soz to have woken u from ur slumber... ;-)
all the posts are relevant to the original question ?
Please enlighten me to the real truth if u wud be so kind... the only entity in the universe that knows the answer is now going to impart the truth on us all.. go ahead ;-)
I was actually enjoying the recent discussion.
If I could add my own speculative two cents, it seems highly unlikely that the speed of light would be an absolutely fixed constant. Isn't it more plausible that the speed of light is not absolute, but that its rate of change relative to us would be so slow as to appear constant?
If I could add my own speculative two cents, it seems highly unlikely that the speed of light would be an absolutely fixed constant. Isn't it more plausible that the speed of light is not absolute, but that its rate of change relative to us would be so slow as to appear constant?
Einstein's theory rests upon the postulate of the constant speed of light.
All the tests that have ever been done have confirmed the theory. Therefore, this postulate is quite well founded.
Yay
its only a constant because it fits our limited understanding ? Clearly the speed of light is not a constant ? What is light ? Some lepton thingys that scoot around ? The very belief that we think we know how the universe came into being means there was a time when the speed of the early leptons had to be a quicker than ur average photons that we now call light ?
I am reminded of a novel by Kurt Vonnegut, in which it was discovered that the gravitational constant was not, in fact, constant, but was variable and had simply had the same value for most of human existence. Then one day, for no apparent reason, the rate of change of that variable went from zero to random fluctuations, changing physics. The protagonist is able to detect subtle changes in gravity, for example by the way it affected certain biological functions peculiar to male anatomy.
Isn't fiction fun compared to reality?
Isn't fiction fun compared to reality?
E=mc^2
Which of the other two would you have a constant, and what would be the implications.?
Perhaps the most elegant solution would be to redefine "2" to "that value which makes the equation E=mc^2 valid for any value of c".
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Light is a natural condition and one of persistent features of natural conditions is that they appear almost inevitably to be mutable and subject to change of some sort. As far as I understand it, even the accepted laws of nature only seem applicable to certain periods of the universe's history, thereby suggesting that they themselves came into being historically (unless you think of such laws as Platonic-like, 'metaphysical' principles that pre-exist the natural conditions to which they apply). To assume that light is an absolute, eternally fixed, naturally existing constant seems to be at odds with our broader sense of what it means to be a natural condition.
I understand the value of taking something as constant in some absolutely fixed sense. You find the same thing in the history of logic (e.g. the principle of non-contradiction), the history of metaphysics (e.g. Platonic Forms, the traditional notion of substance, Categories), and so on. Unless you take something as constant it seems difficult, arguably impossible, for us to know or understand things in any absolute or ideal sense. The problem for me likes in taking some natural condition as constant, for natural conditions seem almost inevitably to be subject to change.
Now people will cite empirical evidence in support of the constancy of light, but measuring devices are always limited in their precision (they have to be, otherwise there would be no particular measurements). Also, there are good reasons for believing that no amount of evidence will ever verify a theory in any absolute sense, for theories always (and seemingly inevitably) appear to be underdetermined by the available evidence, no matter how extensive that evidence might be (which is why many people side with Popper over Ayer and many other logical positivists in distinguishing science by its falsifiability rather than its verifiability). Evidence can support a theory, of course, but it can never verify one in any absolute sense (which is why scientific claims have to be taken as inherently provisional, a feature that many people, including scientists, sometimes forget).
Now I would venture that the available evidence regarding the speed of light is likely compatible with a number of different theories about the nature of light, including the idea that it is not a constant but something whose rate of change is so slow relative to us that we can take it as constant for all practical purposes. Give our general sense that nothing in nature every remains eternally the same, it seems unlikely that light, as a natural condition, would be an exception to that general 'rule.' Now I don't rule out the possibility of this (because all general rules seem to allow for exceptions), but my own view is that it makes more sense to take is as a constant for practical purposes while remaining open to the likelihood that it may not be exactly as our theories posit it to be.
That is just playing with words.rayma said:
The constancy of the speed of light in an inertial frame in a vacuum is now assumed, so that it is now defined to be constant. I'm not convinced that is a wise move. The result is that if in fact c is changing then one day we will notice it as a change in the length of the metre!
ok, some 'licsense' on my part. But, at the moment of the B/B, the theory says the whole of what is now the current universe was contained in an incredibly small space. CBR, inflationary universe, and intergalactic 'clumpiness all point to a begining state that was very small.
"I think you will find that gravitational lensing is ample evidence that the velocity of light changes in a gravitational field. "
I presumed it remained constant, but that because of space time curvature, caused by gravity, it travelled further and was bent.
