superluminal

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killing raven sun
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superluminal

Post by killing raven sun » Sun Aug 12, 2018 4:16 pm

In the early 1900s, the opponents of Einstein’s Special Relativity put forward the theoretical possibility of superluminal speeds of light in refractive media with indices less than unity, the so-called fast-light media.

Despite its hypothetical nature, this objection caused a quite stir among Einstein’s supporters who devoted several sessions of their conferences to the problem.

Finally, A. Sommerfeld and L. Brillouin came up with what was deemed at the time to be a convincing theoretical demonstration that Relativistic causality is preserved and superluminal speeds of light are not physically meaningful. Their proof hinges entirely on a rather artificial distinction between two loosely defined speeds of light, namely the phase speed and the group speed of pulses or collections of elementary waveforms with various frequencies.

In recent years, however, many experiments on fast-light media have shown that superluminal speeds of light are real and the Sommerfeld-Brillouin supposed proof is completely wrong.

The main purpose of this paper is to investigate the far-reaching consequences of these extraordinary experimental developments in physics and to evaluate the present threat to the theory of Special Relativity.


The following is a brief list of the crucial experiments:

1. The Nimtz experiment:
In this experiment, a famous symphony of Mozart is encoded in a microwave beam and transmitted to a receiver at 4.7 times the speed of light. It’s a decisive experimental refutation of the current attempts at redefining the speed limit of Relativity as the limiting speed of information rather than limiting speed of objects.

2. The Ranfagni experiment:
In this experiment, observed pulses of reflected microwaves are clocked at up to 1.25c in open air. Thus, the supposition that superluminal speeds of light are possible only inside artificial optical materials is experimentally falsified. Light indeed can travel at superluminal speeds in open air, and by simple inference, in vacuum as well

3. The Wang experiment:
In this experiment, a laser pulse travels through gas-filled cells at a record superluminal speed of 310c.

4. The Stenner experiment:
In this experiment, a refractive index of –19 ± 0.8 is inferred. It’s designed to investigate the so-called velocity of information. A critical analysis of the Stenner experiment will be given later in this discussion.

5. The Munday experiment:
In this experiment, superluminal speeds of light are achieved for the first time inside fibre optics.

6. The Thévenaz experiment:
In this experiment, superluminal and subluminal speeds of light are achieved inside fibre optics.
http://gsjournal.net/old/science/faraj8.htm

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jliat
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Re: superluminal

Post by jliat » Mon Aug 13, 2018 1:25 am

:kitty:
Chris Lee has stated that there is no new physics involved here, and that the apparent faster-than-c transmission can be explained by carefully considering how the time of arrival is measured (whether the group velocity or some other measure)..

further authors have published papers arguing that quantum tunneling does not violate the relativistic notion of causality, and that Nimtz's experiments (which are argued to be purely classical in nature) don't violate it either.

lthough his experimental results have been well documented since the early 1990s, Günter Nimtz' interpretation of the implications of these results represents a highly debated topic,[24] which numerous researchers consider as incorrect..


researchers say the effect may be an illusion caused by light taking a shorter route through the optical system than expected.


Most physicists would say they are interesting but that in every case there will be a loophole that will allow nature to protect the causality effect.


For years, scientists have been gathering evidence of faster than light, so-called superluminal, phenomenon.
On a simple level, a flashing row of lights can display signals that move from one end of the row to the other end faster than c if the lights flash on and off in time.


But scientists point out that the effect is an illusion and that nothing physical is travelling faster than c.
In space, some 20 years ago, astronomers were puzzled, briefly, by distant objects that appeared to go faster than c.
The explanation was that when an explosion occurs at speeds comparable to c then it can appear from the outside that the lightspeed limit is being violated.

There are situations in which it may seem that matter, energy, or information travels at speeds greater than c, but they do not. For example, as is discussed in the propagation of light in a medium section below, many wave velocities can exceed c. For example, the phase velocity of X-rays through most glasses can routinely exceed c,[42] but phase velocity does not determine the velocity at which waves convey information.[43]
If a laser beam is swept quickly across a distant object, the spot of light can move faster than c, although the initial movement of the spot is delayed because of the time it takes light to get to the distant object at the speed c. However, the only physical entities that are moving are the laser and its emitted light, which travels at the speed c from the laser to the various positions of the spot. Similarly, a shadow projected onto a distant object can be made to move faster than c, after a delay in time.[44] In neither case does any matter, energy, or information travel faster than light.[45]
The rate of change in the distance between two objects in a frame of reference with respect to which both are moving (their closing speed) may have a value in excess of c. However, this does not represent the speed of any single object as measured in a single inertial frame.[45]
Certain quantum effects appear to be transmitted instantaneously and therefore faster than c, as in the EPR paradox. An example involves the quantum states of two particles that can be entangled. Until either of the particles is observed, they exist in a superposition of two quantum states. If the particles are separated and one particle's quantum state is observed, the other particle's quantum state is determined instantaneously (i.e., faster than light could travel from one particle to the other). However, it is impossible to control which quantum state the first particle will take on when it is observed, so information cannot be transmitted in this manner.[45][46]
Another quantum effect that predicts the occurrence of faster-than-light speeds is called the Hartman effect: under certain conditions the time needed for a virtual particle to tunnel through a barrier is constant, regardless of the thickness of the barrier.[47][48] This could result in a virtual particle crossing a large gap faster-than-light. However, no information can be sent using this effect.[49]
So-called superluminal motion is seen in certain astronomical objects,[50] such as the relativistic jets of radio galaxies and quasars. However, these jets are not moving at speeds in excess of the speed of light: the apparent superluminal motion is a projection effect caused by objects moving near the speed of light and approaching Earth at a small angle to the line of sight: since the light which was emitted when the jet was farther away took longer to reach the Earth, the time between two successive observations corresponds to a longer time between the instants at which the light rays were emitted.[51]
:kitty:

