion is the belief that science already understands the nature of reality.

That is definitely a delusion. However, it has nothing to do with science. Science has adopted methdological naturalism. This is implicitly indifferent to the character of reality. It basically says 'Let's just assume what you see is what you get; that the universe is a logical place that can be understood; that things happen in a consistent fashion for a reason; that there are no supernatural events. We have no idea whther these assumptions are valid or not - they seem to be - but we will work on the basis that they are true and then we'll see what we can find out.

Some individual scientists, acting as individuals, may very well not understand this, but that's where science is at. So your opening claim of delusion reveals a delusion of your own.

Originally Posted by question for you

The fundamental questions are answered leaving only details to be filled in.

Can you find me six serious scientists of quality who believe such nonsense? Really! Go ahead - I'm eager to learn who they are. If what you say is true it should not be difficult to find six out of several thousand.

Originally Posted by question for you

All reality is material or physical.

we've already dealt with this. Science does not deal with reality. It does however deal with the material and the physical. That's its sphere of interest. I don't go to a cookery book to find decompression rates for scuba diving.

Originally Posted by question for you

The World is a machine made up by dead matter. .

You really haven't studied much cutting edge science, have you?

Originally Posted by question for you

Nature is purposless.

Teleology was tried and found wanting as a scientific concept. Personally, I can make quite a strong argument for reintroducing it into the scientific armoury, for it is not anathema to the scientific method, though you seem to think it is. It's just generally found unecessary for the questions that presently interest us in science.

Originally Posted by KALSTER

I suppose Rupert Sheldrake is a great mind? Wrong. Pseudo.

I wouldn't have thoughts so. I get the impression he has developed a belief and he wants to prove it. But to be fair he seems to be quite scientific and rational about it and I admire his stance on freeing the spirit of enquiry which could do his reputation far more harm than good.

Originally Posted by question for you

I get the impression he has developed a belief and he wants to prove it.

That is true.

But to be fair he seems to be quite scientific and rational about it

That, not so much.

I found some of his earlier work imaginative but in danger of giving speculation a bad anme.

Originally Posted by question for you

Originally Posted by KALSTER

I suppose Rupert Sheldrake is a great mind? Wrong. Pseudo.

I wouldn't have thoughts so. I get the impression he has developed a belief and he wants to prove it. But to be fair he seems to be quite scientific and rational about it and I admire his stance on freeing the spirit of enquiry which could do his reputation far more harm than good.

Remember, you're talking about a man who claims that your pet is psychic, among other things. He has no reputation left to harm. He is a classic New Age mystic, selling magic to people who Need To Believe.

Originally Posted by John Galt

question for you, do you understand that the apparent variations in the speed of light through the early part of the century were reflections of steadily improving measurement techniques?

You seem to working to be working to an agenda that involves 'proving' conspiracies within the scientific community. I imagine that can be quite fun, but its hardly educational. I think you would ultimately get a lot more pleasure from your study of science if you were to remain grounded. What do you think?

I don't understand the ins and outs of it John. Was there a different type of equipment used globally between 1928 and 1945, to that which has been used after? If so, that would implie very strongly that it was down to the equipment.

Sheldrakes book does seem to imply a conspiracy of the orthodox scientific comunity... He certainly talks about dogmas and worldviews and from where im sitting, it makes sense.

The question remains... will we ever know if this 'constant' varies? That's an important question isnt it?

Ofcourse I am looking to understand more about this, but I will not learn from those who cannot be grounded when they explain the ins and outs, and neither will anybody else.

I'm not trying to prove a conspiracy, but i'm perfectly open minded to them existing, and that imo is grounded. It might be impossible to tell if the conspiracy is a good thing or a bad thing, or if it's been highjacked... but it's more down to earth to be 'skeptical' to a certain degree.

I'm sorry that sounds off, it really isn't, it's just my response.

Originally Posted by Strange

Some people on here would comment on this viciously and condemn the sharing of evidence that goes against their own indoctrinated, dogmatic belief system when in truth, they have never done an experiment or probably ever heard of this before.

That is just nonsense. And slightly offensive to people who prefer solid evidence to fantasy.

In truth I had only one person in mind at the time. Nonsense it is not.

Originally Posted by John Galt

Neverfly, frustrating as q-for-you's position is let's try to keep it civil.

Trust me- for me, that was civil. This forum's been lucky enough to not see me when I get uncivil.
When it does, you're fingers will be twitching at the ban button like you won't believe.

Point noted- I'll attempt to put in a greater effort to reign in my slavering disgust of the hypocritically willfully ignorant ramblings of a deluded madman.

Originally Posted by question for you

but i'm perfectly open minded to them existing

No, you really aren't. You've made this clear consistently in your time that I've observed your posts and you have done so in this thread; claiming your beliefs as facts, stating that "we can or never will know" and so on. You are not posting open minded observations- not by a long shot.

Originally Posted by John Galt

Science has adopted methdological naturalism. This is implicitly indifferent to the character of reality. It basically says 'Let's just assume what you see is what you get; that the universe is a logical place that can be understood; that things happen in a consistent fashion for a reason; that there are no supernatural events. We have no idea whther these assumptions are valid or not - they seem to be - but we will work on the basis that they are true and then we'll see what we can find out.

Methodological naturalism sounds decent. not quite sure what indiferent to character of reality means as yet.
The quote was from Sheldrakes book, he doesn't claim anything to be supernatural, neither would I, or anybody who has thought about that word.

It's just that there is a danger some aspects of nature are not going to be understood because of dismissal of phenomena as 'supernatural' and therefor impossible.
If telepathy for example is in a way real, it would be perfectly natural and would be able to be detected.

'God' may in some peoples view be beyond or before nature, but everything on this planet is a part of ever evolving nature, 'science' or scientists should well study it methodologically and the dogma surrounding 'science' should be exposed and removed, as Sheldrake explains clearly and well. That's 'conspiracyesque' I suppose, but never mind why the dogma exists maybe not so much in science, maybe just in believers of the science world view.
You admit science does not understand the nature of reality and therefore must admit that those who spout off, are believers in a beleif which Sheldrake has described as becoming dogmatic. I have to agree with that point.

Originally Posted by John Galt

Some individual scientists, acting as individuals, may very well not understand this, but that's where science is at. So your opening claim of delusion reveals a delusion of your own..

I don't get quite howrevealed a delusion.

That's where science is at indeed, but this is where science needs to be heading... indoctrinated people are indoctrinated people. A scientist is a person of decent intellectual faculties, part of there learning should be freeing there 'spirit of enquiry'... how can it be that they do not understand the limits of science at present? How can they have such a belief system? is it not a conspiracy? fine, but education must be seriously lacking.

Originally Posted by question for you

All reality is material or physical.

we've already dealt with this. Science does not deal with reality. It does however deal with the material and the physical. That's its sphere of interest. I don't go to a cookery book to find decompression rates for scuba diving.[/QUOTE]

It deals with reality!

How about psychology and philosophy?

Material science deals with material and physical aspects of reality. Whose to say there is anything other than this? It's all for science to find out objectively.

Originally Posted by John Galt

Originally Posted by question for you

The World is a machine made up by dead matter.

You really haven't studied much cutting edge science, have you?

Not too much. You don't need to ask that. Point us to it please. I've been around on the science forum for a while, i've been exposed to that which i've been exposed.

The whole post that you are quoting me on is the printed on the inside cover of the book 'The Science Delusion' 2012 Rupert Sheldrake.

Originally Posted by John Galt

Originally Posted by question for you

Nature is purposless.

Teleology was tried and found wanting as a scientific concept. Personally, I can make quite a strong argument for reintroducing it into the scientific armoury, for it is not anathema to the scientific method, though you seem to think it is. It's just generally found unecessary for the questions that presently interest us in science.

I was thinking of messaging you about that, I seem to remember you said you will have something together by mid winter. I'd be very interested.

I wouldn't speculate that it has been exiled or considered evil. by orthodox science.

Sheldrake said some interesting stuff about end goals, purposes... I would say it very much plays a part in affecting evolution. Life designs itself to be how it is, limited by it's environment, I would have thought. I'm not sure if that fits the tight definition of teleology or not.
Following cherodes. Goal direted behaviour, atractors that pull from the future...
Tele means far or end right? so teleology studies the means by which life/nature meets its ends?

Originally Posted by John Galt

Originally Posted by question for you

The fundamental questions are answered leaving only details to be filled in.

Can you find me six serious scientists of quality who believe such nonsense? Really! Go ahead - I'm eager to learn who they are. If what you say is true it should not be difficult to find six out of several thousand.

No I cannot. I never said the leading scientists are suffering from the science delusion. How about Dawkins, he seems to think he has the answers? Anything outside the, how you say? Paradigm? is irrational and not worthy of consideration without exceptional proof?

Exceptional claims require exceptional evidence is a term well used by skeptics, I mean often used. If there is evidence from a massive amount of people for telepathy, then it is not exceptional, it is quite common and something that has become normal. To claim that all these people are deluded about their own experience is an exceptional claim, wheres the exceptional evidence for that?

It's important you remember most of this I am parroting from this book, previously detailed. It seems a decent book in which some good points are made, which I hope people take note of.

