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January 21, 2018

ARTICLE: Crawling at the Speed of Light [back to article]
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Lawrence B. Crowell wrote on Nov. 11, 2010 @ 20:42 GMT
This could lead to some lab bench simulations of gravitation as well. A region of optical propagation which slows light down along some distance sould be a simulation of a black hole.

Cheers LC

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Lev Goldfarb wrote on Nov. 14, 2010 @ 22:28 GMT
Typically modern situation: the life without good theory: so much work ("over 50 research groups") and so little to show for it. ;-)

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T H Ray replied on Nov. 15, 2010 @ 02:39 GMT
As the saying goes, one must crawl before one can walk. Persistent research in the right direction may be slow, but the rewards are proportionate to the risks.


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Lev Goldfarb replied on Nov. 21, 2010 @ 23:47 GMT
We live in the transitional period (of unprecedented scale). "Crawling" will not get you across the huge fissure, which has been expanding over the last century.

We need huge and "calculated" jumps. ;-)

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T H Ray replied on Nov. 23, 2010 @ 12:09 GMT

How would one know that one is living in a transitional period? It seems to me that, like the continuum hypothesis, one can assume it or not. In a historical record one can differentiate periods of stasis from big spikes, but the record is scale dependent, in a world that is apparently scale invariant and infinitely self similar.


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Peter Jackson wrote on Nov. 19, 2010 @ 17:36 GMT
Not new guys. Feynman commented on Lene Hau slowing light down to 30mph in BEC in the 1950's. She first stopped it dead a few years ago (Harvard). But we haven't been brilliant in analysing, applying or drawing any conclusions yet.

For any proponents of ballistic photons, any idea how it instantly achieves almost 300,000 miles/sec when released? (which it does).

Or precisely how it does an instant sharp left turn entering a prism at full speed?

Or how it reaches superluminal velocity when the scattering harmonics are right in the absorption bands each side of the visible spectrum? (which it does).

Can anyone help here?


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Roy Johnstone wrote on Nov. 22, 2010 @ 03:03 GMT
My understanding is that the photons themselves aren't slowed down, being massless they must travel at light speed (or close to depending on the medium), but in a dense enough medium or at least one which initiates a very strong coupling to photons, eg Bose-Einstein condensates, a light beam can be slowed due to the strong coupling or scattering of it's constituent photons. So that "when released" from the medium, the photons resume their naturally *straight* trajectory correlated as a beam, without changing velocity.

As for superluminal velocity, I don't understand what you are saying Peter? You seem to be implying that in the UV & IR spectrum photons can exceed 300,000 kms/s in conditions which becomes apparent in the visible spectrum?! Or are you talking about Cherenkov radiation?


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Peter Jackson wrote on Nov. 22, 2010 @ 11:00 GMT

Thanks. That seems only a very loose fit with the Hau lab and others, where the findings seem more consistent with classic superposed wave energy rather than discrete photons. I also don't understand your solution to how they can be slowed right down and stopped 'frozen', then going instantly back up to 'c'; 'without changing speed.' Unless of course 'c' is just relative, which seems to rather opens up a whole can of worms with relativity.

The FTL conditions are simply where 'n' becomes slightly less than 1 for short bands between visible, IR and UV. A similar phenomena to Cherenkov but due to relative scattering harmonics at those wavelengths not the emitter itself moving. I gather we're now up to over 50 'superluminal' cosmic sources, mainly Quasar gas jets, and in quantum optics and 'tunneling' relative superluminal motion is now very common, but only proving c/n in a dielectric 'irrespective of the relative speed of the observer', which has never anyway proved false. It may often be looked at as 'group velocity,' with FTL signalling not yet proved. There are very many PR papers, I'll put a link to one below.


