Is Faster-Than-Light communication possible?

servantx

servantx

Quantum Scribe
1997-98 article
Faster Than Light

If yes, as we know that NIST has achieved superluminal light pulses, how about using it for communication?

First Light: NIST Researchers Develop New Way to Generate Superluminal Pulses

Researchers at the National Institute of Standards and Technology (NIST) have developed a novel way of producing light pulses that are "superluminal"—in some sense they travel faster than the speed of light.* The technique, called four-wave mixing, reshapes parts of light pulses and advances them ahead of where they would have been had they been left to travel unaltered through a vacuum. The new method could be used to improve the timing of communications signals and to investigate the propagation of quantum correlations.
 
We'll see how this works out. They're refering to the group velocity of the wave chain and it is not new news that under certain circumstances the group velocity can exceed c. The phase velocity can also be FLT. What remains to be seen is whether information can be transmitted FTL. The answer has always been no for both group and phase FLT velocity waves.
 
I'm afraid, I can only give an analogy to relate to this.

I am no expert in light communications (dumbo really)- but in RF (Radio Frequency) you can make all sorts of things change by radiating waves in a "peculiar" atmosphere, and therefore change the velocity factor.

This often makes the length of the radiating element (Antenna/Aerial) sometimes appear much shorter than in normal "Free Space" (Normal atmoshhere- not enclosed) conditions.
For Example: just think of TV/Satellite Coaxial cable- this can reduce the velocity factor (Effective Wavelength) by times approx. 66 to 95 percent). This roughly means a cable can be reduced by a significant amount to suit a "matching" need.

Measurements can easily be fooled by taking them too close to the point of radiation too. There are near field and far fields of radiation.
Near fields are Reactive, then locally radiating (Fresnel) whereas far fields are radiating freely.
Any RF measurement within these near field should normally be ignored for any time/freq (less so)/Amplitude (more so) measurement as they are seemingly inconclusive (unreliable!!!).

My practical rule of thumb is get as far way as poss from the source of radiation before taking any measurement (MANY wavelengths), and certainly much farther than any absorption at the given wavelength can have any effect. (The higher the frequency, the easier this becomes of course).

What I am saying is, measurements at any frequency can be somewhat misleading, under certain measurement conditions- be careful!

If I am right, the above scenario is relating to a similar technology to multiplexing, as used in comms. I would hope the measurements would be accurate, simulations rarely tell the real truth though (and certainly not the whole story).
Sometimes, simulations can be "ahead of themselves" therefore, winning the race before it has started- looping in user data/software blindness can cause this though.
Computers are dumb- nice workers though!
Or, are we humans to blame- the input comes from us after all!;)
A little abstract this analogy, apologies- hope it makes reasonable reading if so.
Dave
 
Darby said:
We'll see how this works out. They're refering to the group velocity of the wave chain and it is not new news that under certain circumstances the group velocity can exceed c. The phase velocity can also be FLT. What remains to be seen is whether information can be transmitted FTL. The answer has always been no for both group and phase FLT velocity waves.
Click to expand...

If a no becomes yes than it will be a scientific breakthrough!
 
Dave, since light and radio frequencies are part of electromagnetic spectrum, do we use the same sort of measurement for both type of transmission?
Click to expand...

Well Servantx, Yes and no!

The principles are the same, but the actual senders and sensors are not the same to transmit receive and analyse the findings.
But, I guess similar in many ways. The higher the frequency you go- the smaller it all becomes!
It really doesn't matter what you use- albeit a crystal diode (cats whisker) as in an old "crystal set" or the most expensive electromagnetically controlled light bending accellerator at CERN-it's all basically a form of receiving device measuring what comes from an emitting device via whatever route.
The measurements, accuracy and interpretation are equally as important as the equipment at either end of the chain, if not more so.
We can all fool ourselves to reach the answer we WANT, sadly! That is human nature.

I have rarely gone into the light spectrum within my professional and amateur work realm- but only using Lasers and Infra Red link systems.
The way I did that was very simply done empirically finding the best answer to a problem on the light side of the spectrum.
I have always concentrated on the communications side of things- so, use light as a pure transport system! Modulate it with information between point a and b!
Boring perhaps to some, but- not to me.
Dave:)
 
May I add, almost all RF spectrum (receiving) measurements can be made with an RF spectrum analyser- I guess there is an equivelant for light measurements.
 
The measurements, accuracy and interpretation are equally as important as the equipment at either end of the chain, if not more so.

We can all fool ourselves to reach the answer we WANT, sadly! That is human nature.
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That's a good observation.

As I generally caution, reading the pop-sci news version of a cutting edge experiment might be interesting but pop-sci articles generally dummy down the facts so the average reader can understand. I do appreciate that at the bottom of the article they did refrence the Physical Review Letters article so that a subscriber or someone who wants to purchase the article can find and read it.

