Why is the speed of light constant?

[physicsnoob12]

why does light travel so fast?

 

[The_Duck]

Because we live so slow.

 

[physicsnoob12]

but why is it not instantaneous because it is not actually matter so it does not have to overcome friction to move.

 

[Pengwuino]

but why is it not instantaneous because it is not actually matter so it does not have to overcome friction to move.

So? Even in a frictionless world, objects don't have to travel fast.

 

[cryptist]

This question is about philosophy, not physics.

 

[unusualname]

but why is it not instantaneous because it is not actually matter so it does not have to overcome friction to move.

That's a better question. No one knows the answer, but one possibility is that the computational speed of the universe is limited (Wolfram), or even more simply, the universe may evolve in discrete finite time intervals.

 

[haael]

Because we live so slow.

No matter how fast we live, the speed of light is allways the same. And you, the observer, will allways move with zero speed relative to youself, so it allways would seem that the light moves at the speed of light and you are at rest.

 

[epenguin]

why does light travel so fast?

Because we live so slow.

This question is about philosophy, not physics.

I think it is about physics not philosophy and the solution is of the type of The_Duck's.
We live so slow and we are so small because of the size of atoms (not complete explanation) and that depends among other things on the speed of light.

 

[Maui]

but why is it not instantaneous because it is not actually matter so it does not have to overcome friction to move.

Light is both a classical and quantum phenomenon and its classical aspect 'prevents' it from being instantaneous, as in the macro realm nothing is instantaneous(which is also forbidden by a postulate of special relativity). It's how nature is.

 

[cryptist]

I think it is about physics not philosophy and the solution is of the type of The_Duck's.

Asking that "why light travels at c instead of another speed or instantaneously" is a philosophical question and nothing to do with physics. It is a universal constant. Like pi for example..

If that's not philosophical, then I can ask you; why pi is 3,14... and not something else? Then is this mathematical?

 

[Gear300]

but why is it not instantaneous because it is not actually matter so it does not have to overcome friction to move.

I'm just spouting stuff here, but it may have something to do with gravity. Light is confined to space-time, so there might be some relevance.

 

[epenguin]

Asking that "why light travels at c instead of another speed or instantaneously" is a philosophical question and nothing to do with physics. It is a universal constant. Like pi for example...

I have given a very crude version of what would be a physical argument. When you say the speed of light is so many m/s like any other physical measurement it is a comparison. You can make it into a comparison with e.g. the size of atomic structures and the times of atomic events. As light is more fundamental than the atom the most meaningful comparison is the other way round. It is asking why atoms have the size and frequencies they do, more exactly try an explain why the size is such that light can get back and forth between two adjacent atoms in the time it takes for x flips of a Cs nucleus or something like that, thousands of things like that. Physical questions.

Like pi for example..

If that's not philosophical, then I can ask you; why pi is 3,14... and not something else? Then is this mathematical?

Not sure what your point is here but yes that is mathematical, once we define pi as twice the circumference of the unit circle. The mathematics answers of is the answer to any 'why' question.

 

[cryptist]

Pi is the ratio of the circumference of a circle to its diameter. It is 3,14... Asking "why it is 3,14... and not something else" is not a mathematical question. It is a philosophical question. There is no single living thing that can answer why pi is 3,14...
And this is the same case. Pi is a mathematical constant, c is a physical constant. Therefore, asking why speed of light is c is not physical question but philosophical.
Physics and mathematics (in fact any positive science) do not ask "why" questions.

 

[epenguin]

Pi is the ratio of the circumference of a circle to its diameter. It is 3,14... Asking "why it is 3,14... and not something else" is not a mathematical question. It is a philosophical question. There is no single living thing that can answer why pi is 3,14...
And this is the same case. Pi is a mathematical constant, c is a physical constant. Therefore, asking why speed of light is c is not physical question but philosophical.
Physics and mathematics (in fact any positive science) do not ask "why" questions.

Puzzling and contradictory IMHO.

