speed of light

i have a few questions for someone who could give an intelligible explaination.

1)on what grounds did einstein make the assumption that speed of light is the speed limit for everything?

2)and also, why is light speed always the same from all frames of reference?

example - two people run in opposite directions each at a speed of 5 MPH. the south runner could look back and see the north runner traveling 10 MPH.

a man runs 5 MPH south while light is going 670,616,629.384 MPH north. according to einstein's theory, the man looking back at light does not see light traveling at 670,616,634.384 MPH, but he still sees it moving at 670,616,629.384 MPH. why wouldnt you add 5MPH like with the two runners? Is there any explaination with that or does the conclusion come with a math problem?

Thanks for reading
-Cliff

This post has been edited by clifflindsey85 on Aug 19 2006, 07:51 AM

On the base of the Maxwell's Aether theory of Light (1867), from which the light speed invariance can be derived (Lorentz 1895) on the base of result of Michelson-Morley experiment (1887). The another conceptual source of relativity was Lorentz invariance principle and Lorentz transforms.

The special relativity is in fact just thin philosophy shell above Aether theory, all the important equations were derived more years before. Now we can understand, the separation of results of Aether theory into ad-hoc SR postulates (i.e. the assumption without proof) was unwanted sort of reductionism, which accelerated the derivation of some math formalism without true understanding, but now it's conceptually overcomed. At the first line, it doesn't explains the wave character of energy spreading at all. Therefore, Einstein tried to return to the Aether concept later, but he was limited by it's own ideas and Poincare concurrence too much.

The Maxwell's Aether theory of Light was derived from assumption of transversal wave spreading in fluids. The transversal waves spreading speed has no relation to the environment motion speed, which are formed by. For example, with respect of so called capillary waves at the water surface, the water behaves like passive membrane and the underwater motion has nothing to do with surface wave motion.

The Aether Wave Theory (AWT) supposes, the vacuum is formed by elastic massive foam, in which most the energy is spreading by transversal waves by such way, the environment reference frame is quite subtle and cannot be observed easily.

This post has been edited by Zephir on Aug 19 2006, 08:58 AM

Speed of light. Oh dear. This could be a contraversial answer.

Imagine you are a photon ( a bit of a beam of light). Because you are a photon and you have no mass you have no choice but to travel at the speed of light. Because you are travelling at the speed of light you do not experience 'time' .. it just doesn't happen for you.. all this stuff about clocks running slow .. at the speed of light your clock has stopped completely. Einstein made the assumption (perhaps not in this way) that clocks don't go backwards and 'stopped' is what happens at the speed of light so the speed of light is going to be as fast as you can go.

In all frames of reference the clock for a photon is stopped .. as far as it is concerned it can go anywhere in no time whatsoever.. so the motion of any frame of reference with respect to any other makes no difference to the length of time the journey takes as far as the photon is concerned.

The 'trick' nature plays is that space has got 'time' built into it. Things are not just an amount of distance apart they are also an amount of time apart. If the speed of light is 670,616,629.384mph then guess how far apart in time two points that are 670,616,629.384 miles (in distance) just 'happen' to be? Hopefully you've guessed one hour .. which would be right. The light itself has taken no time to cover that distance so the apparent 'time of flight' is just the time difference between the two points. To get the 'conventional' speed of light we just divide the distance by the time 670,616,629.384 / 1 .. which gives us the speed of light .. every time. The 'speed of light' is just the distance separation divided by the time separation .. clearly this is not really a 'speed' in the conventional sense.

Your question about adding 5mph to the speed of light .. since the speed of light isn't really a speed it's not a question that can be answered.

Probably enough contraversial stuff for one post.

Best wishes,

-C2.

See also (it may tell you rather more than you want to know at this stage)
http://en.wikipedia.org/wiki/Spacetime

This post has been edited by Confused2 on Aug 19 2006, 10:48 AM

C2,

Yes, all due to a phase differential produced by lower dimensional 'vacuoles' interacting with a primary brane.....projected as our reality; mechanism.... fourier processing.