In the above referenced experiment nothing is moving faster than light in a vacuum (or faster thasn light in a rubidium gas). They've advanced the wave peak within the wave form. That means they can get the wave peak to arrive a bit sooner but the limit would be (lambda/2) ( 1/300,000,000 m* sec^-1) (where lambda is the wave length). But that's it.

One could look at it like this:

F-1 racing changes its rules. The winner of a race is determined not by which car's leading edge crosses the finish line first but which driver's helmet crosses the finish line first. So, we have two otherwise identical cars running in a dead heat so far as the leading edges of the cars are concerned but at the last second just before they cross the finish line one driver slides his seat forward a bit so his helmet crosses ahead of the other driver's.

Both cars were travelling at exactly the same velocity and in every respect were precisely tied for the lead as they crossed the finish line but one driver advanced his "wave peak" (helmet) a bit and won the race.
 
Nice analogy there Darby regarding the F1 helmets and cars!

IT is sooooooo easy to modify any waveform by either chopping it up and reinserting bits, modulating it/ distorting it- that you can make it any sort of sine/square/triangle/sawtooth or other wave shape you wish. Pulse shaping is an easy task to perform at Radio frequencies at least.

There is s method that is well known in AM broadcast where you apply 130 percent POSITIVE going modulation, without exceeding the negative going modulation (if you do that, it literally cuts the carrier off- causing distortion and spurious emissions).
This would give very similar results to those you mention.

Surely, there has to be some standard applied where there is a pure reference that the tests must adhere to?
For example: Like a simple square wave with an equal mark to space ratio (evenly spaced, or symmetrical if you like).
Then time relative to leading and falling edges can be openly compared.


If all that is happening is changing the shape of the wave to get the desired result in relation to no known reference point, then it seems little more than a cheap Magicians trick to me.
But, I have to add- I have done little with light waveforms.
All the best,
Dave :)
 
daver said:
Nice analogy there Darby regarding the F1 helmets and cars!

IT is sooooooo easy to modify any waveform by either chopping it up and reinserting bits, modulating it/ distorting it- that you can make it any sort of sine/square/triangle/sawtooth or other wave shape you wish. Pulse shaping is an easy task to perform at Radio frequencies at least.

There is s method that is well known in AM broadcast where you apply 130 percent POSITIVE going modulation, without exceeding the negative going modulation (if you do that, it literally cuts the carrier off- causing distortion and spurious emissions).
This would give very similar results to those you mention.

Surely, there has to be some standard applied where there is a pure reference that the tests must adhere to?
For example: Like a simple square wave with an equal mark to space ratio (evenly spaced, or symmetrical if you like).
Then time relative to leading and falling edges can be openly compared.


If all that is happening is changing the shape of the wave to get the desired result in relation to no known reference point, then it seems little more than a cheap Magicians trick to me.
But, I have to add- I have done little with light waveforms.
All the best,
Dave :)
Click to expand...

Dave,

So, do you think it is achievable in distorting light pulse by changing it's shape, and vary/increase it's speed?

There is a big vacuum in space to do it, just bounce it back to the satellites....
 
Dave,

So, do you think it is achievable in distorting light pulse by changing it's shape, and vary/increase it's speed?

There is a big vacuum in space to do it, just bounce it back to the satellites....
Click to expand...

This is a question I think lies in semantics for most.

I personally believe that it will be such a small gain (if any?) as to be totally insignificant.

It would not have any physically significant affect in my view, but- hey, there may be many, many greater thinkers or philosophers than I, on this planet.

I don't profess to be a physics expert (far from it)- and can only relate to what I know in my own field, and have invariably experienced, and been involved in directly (thankfully!).

For Example:
I could re-create an experiment I did in pulse shaping I made from scratch some decades back now (accidentally may I add), that even convinced me that I was looking at something running "ahead of its time" (so faster than light if you like) but, I didn't let it rest, and found after some re-working that I was only actually fooling myself.

That day taught me a lesson- always doubt yourself!
But, at the same time- have confidence in what you believe.

The answer to your question?
NO- I don't believe this approach to be the answer. If only it were that simple.
Dave
 
Besides the point, what if they can actually pull this one off, what good would it be? It would take at least a century to actually put it to any "good" use. Not that I am against reasearch, but there are some investigations that really need to be thought at thoroughly before they hit the stands.
 
Thanks Dave and Darby for explaining it.

Transient001, how do you know that it would take at least a century to put it in practical use?
 
Hello Servant X

By using a statistical formula and taking into consideration the current pase of scientific theory applied into or converted into accessible technologies it would take us approximately 107 years to achieve such concept.