It was mathematically proved that pi when defined as you have is that decimal. So it was a mathematical question answered. The mathematical proof is the answer to the why. In ordinary parlance - maybe you can argue deeply that you cannot give a logical sense to the word 'why' that applies here.

Your 'therefore' is completely unwarranted since math and physics are of completely different status and nature - it is not like statements about physics carrying over to chemistry.

At first your use of the word 'philosophical' suggested to me you were one of those scientists who used 'philosophical' as equivalent to 'pointless, unworthy of an adult's attention'. But when I saw 'positive science' I thought you might come from a very definite philosophical position. Unless you just copied the expression. In any case just one position.

Would you say the Boltzmann constant is just what it is, asking why it has that value is a philosophical question?

 

[NobodySpecial]

why does light travel so fast?

It doesn't travel fast - it's appallingly slow.

If you are designing high speed computers it's annoyingly slow- and if you want to rule a galactic empire it's very frustrating.

 

[cryptist]

Puzzling and contradictory IMHO.

It was mathematically proved that pi when defined as you have is that decimal. So it was a mathematical question answered. The mathematical proof is the answer to the why. In ordinary parlance - maybe you can argue deeply that you cannot give a logical sense to the word 'why' that applies here.

I don't think it is contradictory and I don't think the mathematical proof is the answer to the why. "Why" has more deep meaning. Of course we know pi is 3,14... and not something else. But why it is? Can you answer? All you can say is that "Because for any circle circumference over diameter gives 3,14..". Then "Why for any circle circumference over diameter gives 3,14...?". You can ask these but you cannot find an answer. That's why there is a thing called philosophy :)

Your 'therefore' is completely unwarranted since math and physics are of completely different status and nature - it is not like statements about physics carrying over to chemistry.

I don't think math and physics have completely different status. Physics derived from mathematics. Physics can be considered as applied math. (I think)

At first your use of the word 'philosophical' suggested to me you were one of those scientists who used 'philosophical' as equivalent to 'pointless, unworthy of an adult's attention'. But when I saw 'positive science' I thought you might come from a very definite philosophical position. Unless you just copied the expression. In any case just one position.

No, I never use "philosophical" as pointless or unworthy. I know the boundaries of philosophy and science, so I am not saying that "Do not discuss why does travel so fast! It is pointless." , I am saying "Quantum Physics forum is not the right place to discuss this kind of why questions". Because it is philosophy.

Would you say the Boltzmann constant is just what it is, asking why it has that value is a philosophical question?

Every constant in science has a meaning. But "why it has that meaning" is something else.

 

[Naty1]

No one knows why the speed of light is what it is, nor even why it is fixed; nor why the charge of an electron is what it is, nor why gravity has it's particular value...

 

[DevilsAvocado]

why does light travel so fast?

Yes, from "the human perspective" it is fast; 299,792,458 meters per second. But remember that meters and seconds are related to humans, living on the planet Earth.

One meter was originally intended to be one ten-millionth of the distance from the Earth's equator to the North Pole.

One second was originally intended to be 1⁄86,400 of the mean solar day (24 x 60 x 60).

Now imagine an alien civilization of terrible large giants visiting our solar system, where the Earth had the size of a head of a pin and the Moon the pin tip, form their perspective (impossible but just for fun). Imagine that these alien visitors saw a laser beam leaving Earth towards the Moon.

– What would that look like to them?

[URL]http://upload.wikimedia.org/wikipedia/commons/thumb/6/60/Speed_of_light_from_Earth_to_Moon.gif/400px-Speed_of_light_from_Earth_to_Moon.gif[/URL]
A beam of light is traveling between the Earth and the Moon in 1.255 seconds

As you can see, these giant aliens could most probably walk faster-than-light!

But this is not possible; it’s just science fiction to give you some "perspective". Absolutely nothing can move faster than the speed of light in space (the expansion of space itself is another story), and this has to do with causality. If you could travel faster than the speed of light (FTL), then you could do time travel, which in turn would cause unsolvable paradoxes with observers going back in time to erase the cause of their own "present" existence, etc.