I see here some insults of the author, I find it hard to pay them any attention unless they come with reasoning. In the rant format they are expressed, without even any logic to back them up, they just serve to strengthen the case Sheldrake makes about those who are under what he terms as 'The Science Delusion'.
For those who have not read it, it's written by an apparently prominent biologist and is pro science, unlike Dawkins book which is anti God/religion more than it is pro science I pressume. The author merely makes some good points and gives some good background to the situation, dogmatic world views spouted by those who claim to be pro science and believe that science has taught them the nature of reality. We all know the types.

Theres your typical scientist who is constantly subjected to this dogma, but thinks for himself outside the lab. Then there are these millitant Atheist puppets who can't stop preaching their delusions to all who will listen. They get on my nerves, the book is just aimed at them really I think and the pupeteers who do in reality create them one way or another. (thats not a conspiracy theory, just an observation).

*Sorry if the quotes and spelling got a bit messy, hopefully I fixed it adequately.

Originally Posted by question for you

If there is evidence from a massive amount of people for telepathy ...

There is not a massive amount of evidence, in the scientific sense. In fact there is none. There are a lot of anecdotes and stories. No evidence.

Originally Posted by Neverfly

Originally Posted by John Galt

Neverfly, frustrating as q-for-you's position is let's try to keep it civil.

Trust me- for me, that was civil. This forum's been lucky enough to not see me when I get uncivil.
When it does, you're fingers will be twitching at the ban button like you won't believe.

Does he honestly delude himself into thinking that the people on this web site can't see through his attempts to project a civil demeanure?

Originally Posted by Neverfly

Point noted- I'll attempt to put in a greater effort to reign in my slavering disgust of the hypocritically willfully ignorant ramblings of a deluded madman.

Hillarious.

Originally Posted by Strange

Originally Posted by question for you

If there is evidence from a massive amount of people for telepathy ...

There is not a massive amount of evidence, in the scientific sense. In fact there is none. There are a lot of anecdotes and stories. No evidence.

According to the book which has been mentioned repeatedly, there is 'statistically significant evidence' from many sources including labs and research institutes.

Have you read it yet?

Originally Posted by question for you

The question remains... will we ever know if this 'constant' varies? That's an important question isnt it?

Well my understanding, we will most likely notice rather quickly if it does start varying because technology like GPS will suddenly start becoming highly inaccurate.

As far as I understand it, the constant is so mired in our current models that if it alters in any significant way, our resulting numbers will suddenly go rather crazy on us.

Originally Posted by tk421

Originally Posted by question for you

Originally Posted by KALSTER

I suppose Rupert Sheldrake is a great mind? Wrong. Pseudo.

I wouldn't have thoughts so. I get the impression he has developed a belief and he wants to prove it. But to be fair he seems to be quite scientific and rational about it and I admire his stance on freeing the spirit of enquiry which could do his reputation far more harm than good.

Remember, you're talking about a man who claims that your pet is psychic, among other things. He has no reputation left to harm. He is a classic New Age mystic, selling magic to people who Need To Believe.

You might be right, but I think this word magic is one of the major misconceptions.

I don't think Sheldrakes sell anything other than nature, natural phenomena.

There was stuff about dogs sensing when there master is returning. Usually spending 4% of time at window but 55% whilst master is homeward bound, regardless of time of day or routine, all these factors were aparently dealt with to make it a proper experiment. Sheldrake does after all understand the scientific method, surely.

You read the book? or just heard the rumours?

I admit, sometimes he does seem to be on shaky ground, it makes me wonder. Much of the stuff on the other hand, seems quite intriguing.

Originally Posted by Kompi

Originally Posted by question for you

The question remains... will we ever know if this 'constant' varies? That's an important question isnt it?

Well my understanding, we will most likely notice rather quickly if it does start varying because technology like GPS will suddenly start becoming highly inaccurate.

As far as I understand it, the constant is so mired in our current models that if it alters in any significant way, our resulting numbers will suddenly go rather crazy on us.

Would 20 metre per sec have any real affect on any equipment? if so, how? Surely it would just carry on working but a tiny tiny tiny tiny tiny bit slower?

Originally Posted by question for you

According to the book which has been mentioned repeatedly, there is 'statistically significant evidence' from many sources including labs and research institutes.

Is there any 'statistically significant evidence' in peer-reviewed journals?

Originally Posted by question for you

I don't understand the ins and outs of it John. Was there a different type of equipment used globally between 1928 and 1945, to that which has been used after?

I do not know for a fact that the equipment was quantitatively or qualitatively different. I do know, from decades of involvement with sensors, that a) precision and accuracy of equiment is a moving target; b)large fluctuations in values that are likely steady are typically associated with instrumentation not the measured property. The most probable explanation is that the variations were due to improved instrumentation.

I offer two further pieces of evidence in support of that:
1. I recall from my 1959 Space Facts Diary that the speed of light had been measured more accurately at 186,284 mps.
2. Some researchers considered the possibility that the speed of light was variable. One may be assured that they would have fully investigated these differences to see if they were evidence for real changes.

I have no doubt that if you took the time and trouble to investigate this properly, with an open mind, that you would find that what I am saying is exactly the case. Why you could even write a best selling popular science book "C - The Story of the Men Who Trapped the Photon".

Sheldrake may be exciting and entertaining and challenging and visionary, but ultimately he's as screwed up as an aardvark's turd.

Originally Posted by question for you

Would 20 metre per sec have any real affect on any equipment?

Off the top of my head, that is roughly 1 part in 10⁸ while I believe GPS has to be more than 100 times more accurate than that in the calculation of relativistic effects.

Compare this 20m/s "variation" in c to the accuracy of GPS relative to the circumference of the Earth (it is used to track the tectonic drift of continental plates of a few cm per year).

So, yes. It would be immediately noticeable.

Originally Posted by question for you

I admit, sometimes he does seem to be on shaky ground, it makes me wonder. Much of the stuff on the other hand, seems quite intriguing.

You know what? These types of issues sometimes are intriguing, but they are extraordinary claims that often go against very well understood physics. Shouldn't the default position be that you find it intriguing, but that it is probably not true?

The scientific method and peer review systems may not be perfect systems, but surely they are vastly superior scientific devices than simply publishing book after book on paranormal stuff? You might think a lot of his stuff sounds plausible, but how can it be any more than that and how can you seriously expect us to take it seriously? His stuff is basically just his say-so, precisely because he foregoes going through the usual meat grinder of the scientific method. His evidence is NOT of extraordinary quality or unambiguity and places him firmly within the huge crowd of peddlers of nonsense. There is simply no good reason to take anything he says very seriously.

I think that is why a lot of us get so frustrated when you make threads like these or when you defend people's woo nonsense. You go about it in a manner that would suggest you believe that there is a clear "maybe" about whether the claim is true or not, that the answers these people propose are sometimes just as likely to be true as the current majority view and that we are all just being terribly closed-minded and dogmatic about the whole thing. That is why we have frequently commented on your lack of consideration of the necessity of the scientific method and have been aghast at having the same accusations spewed back at us. The simple truth is that these people are on very shaky ground indeed and they simply do not meet the requirements of needing serious closer attention.

I don't stay in fortified bunkers all my life because there is a slight possibility that I might be struck by an asteroid, I go outside and live my life knowing that the changes of that becoming true are so small that it doesn't merit serious consideration, at least not until someone can show me directly that an asteroid will hit my general area on a certain date to within a reasonable degree of probability.

Do you understand what I am trying to say?

Originally Posted by question for you

Originally Posted by Kompi

Originally Posted by question for you

The question remains... will we ever know if this 'constant' varies? That's an important question isnt it?

Well my understanding, we will most likely notice rather quickly if it does start varying because technology like GPS will suddenly start becoming highly inaccurate.

As far as I understand it, the constant is so mired in our current models that if it alters in any significant way, our resulting numbers will suddenly go rather crazy on us.

Would 20 metre per sec have any real affect on any equipment? if so, how? Surely it would just carry on working but a tiny tiny tiny tiny tiny bit slower?

The thing is, GPS is basically just a set of atomic clocks flying around in orbit, and by measuring the time difference to communicate with one compared to communicating with another, you can triangulate where your position is. Due to relativity, these atomic clocks will aways tick at a very, very slightly different rate than one on Earth, so to make GPS accurate you have to compensate for that difference.

Now I admit, I don't know the mathematics required to tell what degree of thresholds would be required notice an obvious discrepancy in a very short amount of time, but considering how finely tuned the system must be (Brian Cox and Jeff Forshaw note in their book "Why E=MC^2" that if we stopped compensating for relativity, these clocks in orbit would speed up by about 38 microseconds per day, which may not sound like much but would result in a drift in position of about 10 kilometers per day), it suggests that at least unless our value for the speed of light is a consistent average, then we would note a steady drift in accuracy over time.

Edit: Strange and his superior mathematical skills beat me to it

Originally Posted by John Galt

The most probable explanation is that the variations were due to improved instrumentation.

On it's own I find that slightly hard to swallow. The speed dropped consistently and globally on all equipment, pressumable if new equipment was used, then the old equipment was used to double check results.

The important things is that we define speed of light by unit of measurement which itself is defined by speed of light. No changes can ever be recorded with this system can they? it will always be constant. Bearing in mind our awareness of the failability of equipment, that really does seem quite ironic. What is a person to make of that? honestly?