killing raven sun
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Re: superluminal

Post by killing raven sun » Mon Aug 13, 2018 2:48 am

haha! kudos on quoting wiki, in this case a wiki which doesnt refute superluminosity, only casting aspersions through opinion

read the research dim bulb

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Re: superluminal

Post by jliat » Mon Aug 13, 2018 3:11 am

killing raven sun wrote:
Mon Aug 13, 2018 2:48 am
haha! kudos on quoting wiki, in this case a wiki which doesnt refute superluminosity, only casting aspersions through opinion

read the research dim bulb

Not just wiki - and why is that so wrong, its open to question by authorities unlike the nutters own web site from which you gleaned your decitful half truths written by who knows who with no qualification.

I like you and many cant do the reading because we cant do the maths. And it does refute it - what is unclear about

"There are situations in which it may seem that matter, energy, or information travels at speeds greater than c, but they do not. "

Much as it would be good (maybe not) to travel faster than light C as a maximum, no one has done so yet convincingly. It may well occur, but all the examples so far can be explained...

And neither you nor i are in a position to judge. Using fonts as large as you like... :doh:

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Re: superluminal

Post by killing raven sun » Mon Aug 13, 2018 3:39 am

Finally, when the transparent anomalous dispersion
becomes very steep such as for the case illustrated in
Fig.1, the dispersive term ν dn/dν which is negative be-
comes very large in its magnitude such that |ν dn/dν| ≫
1, resulting in a negative group velocity vg = c/[n +
ν dn/dν] < 0. In this case, Eq.(18) gives I(L, t) =
I(0, t + |L/vg|), where the quantity |L/vg| = |ng|L/c
is positive and can becomes very large compared to the
vacuum transit time L/c. This means that the intensity
at the output of the medium of length L, I(L, t), will vary
in time earlier than that of the input pulse I(0, t). Thus
in this case, a “negative transit time” can be observed.

The time difference between the output pulse and the in-
put pulse in the form of a pulse advancement, is |ng| fold
of the vacuum transit time L/c. Practically, since the
shape of the pulse is not changed, this results in a rather
counterintuitive phenomenon where a certain part of the
light pulse has already exited the medium before the cor-
responding part of the incident light pulse even enters by
a time difference that is |ng| times of the vacuum transit
time L/c.

This rather counterintuitive effect is a result of the
wave nature of light.

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Re: superluminal

Post by jliat » Mon Aug 13, 2018 4:04 am

This is stuff above you posted is from a paper by L.J. Wang which concludes....



light.jpg
light.jpg (96.2 KiB) Viewed 105 times

The publication also includes the physics of black holes.... as i said
we haven't the maths to understand - we can only go on the conclusion - which is....

"is not at odds with the causality of special relativity... is associated with the basic requirement of causality that states no "signal" can be transmitted faster than c."

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Re: superluminal

Post by killing raven sun » Mon Aug 13, 2018 4:08 am

my quoted science from observation trumps your attempted refutation of reality by maths, anyway...
jliat wrote:
Sun Aug 12, 2018 11:24 pm
So i cant do the reading because i wont understand it.
so just give up stupid

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Re: superluminal

Post by killing raven sun » Mon Aug 13, 2018 4:15 am

In four-wave mixing, researchers send 200-nanosecond-long "seed" pulses of laser light into a heated cell containing atomic rubidium vapor along with a separate "pump" beam at a different frequency from the seed pulses. The vapor amplifies the seed pulse and shifts its peak forward so that it becomes superluminal. At the same time, photons from the inserted beams interact with the vapor to generate a second pulse, called the "conjugate" because of its mathematical relationship to the seed. Its peak, too, can travel faster or slower depending on how the laser is tuned and the conditions inside the laser.

In the experiment, the pulses' peaks arrived 50 nanoseconds faster than light traveling through a vacuum.