In the theory of relativity, the speed of light (c) is invariant. If you had an extremely fast "science-fiction-car" doing 0.5 x the speed of light, at what speed would the light of your headlights leave the car? Well the natural answer is 0.5 x the speed of light, as the sum up speed would be 0.5 + 0.5 = 1 x the speed of light, which is maximum speed, right?

But this is wrong! The speed of the light leaving your headlights will always be 1 x the speed of light, no matter how fast you drive, when you measure that speed.

In special relativity, space and time is a unified structure known as spacetime, with c relating the units of space and time, and c = 1, i.e. the speed of light = 1.

but why is it not instantaneous because it is not actually matter so it does not have to overcome friction to move.

There is no friction in outer space, whether you are a spaceship or a light beam. If the speed of light was instantaneous, there would not be any time = crazy mess... where everything happens at once...

"The only reason for time is so that everything doesn't happen at once." -- Albert Einstein​

 

[physicsnoob12]

The problem here is that some people are solving this by just saying " it just does" but imagine if Newton wondered "why did this apple fall?" and then just said " oh yeah, it just does" we have to to a crack at the question.

 

[physicsnoob12]

don't mind my last comment thanks for the explanation Devilsavacado

 

[DevilsAvocado]

Are you talking to me!?

()


EDIT: Ahhh OK! ()

 

[epenguin]

Would you say the Boltzmann constant is just what it is, asking why it has that value is a philosophical question?

Every constant in science has a meaning. But "why it has that meaning" is something else.

Well the Boltzmann constant comes in a bit everywhere at least in bulk matter theory. So it can have the appearance of a fundamental constant. But if you analyse it it is nothing but a property of water, its solid/liquid/gas states. If you can predict the energy of its melting and boiling you have it. So a property of atoms in the end. I suggest the speed of light is a property of atoms in the same kind of way.

 

[TylerH]

The problem here is that some people are solving this by just saying " it just does" but imagine if Newton wondered "why did this apple fall?" and then just said " oh yeah, it just does" we have to to a crack at the question.

No he went much further, and said "oh yeah, it just does, because of gravity". And we're still at that point now + a few unexplained constants. :P

 

[Drakkith]

The problem here is that some people are solving this by just saying " it just does" but imagine if Newton wondered "why did this apple fall?" and then just said " oh yeah, it just does" we have to to a crack at the question.

No, the problem is that we don't actually know WHY light travels so fast, only that it DOES. We can explain how light works to the best of our knowledge, but that's it. It's like the little kid that continually asks why when you explain something too them. Eventually, you HAVE to say "It just does" or "Thats just the way it works". Either because its far to complicated to explain, or because we just don't know.

We can follow up on this with a detailed explanation on an electromagnetic wave and other related subjects, but the first answer might have been enough for the poster.

 

[Rap]

I think its a valid question. It could be restated as "why have Earth life forms evolved to deal with only Newtonian physical situations?" (i.e. the speed of light is large compared to any velocities that are relevant to the survival of the organism). It probably has something to do with the fact that life forms cannot be (or have not been) "built" which have "circuits" (neurons) that can send signals at anywhere near the speed of light, nor can they generate forces which would accelerate anybody part to anywhere near the speed of light. If they could, then organisms would have to respond relativistically in order to survive either as predator or prey, and the speed of light would not seem so fast.

 

[DevilsAvocado]

There are many physical constants and most are associated with physical dimensions, e.g. speed = length divided by time.

But there is one fundamental physical constant which is dimensionless – the Fine-structure constant (α).