Why should we have a metre defined by how far light travels? whats the logic? or a second by cessium 133? (wasn't it quartz once? is cessium quartz? I have no clue), surely a second is a 60th of an hour, and hour is a 24th of a day, which is slightly longer than a sidereal day and fits into a solar year 365.25 times. I can see how it seems to make sense defining it by some obscure vibratory rate of an atom, but what if the atom does speed up significantly? are we going to change out method of recording time? our whole calendar? it seems really odd.

Originally Posted by John Galt

I have no doubt that if you took the time and trouble to investigate this properly, with an open mind, that you would find that what I am saying is exactly the case. Why you could even write a best selling popular science book "C - The Story of the Men Who Trapped the Photon".

Gimme a break, im a human being not a researcher, I do what I can. I can't afford journals etc and google gives me a load of rubbish to sort through. I'm open minded enough though, this is part of my research, I will check out your peices of evidence.

Originally Posted by John Galt

Sheldrake may be exciting and entertaining and challenging and visionary, but ultimately he's as screwed up as an aardvark's turd.

You obviously know him better than me then... but who isnt nuts? and isnt there a fine line between madness and genius? just because somebody is too mentally dull to notice anything but that right under their nose, it doesn't mean they are a more reliable source.

If you think Sheldrake is screwed up then you should come and see these people I live around. I'd like to find out more about him though, you know of any t.v apearances? I like to see a persons mannerism etc. He apeared on one of Dawkins debunking projects I think.. Or what are your sources? you say it just from reading his books? you met him? you read books about him? I'd like to get an idea about him.

Heres a transcript from a royal society debate with Wolpert if anybody is interested, it's in audio format too I think.

Dialogues and Controversies - Controversies - RSA Telepathy Debate - Text

Originally Posted by KALSTER

Originally Posted by question for you

I admit, sometimes he does seem to be on shaky ground, it makes me wonder. Much of the stuff on the other hand, seems quite intriguing.

You know what? These types of issues sometimes are intriguing, but they are extraordinary claims that often go against very well understood physics. Shouldn't the default position be that you find it intriguing, but that it is probably not true?

The scientific method and peer review systems may not be perfect systems, but surely they are vastly superior scientific devices than simply publishing book after book on paranormal stuff? You might think a lot of his stuff sounds plausible, but how can it be any more than that and how can you seriously expect us to take it seriously? His stuff is basically just his say-so, precisely because he foregoes going through the usual meat grinder of the scientific method. His evidence is NOT of extraordinary quality or unambiguity and places him firmly within the huge crowd of peddlers of nonsense. There is simply no good reason to take anything he says very seriously.

I think that is why a lot of us get so frustrated when you make threads like these or when you defend people's woo nonsense. You go about it in a manner that would suggest you believe that there is a clear "maybe" about whether the claim is true or not, that the answers these people propose are sometimes just as likely to be true as the current majority view and that we are all just being terribly closed-minded and dogmatic about the whole thing. That is why we have frequently commented on your lack of consideration of the necessity of the scientific method and have been aghast at having the same accusations spewed back at us. The simple truth is that these people are on very shaky ground indeed and they simply do not meet the requirements of needing serious closer attention.

I don't stay in fortified bunkers all my life because there is a slight possibility that I might be struck by an asteroid, I go outside and live my life knowing that the changes of that becoming true are so small that it doesn't merit serious consideration, at least not until someone can show me directly that an asteroid will hit my general area on a certain date to within a reasonable degree of probability.

Do you understand what I am trying to say?

Yeah I get what you're saying Kalster, sure.

I think I have approached this neutrally though.

What you need to understand is that for me, this is a scientific man, he's been through the scientific education system... I cannot dismiss what he say's purely because it doesn't meet with what is supposed to be understood already.

Really, would anybody who care about there own career give a honest peer review? I don't know exactly how that system works, but this kind of stuff is considered woo, no scientist wants to be considered as a woo peddler(unless he is earning from it or peddling some kind of social or political agenda, which i'm open to).

So for me, if this orthodox materialist science stuff has something in it, then ofcourse nobody will be brave enough to stick head above parapet and support Sheldrake.

The man gives a lot of refferences to institutions and other scientists, are they all woo? is all their results dubious?

I have no reason to assume Sheldrake is lieing. I have no reason to believe the orthodox or peer reviewed papers findings anymore or less than Sheldrakes. In my mind, if he is found to be leing and misinforming deliberately then he can be prosecuted and locked up. I have no reason to think that scientific orthodox 'world view' is any more honest than Sheldrake. In fact we all know the realities of this world, we all know how politics influences things.

Sheldrake didn't claim a cover up, he didn't claim anything, he just presented the data on velocity of C. and the facts about how the speed of c is now defined by a unit of measurement which itself is defined by c, and thats the thing i'm interested in understanding in this thread. I'm not supporting anybody or against anybody and that wont change. I just want to understand what has gone on here and if it is kosher? Does it make sense? is it logical? rattional? reasonable? So far I didn't notice anybody who knows the reasons that light is measured by a unit of length (m) which is itself defined by light. Can anybody else see a problem with that? perhaps after posting the answer might be here.

I see the book as an inspiration to people, giving ideas on areas of further research via this scientific method. But also I have as many questions from it as I have answers. If it irks you to see this kinds of things discussed here perhaps? then you have to ask why, its about the study of nature, we all know we don't understand it, so whats the problem? All is fair game in our pursuit of understanding.
The problem seems to be as Sheldrake either bravely or insidiously states: Economic and political motives are behind this dogmatic 'scientific' world view to the study of natural reality.

You have to admit, that makes some sense... There might be people who think it is better or safer if everybody has a certain mechanist, materialist worldview. They might be very powerful people. It's doesn't necesarily mean they are right or any good. It is well possible and the evidence suggests it is a real factor, in my opinion.

Yes, I expect people to take the book seriously as with pretty much all the evidences he puts forward within it. Anything else would be quite irrational in my honest opinion.

He either needs to be listened to, or arrested, depending on his integrity. I'm sure it's all legit, if not, punish him.


Please explain to me, ignoring the peer review sytem, which is flawed, especially in a case such as this.. even I can work that out... how is the evidence he has acquired not conforming to the scientific method of accumalating evidence?

Originally Posted by question for you

Please explain to me, ignoring the peer review sytem, which is flawed, especially in a case such as this.. even I can work that out... how is the evidence he has acquired not conforming to the scientific method of accumalating evidence?

The whole point of the peer review system (which is not perfect, obviously) is to subject people's work to critical review in order to confirm that the methodology, data, analysis, etc are well handled and support the claimed conclusions.

The fact he is unwilling and/or unable to have his work reviewed is damning enough, to my mind. The (informal) reviews of his work I have read demonstrate a blatant disregard for good methodology and data analysis (e.g. discarding data that doesn't suit his chosen conclusion).

Peer review may not be perfect but it is the best we have. It works in the long run. Even if some ideas get rejected initially, if they are are sound they will eventually get published (and, alternatively, if they are published and are bogus they will eventually be found out).

Sheldrake has been peddling this nonsense for as long as I can remember (which is quite a long time!) and, as far as I know, hasn't yet managed to get anything published in a serious journal. Which is why he writes books and popular articles - because the naive and uninformed will lap it up.

Originally Posted by Strange

Originally Posted by question for you

Please explain to me, ignoring the peer review sytem, which is flawed, especially in a case such as this.. even I can work that out... how is the evidence he has acquired not conforming to the scientific method of accumalating evidence?

The whole point of the peer review system (which is not perfect, obviously) is to subject people's work to critical review in order to confirm that the methodology, data, analysis, etc are well handled and support the claimed conclusions.

So in all cases 'methodology', and data colletion can be accurately reviewed by peers?

And if the conclusions claimed (not sure he makes any conclusions) are supported by the evidence, and peers confirm that, even though it is 'far out' and outside the orthodox paradigm, then peers are in no way jepodising there own reputations?

Do they review the method of data collection? or the integrity of data? or the interpretation?

Basically, if peers who were of the orthodox view got hold of his work, they would possibly say 'the data is honest but the experiments have this and that missing which might have given different results, this and that evidence would suggest to us that is is caused by chemical interactions etc etc?

I don't get the review system, can you show me an example of a negative peer review? how about a standard one?

Why can't people just get the book, and review it? Whats the difference? Authors have to give more details on sources in a paper? All the experiments seem to be referenced and can be reviewed independently.

I only heard of Sheldrake very recently myself... very very recently..

Originally Posted by question for you

So in all cases 'methodology', and data colletion can be accurately reviewed by peers?

Not in all case, no. Obviously. Good papers get rejected. Bad papers get through. But, in the long run, the process works. As I say, Sheldrake has been going on about this long enough that if he had anything it would have been published somewhere by now.

And if the conclusions claimed (not sure he makes any conclusions) are supported by the evidence, and peers confirm that, even though it is 'far out' and outside the orthodox paradigm, then peers are in no way jepodising there own reputations?

Reviewers are anonymous. So, no. Extraordinary papers get reviewed and approved. Paradigm shifting breakthroughs such as quantum mechanics, relativity, plate tectonics, etc.

And, re: "not sure he makes any conclusions": psychic dogs? Really?

Do they review the method of data collection? or the integrity of data? or the interpretation?