Good Elf,

I know you've been 'digesting'......as I!.....Now's the time to deliver history!


p.s I'd like to do so.....but you'll do it in a fashion people might understand!


......Humanity is waiting.

p.p.s.......no pressure mate

The answer lies in special relativity - specifically time dilation and length contraction. When and object (or person) moves through space relative to someone else (like running), their time will dilate and their length will contract. This means that if they are wearing a watch, it will tick just a tiny bit slower than someone's who is at rest, and if they originally have a 30-inch waist, it would look to someone at rest to be maybe 29 and 99/100ths of an inch instead. Now relativity dictates that all motion is relative, so this means that the runner could say just as correctly that he is at rest and the whole world is moving by him. This means that to the runner, time has dilated and length has contracted for everything else at rest relative to him. Okay, so lets pretend that we can measure the speed of light by timing how long it takes for light to travel between two telephone poles. So when the runner is running at 5 mph, he should measure the speed of light to be 5 mph above what it should be. However, remember that the telephone poles are at rest - and everything at rest to the runner is length-contracted. So when the runner times how long it takes for the light to travel the distance (he has a stopwatch on his watch), he is actually looking at a shorter distance than someone else standing on the road. Now remember speed = distance/time. So now the distance is a little bit shorter. For our intents, let's say that the speed of light is 10 feet per second, and the telephone poles are 20 feet apart. Someone on the ground would measure the time it takes for light to travel between the poles as 2 seconds. So our runner might see the distance as only 19 feet (you can calculate all this with math). Now remember, since this runner is moving faster than the guy on the street, his watch is going a tiny bit slower. So instead of 2 seconds, he measures 1.9. He does the math and finds the speed of light to be 19/1.9 = 10 feet per second - just like everyone else. This is the same for everyone, regardless of how fast they are moving - they will always measure the same speed.

I think Confused2 said it rather well.

The issue is that the "speed" of an individual photon can't be measured in the same way as we use light to view larger masses moving through space. Light itself is what we use to measure velocities and so it must move faster than a mass for us to be able to see that mass. At least if a mass was moving away from us at faster than the speed of light, then light couldn't reflect off it and we'd have no way of even knowing it existed, much less measure its velocity.

Some problems that occur when trying to measure the speed of light itself are:

1) You can't actually verify the path of an individual photon through space, because you can't follow along with it, or run ahead of it at various points because no matter what your velocity is, it's always faster than you (unless possibly if you were light itself, but this leaves the question of how can light measure its own speed and how can it communicate that information to the rest of us moving slower).

2) If you attempt to detect where a photon was at some envisioned midpoint during the trip, you alter it and it no longer travels the same path as before. So you're continually stuck making measurements from the 'endpoint' of a path.

3) Time dialation and spacial compression distort references for distances and time while moving, so whatever distances and times you measure for a speed of light aren't easily converted to other observations.

4) Light speed is considered constant, at least on average, in a vacuum. But space doesn't appear to be an absolute vacuum (The Casimir Effect is a good example), and we know light travels slower through mediums. So the stated speed of light in a vacuum is actually the average speed of light in space, which may very well not be a vacuum and this leaves the question of what the speed of light through a true vacuum would be (which seems likely close to infinite).

5) Relativity takes a third person "God's eye" view of space, in which we could theoretically view photons travelling through space similar to looking down on the world from above and seeing waves travel through the ocean. But this viewpoint isn't physically possible, as we're stuck being part of these waves ourselves and because we can't travel faster than these waves we're also stuck waiting for them to hit us and guessing how they move beyond those local detections.

6) The idea of an effectively infinite speed of light was shot down in the past by the claim that if it were the case, everything in the universe would happen simultaneously. But this doesn't necessarily need to be the case. If not everything in the universe is operating independently and in parallel but instead if only one thing happens at a time, this single event could operate infinitely fast without conflicts.