This seems like a much bigger "mystery" than the speed of light, according to Nobel laureates:

There is a most profound and beautiful question associated with the observed coupling constant, e the amplitude for a real electron to emit or absorb a real photon. It is a simple number that has been experimentally determined to be close to 0.08542455. (My physicist friends won't recognize this number, because they like to remember it as the inverse of its square: about 137.03597 with about an uncertainty of about 2 in the last decimal place. It has been a mystery ever since it was discovered more than fifty years ago, and all good theoretical physicists put this number up on their wall and worry about it.) Immediately you would like to know where this number for a coupling comes from: is it related to pi or perhaps to the base of natural logarithms? Nobody knows. It's one of the greatest damn mysteries of physics: a magic number that comes to us with no understanding by man. You might say the "hand of God" wrote that number, and "we don't know how He pushed his pencil." We know what kind of a dance to do experimentally to measure this number very accurately, but we don't know what kind of dance to do on the computer to make this number come out, without putting it in secretly!

— Richard P. Feynman (1985)

 

[f95toli]

Well the Boltzmann constant comes in a bit everywhere at least in bulk matter theory. So it can have the appearance of a fundamental constant. But if you analyse it it is nothing but a property of water, its solid/liquid/gas states. If you can predict the energy of its melting and boiling you have it. So a property of atoms in the end. I suggest the speed of light is a property of atoms in the same kind of way.

This is sort of correct. However, the "everyday use" of kb is to relate temperature to energy (W=kBT) and this is done even for situations where the temperature scale is not defined (meaning you can't relate it to the tripple-point of water) so kb is -when used in this context- certainly fundamental.
It is almost certain that kb will in a few years time be defined to have a certain value, thereby removing all references to the triple point when using the Kelvin. This will be done as part of a larger overhaul of the SI, where the principle of "one unit-one constant" will be used (i.e. c for length, kb for the kelvin, A for mole etc).

 

[Oldfart]

Reading through this fastinating thread makes me wonder: Do at least some of you believe that it is beyond human capability to ever mathematically derive the speed of light, i.e., to explain why it must travel at the speed that it does? And if so, why?

 

[Rap]

Reading through this fastinating thread makes me wonder: Do at least some of you believe that it is beyond human capability to ever mathematically derive the speed of light, i.e., to explain why it must travel at the speed that it does? And if so, why?

This question has no answer, in the sense that you mean. The speed of light is given as some multiple of a reference distance (e.g. the meter) divided by some reference time (e.g. the second). If we assume that the speed of light is a constant, then we can set its numerical value to anything we want by choosing our reference distance and our reference time. The best we can do is to ask why is its value what it is compared to, say, some other velocity. Then we could take the ratio of those two velocities and get a dimensionless number and about THAT we could ask why. Its pointless to ask why a dimensioned quantity (like the speed of light) has the value it has without inquiring into the reference quantities used to calculate it. The real question is why is the meter as long as it is, and why is the second as long as it is? These are answerable - because they are lengths and times that we as humans need to easily grasp in order to survive - we are evolutionarily programmed to be very concerned about lengths on the order of a meter and times on the order of a second (to within a few orders of magnitude). And velocities on the order of a meter per second. In this sense, the question "why is light so fast?" is a much better question. Saying it another way, we could say "why does the ratio of light velocity to evolutionarily important velocities have the value it does?" And again, that is a ratio of velocities which is a dimensionless number. Only dimensionless quantities (e.g. the fine structure constant mentioned above) have absolute physical meaning, and whose meaning may be questioned.

 

[Oldfart]

Thanks, Rap!

Your explanation is sensible throughout, but seems to sort of duck what I'm asking. Not that you would know that, from my simplistic question. I'll try again...

I got the feeling from some of the posts here that the speed of light is just what it is, sort of a philosophical speed, and was wondering if it might be possible for humans, after a million years of math/phiysics, to change that outlook, to prove that c must be what it is, rather than just accept is as a sort of "god number." The approach to this solution can involve whatever methods you can imagine, ratioing velocities as you cite or whatever. The deep question here is "could this ever happen?" Or to put it another way, is such a feat fundamentally impossible?