All that and more, I believe. They are supposed to work through all the analysis and data sources and check it is correct. There was an outcry a while ago because reviewers let a paper through which had accidentally included the same diagram twice with different labels. Allowing a little error like that caused a lot of discussion about the sloppiness of the review and how the paper should have been rejected.

Basically, if peers who were of the orthodox view got hold of his work, they would possibly say 'the data is honest but the experiments have this and that missing which might have given different results, this and that evidence would suggest to us that is is caused by chemical interactions etc etc?

So you do more work to eliminate the possible sources of error and re-present the work. That is what makes the process so rubust.

I don't get the review system, can you show me an example of a negative peer review? how about a standard one?

I am not involved in science so no. They are generally considered confidential and so rarely get leaked (for exactly the reasons you mention; so reviewers don't feel intimidated by rejecting a paper by someone famous or accepting a paper with novel ideas).

But I can tell you from experience in engineering that a thorough review process is vital to producing complex systems that work.

Why can't people just get the book, and review it? Whats the difference?

Firstly, how do you judge the quality of the reviewers? The whole point of the peer review process is that it is done by "peers"; people with relevant knowledge and expertise.

And people have reviewed his books. That is why I am convinced that his work is shoddy and unscientific.

I'm not going to lie about it, the whole process seems a bit suspect to me. Peers cannot be truely annonymous. If they are then how do you know how credible they are?

Perhaps this is why Sheldrake goes on about the Dogma of orthodox science? because he feels he never got treated fairly by peers?

It's important to note, much of the data isnt his own and he refferences it. Perhaps those institutes did release papers?

Lets take a look at the Parapsychology Lab at Duke university in North Carolina who have been studying this stuff since 1920 at least. Have they ever produced a peer reviewed a peer reviewed paper?

They did experiments on dreamers and 'senders' with some interesting results. E.g one dreamer dreamed of a rat in a cigar box, while the sender was veiwing pic of a ganster in a coffin. Another, dreamed of buying tickets for a boxing match while the 'sender' watched a boxing match.
They also carried out the Ganzfeild sensory deprivation experiements.

This closed minded response that I have recieved and the mockery as king of speudoscience etc must be exactly what Sheldrake is talking about in his book.

It's assumptions... why make assumptions? why beleiv what others say? people pick and choose what it's ok to have faith in and what its ok to dismiss, for the most part. That is dogmatic.

I know you haven't been rude strange and your patiently informing me, but you have to admit, you're not taking a scientific aproach to the matter either.

All this peer review stuff reminds me of highschool when it mattered what your mates thought of your new friend, otherwise your no longer part of the in crowd... It's almost on that level of thinking, only a formalised process which takes itself seriously.

When, where and by who did peer reviews first come about?

Here's another 'speudoscience link for you:

Rupert Sheldrake - The Science Delusion | London Real - YouTube

Rupert Sheldrake educated at cambridge talking about the subject at hand... probably not such much the physical 'constants', but his book about the dogmas of conventional science.

Interesting book.

Cheers,i thought the thread was about c,or has anyone said anything that says c ain't constant? Forgive me please.i dnt wanna start reading from post one.

Originally Posted by merumario

Forgive me please.i dnt wanna start reading from post one.

You won't miss anything.

Originally Posted by merumario

Cheers,i thought the thread was about c,or has anyone said anything that says c ain't constant? Forgive me please.i dnt wanna start reading from post one.

Capsule summary: QFY continues to cling to anti-scientific beliefs. This is necessary for him, since science's rigor prevents him from enjoying a magical world.

There is no evidence of c changing. It would be more accurate to say that the fine structure constant seems to be quite constant, over a period of two billion years, to within some ridiculously tight bound. A summary may be found here: http://www.int.washington.edu/talks/...ld_C/gould.pdf

As Strange has pointed out, if c were really varying as much as QFY keeps going on about, GPS would be observably unreliable. As GPS is manifestly quite reliable, we can rule out variations in c over the period of time during which GPS has been operating.

John Galt has correctly observed that considerable advances in metrology have been made over the last century. As measurements have improved, the error bounds have tightened. QFY prefers to view the tightening as evidence of a variation in c itself. However, the constancy of the fine-structure constant rules out that interpretation, unless you argue that both the charge of the electron, and the value of Planck's constant, have magically varied in just the right way to compensate. In the absence of any evidence to support that view, Occam demands that we provisionally assume that c has remained constant.

That's the way science works. It's all about the evidence. QFY prefers to cast scientists as sloppy, venal, conspiratorial and cliquish, as that serves his purpose of casting doubt on the entire scientific enterprise, and thus of cracking the door open for magic.

Psychic dogs.

Really?

Sheldrake may have studied the scientific method, but he sure as hell doesn't practice it.

Okay.thanks for the overview

Well, exceeding speed of light have been broken, and I'm not joking

Here is a NYT article for the less scientific description
Light Exceeds Its Own Speed Limit, or Does It?
another article
Laser smashes light-speed record - physicsworld.com

Here is the Nature publication they are talking about with abstract:

Gain-assisted superluminal light propagation

L. J. Wang, A. Kuzmich & A. Dogariu


Einstein's theory of special relativity and the principle of causality imply that the speed of any moving object cannot exceed that of light in a vacuum (c). Nevertheless, there exist various proposals for observing faster-than- c propagation of light pulses, using anomalous dispersion near an absorption line nonlinear and linear gain lines or tunnelling barriers. However, in all previous experimental demonstrations, the light pulses experienced either very large absorption or severe reshaping resulting in controversies over the interpretation. Here we use gain-assisted linear anomalous dispersion to demonstrate superluminal light propagation in atomic caesium gas. The group velocity of a laser pulse in this region exceeds c and can even become negative, while the shape of the pulse is preserved. We measure a group-velocity index of ng = -310(+/-5); in practice, this means that a light pulse propagating through the atomic vapour cell appears at the exit side so much earlier than if it had propagated the same distance in a vacuum that the peak of the pulse appears to leave the cell before entering it. The observed superluminal light pulse propagation is not at odds with causality, being a direct consequence of classical interference between its different frequency components in an anomalous dispersion region.

Originally Posted by bugfrag

Well, exceeding speed of light have been broken, and I'm not joking

Here is a NYT article for the less scientific description
Light Exceeds Its Own Speed Limit, or Does It?
another article
Laser smashes light-speed record - physicsworld.com

Here is the Nature publication they are talking about with abstract:

Gain-assisted superluminal light propagation

L. J. Wang, A. Kuzmich & A. Dogariu

<shrugs> So? This is old news, and not relevant at all to the OP's topic.

Originally Posted by tk421

Originally Posted by bugfrag

Well, exceeding speed of light have been broken, and I'm not jokingHere is a NYT article for the less scientific descriptionLight Exceeds Its Own Speed Limit, or Does It?another articleLaser smashes light-speed record - physicsworld.comHere is the Nature publication they are talking about with abstract:Gain-assisted superluminal light propagation

L. J. Wang, A. Kuzmich & A. Dogariu

So? This is old news, and not relevant at all to the OP's topic.

Well, I found the topic not very interesting. Speed of light is not constant. Thats why we see rainbow.As far as human could test, speed of light in vacuum is accurate to at least the eight significant digit.Would it ever get revised? Wait for better instrument

Originally Posted by bugfrag

Well, I found the topic not very interesting. Speed of light is not constant. Thats why we see rainbow.As far as human could test, speed of light in vacuum is accurate to at least the eight significant digit.Would it ever get revised? Wait for better instrument

This is not accurate. The speed of light is constant, even when a photon interacts with an electron. The speed of light doesn't change or slow down. There is just a very short delay due to the interaction and conservation of energy with the photon and the electron. Your rainbow example simply does not show light as having a variable speed.

Originally Posted by bugfrag

Well, I found the topic not very interesting.

I see. So you hijacked this thread because you were bored. Got it.

Speed of light is not constant. ... speed of light in vacuum is accurate to at least the eight significant digit.

Speed of light in a vacuum is constant, as far as we know.

Would it ever get revised? Wait for better instrument

Or different experiments. Science is always on the lookout for something new (contrary to what QFY seems to think). There are big rewards for revolutionary discoveries.

The property of light to be refracted or dispersd does'nt change the nature of c.it only shows what c appears like in different medium.think of the vacuum of space as a better propergater or medium.

The fundamental questions are answered leaving only details to be filled in.

No real physicist would ever think in this way - modern science is very much aware of the fact that many of the fundamentals are yet resolved, e.g. the connection between gravity and the other fundamental forces, or why the elementary particles are just the way they are.

Originally Posted by question for you

I read that though the speed of light is considered and taught to be constant which is important in regards to a lot of current theories in physics, hard evidence suggests that it is not always constant.

Early reading of the speed of c (light) were 'suprisingly variable but by 1927 speed of light was thought to be 299,796 kilometres per second which was considered a very accurate reading. But from 1928 until through till 1945 the speed of light dropped all around the world by 20 kilometres per second. Suggesting perhaps cyclical rhythems in light speed. In the lates 1940's the speed of light increased again by 20 m/s.