The show that I watched a few years ago, claimed that the speed of light in the early universe was much faster than it is today. So although we can look anywhere in the universe now, and see the speed of light as 330 x 10^6 meters/s, it was not the case in the very early universe.
The guy that postulated the theory was a young Spanish physicist - unfortunately I forget his name.
I presumed it remained constant, but that because of space time curvature, caused by gravity, it travelled further and was bent.
The show that I watched a few years ago, claimed that the speed of light in the early universe was much faster than it is today. So although we can look anywhere in the universe now, and see the speed of light as 330 x 10^6 meters/s, it was not the case in the very early universe.
The guy that postulated the theory was a young Spanish physicist - unfortunately I forget his name.
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Time is effectively constant(ish) for an individual. (You may gain or lose weight, or speed.)
Whether it is the resting mass, some internal mechanism, or both "time" is directly related to mass and speed.
Again we should disassociate light as a constant measurement, it is after all called the theory of relativity, not constantivity.
Why?, because our traditional speed measure is based on a unit of perception, time, specifically human perception. The less you can "see" of it, the faster it goes, relative to something/someone else.
The quasi-literal analogy is easy to see.
Smaller,(species dependent) higher-metabolic animals generally have a higher critical flicker fusion frequency, they can see faster.
Your dog can easily spot flicker on the television, they can see higher refresh rates.
It is not that a house fly is faster then you, it is that you are taking more "time" trying to swat him then he needs to get away.
His perception of time is 4 times faster then ours, this is why we need a swatter, to try and overcome this time dilation with improved mechanical radius.
Who would have thought that dirty old fly swatter was in effect a time machine.
Now this "speed" appears to have a consequence, a short life, it appears that way relative to us, however it is quite possible that some of these animals have already out lived you, time wise, even though they were born after and die before you.
Turtles are so slow they are almost universally accepted as the icon of slow.
It is no coincidence the have the slowest visual systems and metabolisms.
This even changes with age, or slightly with training, within the same animal.
Remember when you were a small kid and those car rides seemed really long? They were.
Where did the time go?
It appears that going faster to save time, can take it away somewhere else.
Driving to work causes you to age slower relative somebody walking, yet somebody walking will have had more time to "live".
Lets say a traveling salesman had the option to do a lifetime of traveling really really fast, allowing him to spend more time with his family.
If he travels too fast his kids will have died from old age before he returns home from his trip.
One could also say the high speed of his trip caused his family to age faster, this would also be correct.
So it seems that "the speed of light" really has a deeper definition buried within that definition. The speed of time.
Thus Einstein's formula could be interpreted as Energy = Mass x Time²
Energy exists as a Mass, or as Time, or a combination of both.
Whether it is the resting mass, some internal mechanism, or both "time" is directly related to mass and speed.
Again we should disassociate light as a constant measurement, it is after all called the theory of relativity, not constantivity.
Why?, because our traditional speed measure is based on a unit of perception, time, specifically human perception. The less you can "see" of it, the faster it goes, relative to something/someone else.
The quasi-literal analogy is easy to see.
Smaller,(species dependent) higher-metabolic animals generally have a higher critical flicker fusion frequency, they can see faster.
Your dog can easily spot flicker on the television, they can see higher refresh rates.
It is not that a house fly is faster then you, it is that you are taking more "time" trying to swat him then he needs to get away.
His perception of time is 4 times faster then ours, this is why we need a swatter, to try and overcome this time dilation with improved mechanical radius.
Who would have thought that dirty old fly swatter was in effect a time machine.
Now this "speed" appears to have a consequence, a short life, it appears that way relative to us, however it is quite possible that some of these animals have already out lived you, time wise, even though they were born after and die before you.
Turtles are so slow they are almost universally accepted as the icon of slow.
It is no coincidence the have the slowest visual systems and metabolisms.
This even changes with age, or slightly with training, within the same animal.
Remember when you were a small kid and those car rides seemed really long? They were.
Where did the time go?
It appears that going faster to save time, can take it away somewhere else.
Driving to work causes you to age slower relative somebody walking, yet somebody walking will have had more time to "live".
Lets say a traveling salesman had the option to do a lifetime of traveling really really fast, allowing him to spend more time with his family.
If he travels too fast his kids will have died from old age before he returns home from his trip.
One could also say the high speed of his trip caused his family to age faster, this would also be correct.
So it seems that "the speed of light" really has a deeper definition buried within that definition. The speed of time.
Thus Einstein's formula could be interpreted as Energy = Mass x Time²
Energy exists as a Mass, or as Time, or a combination of both.
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