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Re: superluminal

Post by jliat » Mon Aug 13, 2018 4:19 am

killing raven sun wrote:
Mon Aug 13, 2018 4:08 am
my quoted science from observation trumps your attempted refutation of reality by maths, anyway...
And its conclusion is -


"is not at odds with the causality of special relativity... is associated with the basic requirement of causality that states no "signal" can be transmitted faster than c."

CAN YOU READ THIS?

And I didn't say refutation - but the conclusion basically shows you are no card player ...
killing raven sun wrote:
Mon Aug 13, 2018 4:08 am
jliat wrote:
Sun Aug 12, 2018 11:24 pm
So i cant do the reading because i wont understand it.
so just give up stupid
Well there is stupid and you citing this-

"is not at odds with the causality of special relativity... is associated with the basic requirement of causality that states no "signal" can be transmitted faster than c."

As i said we can only go on the conclusions.. well i'm prepared to. Here is a tip, when you cite something you clearly dont understand - try reading the conclusion...

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Re: superluminal

Post by killing raven sun » Mon Aug 13, 2018 4:22 am

killing raven sun wrote:
Mon Aug 13, 2018 4:08 am
my quoted science from observation trumps your attempted refutation of reality by maths, anyway...
jliat wrote:
Sun Aug 12, 2018 11:24 pm
So i cant do the reading because i wont understand it.
so just give up stupid
you positing your alternate reality isnt helping your case

light has no fixed speed, end of story

grow up you fucking moron

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jliat
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Re: superluminal

Post by jliat » Mon Aug 13, 2018 4:29 am

killing raven sun wrote:
Mon Aug 13, 2018 4:22 am

light has no fixed speed, end of story


But its not the end as YOU posted a story - (a paper) which concludes...


"is not at odds with the causality of special relativity... is associated with the basic requirement of causality that states no "signal" can be transmitted faster than c."


So in SR light has an upper fixed speed and YOU cited a paper which states this....

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Re: superluminal

Post by killing raven sun » Mon Aug 13, 2018 4:30 am

jliat wrote:
Sun Aug 12, 2018 11:24 pm
So i cant do the reading because i wont understand it.

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jliat
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Re: superluminal

Post by jliat » Mon Aug 13, 2018 4:42 am

killing raven sun wrote:
Mon Aug 13, 2018 4:30 am
jliat wrote:
Sun Aug 12, 2018 11:24 pm
So i cant do the reading because i wont understand it.
You're obviously very upset at posting a paper which supports a fixed upper limit to light speed when you could not read the science and didnt bother to read the conclusion. So you are now posting an edit of my point, I and now obviously you, cant read this science as the maths is way beyond us. And so you are posting these everywhere, which is fine by me, it just makes you look silly IMO.

So i'll leave just this reply to the others. Get over it, go for a walk or something. The 'reading' relates to the maths involved with SR.

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Re: superluminal

Post by killing raven sun » Mon Aug 13, 2018 4:45 am

killing raven sun wrote:
Mon Aug 13, 2018 4:15 am
In four-wave mixing, researchers send 200-nanosecond-long "seed" pulses of laser light into a heated cell containing atomic rubidium vapor along with a separate "pump" beam at a different frequency from the seed pulses. The vapor amplifies the seed pulse and shifts its peak forward so that it becomes superluminal. At the same time, photons from the inserted beams interact with the vapor to generate a second pulse, called the "conjugate" because of its mathematical relationship to the seed. Its peak, too, can travel faster or slower depending on how the laser is tuned and the conditions inside the laser.

In the experiment, the pulses' peaks arrived 50 nanoseconds faster than light traveling through a vacuum.

killing raven sun
Posts: 637
Joined: Wed Jun 13, 2018 2:01 pm

Re: superluminal

Post by killing raven sun » Mon Aug 13, 2018 4:45 am

killing raven sun wrote:
Mon Aug 13, 2018 3:39 am
Finally, when the transparent anomalous dispersion
becomes very steep such as for the case illustrated in
Fig.1, the dispersive term ν dn/dν which is negative be-
comes very large in its magnitude such that |ν dn/dν| ≫
1, resulting in a negative group velocity vg = c/[n +
ν dn/dν] < 0. In this case, Eq.(18) gives I(L, t) =
I(0, t + |L/vg|), where the quantity |L/vg| = |ng|L/c
is positive and can becomes very large compared to the
vacuum transit time L/c. This means that the intensity
at the output of the medium of length L, I(L, t), will vary
in time earlier than that of the input pulse I(0, t). Thus
in this case, a “negative transit time” can be observed.

The time difference between the output pulse and the in-
put pulse in the form of a pulse advancement, is |ng| fold
of the vacuum transit time L/c. Practically, since the
shape of the pulse is not changed, this results in a rather
counterintuitive phenomenon where a certain part of the
light pulse has already exited the medium before the cor-
responding part of the incident light pulse even enters by
a time difference that is |ng| times of the vacuum transit
time L/c.

This rather counterintuitive effect is a result of the
wave nature of light.

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