This is where it gets a little dark, so to speak: The embarresing possibility of variations in this physical 'constant' was eliminated when the speed of light was fixed by definition. Further to that, in 1983 the unit used to measure light, was redifined, in terms of light! The metre is now defined as the length of path travelled by light in a vacum in 1/299,792.458 of a second. Further more, the second is also defined in terms of light 'the duration of 9,192,631 770 periods of vibration of the light given off by cesium 133 atoms in a particular state of excitation (the transition between two hyperfine levels of the ground state, who knew!).

So what this all means, is that from 1983 onwards, any further changes in the speed of light will be undetectable by science and it will always be considered a physical constant.

This remarkable episode is attributed to the 'psychology of meteorologist' and brushed aside as experimental error, though the readings coincided across the entire globe. Brian Petley a british meteorologist claims that 'the tendency for experiments to coincide within a given epoch has been described by the delicate phrase 'intellectual phase locking (Ba, baaaa)... More likely that either the speed of light changed, or something affecting the entire globe cause the equipment to faulty consistently by a mere 20 metres per sec speed of light variation.


I'd be interested to know more about this near 20 year fluctuation in our readings of the speed of light.

Is it a good idea that we measure the speed of light by units (metres and seconds) which are themselves defined by speed of light, meaning that should speed of light change.... we will never know.

My next interest would be why on earth these decisions were made to measure light by units defined by light itself... unbelievable!

Is that a scientific way to operate? my instincts suggest it is not.

Just thought I'd share my new finding with those of you who didn't know, and hopefully get some explainations/further knowledge from those who do understand the ins and outs of this remarkable series of facts.

Part 1.

there are actual and apparent speeds involved. Einstein said :- If you are moving with respect to me, we shall not agree upon the rate of flow of time. Your clock runs slower than mine when you move, and all processes that change with time (including speed eg S=D / T) change at a slower rate when observed in motion . One clock does not beat out time for the whole universe, a seperate clock is needed for each state of motion . . .

Basicly, when you observe any body in motion you see it's apparent speed.
When moving at an actual speed of say 99.9% the speed of light or 186056 mps, the stationary observer will see an apparent speed 22 times slower, just 4.545% c or 8318 mps . . . using Einstein's equation, you can only observe matter to travel at a maximum 75% c . . . .

Originally Posted by AtoMiku235

using Einstein's equation, you can only observe matter to travel at a maximum 75% c . . . .

Huh? Protons in the LHC travel at 99.9999991% the speed of light.
LHC: How fast do these protons go?

idk, but i thought i remember a quote of einstein where he said the speed of light can be broken or reached?, but in these cases, transmitting/communication doesn't work ... something along these lines.

There is something called quantum entanglement, where measuring the state of one entangled particle instantly determines the state of another entangled particle, no matter how far apart they are. Like you said though, you can't send information that way.

i don't know if that was it, i just remember him saying that reaching c/going past, is possible but had no use/value at that time. but that looks like his claims was/is valid for now..

You must have misheard then. Nothing can go faster than light. There is a hypothetical particle, a Tachyon, that works the other way around, i.e. the more energy you apply the slower it moves and closer to C and the less energy you apply, the faster it goes. It is only hypothetical though and is incompatible with the current standard theory if I am not mistaken.

nope, he said the speed of light can be broken under certain circumstances, but it won't be of any use.

Originally Posted by curious mind

nope, he said the speed of light can be broken under certain circumstances, but it won't be of any use.

Find the quote and show it.

Originally Posted by curious mind

nope, he said the speed of light can be broken under certain circumstances, but it won't be of any use.

You're going to have to give a citation for this.

ok, i couldn't find it so far, but i know it is there. i'll post it w/e i find it.

Originally Posted by curious mind

ok, i couldn't find it so far, but i know it is there.

Yes, please find a reference. I can guarantee you that this idea does not appear in any of his refereed works, so I am eager to know the context in which he said such a thing (if he said it at all).

it was a reply/quote/comment regarding time travel. the telegraph into the past was one of the problems mentioned in it.

he explained there why it wasn't possible and then also said in a reply something along the line: that those particles or photones (can't remember the correct wording) wouldn't hold any information, or were useless to transport communication.

Originally Posted by curious mind

it was a reply/quote/comment regarding time travel. the telegraph into the past was one of the problems mentioned in it.

he explained there why it wasn't possible and then also said in a reply something along the line: that those particles or photones (can't remember the correct wording) wouldn't hold any information, or were useless to transport communication.

I think that you are remembering seeing about metamaterials which have the phase velocity greater than c but group velocity less than c. The group velocity carries the information, and it is often said that "special relativity forbids information traveling faster than light, not waves." This was never to my knowledge said by Einstein. It may even be a bit metaphorical as well, if in fact the materials are "analogous to" dielectrics and the velocity is "analogous to" the speed of photons.

the topic of it, i think, was about the history of computers, which somehow included that subject and as far as i remember it was a reply of einstein by letter to someone. i wish i could find it.

Originally Posted by curious mind

it was a reply/quote/comment regarding time travel. the telegraph into the past was one of the problems mentioned in it.

Tachyonic antitelephone ?

Originally Posted by Strange

Originally Posted by curious mind

it was a reply/quote/comment regarding time travel. the telegraph into the past was one of the problems mentioned in it.

Tachyonic antitelephone ?

that's how it was called later on i believe. but that term wasn't used in that context. and it was only about traveling back in time.

the only thing seemingly approaching the issue, but far from what i mean is:

From this we conclude that in the theory of relativity the velocity c plays the part of

a limiting velocity, which can neither be reached nor exceeded by any real body.


Of course this feature of the velocity c as a limiting velocity also clearly follows

from the equations of the Lorentz transformation, for these become meaningless if

we choose values of v greater than c.

tachyonics are still highly hypothesis ed and so also neutrinos that still are believed to travel faster that light.

quantum entanglement although is still not explained by modern physicist for why it has to contradict principle of locality.



einstein quoted that the universe is expanding and the farther galaxies are receding away from us faster than the speed of light. but this quote was placed under joke,because clearly the we do not know how fast the universe is expanding.

can we even really say 100% that the whole universe itself is expanding, just because, for a few decades, we're able to meassure change in distance in our/the orbservable portion we're limited to?

we can only assume that it applies to the whole universe, as long as the numbers match up.

Originally Posted by curious mind

can we even really say 100% that the whole universe itself is expanding, just because, for a few decades, we're able to meassure change in distance in our/the orbservable portion we're limited to?

we can only assume that it applies to the whole universe, as long as the numbers match up.

That is true. But there is an explicit underlying assumption (the cosmological principle) that there is nothing special about "our" bit of the universe and that, on average, the universe is (roughly) the same everywhere. It would certainly be odd if immediately outside the observable universe there was no expansion. But it is possible that, some distance away, conditions are different. As we have no evidence for that, then it can't really form part of the science (but there is all sorts of speculation).

so it could also be possible that the whole universe is in motion, having stream like propperties in some (i also say valume here?), which could either be observed as expanding/shrinking/stable by us?(depending on the location, within the universe, of our observable universe at that time?)

Originally Posted by curious mind

so it could also be possible that the whole universe is in motion, having stream like propperties in some (i also say valume here?), which could either be observed as expanding/shrinking/stable by us?(depending on the location, within the universe, of our observable universe at that time?)

It is possible. But any speculation along those lines is, at the moment, baseless. At large scales the universe appears to be very nearly homogeneous (the same everywhere) and isotropic (the same in all directions). The accuracy with which these have been measured puts limits on how far that speculation can go. (But I am way beyond my area of expertise now...)

Originally Posted by Strange

At large scales the universe appears to be very nearly homogeneous (the same everywhere) and isotropic (the same in all directions). The accuracy with which these have been measured puts limits on how far that speculation can go.

So what exactly is the difference, in meaning, between the words "homogeneous" and "isotropic"?

Originally Posted by Halliday

Originally Posted by Strange

At large scales the universe appears to be very nearly homogeneous (the same everywhere) and isotropic (the same in all directions). The accuracy with which these have been measured puts limits on how far that speculation can go.

So what exactly is the difference, in meaning, between the words "homogeneous" and "isotropic"?

It might be clearer if we think about a spherical, finite object. You can describe location within a sphere by a radial coordinate and two angles. If the sphere is homogenous, its properties do not depend on radius or angle. If it is isotropic, its properties do not depend on angle but might depend on the radius. A homogeneous object is isotropic, but an isotropic object need not be homogeneous. Saying that the universe is homogeneous and isotropic emphasizes that the universe is essentially infinite, so that it is isotropic at any point.

Originally Posted by mvb

It might be clearer if we think about a spherical, finite object. You can describe location within a sphere by a radial coordinate and two angles. If the sphere is homogenous, its properties do not depend on radius or angle. If it is isotropic, its properties do not depend on angle but might depend on the radius. A homogeneous object is isotropic, but an isotropic object need not be homogeneous. Saying that the universe is homogeneous and isotropic emphasizes that the universe is essentially infinite, so that it is isotropic at any point.

I don't fully understand the difference, from your explanation, but that is due to my own limitations in this field.
Another word which can be confusing, for the layperson, is when the Universe is described as FLAT. I think I understand what that means but any further basic explanations are welcome.
Last, is there any difference, in meaning, between the statements that "the universe is infinite" compared with "the universe is essentially infinite" as in the post, by mvb, above?