 

[Rap]

Well, I don't mean to duck the question, I'm trying to explain why its a bad question, and not doing to well, I admit. The short answer is yes, its fundamentally impossible. As a number, the speed of light is not a "god number", because its numerical value depends on your chosen unit of length and your chosen unit of time. The only "god numbers" are dimensionless, like the fine structure constant, because they don't depend on your choice of units. Suppose the speed of light were to suddenly double what it is now. Then all of our physics would change, because some or all of our "god numbers" (fine structure constant and maybe a few more) would change. If the speed of light were doubled, but all other constants were modified too, such that all our "god numbers" stayed the same, then we would live in a world where all the physics is the same. We could detect no change. If, after the change, we chose to define the meter and the second in the same way we do now, the numerical value of the speed of light would be the same as it is now! We could never detect the change.

 

[Nano-Passion]

Perhaps one reason light travels so fast in comparison to other velocities because it holds no mass and therefore no friction or colliding against other atoms?

Just a little speculation.

 

[NobodySpecial]

but imagine if Newton wondered "why did this apple fall?" and then just said " oh yeah, it just does"

The whole point of the enlightenment and modern, as opposed to medieval and greek science, is that we can say "it just does".

Newton worked out that objects behave as if there was a force between them that was GMm/r^2 WITHOUT having to know why - there is nothing in Newton's theory that has any clue why things behave like that - he just created a mathematical description to explain how they behaved.

Earlier science was hampered by the need to explain why. So the apple fell because it was made of the same element as earth, or it's natural place was place earth, or because it wasn't godly - none of this reasoning gets you to a law describing how things fall.

 

[doppelganger]

none of this reasoning gets you to a law describing how things fall.

I don't think any of the reasoning that you mentioned was ever intended to get you a law describing how things fall. Explaining why and describing how are not equivalent tasks.

 

[Nano-Passion]

I don't think it is contradictory and I don't think the mathematical proof is the answer to the why. "Why" has more deep meaning. Of course we know pi is 3,14... and not something else. But why it is? Can you answer? All you can say is that "Because for any circle circumference over diameter gives 3,14..". Then "Why for any circle circumference over diameter gives 3,14...?". You can ask these but you cannot find an answer. That's why there is a thing called philosophy :)

I don't think math and physics have completely different status. Physics derived from mathematics. Physics can be considered as applied math. (I think

No, I never use "philosophical" as pointless or unworthy. I know the boundaries of philosophy and science, so I am not saying that "Do not discuss why does travel so fast! It is pointless." , I am saying "Quantum Physics forum is not the right place to discuss this kind of why questions". Because it is philosophy.

Every constant in science has a meaning. But "why it has that meaning" is something else.

I'm sorry, I'm going to have to stop that assumption right there. That is exactly what does NOT progress physics. That claim can be compared to people that have said in the past "everything that has been invented, has already been invented." It is simply your limited perspective.

Learning something such as why light travels at such a magnificent speed would ultimately help push physics further as a science. it would help us unveil the laws of physics as it is. Because truly, we don't really understand much at all.

 

[Oldfart]

Well, I don't mean to duck the question, I'm trying to explain why its a bad question, and not doing to well, I admit. The short answer is yes, its fundamentally impossible. As a number, the speed of light is not a "god number", because its numerical value depends on your chosen unit of length and your chosen unit of time. .

Rap, perhaps we remain disconnected because of my misuse of the term "god number." I have no interest in defending or defining a particular "numerical value" for c,

Lets go back a few thousand years, Zog the caveman, who has no notion of meters or seconds, cleverly observes that light is very fast and wonders if someday science will be able to explain why it goes at the fastness that it does. What do you tell him?

 

[Rap]

Rap, perhaps we remain disconnected because of my misuse of the term "god number." I have no interest in defending or defining a particular "numerical value" for c,

I fully understand.

Lets go back a few thousand years, Zog the caveman, who has no notion of meters or seconds, cleverly observes that light is very fast and wonders if someday science will be able to explain why it goes at the fastness that it does. What do you tell him?

I would say "tell me, how fast does it go?" What would he respond?

 

[Oldfart]

I would say "tell me, how fast does it go?" What would he respond?

"Zog unhappy you impolitely answer his question with a question...but anyway, Zog not know, wonders if Mr. Smartguy here from advanced civilization can explain how to reckon its fastness."