Superluminal propagation in resonant dissipative media  Original Research Article Optics Communications, Volume 282, Issue 6, 15 March 2009, Pages 1095-1098 P. Chamorro-Posada, F.J. Fraile-Pelaez

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Steve Dufourny wrote on Nov. 22, 2010 @ 15:04 GMT
As a beautiful color of meconopsis betonicifolia, the radiations around the heart of a nuclear system seem showing the road ,because it's the water of course and its radiations due to the v of the particule.The blue is beautiful as the UV.

At my knowledge for the Chernkov effect.

n .....implies c1=c/n.......the particles emits due to the particle as a choc of wave.a little as the sound and an airplane ,we put a particule for an airplaine and we see the cherenkov radiation.

The mach number I suppose can be extrapolated and improved.That permits simply to know the mass easilly.

We see an equilibrium at the instant of shock.It's important this return at the equilibrium emmiting radiations due to the interaction.

If the perception can imply acceleration and decceleration where light ......what I find interesting is the fact what the centers of galaxy can have acceleration passing our perception.But above the ligtht perception thus, that's why peter we can't see them in logic .


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Roy Johnstone wrote on Nov. 23, 2010 @ 03:23 GMT

The way I see it is that they are controlling to a very high degree the interaction between the medium, hot gas, condensate etc, and the photons. The *appearance* of individual photons being slowed down or "frozen" would be due to the way the light pulse is effectively "contained" by an extremely strong interaction coupling, I don't think they are claiming to stop light/photons completeley, just to a workably slow speed for manipulation & information processing.

The FTL phenomena you mentioned do seem to be, as you say, a classical wave interference effect. A quick look at the abstract of the work you linked to seems to be talking about an artificial set up for the interference of an input wave with a resonant wave so that the superposed state may have modes that *effectively* to propagate FTL? (I think Special Relativity would still be safe!) But I need to understand it much better to have anything really worthwhile to say!!!


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T H Ray wrote on Nov. 23, 2010 @ 11:51 GMT
You're right, Roy. A common misconception is that special relativity forbids faster than light travel. Not exactly true. Special relativity is classical -- the theory says that particles cannot communicate at speeds faster than light. Entangled massless particles like photons obey quantum statistics; particle state changes do not imply that classical relativity is violated, since the particles are not communicating with each other in the classical (local) sense -- it's just that what one knows about one particle determines the state of another. In the context of the experiment, the quantum state is communicating with the experimenter in the classical domain, so no signals are being exchanged faster than light. This is an obvious crucial requirement for quantum computing, because infomration in a superposed state is not useful to us in the classical world in which we live.


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Steve Dufourny wrote on Nov. 25, 2010 @ 15:14 GMT
It's impossible that the light pass this c limit.

But on the other side , non perceptible particles are possible above our light limit of perception.

Hope you understand what I say.In fact theses effects are just optical effects as M87.

If you want find a speeder particle,search in the invisibility due to our special relativity.

If it exist an accelerator, there also we can't see them .


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Peter Jackson wrote on Nov. 29, 2010 @ 19:44 GMT
Tom / Steve

Steve,"It's impossible that the light pass this c limit." Yes, that's virtually what the experiments say, but, when considering phase velocity, except for short local 'boosts' it gets, probably from harmonic interaction, in the narrow 'absorption bands", diving below n = 1 only momentarily.


Interesting view, as always. The 'reason' you give is not however quite what all the optical fibre research says. In fact there are two elements, one is the very local and short range harmonic one mentioned above, the other is that when dealing with dielectric media c/n remains a universal law in that frame. In other words, if a light pulse in an optical fibre cable does precisely, or even just over or just under, 'c', if that cable is in motion wrt the observer the v of the observer is simply added or subtracted. The light emitted towards the observer is a result of scattering from the particles, and it will pass through the optical fibre at c/n of the medium, and air at c/n of air, and be measured by the observer at c/n.

We may therefore observe light at apparently greater than 'c', but we are only observing a 'rate of change of position', as it rarely does much more than 'c' locally.