Originally Posted by mvb

Originally Posted by Halliday

Originally Posted by Strange

At large scales the universe appears to be very nearly homogeneous (the same everywhere) and isotropic (the same in all directions). The accuracy with which these have been measured puts limits on how far that speculation can go.

So what exactly is the difference, in meaning, between the words "homogeneous" and "isotropic"?

It might be clearer if we think about a spherical, finite object. You can describe location within a sphere by a radial coordinate and two angles. If the sphere is homogenous, its properties do not depend on radius or angle. If it is isotropic, its properties do not depend on angle but might depend on the radius. A homogeneous object is isotropic, but an isotropic object need not be homogeneous. Saying that the universe is homogeneous and isotropic emphasizes that the universe is essentially infinite, so that it is isotropic at any point.

I understood that homogeneous doesn't necessarily mean isotropic.
Imagine a space the same everywhere yet lit by light from one side. Place an object anywhere in it and it would throw a shadow, the same shadow.
Hence the need to say isotropic too which means the same in any orientation.

Originally Posted by Halliday

Another word which can be confusing, for the layperson, is when the Universe is described as FLAT

This typically means that normal high school geometry holds for the universe as a whole, i.e. large triangles have angles which sum to pi degrees, pi is the ratio of the circumference to the diameter of a circle etc.

[QUOTE=Halliday;390700]

Originally Posted by mvb

Last, is there any difference, in meaning, between the statements that "the universe is infinite" compared with "the universe is essentially infinite" as in the post, by mvb, above?

What I meant by "essentially infinite" is that we can see no effects of boundaries in our observations. The speed of light severely limits how much of the universe we can see, so we can never prove by observation that the universe is infinite. However, we see nothing that tells us that the universe is finite. It is therefore simplest to construct models in which the universe is infinite, leaving out any complications that might be introduced by undetected edges.

An overall curvature of space could conceivably produce a finite universe without edges, but at the moment we see an overall flat or near-flat space that would be infinite if it is the same where we can't see it as it is where we can.

Originally Posted by tk421

Originally Posted by merumario

Cheers,i thought the thread was about c,or has anyone said anything that says c ain't constant? Forgive me please.i dnt wanna start reading from post one.

Capsule summary: QFY continues to cling to anti-scientific beliefs. This is necessary for him, since science's rigor prevents him from enjoying a magical world.

There is no evidence of c changing. It would be more accurate to say that the fine structure constant seems to be quite constant, over a period of two billion years, to within some ridiculously tight bound. A summary may be found here: http://www.int.washington.edu/talks/...ld_C/gould.pdf

As Strange has pointed out, if c were really varying as much as QFY keeps going on about, GPS would be observably unreliable. As GPS is manifestly quite reliable, we can rule out variations in c over the period of time during which GPS has been operating.

John Galt has correctly observed that considerable advances in metrology have been made over the last century. As measurements have improved, the error bounds have tightened. QFY prefers to view the tightening as evidence of a variation in c itself. However, the constancy of the fine-structure constant rules out that interpretation, unless you argue that both the charge of the electron, and the value of Planck's constant, have magically varied in just the right way to compensate. In the absence of any evidence to support that view, Occam demands that we provisionally assume that c has remained constant.

That's the way science works. It's all about the evidence. QFY prefers to cast scientists as sloppy, venal, conspiratorial and cliquish, as that serves his purpose of casting doubt on the entire scientific enterprise, and thus of cracking the door open for magic.

Psychic dogs.

Really?

Sheldrake may have studied the scientific method, but he sure as hell doesn't practice it.

What an arrogant load of unfounded tripe... what's really disapointing is the 'liking' of such rubbish by suposedly scientific thinkers who hold positions of 'authority' in this tiny corner of the internet.

Its easy to allow this vitriol to affect ones feelings, but I am used to it enough from certain users to not let it bother me.

Needless to say I was questioning peoples contributions to the thread and aiming to learn from any information presented by others.

I still haven't heard any remotely satisfactorary explainations for the variation in the speed of light in a vacum found using scientific methods of observation from 1925 to 1948 (was it?). I also didn't get much of an explaination about the reason for or ins and outs of defining the speed of light by a unit of measurement which itself is defined by the speed of light.

Needless to say tk whats his name did not offer you an honest overview of the thread and your willingness to accept his/her overview without examining the evidence for yourself show some serious inadequacies in the methods you adopt when seeking knowledge merumario.

tk was simply exhibiting a hostile reaction to my aqttempt to learn more about this subject as he has adopted a word view, a beleif system, which is politically motivated and seeks to manipulate the way people think about and investigate reality for some obscure and contrived reasons.

Needless to say that belief system is pseudoscientific and is built on assumptions which have hardened into dogmas.

Basically tk21 is part of a religion and has a belief system, a fact which he is in denial of. When he projects this 'believing in fairy tales' quality onto others such as me, he is completely unaware of his hypocrasy and pseudoscientific thinking.

My best advice for you merumario would be to check things out for yourself rather than expect anybody else to present you with an accurate, unbiased, comprehensive and honest summary of anything. Advice that I will try to follow myself next time I seek to know something.

Originally Posted by question for you

I still haven't heard any remotely satisfactorary explainations for the variation in the speed of light in a vacum found using scientific methods of observation from 1925 to 1948 (was it?).

What is "unsatisfactory" about improvements in technique, instrumentation, etc? If you could be specific about which aspects of changing instrumentation, technique, etc you are doubtful about, perhaps that could be addressed.

Also, the table here: http://en.wikipedia.org/wiki/Speed_of_light#History
doesn't seem to support what you are saying. Could you provide a reliable (i.e. not Shelduck) source for this variation?

I also didn't get much of an explaination about the reason for or ins and outs of defining the speed of light by a unit of measurement which itself is defined by the speed of light.

That may be because that would be a meaningless thing to do so we don't do it.

The sped of light is taken as a fundamental constant. The meter is defined in terms of the speed of light (not the other way round). We happen to use units of m/s to quantify/measure velocity (including that of light) but that is not how the speed of light is defined.

Originally Posted by Strange

What is "unsatisfactory" about improvements in technique, instrumentation, etc? If you could be specific about which aspects of changing instrumentation, technique, etc you are doubtful about, perhaps that could be addressed.

Lets focus on the positive not the negative.

A satisfactory explaination would involve details of developments in the technology used to gather the data, including what machines produced what results in what places at what times. This would have to be a quite comprehensive study of the technologies employed to gather the data.

I also didn't get much of an explaination about the reason for or ins and outs of defining the speed of light by a unit of measurement which itself is defined by the speed of light.

Originally Posted by Strange

That may be because that would be a meaningless thing to do so we don't do it.

The sped of light is taken as a fundamental constant. The meter is defined in terms of the speed of light (not the other way round). We happen to use units of m/s to quantify/measure velocity (including that of light) but that is not how the speed of light is defined.

Well could you explain that in a bit more detail.

I don't get how one can use meters per second to measure velocity without using the meter unit which itself is defined by the speed of light.

Without wanting to sound caustic... just give a clear explaination would ya, im sure this is not the case but it almost seems like you want to hide the facts behind clever word play.

The speed of light is defined as the speed at which light travels.

The speed at which light travels is defined by a series of numbers representing the amount of meters light travels in a second of time.

The meter is defined by the distance light travels in a second of time.

Therefor it seems that at whatever speed light travels relative to how it travelled yesterday or tomorrow... the 'speed of light' as we know it in m/s will always be the same, because if the actual speed it travels changes, then so to do the units of measurement we used to measure the speed of light. Is that correct or not? if not, why?

The second unit involed in the measurement of light velocity is time, in seconds... time in seconds is also set by the electromagnetic actions within a cessium 133 atom, right? So that just complicates the issue and for now i'd like to understand the implications of the way we set the meter's length, and the way we use meters to describe the velocity of light.

Originally Posted by Strange

Also, the table here: Speed of light - Wikipedia, the free encyclopedia
doesn't seem to support what you are saying. Could you provide a reliable (i.e. not Shelduck) source for this variation.

I hope the table below from the link satys in shape after it's posted. I find it interesting that according to wikipedia the measurement of light was consider exact the vary same year that sheldrake informed us was the year that the meter became defined by the speed of light. 1983. In otherwords, from 1983 onwards, the meter is defined as the distance that light travels in a fixed amount of time (in seconds). I think it was in 1972 that time (seconds) was defined as the period in which cessium vibrates a certain amount of times or something simmilar?

1675	Rømer and Huygens, moons of Jupiter	220,000[85][106]
1729	James Bradley, aberration of light	301,000[91]
1849	Hippolyte Fizeau, toothed wheel	315,000[91]
1862	Léon Foucault, rotating mirror	298,000±500[91]
1907	Rosa and Dorsey, EM constants	299,710±30[96][97]
1926	Albert Michelson, rotating mirror	299,796±4[107]
1950	Essen and Gordon-Smith, cavity resonator	299,792.5±3.0[99]
1958	K.D. Froome, radio interferometry	299,792.50±0.10[103]
1972	Evenson et al., laser interferometry	299,792.4562±0.0011[105]
1983	17th CGPM, definition of the metre	299,792.458 (exact)[81

if c had changed, you would notice it in results not matching the calculation, wouldn't it?

Originally Posted by question for you

Lets focus on the positive not the negative.

