Some things can reach the speed of light and some can't

Can amplitude and phase of a EM wave change faster than speed of light?

 

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James R

Q - You are incorrect about the Wang experiment. It did observe a pulse of light moving faster than c. Nothing in physics prevents that from occurring, and Wang explicitly made the point in his paper that his experiment did not violate relativity.

The NEC experiment was simply a reshaping of a light pulse, which as you say does not violate, but is actually predicted by relativity. No information transfer and no FTL.

Heres a few comments taken from the NEC site:

However, our experiment does show that the generally held misconception "nothing can move faster than the speed of light" is wrong. The statement only applies to objects with a rest mass. Light can be viewed as waves and has no mass. Therefore, it is not limited by its speed inside a vacuum.

Information coded using a light pulse cannot be transmitted faster than c using this effect. Hence, it is still true to say that "Information carried by a light pulse cannot be transmitted faster than c."

You may read about the NEC post mortum here:

http://www.salon.com/people/feature/2000/08/03/light/

 

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James R

Group velocity experiments are old news which makes the NEC experiments, in my opinion, insignificant. The way in which the results were publicized however, caused quite a stir, hence the embarrasment by NEC. I believe Adam was dead on when he asked if the results were bullocks.

Light may travel at any fixed speed up to 'c', however that speed is invariant *within* that medium.

 

I read that link of Q and wasn't really getting it what that guy was trying to make clear

"""I'd just like to re-emphasize that the pulse in that experiment travelled faster than c."""

a pulse of light -> what is that exactly? like thousands of photons who travel together?

"""I agree that no information can be transmitted faster than c, but that's a different thing all together."""

they all travel faster than c but they don't carry "information"
I still don't know what people mean with this "information" --> they do carry information about themselves no? (velocity, etc.)

"""To put it more precisely, the pulse had a group velocity faster than light (actually a negative group velocity)."""

And I really don't get this groupvelocity which seems to be the key to understand this.

from that site:

it seems that Wang's experiment has nothing to do at all with group velocities etc.

"""light traveling "faster than its acknowledged speed"""

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dispersion? huh?
"true but misleading "--> not that's what I call Misleading talk

 

James R

I disagree with you that the fast and slow light experiments are "insignificant". Wait a few years and you'll start to see applications.

Can you offer a glimpse into the future?

 

Well you should know looking into the future isn't permitted as a fundamental law.

After all if you could stem information from the future, as soon as you got it your future would be out of date. Your whole timeline would suffer increased entropy as you wouldn't be able to get some information from the future directly in front of you, but more like diagonal to a parallel future.

This is where you would be getting into Fractal algorithms and quantum compression of information to fit into the constantly evolving pattern.

In the most part you would have to manipulate a framed constant throughout the algorithm for point of reference.
You'd also be turning the dial on the frequency modulation and tuning into a parallel.... but would it be your timelines future you would be receiving?

There are many parody’s created such as the "42" effect, getting your answer, before you've even considered the question, and then on another parallel they wouldn't even consider considering the question it would just get forgotten through entropy and just gain an answer.

There’s also universal mass to look at, you might stay true to your timeline and not manipulate anything out of place, but if news of a terrorist act where hundreds or thousands of people are hurt or killed, you can't even inform an evacuation, because all those people being moved to different locations and surviving would cause a chaos "Butterfly" effect. Where children have a parent, sisters have a brother.

This in fact could cause a larger chain reaction.

If of course it was possible to change such an event, it would have to continue holding at least the event at some stage, otherwise such an evacuation would have no reasoning from no one seeing what they are evacuating from, so the event would occur again. a bit of a Lazarus effect or grandfather paradox.

I know this for something I was once designing that could of followed the entropy pattern (a machine for converging parallels) I only stopped the design due to the theoretics on the ethics involved, and an understanding of what damage could occur. So I set about bean counting.

 

What are you talking about??????

You're making this up as you go along, arn't you. First of all, no object with mass can reach the speed of light, end of story, no point in discussing what would happen if it could. Second, what the hell is all this about unbonding? Rather than ridicul you, I will simply ask you where you found that out, because I have NEVER heard anything like that, and it makes No logical sense to me.

<I>Yet, it is known as a fact that a photon (subatomic particle that light is constructed of) does indeed have a mass,
this is proven by when light is passed by a black hole it is sucked in,</I>

You are stupid. Light has no mass, that is why it travles at C. Light gets sucked into a black hole (still theoretical I might add) because gravitational force is defined as a warping of spacetime, so any obect, including light, always travles straight, but they dip when they come near a massive objet. Non-Euclidian geometry.