7) If you travelled to a star 100 light years away, you theoretically could do this, even under relativity in a time that would appear to you to be less than 100 years. Because reality is whatever first person perspectives see them as, you could easily consider your motion to be faster than 300 million meters per second. Yet during this trip light would still be hitting you at what we'd expect would still appear to be 300 million meters per second and no matter how fast you travelled light could still be interpreted as being infinitely faster because your motion wouldn't even appear to slow it down. So even if you travelled 100 light years, in 1 day, by your clock, light would still be travelling just as fast ahead of you as it did when you were standing still. From this local first person perspective, light speed might as well be infinite.

8) For some envisioned paths that light travels through, faster than light speed observations can be made. In theory nothing travels faster than light, so if we want to maintain this claim, then we need to find explanations of how things didn't actually travel faster than light, which can be tough.

Anyway, now instead of confusing the issue, what I think is happening is that a single event is operating throughout the universe making individual changes one at a time, though effectively infinitely fast (or even virtually infinitely slow as all our understand of time is also created by this and so the rate at which it changes things isn't directly detectable to us ... time simply stops for a particle or object until the next time this event comes around and then the next 'tick' occurs and we take a long string of these ticks and learn how to perceive spacetime using them).

Space isn't a vacuum but instead, as Confused2 said, a network of delays (or distances). We might measure a delay between points of 1000 units of space, but we don't know the exact units except in comparing things to some other path, that for example might be 2000 units of space. In this case we say one path is half as long or twice as fast as the other but light itself didn't necessary travel through all points of space between the endpoints, it likely simply hopped from point to point with something equivalent to an infinite velocity in the terms of velocity for masses the we're familiar with.

Anyway, yes, light travelling through space on large scales does appear to have a rather constant speed as ~186,000 miles per second or ~300 million meters per second. These measurements can be made by timing a reflection of light off a mirror, and the limits and effects specified by relativity are probably rather accurate when working with typical masses but there are many (hidden) assumptions made and statistical averages that don't necessarily hold out to all extremes (especially on small scales), so I don't think it's a bad idea trying to push the envelope a bit on what's possible.

This post has been edited by StevenA on Aug 19 2006, 10:24 PM

clifflindsey85,*vanadesse,Zephir,

The 'speed of light' is one of the most puzzling things in the universe. A good question .. which you chose to link to Einstein .. he 'discovered' it but certainly didn't 'create' it.
So far we have (apparently) three completely different reasons why the speed of light is the 'speed limit' for everything.
Zephir's explanation has its origins outlined here http://en.wikipedia.org/wiki/Luminiferous_aether

Mine is rooted in General relativity ( Einstein 1915 ) http://en.wikipedia.org/wiki/General_relativity

*vanadesse's in Special Relativity ( Einstein 1905 ) http://en.wikipedia.org/wiki/Special_relativity


In reality we're looking at two Einstein theories and one that (arguably) Einstein discredited. Of the Einstein theories there is no contradiction just a change of approach, the Special Theory deals only with 'flat' spacetime and the General Theory is .. more general (!). My opinion (without proof) is that Einstein combined acute observation, intuition and intelligence so he actually knew the result he was seeking to justify long before either Special or General relativity were published. Some years earlier than Einstein a chap called Lorentz ( http://en.wikipedia.org/wiki/Hendrik_Lorentz ) had nearly got it sussed but he doesn't seem to have quite had enough confidence in his own results and it was left to Einstein to actually 'announce' relativity as a fact in the form of 'Special Relativity'. The first publication on relativity was based on the results Lorentz had already derived with the added insight .. THE UNIVERSE REALLY IS LIKE THIS! Although 'spacetime' is clearly at the root of Special Relativity I don't feel it emerges fully until general relativity and it is quite possible to apply the equations of special relativity with no 'feel' for their origin. Given the ability and time I would try to show that relativity IS how it is because the universe is built that way rather than because we have a whole set of equations that help us pass exams when we apply them correctly.

My explanation of the 'speed limit' of light was a bit of a mixture of Special Relativity , General Relativity and maybe a bit of Quantum Mechanics thrown in .. otherwise known as cheating. The challenge is open to all to do better.

I am pleased to see StevenA has entered the fray.. I regret I don't have time to read his post in full ..

-C2.