There are scores of excellent papers on atomic scattering, PMD and various aspects of Optical Fibre science and chromatic dispersion which all seem to lead to the same or similar conclusions. This does not conflict with the SR postulates but, again, does seem to conflict with a common misconception.


PS. Roy; I understand the Hau lab (Harvard) can now freeze it temporarily to a dead halt, but I suspect you are right and that may be just our 'perception' of stopped. It seems to support the concept of a temporarily 'imprinted' wave/oscillation pattern, with velocity slowed subject to temperature.

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Steve Dufourny replied on Dec. 2, 2010 @ 15:00 GMT
Hi Peter,

It's so important for the perception this c limit.

If the harmonic intereactions permits a short momment about c'.

That means that the return towards an equilibrium is logic.

Now if we consider the informations, we can imagine that this return at equilibrium can imply a transfert of informations.Now ity's just an extrapolation of course.



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Peter Jackson wrote on Dec. 3, 2010 @ 19:02 GMT
Hi Steve

The 'party line' is that it's group velocity, which helps because many don't understand the differences with phase and signal velocities - a bit like lambda and f between co-moving media/reference frames, it needs high conceptual mental dexterity. (I had to do myself a simple 'idiots guide' to refer to!).

It's true in space too. Did I post this?;

Lin Rui-guang, Fan Jun-hui, Liu Cui-hong, Xie Guang-zhon.g Superluminal motion and the acceleration model Optical magnitude & radio flux density Analysis of 48 Superluminal Sources. Chinese Astronomy and Astrophysics, Volume 21, Issue 1, January-March 1997, p24-27

It's pretty good, I think there's a link if you Google it.

The solution is relatively simple. I'm writing the idiots guide now before I forget! Do you understand Georgina's brilliant bit of logical perception?

If I were just outside one of your rotating spheres and you were just inside, moving past me, would we both measure the same bit of light at 'c'?


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Steve Dufourny replied on Dec. 4, 2010 @ 17:46 GMT
Hi Peter,

Interesting point of vue, geaorgina is an interesting person also like many here,like you.I like her politness and her style of writing, her works and extrapolations are ver relevant in a philosophical and physical point of vue.

The subjetcivity dances around the objectivity where the creativity permits to harmonize the perceptions.Interesting in all case.

,you ask "If I were just outside one of your rotating spheres and you were just inside, moving past me, would we both measure the same bit of light at 'c'?"

In fact Peter ,you shall be always inside the Universal sphere.

Now if you focus simply on moons planets, stars, Bh,Super groups...mega groups ....and the center of our Universe.You shall see a kind of spherical relativity.The volumes are important because the volumes increase towards the main central sphere.Like the quantum world.A specific system possesses the same number....

Now if the volumes and the thermodynamic are inserted like the GR and the QM....all is proportional with THE ROTATING SPHERES.

If BH has a's due to its mass and thus its volume.....The otehrs centers have a rule also for the rotation, universal around the universal center.

In conclusion you shall be always also on a sphere, outside of always an smaller thus....perhaps hihihi

The planets are smaller........thermo Peter Thermo ..others are bigger.THE SPHERICAL THERMODYNAMICS ANSWER



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Steve Dufourny wrote on Dec. 9, 2010 @ 14:16 GMT
Peter have you write a film for the sphericentrism or the c' centrism and its sister the politness hihihihi


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STEVE A JEFFREY wrote on Jan. 13, 2011 @ 10:18 GMT
You can build a virtual quantum reality where everything is determined by Einsteins dice.

Then you can compare that reality to a real world simulation that uses random dice.


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Peter David Mastro wrote on Feb. 28, 2011 @ 12:58 GMT
This is really neat stuff. It always makes me wonder, however, why science continues to characterize the speed of light as a universal constant. It is obviously dependent on media. Why not say the speed of sound is a universal constant?

You can say it is because no sound can move through a vacuum I suppose. My take is if that is the case then it is probably the case that light also can not move through a vacuum. If it could then there would be no need for photons to jump between different discrete energy states.