This is the formula, its actually a derivation of Altman's Z-scores finance formulas. They are used widelyu to predict stock market, tsunamies, trends and even weather. We made a modification to its intricacies and ended up with this:


Z = (5.98 (X1) + 2.01 (X2) + 8.24 (X3) + 9.37 (X4))/ 11.3(X5)/.2
X1, Actual amount of technology present needed to accrue future technology.
X2, technologies present which are similar to related technology.
X3, Success of investigation/amount of technology present to further investigation.
X4, Amount of difficulty in experimentation/developers present in the actual fields of investigation/level of advancement in such investigative fields.
X5, Level of interest or demand by public society

5.98x.20 1.96
2.01x.10 .201
8.24X.30 2.472
9.37x .80 7.496
11.3x. 05 .565
12.129/.565= 21.46 / .2 =107 years

I hope you like it.

edited the formula you were right there is a wrong number which is .02 it should be .2
 
I guess no-one had that formula before technology had to take a giant leap during WW2?
If we did- we may well have given up before a fight and Hitler could well have become the boss!

Predicitive formula is all well and good- and very clever, for lovers of maths.

But, the REAL world changes drastically and quickly at important (0ften random beyond imagination) intersections.

as they used to say "Anything could happen in the next half hour!"

Dave.
 
On the contrary Dave, they did. They had 98% chance of turning biplanes into bombers, 89.5% of turning boats into destroyers and 115% chance of turning hydrogen technologies into an atomic bomb. That is really horrible. Technologies turned into war equipment is not good for anyone. The whole world loss that one and is still oosing with every war. On the other hand predictive formulas had always been around, they help us learn many things, from a mathematical piint of view, after all that is quite neccesary in order to understand the basis of the universe.
 
Can you verify those claims please?

Somehow, I would like to think that the intelligence agencies had for more to think about than those stats you point out, at a time of pure desperation and survival.

I don't believe that they would have sat down and discussed the war in terms of percentages, probabilities and what could be achieved in numbers on a piece of paper.

Sure, wins and losses and hopes, but not decisions made on a formula, or two- yikes!
WW2 was no simulation, it did not happen on a PC screen. It was no little game of Chess, it far more complex (and horrific than you, or I can Imagine!!!)
PLEASE do not "diss" it as a secondary thing!!! It was, and never will be something to be thrown away as a part of any secondary discussion anywhere.

My father was a Navigator before and during WW2, and he was trained up to fly the Lancaster- we in GB knew the war was coming- and he would not have lost so many friends he grew up with if the mathemeticians could forsee it all before.

May I add - I really cannot understand how someone can be so definitive, and specific.
I am sorry to say this, but-Life really isn't that simple.
If it were, life would really be quite pointless- we would all know what happens tomorrow- so, why bother?

What is the old saying Lies, damned lies, and statistics - Wikipedia, the free encyclopedia

I obviously understand the horrors of war- but, I somehow think that the Homo Sapien race shall never lose the tribal and self protective instinct- as with many animals on the planet.

And, besides- when push comes to shove, you, and your loved ones come first.


Thanks, Dave
 
Can anything travel faster than the speed of light?
The conventional thinking right now is that because light is approaching virtually negligible mass that negligible mass isn't massive enough.
Light itself has mass and that mass falls on a "negligible" scale.
We're going to need to understand this scale in great detail before we can master such things as gravity, time and space.
What is needed is a field of energy that repels gravity Higgs so that our craft can travel much the way electrons do -- and perhaps slip and glide through time and space.
 
Yes Thomas, Many things can travel faster than the speed of light, mainly sub particles. About travelling at the speed of light that might be difficult for us. You see we are relative to light and light is relative to us, in that sense we are bound by it and we bound light at the same time. In other words in order to travel faster than the speed of light we would need to unbound us from the general structure which holds us relative to light. However, in order to travel in time we dont need to travel faster than light. We could sink in a super massive gravity well, we could puncture time-space, we could employ a Cassimir Bridge or breach the reaches of Clifford Space or Kaluza Space for that matter or open a series of trascendental Calabi-Yau hypercubic manifolds. What we need is sufficient power to achieve such things and of course the engineering to put such theories into practical truths.
 
Ah Transient001, I like the fact that you can follow my comments.
You're saying that because we humans reflect light, we are bound to its speed limitations.
You said so yourself, just now. If we surround ourselves in a bubble of something that is not subject to the laws of light, that something can transport us faster than light. And perhaps one day, speed will be irrelevant regarding travel. That is, the only speed that is really relevant is instant speed. Arriving from point A to point B in an instant.
How close are they to the unified field theory that contains the math relating the basic four forces? I see that the understanding of gravity force is still vague.

Ah, travel in time.
Have you seen the 2012 movie "Prometheus". That technology that is used to view the past, such as the family history of one of the passengers, and how the aliens were attacked, that technology actually exists and is being experimented with by the U.S. military. They have history viewers, for want of a better term.
 
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