There is (somewhere) a page which lists many of experiments confirming relativity (and also the areas of doubt) .. I regret that I am unable to find it in the time available .. the following may be of interest and may lead you to the page I can't find.

http://math.ucr.edu/home/baez/RelWWW/group.html

I suppose the wave character of light is just a "puzzling question" in context of widely spreaded disbelief in massive environment for light spreading, i.e. the aether. If we consider the light as the wave phenomena, such behavior is quite natural, because the speed of all the waves doesn't depends to the speed of it's source (being a material constant in fact) and at the case of transversal waves it even doesn't depend on the absolute motion of environment.

From such perspective, the light wave behaves like quite normal transversal wave in massive environment and nothing strange is about such behavior. So we can say, the contemporary physic is making problem from nothing and the whole understanding of the light is in very primitive stage by now. The contemporary physicists knows nothing about photon nature and mechanism of its formation, they knows nothing about principle of particle-wave duality of light, they even don't know, why the light is forming the waves at all!

Pretty medieval times, if you'll try to think about it, I can tell ya...

Such delicate situation isn't quite new in physic. For example at the case of Ptolemaian epicycles the math model of reality had existed a nearly 1600 years before real undestanding of reality.

The reason was very same, afer all: the blind religion in nonexistence of heliocentric model by the same way, like the belief in nonexistence of Aether.

This post has been edited by Zephir on Aug 19 2006, 10:59 PM

A question I have is whether or not everything is truly quantized. It seems likely mass results from making observations on 'massive' scales, as you say and the difficultly in intergrating quantum mechanics with relativity is probably due to complex interactions on a larger scale that aren't immediately obvious on fine scales.

If you rewrite E=Mc^2 in terms of a velocity you'd have:

(distance/time)^2=E/M

Time appears quantized as it requires discrete events to create. Energy also appears quantized. If mass is also quantized (questionable) then the E/M term would be quantized and this would require distances to be quantized as well and would make light speed be better equated with units of light delay instead of a constant velocity through a continuous space (and you might be able to remove the squaring of the term as well). Trying to use light to both specify delays (time) and distances makes velocity (distance/time) constant and this doesn't really help explain masses moving less than light speed, or light travelling slower than light speed through different mediums, and you can see this from the conflicts in integrating quantum mechanics with relativity. I think it stems from a mismatch in our intuitive 3-D view of space to the actual structure of space at fine scales, which don't operate in typical Euclidean notions of constant light speed.

But if the universe is finite (though possibly growing toward infinite), you'd assume some finite measure of mass should exist. Otherwise if masses can vary over an infinitely precise value, then the potential information present in a mass is infinite also (not impossible, but I still think apparently infinite scales are a product of either 1) a continual growth in the system and/or 2) a recursive relationship between finite units that gives an illusion of infinite scales or levels of interactions).

If we look at the paradox of black holes, some upper limit exists to the information content available from a black hole over time, if spacial positions are quantized, as it seems there's a finite limit to information that can be conveyed across a boundary, unless each unit carried across this can be interpreted as infinitely precise in some quantity.

For example, if the distance between a pair of particles could be measured with infinite precision and accuracy, then potentially just this one distance would contain more information than all the discrete quantities of energy in the universe ... I won't say it's impossible but it seems that, for example, the Uncertainty Principle denies us accurately measuring this precision and so the effective bandwidth of information is less than infinite, or alternately it could take an infinite amount of time to measure this distance accurately.

This post has been edited by StevenA on Aug 19 2006, 10:58 PM

Such question has nothing to do with speed of light, but the energy density. If the energy density (frequency) exceeds certain limit, the energy can undergo the phase transform and it becomes quantized, being confined in the energy density blob of its environment like quantized wave pocket.

Why such wave pocket becomes quantized at all? Because it encloses just a distinct total energy (i.e. Hamiltonian). It the energy becomes slightly lower, the energy density of such blob isn't sufficient to keep the wave together and the particle dissolves in the vacuum again. It's evident, the more dense is the surrounding vacuum, the energy density inside of particle becomes less significant and this is why most the particles becomes unstable in high gravitation fields, decomposing into radiation again.