That is what I was trying to do: get you to focus on specific problems so they could be addressed; i.e. a constructive/positive discussion.

A satisfactory explaination would involve details of developments in the technology used to gather the data, including what machines produced what results in what places at what times. This would have to be a quite comprehensive study of the technologies employed to gather the data.

In other words, you don't know anything about the measurements and how they were made. But you think there is something wrong. Great scientific attitude. How about getting some data before forming a hypothesis.

Well could you explain that in a bit more detail.

I don't get how one can use meters per second to measure velocity without using the meter unit which itself is defined by the speed of light.

Well, one way you could think of it is that all velocities are measured as a fraction of the speed of light (which is a fundamental constant that defines distance, and hence velocity) scaled by 299,792.458.

With this definition, we do not need to measure the speed of light. It is a given.

The speed at which light travels is defined by a series of numbers representing the amount of meters light travels in a second of time.

No. That isn't how it is defined. It doesn't need to be defined, it just is. It travels at the speed it travels at. That is constant so we can use it as the basis for measuring other things.

The meter is defined by the distance light travels in a second of time.

Correct.

Therefor it seems that at whatever speed light travels relative to how it travelled yesterday or tomorrow... the 'speed of light' as we know it in m/s will always be the same, because if the actual speed it travels changes, then so to do the units of measurement we used to measure the speed of light. Is that correct or not? if not, why?

It is correct that if the speed of light changed, then the meter would change and the numerical value of the speed of light would be the same.

BUT if the meter changed, do you think we might notice? To take an extreme example. If the speed of light doubled so the meter got twice as long, do you not think people would notice that, "Hey, I'm sure I used to be neraly 2 meters tall but now I'm barely 1 ..."

On a more realistic level, if the speed of light changed fractionally, we would notice it in the many extremely precise measurements that are made regularly. It would only need to change by a small amount before GPS went wrong, for example. And there are plenty of things much more sensitive to it than that.

You seem to be stuck on the numeric value rather than the actual measurements.

The second unit involed in the measurement of light velocity is time, in seconds... time in seconds is also set by the electromagnetic actions within a cessium 133 atom, right?

Wrong. But I don't really want to get into quantum theory and hyperfine energy levels (mainly because I don't understand it).

Originally Posted by question for you

I find it interesting that according to wikipedia the measurement of light was consider exact the vary same year that sheldrake informed us was the year that the meter became defined by the speed of light. 1983.

Well, of course. It is taken as a fundamental constant that never changes and defines the units that it is represented in.

I was more interested in the fact that it appears to contradict your claim that the speed of light was changing...

Originally Posted by curious mind

if c had changed, you would notice it in results not matching the calculation, wouldn't it?

Exactly.

Originally Posted by Strange

That is what I was trying to do: get you to focus on specific problems so they could be addressed; i.e. a constructive/positive discussion.

There was nothing destructive or negative about my efforts to discuss this subject.

Originally Posted by Strange

A satisfactory explaination would involve details of developments in the technology used to gather the data, including what machines produced what results in what places at what times. This would have to be a quite comprehensive study of the technologies employed to gather the data.

In other words, you don't know anything about the measurements and how they were made. But you think there is something wrong. Great scientific attitude. How about getting some data before forming a hypothesis.

You call this constructive and positive?

In other words strange one, I know nothinng ablout the instruments or experiments which have been gathering data which indicates that the speed of light may not be constant and I would like to know more about these instruments and experiments... particularly regarding developments in these instruments and experiments which might possible account for the data which was gathered between 1928 and 1945 as well as what changed around 1972 and 1983.

It's not a case of if i think something is wrong... its a case of the data suggesting something is wrong with the assumption that the speed of light is constant. Therefor i am seeking to learn more about how this data was gathered and what reasons might explain the inconsistencies found in the so called constant.

Originally Posted by Strange

Well could you explain that in a bit more detail.

I don't get how one can use meters per second to measure velocity without using the meter unit which itself is defined by the speed of light.

Well, one way you could think of it is that all velocities are measured as a fraction of the speed of light (which is a fundamental constant that defines distance, and hence velocity) scaled by 299,792.458.

With this definition, we do not need to measure the speed of light. It is a given.

I'm still none the wiser. My car's velocity is measured in mph, not as a fraction of c.

I dont get what you mean when you say c defines distance or is scaled by 299,792,458.

Originally Posted by Strange

With this definition, we do not need to measure the speed of light. It is a given.

I don't get it. Our definitions shouldn't bear any relevance. Light moves at a certain speed. We should measure that speed using units which are not defined by that speed themselves. It's baffling.

Originally Posted by Strange

The speed at which light travels is defined by a series of numbers representing the amount of meters light travels in a second of time.

No. That isn't how it is defined. It doesn't need to be defined, it just is. It travels at the speed it travels at. That is constant so we can use it as the basis for measuring other things.

How do you know it's constant? why did data indicate it might not be?

The speed of light is defined... in meters per second, as of 1972 I think... and has been defined long before then. Mere word play from you but it doesn't help me or anybody else understand the situation.

Originally Posted by Strange

The meter is defined by the distance light travels in a second of time.

Correct.

And that distance which light travels in a second is measured in meters.

And those seconds are also measured or defined by electromagnetic actions which would vary if the speed of light varied?

Originally Posted by Strange

Therefor it seems that at whatever speed light travels relative to how it travelled yesterday or tomorrow... the 'speed of light' as we know it in m/s will always be the same, because if the actual speed it travels changes, then so to do the units of measurement we used to measure the speed of light. Is that correct or not? if not, why?

It is correct that if the speed of light changed, then the meter would change and the numerical value of the speed of light would be the same.

BUT if the meter changed, do you think we might notice? To take an extreme example. If the speed of light doubled so the meter got twice as long, do you not think people would notice that, "Hey, I'm sure I used to be neraly 2 meters tall but now I'm barely 1 ..."

On a more realistic level, if the speed of light changed fractionally, we would notice it in the many extremely precise measurements that are made regularly. It would only need to change by a small amount before GPS went wrong, for example. And there are plenty of things much more sensitive to it than that.

You seem to be stuck on the numeric value rather than the actual measurements.

We? me? certainly not. meterologists? sure they would know if they change the meter.. or the second. But who else would know?

What does a 20 m/sec drop in c equate to as a change in the meter, in millimeters? I would never know it had changed and neither would anybody else, except meterologists.

As for gps, and im not sure how that works... Doesn't the gps system automatically update metric definitions as and when they change? so if the meter had to be redifined, then the gps would know that although the speed of light is the same in m/s, the m's and even the seconds have changed and so why would the gps have any problems adapting to a new set of measurements instantly, as soon as the new data is uploaded... why would it cause a problem?

Originally Posted by Strange

The second unit involed in the measurement of light velocity is time, in seconds... time in seconds is also set by the electromagnetic actions within a cessium 133 atom, right?

Wrong. But I don't really want to get into quantum theory and hyperfine energy levels (mainly because I don't understand it).

Well I suggest one needs to understand how the second is set or discerned if one is to understand the implications of having the meter defined by the distance light travels in a second...

If the speed of light changed... how would we know? the numerical representation in m/s would not change. The numerical representation of a metre wouldn't change. The numerical representation, or definition, of the second wouldn't change.

The only thing that would change is that meter sticks would come out of factories at a minutely different size from those of yesteryear, which would be completely undiscernable to the layman. What else?

But I supose what i'm really interested in is: Why would it be decided to define, yes numerically define, the speed of light by units of measurement which themselves are defined by the speed of light.

Thats the question. It could easily seem like some kind of weird cover up to ensure that c is always considered a constant but I didn't realise I made that claim. The question is... why was it done like that?

Originally Posted by Strange

Originally Posted by curious mind

if c had changed, you would notice it in results not matching the calculation, wouldn't it?

Exactly.

How exactly?

Calculations are usually done using numerical representations. If the numerical representations do not change due to some obscure quirk in the way the numbers are arrived at... then how on earth would this affect any calculation what so ever?

Originally Posted by question for you

It's not a case of if i think something is wrong... its a case of the data suggesting something is wrong with the assumption that the speed of light is constant. Therefor i am seeking to learn more about how this data was gathered and what reasons might explain the inconsistencies found in the so called constant.

Please present this data (with sources) that shows variation/inconsistencies in the speed of light. The table from Wikipedia (which references published scientific work) does not appear to show what you claim.

I'm still none the wiser. My car's velocity is measured in mph, not as a fraction of c.

I dont get what you mean when you say c defines distance or is scaled by 299,792,458.

I don't know (nor care) what the definition of the m ile is, but I assume today it is defined in terms of the meter. So your car's velocity is measured as a fraction of c with a suitable scaling factor applied to convert it to the units you call "MPH".

I don't get it. Our definitions shouldn't bear any relevance. Light moves at a certain speed. We should measure that speed using units which are not defined by that speed themselves. It's baffling.

Let's try a comparison with another unit of measurement: temperature. The centigrade scale define zero to be the freezing point of water and 100 to boiling point of water. How on earth can we measure the temperature at which water freezes!!! Or boils!!! What if they changed?!?!

Similarly, we define velocity relative to some known standard. The obvious choice is the fastest possible velocity: c. All other velocities are a fraction of that (scaled by some number to converr them to m/s or mph).