I don't think that asking Zog will be much help here, as he (and I) is here to ask, not explain stuff.

 

[Drakkith]

I'm sorry, I'm going to have to stop that assumption right there. That is exactly what does NOT progress physics. That claim can be compared to people that have said in the past "everything that has been invented, has already been invented." It is simply your limited perspective.

Learning something such as why light travels at such a magnificent speed would ultimately help push physics further as a science. it would help us unveil the laws of physics as it is. Because truly, we don't really understand much at all.

There's nothing wrong with trying to figure out HOW light travels so fast. Currently, it is simply a physical constant that we cannot explain. When we answer the question by saying that "It's just the way it is" doesn't imply that we will NEVER figure it out, but only that at this time we have no way of explaining it.

 

[Delta2]

I can give a scientific answer why light has a finite speed. If it had infinite speed all the wave phenomena related to it would break down and our world would be much different.

But i can't answer why it is c and not 2c or 10c or pi*c, seems if it was faster like 10c it would be good for telecommunications but don't know what other implications this could had.

 

[jhmar]

Assuming that gravitons are real, then experiments on the speed of light can be explained by assuming that light travels throught a given number of particles in a given unit of time.

 

[Drakkith]

Assuming that gravitons are real, then experiments on the speed of light can be explained by assuming that light travels throught a given number of particles in a given unit of time.

How so? Light doesn't travel slower or faster when gravity differs, but merely changes frequency.

 

[Brandon_R]

https://www.youtube.com/watch?v=wMFPe-DwULM

 

[PhysDrew]

Haha nice

 

[Rap]

"Zog unhappy you impolitely answer his question with a question...but anyway, Zog not know, wonders if Mr. Smartguy here from advanced civilization can explain how to reckon its fastness."

I don't think that asking Zog will be much help here, as he (and I) is here to ask, not explain stuff.

See Brandon's Feynman answer - it's getting to the core of things. Of course, its Feynman :).

The thing is, Zog cannot conceptualize a velocity as something isolated and alone, without reference to something else. A dog or a cat can deal with velocity, by reacting to it, but only Zog and Mr. Smartass can conceptualize it. Mr. Smartass needs to know how Zog conceptualized it in order to answer.

Suppose the speed of light were constantly varying, but Zogs idea of length and time were constantly varying too, in such a way that length divided by time made it look like the speed of light were constant. Zog and Mr. Smartass would never know it, never be able to prove that the speed of light was varying. You cannot talk about the speed of light without referencing it to something, another speed, or a length and a time. So it makes no sense to ask why the speed of light is what it is. It only makes sense to ask why it is so much faster than Zog can walk, or why it covers 300 billion of Zogs arm spans (i.e meters) divided by the time between his heart beats (i.e seconds). You cannot conceptualize the speed of light without some reference points, even if they are very primitive (i.e. it moves VERY fast compared to speeds I encounter in every day life). Mr. Smartass needs to know how Zog has come upon his idea of "fastness" of the speed of light in order to explain why it is so fast.

Take another situation - two scientists are communicating from different parts of the universe, and they wonder if the speed of light is the same for both of them - how do they do it? They cannot do it without agreeing on a unit of length and time, like the radius of a hydrogen atom, and the time between the peaks of the radiation from the Balmer line of hydrogen. But then they will wonder if maybe the hydrogen atom is bigger for one of them than for the other. Is the time between the peaks the same? IT WILL NEVER REALLY BE SETTLED. And so, the constancy of the speed of light will never be really settled until one of them meets the other and verifies that the hydrogen atom from one's part of the universe is the same size as the atom from the other, etc. What they absolutely CAN settle on is the value of the dimensionless fine structure constant. By measuring the speed of light in whatever units (the units don't have to agree between the two physicists), measuring Planck's constant in whatever units they want, etc, and calculating the fine structure constant, they will be able to absolutely decide whether the fine structure constant is the same.