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Peter David Mastro wrote on Feb. 28, 2011 @ 14:26 GMT
In reading the comment threads concerning photons and the limitation of light speed etc. I get the distinct impression that although science characterizes light as both a particle and a wave and positions or discribes it as such to the "non-science" minded, science doesn't seem to understand or apply it when characterizing the behavior of light. I have often wondered why this is and I have decided that an earth bound analogy is in order.

If you are sitting on the beach, an activity I would highly recommend as opposed to sitting in a lab, and you observe the waves crossing the open water and lapping at the beach, are the water molecules and atoms in the water moving across the sea with the waves? The answer is no. The water molecules are moving up and down and back and forth in a manner that retains balance between gravitational and rotational and thermal forces acting on the water.

Photons are not zipping through space. Space can be viewed as a photonic energy field in which the photons move up and down and back and forth in a manner that retains balance relative to the forces acting upon that particular point in space. Waves are viewing that motion over an area as a function of time.

When it comes to velocity, the only thing constant in the universe is time. The amount of time it takes balance to propagate between two photons is constant. Photon density in space is not. Photon density increases in relation to its proximity to mass. What is viewed as the constancy of the speed of light is actually the speed of time, and the speed of light relative to distance is variable dependent on photon density between any two points in space. As more and more situations are observed where information and events occur at rates far in excess of the speed of light, at some point science is going to have to acknowledge that the speed of light is not a limit or constant and time is not relative.

If this was not the case building materials that "slow light" would not be possible. The characteristics of these materials does not slow light. The structure of the materials serve as piers and breakwaters that simply calm the waves.

In terms of the worth of these experiments it is priceless and well worth gaining greater understanding of the principles at play behind it. I do not view this in terms of creating quantum computers because we already have enough useless information around to process. However its potential application in creating solar cells and batteries and light sources and propulsion systems is phenomenal.

That is my two cents from an artistic perspective.

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Bob wrote on Apr. 1, 2011 @ 22:58 GMT
I have two questions.

1) Is the light really just being absorbed and re-emitted and in between that going at c in the vacuum? So the average velocity is slowed.

2) If the speed of light is slowed in a meduim, does that mean that the momentum of the light is a lot higher if n were really that high?

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Bob replied on Apr. 1, 2011 @ 23:42 GMT
Ok, I just came across an article that stated that you get two different answers depending on whether you consider the photon as a wave or as a particle.

There is a sort of resolution claimed in the article (that both are correct depending on what you are asking) but for me I want to know this

If you have a spaceship in deep space emitting a 1 KW beam in a certain direction (or a laser to make it simple) you get a very very weak kick from the beam.

Now, if the index of space was say 10^9 instead of 1, or say if C=1 m/s in this

space, would there be a substancial kick on the ship as the beam leaves?

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Douglas lipp wrote on Jun. 19, 2011 @ 12:08 GMT
For the John Howell group & other experimenters along this line.

When you slow down light, can you conduct at the same time the double slit experiment. I would like to confirm that the "slow" version of light will act as a particle, while the fast version of light, a wave.

CIG Theory (posted on Out Of The Darkness & Real-Time Physics this same FQXi site - see June 15, 2011 posting) suggests that mass becomes spatial when it travels at or near "c" rates. My guess is, that if you can actually slow light down, it will lose this spatiality. Conducting this experiment will confirm Coney Island Green Theory.

Could you try, and send me results. If I am wrong, I will have to rescind my theory, or at the very least revisit it in its entirety.

Thank You Kindly

Douglas Williaam Lipp

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Douglas William Lipp wrote on Jul. 2, 2011 @ 11:47 GMT




Hi Everyone,

It's me again.

The below June 19, 2011 post this site referenced a June 15, 2011 posting on Out Of The Darkness & Real-Time Physics, also this same FQXi site.Those posts...

view entire post

attachments: MTSFINAL15Rollover12.doc

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