And no, light cannot excede C, or 186 000 mi/s. The quantum tunnling effect you are refering to is a well known phenominon, and is simply the quantum telaportaion through localized mesons (basically the particals that carry the electric charge of a partical) of light through a medium. I suck at explaining things. Just go to a search engine and type in quantum teleportation.

You have no evidence either, just mangled hearsay, no experiments whatsoever.

 

huh???

Which posts did you actually read... I bet you only looked at the beginning of this thread.... The thing is with these threads it's all about the evolution of theory. So where you might write something is wrong from the beginning, it can become right further on. (after a re-think)

As for light speed and faster, I mentioned previously, my explaination was about the Amplitude of frequency, but my explaination was as good as saying "an orange is orange" and not mentioning anything else about an orange.

Personally I gave up trying to explain to the thread anything from the last post, because I need to draw up some diagrams, and well I'm still awaiting the package for doing it in.

 

Experimental observations of superluminal speeds

Am new to the thread and admittedly didn't read most of the older stuff, but thought I'd comment on the experiments that have "observed" superluminal speeds. I think what they are talking about in their results is the observation of a change in width of the wave packet that is the particle in question. I attended a talk at UCI given by one of the scientists doing such work a couple of years ago. His experiment consisted of two photons being sent on two different paths of identical lengths to a detector. One of the two passed through a different medium or apparatus of some sort. I don't honestly remember what. If the speed of the photons does not change one would expect both to hit the detector at the same time. They did not. It was explained, however, that the wavepacket size changes for one of the two, it contracts, but it's center is in the same place. the detector, however, detects the front of the wavepacket, not the center. So the data "looked" like one got their early and therefore went faster than light, but it did not.

 

Thats what I assumed too.

The main reason why light was classed as having a constant speed though is because the originally measurements weren't taken from a "Packet" of light, but of a light "Stream".


<CENTER><IMG SRC="Http://213.48.24.128/images/wave.gif"></CENTER>

In the image, I've shown how a "packet" (B) can be excited into (A). The point here is if the wave sections was 1ft long (just for visualisation purposes) they would travel at the same speed, but with different amplitude and different centre points.

(If that wasn't the case, a computer wouldn't be no good at multitasking, or would be the size of a room again. Or in another case a person wouldn't be able to see an object for what it was, because they wouldn't have cognative skills.)

The same can be said about the packets, light can be "Excited" to distort their "Waves" in amplitude. This does cause a packet to shrinks.

Jthomas, Thanks for putting what you know forwards, as again it suggests that everybody views light with relativity (In relation to some position that might differ, although they are probably arguing a fundemental truth from each of their angles)

 

faster than c

i can think of a scenario where somthing travels faster than light-- a shadow at a distance. now i know this is not the same object traveling at that speed, but imagine a pulsar and a plane perpendicular to it, at some great distance. if the surface of the plane interacted (swelled up, say) with radiation from the pulsar(which is sweeping across the plane faster than c because its at a great distance) then there would be a wavefront on the plane traveling faster than c. however, since observartions are made at c, it probably wouldn't be visible.... anyones thoughts on this?

 

A shadow seemingly moves as fast or faster, because it's the absence of light, and what light there is that cuts the absence out is actually a mergence of light and the amplitude of light.

(If only there was an easier way of explaining the definition

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)

Personally I like using a kind of understanding that when you put your foot into a pool of water it displaces, and when you take it out the water fills that displaced void again. The same can be said about the quanta within the universe and how it fills gaps over time.

From what I can tell of your thoughts on a pulsar, any changes would cause a shift in amplitude and spectral readings, so it would be visible but just in a different area of the spectral scale.

 

okay, so we agree the shadow travels faster than c. i know it is the absence of light, but suppose now that this light pulse has a lateral speed greater than c, and makes some kind of observable reaction on that plane. (suppose the plane is pink and the pulsar EMR turns it blue momentarily) now there is a blue streak traveling across the plane at greater than c. would this be observable, or would there be a resulting difftaction due to the fact the information is carried to our eyes at c?

 

You know how sometimes it just takes a flash of insight to really get something? Like stuff just snaps into place? Well, thanks JamesR, coz some of it did just snap into place. Thanks a lot.