How do you know it's constant? why did data indicate it might not be?

We have very good theoretical reasons for thinking it is constant (Maxwell's laws for example). We also have many observations from the past or from cosmological distances (aka the past) which tell us (indirectly) that it is constant.

And that distance which light travels in a second is measured in meters.

No. It defines the meter. It is measured in seconds (fractions of a second).

And those seconds are also measured or defined by electromagnetic actions which would vary if the speed of light varied?

Nope.

We? me? certainly not. meterologists? sure they would know if they change the meter.. or the second. But who else would know?

Going back to the extreme example. If the standard meter (as defined above) changed, then all the people who make and use meter rules would notice. When they started having to use twice as much steel in their rules, for example.

The point is, if the speed of light changed and therefore the definition on the meter changed, but the real world hasn't then we would soon notice that everything was being measured as a different size. If everyone in the world suddenly found themselves 10% shorter in "standard meters" but their clothes still fit, then we would realise that something had gone wrong.

On a more accurate scale if GPS systems stated saying that things were a few mm closer than before (and people are constantly surveying and re-surveying land) then we would notice.

And the physics experiments that depend on measurements with an accuracy of 1 part in 10¹⁸ (for example) would notice even sooner.

As for gps, and im not sure how that works...

I will try and answer that when I am not so sleepy. But it is a combination of trigonometry, very precise timing and GR.

The only thing that would change is that meter sticks would come out of factories at a minutely different size from those of yesteryear, which would be completely undiscernable to the layman. What else?

Even if, initially, it wasn't detectable to the layman why would that matter? It would be rapidly be detected by people who depend on accurate measurements. And a cry would go up.

But I supose what i'm really interested in is: Why would it be decided to define, yes numerically define, the speed of light by units of measurement which themselves are defined by the speed of light.

Are you doing that deliberately or do you really not get it? THE SPEED OF LIGHT IS NOT DEFINED IN TERMS OF THE METRE.

The metre is an arbitrary unit defined as a fraction of the light-second. That just happens to mean that the speed of light in those arbitrary units is some arbitrary large number.

We could invent a new unit of length called the sponk which is 1/7th of a light second. That means the speed of light is 7 sponks/s.

The question is... why was it done like that?

Previously, the meter was defined by the length of a bar of metal (at a certain temperature, etc). This meant if someone wanted to check that their metre rule was correct, they had to go to Paris and compare it. The standards bodies are always looking for ways to make the basic units depend only on fundamental constants. Any good physics lab can now set up a system to measure a standard metre using an atomic clock.

Originally Posted by question for you

What an arrogant load of unfounded tripe... what's really disapointing is the 'liking' of such rubbish by suposedly scientific thinkers who hold positions of 'authority' in this tiny corner of the internet.

Struck a nerve, did I?

Its easy to allow this vitriol to affect ones feelings, but I am used to it enough from certain users to not let it bother me.

And yet you seem very bothered.

Needless to say I was questioning peoples contributions to the thread and aiming to learn from any information presented by others.

That's what you say, but not how you behave. You behave precisely as someone looking for confirmation of a pre-existing bias. To reference Sheldrake so confidently, for example, already marks you as a credulous, unscientific individual.

I still haven't heard any remotely satisfactorary explainations for the variation in the speed of light in a vacum found using scientific methods of observation from 1925 to 1948 (was it?).

You've been given very "satisfactory" explanations (to the scientifically-minded, that is). I'll expand on some here:

1) Instrumentation has improved greatly since the days of, say, Roemer.
2) Methods of using that instrumentation have also improved greatly over time. You may have noticed, for example, that consumer technology has advanced in just the last several decades. So, too, have scientific instruments advanced.
3) Constant cross-checking by fellow scientists have helped refine these methods by identifying and better quantifying error sources.

I also didn't get much of an explaination about the reason for or ins and outs of defining the speed of light by a unit of measurement which itself is defined by the speed of light.

You actually were given explanations, but you failed to grasp their meaning (or refused to hear them). I'll expand on some here:

First, it is completely false to claim that the speed of light is defined in a circular fashion. Any velocity is dimensionally the ratio of a distance to time. You have a choice of what to fix. In the case of light, we have chosen to fix the numerical value of c, and additionally define the second in terms of a certain number of oscillations of a hyperfine transition in Cs. Having fixed those two parameters, the definition of the meter evolves in consequence. These oscillations have nothing whatever to do with our choice of c, contrary to what you've asserted.

But, you say, having defined c as a constant precludes our ability to say that the speed of light has changed! Aha!

The response is that we can still detect changes in fundamental constants -- be they in c or other quantities -- by looking at ensembles of measurements. The fine-structure constant is dimensionless, and will vary if the speed of light (e.g.) were to vary. Yet, all measurements of the fine-structure constant show that, as far as we can tell, to a tight precision (parts or tens of parts per billion), nature's constants are constant. Of course, it is possible that these constants are varying in some magically correlated way that leads to a precise cancellation of their effects as far as the fine-structure constant is concerned. But without evidence to suggest such a miraculous cancellation, there's no reason to introduce such an idea into physics.

Needless to say tk whats his name did not offer you an honest overview of the thread and your willingness to accept his/her overview without examining the evidence for yourself show some serious inadequacies in the methods you adopt when seeking knowledge merumario.

No, what you are complaining about is that I pushed back on your obvious bias. The standard crank retort is to accuse the accuser. Thanks for not disappointing.

tk was simply exhibiting a hostile reaction to my aqttempt to learn more about this subject as he has adopted a word view, a beleif system, which is politically motivated and seeks to manipulate the way people think about and investigate reality for some obscure and contrived reasons.

Explanations have been offered to you, but you repel them. That's an unscientific attitude. Don't throw around accusations of "manipulation" and adherence to belief systems when you are displaying such dislike for information.

Needless to say that belief system is pseudoscientific and is built on assumptions which have hardened into dogmas.

Ironically un-self-aware.

Basically tk21 is part of a religion and has a belief system, a fact which he is in denial of. When he projects this 'believing in fairy tales' quality onto others such as me, he is completely unaware of his hypocrasy and pseudoscientific thinking.

Yes, you've caught me. I am actually a 12th-degree Mason, Master Illuminato and Second Shooter on the Grassy Knoll.

My best advice for you merumario would be to check things out for yourself rather than expect anybody else to present you with an accurate, unbiased, comprehensive and honest summary of anything.

Yes, Merumario, here QFY speaks the truth. He just doesn't know how to apply it.

Originally Posted by tk421

Ironically un-self-aware.

Your full of hypocrasy. I honestly think you twist things up to suit yourself without being aware of it. To aware of yourself to be really aware of other people and what they have been saying?

But look you went through a lot of trouble with the last post and in spite of the pretentious way you like to string your words together, and the minefeild of your pathetic psychoanalysis, I think I managed to learn one or two things somewhere in the middle of that post. So I will refrain from defending myself and attacking some of your blatant faults any further on this occassion, but I didn't apreciate nor value your judgements in anyway. I think your being dishonest with yourself as well as with me... That sunshine, is unscientific. I won't ask you to provide evidence for your multitude of accusations in spite of the fact that you wouldn't be able to provide it, because lifes far too short!

Just try to be less arrogant, for your own sake... there really is no need for it.

Any chance you could learn to spell correctly (or at least use a spell checker) QFY?
Thanks.

Originally Posted by question for you

Originally Posted by tk421

Ironically un-self-aware.

Your full of hypocrasy.

As you have not cited a specific example in support of this assertion, I must write it off as simple emotionalism.

I honestly think you twist things up to suit yourself without being aware of it.

And, apparently, without your being aware of it.

...and the minefeild of your pathetic psychoanalysis,

I think I managed to learn one or two things somewhere in the middle of that post.

I hope that's true. We'll see.

... but I didn't apreciate nor value your judgements in anyway.

I don't make these judgments to be appreciated. I'm merely pointing out your anti-scientific bias. Again, I am not gratuitously hurling accusations. I have already cited, e.g., your unfounded faith in Sheldrake, and your neglect of explanations offered to you (e.g., why measurements have changed over time).

I think your being dishonest with yourself as well as with me...

You seem to be quite hung up on this theme. Get over it. Just open your mind, and quit complaining when others point out that yours is closed. You like to fling accusations of arrogance, but what you really are complaining about is that your dearly-held beliefs are under attack, so you lash out emotionally.

Grow up. What goes on here is tame compared to how real science is done. If you can't handle the heat of this kitchen of science, then you ought to consider some other activity, like something involving Nerf (tm).

I have just watched a video interview, of Rupert Sheldrake. He explains his new book, and he explains in his words the ten dogmas of science.
He talks about one of the dogmas, and compares science to a new religion.

He states that science is to be questioned, I agree science is to be questioned, but only to be questioned if like me, you do not know the answer.
Most science is fact, with few undiscovered gaps.

My eyes have been opened, as I realized what life was.

We are already immortal, we exist after death on a sub atomic particle level. Molicules break down back to the original components. We may return as a rock or a book, but after a few days of learning, even the scientific ignorant can understand it.

I will also say from an observation view of the interview, I could see the pound signs in his eyes rather than his thoughts.

I do not even think himself, believes what he is saying.

I suppose the Trecky's need a new book.

Asking questions to fully understand a concept, is completely different than trying to change that concept.