On the other hand, if the energy density becomes slightly higher, the wave pocket cannot resist it's own gravity furthemore and it undergoes to the subsequent phase transform into more complex (and heavy) particles or mixture of particles. This is why teach the particle can contain/exchange just a certain bit of energy, i.e. the quantum. Just the Aether Wave Theory insight of massive environment can help you in understating of such trivial things without math, just by simple logic.

This post has been edited by Zephir on Aug 19 2006, 11:22 PM

Ok, what determines the threshold at which some event becomes self contained as a unit in this manner?

(I assume it would depending on a subjective determination made by an observer, similar to the specific location of an event horizon depending on where you're making observations from)

The stability criterion, for example at the case of simple wave eqaution it's the ratio of the time and distance interval, given by the speed of light and mass/energy density of our Universe.

This post has been edited by Zephir on Aug 20 2006, 12:21 AM

Anything that caught up to light would come to the end of its time. Anything approaching light speed becomes heavier in the process. It's mass resists it reacing light speed. You do not need any resistence in space for matter to have its speed limit below the speed of light.

Despite the model of stability criterion which you're using, the principle of singularity formation is always equivalent to quite common phase transform. So if you're able to understand/explain the reason of vapor condensation into droplets, you can explain the origin of singularity in the field, which is mediated by some other interaction, than electromagnetic force.



The AWT supposes, here's really no principal difference between field and common matter behavior. After all, the molecules model of water droplet doesn't differs so much from particle or atom nuclei models with respect of curvature and surface tension phenomena, etc...

This post has been edited by Zephir on Aug 20 2006, 02:20 AM

Hi Nick. Just curious to know what/where you see the 'increasing' effective-mass of the 'accelerated mass value' comes from, if not from the 'medium' through which the 'original' mass 'original value' is being 'push-propagated' through/along by whatever is doing the accelerating?

If it all come from the 'accelerating' energy input itself, then the original mass has effectively been JOINED with MORE mass/energy which is ALREADY TRAVELLING at velocities greater than the accelerated body (otherwise lesser/slower input energy/mass could not accelerate the body in the first place.

But what proportion of that input energy goes to constantly 'breaking' inertia of the accelerated object; and what proportion of the accelerating energy goes into increased velocity per se (or the 'increasing' effective-mass value compared to the original 'rest' effective-mass value?

But THEN we get to the question:

What produces INERTIA? So we come full circle...whatever produces inertial-mass effect might ALSO be responsible for the increasing RESISTANCE-MASS effect.

That is where the 'crux' of the whole situation comes to, I think. And that is something that our TOE special project will (hopefully soon) 'arrive at' with a 'consistent' explanation that will end these 'round-and-round' questions and unsatisfactory answers that lead nowhere much except continued confusion for everyone concerned.

But if you DO come up with any more thoughts on these things, perhaps you might 're-cast them' in the 'light' of what the next few stages of our TOE project "have to say for themselves" on these matters. You and everyone here is most welcome to input your answers to the STAGE-II Q & A SESSION presently underway (it will help if you first read the "PROGRESSIVE THEORY SUMMARY" thread 'pinned' at the top of the "special project" SUB-forum of the "Relativity etc..." forum...and then inputing your responses under the "THEORY OF EVERYTHING BEGUN FROM ABSOLUTE CONCEPT" thread). Thanks.

Cheers all!

PS: Hiya Zephir! I'll soon be sending you and Good Elf something on Electromagnetic wave (photonic) structure/mechanism/propagation etc. Speak to you then. BTW, I'm still enjoying your graphics very much; but I suppose that's because my particular perspective allows me to comprehend their meaning in a way that numbers can never hope to convey (and after all, what do SUPERCOMPUTERS DO except 'crunch' all the numbers/equations to produce SIMULATIONS/GRAPHICS that ANYONE can comprehend at a glance WITHOUT HAVING TO SPEND HALF THEIR LIVES GETTING A MATHEMATICS DEGREE, hey?).

RC.

This post has been edited by RealityCheck on Aug 20 2006, 02:30 AM