When Zog talks about the speed of light, whether he knows it or not, he is referencing it to some speed that he is familiar with. The only question we can really answer is why the ratio of the speed of light to his reference velocity is what it is. Thats why the question "why is light so fast" makes sense, but the question "can we ever derive the speed of light" does not.

 

[gmax137]

Sorry, Rap, I just don't follow this argument that velocity is somehow related to the units we use. If I ask you (or better, the guys at Chevrolet) "how fast will the new Corvette go?" - there is an answer that can be calculated from the aerodynamic coefficient and the motor horsepower. Why is that possible for the Corvette but not for light?

 

[jhmar]

How so? Light doesn't travel slower or faster when gravity differs, but merely changes frequency.

Surely photons slow down as the get closer to a black hole? are not frequency changes caused by compression or decompression? We observe the same speed because the measuring instrument is subject to the same gravitational pressure as the experiment hence regardless of the direction of observation or the speed of the observer, the observer sees light passing through the same number of particles in the same unit of time. How else does gravity alter time? Is there any alternative practical explanation of the Michelson-Morley experiment?

 

[Buckleymanor]

Surely photons slow down as the get closer to a black hole? are not frequency changes caused by compression or decompression? We observe the same speed because the measuring instrument is subject to the same gravitational pressure as the experiment hence regardless of the direction of observation or the speed of the observer, the observer sees light passing through the same number of particles in the same unit of time. How else does gravity alter time? Is there any alternative practical explanation of the Michelson-Morley experiment?

There is an alternative practicle eplanation of the M.M experiment which has not been refuted .Though it might have been and I have not nowticed.
Simply put any gain in the velocity of light in one direction is exactly canceled out when the light is traveling in the opposite direction.

 

[Rap]

Sorry, Rap, I just don't follow this argument that velocity is somehow related to the units we use. If I ask you (or better, the guys at Chevrolet) "how fast will the new Corvette go?" - there is an answer that can be calculated from the aerodynamic coefficient and the motor horsepower. Why is that possible for the Corvette but not for light?

A Corvette can be broken down into pieces, and their connections can be calculated, but a photon is an elementary particle, so unless future physics can break them down somehow, the analogy won't work. Even then, the speed of light is different than the speed of a Corvette, its a universal speed, always the same. I don't understand the workings o a Corvette, but if you ask me how fast will it go, I know it will never go faster than the speed of light.

I don't mean to imply that the speed of light is related to the units that we use. What I mean to say is that you don't conceptualize it as something isolated and alone. If you think of the speed of light, you are always thinking in terms of a distance and a time, or else relating it to some other velocity, something that you are familiar with. You have an arm span of about a meter, a heartbeat of about a second, and that gives you a familiar velocity, and then you look at the speed of light and say "its really fast". What if there were a huge organism, with an arm span of a light year, and a heart rate of once per year. It would take light a heartbeat to go from one hand to the next, and light would seem to travel much more slowly to the big organism. But still the velocity is the same. So you and the big organism would have to settle on a unit distance that you agree is not changing in order to talk about the speed of light. Like the radius of a hydrogen atom. But then it comes down to "why is the radius of the hydrogen atom what it is?" You would have to agree on a fixed time interval like the time between peaks of the radiation from some atom, like the time between peaks of radiation from some line in a Krypton atom. But then "why is that time interval what it is?" etc. etc. What you are really asking is " why does light travel n times the radius of a hydrogen atom in M times the time between peaks of the Krypton radiation? But that brings in other physical constants, like the Planck constant, the charge on an electron, etc. Its not a simple question. Ultimately you realize that the speed of light could be anything, the Planck constant could be anything, etc., etc., but as long as the dimensionless constants that you build up from these values are the same, you will never detect any difference.

 

[jhmar]

There is an alternative practicle eplanation of the M.M experiment which has not been refuted .Though it might have been and I have not nowticed.
Simply put any gain in the velocity of light in one direction is exactly canceled out when the light is traveling in the opposite direction.

Cannot find any reference to the 'explanation' you mention; do you have a reference?