If I want to build a comm device for Interstellar Communication, what is the theory behind that technology will be? Any suggestions?

Light is to daggum slow. Who wants to wait 4 years to recieve a close transmission? Scifi has the neat little invention of hyperspatical transmitter/reciever. It is truely beyond us to understand the principals and practical methods to build such at present. But what would be some ideas on such? How could we speed up the tranismission/reception cycle to make it useful?

We need to look at theoretical physics to see if we can use anything. I have not done any research in this. Any one who has some background, please jump in. I am good in applied science. I can take a good theory and make gadgets out of it.

Hi kmguru, wet1,

As far as theory is concerned, lightspeed is the fastest possible way to transmit information over a given distance. So if that is too slow for you, there are two options:


Either you shorten the distance the information has to travel. There are plenty of theories ranging from wormholes, warping of spacetime, ... to shorten distances in space, but they are rather hypothetical.
Or you resort to FTL particles such as tachyons, which are even more hypothetical and above all, now generally assumed not to exist.


Perhaps you could use some not-too-well documented effect from one of the theories at hand. For example: quantum tunneling. Recent measurements indicate that particles seem to tunnel barriers at speeds exceeding the speed of light. I do not believe this experiment has been verified, but perhaps its usuably somehow.

So it seems we're stuck with lightspeed just for a few decades now.

Bye!

Crisp

Hi Crisp:

Well if we can not use photons to communicate (because it is too slow). We may be able to piggyback someother particle (gluon or boson or ?) that can appear to travel FTL after getting a boost from the photons namely lasers.

Another way could be to make a microscopic tunnel in space to bridge the otherside (is it same as quantum tunneling?).

Can the string theory help in our quest?

Yuu have hit on something I believe to be a new use. I have heard everywhere about trying to use it for a busline to get from A to B, but I have heard no one come up with the idea of using it for the long distance phone call (E.T. phoning home).

If I usderstand the theory correctly, the string is not that large in cross section. There is also the idea that a string crossing another causes a disconnection, which turns into a closed loop. So if you message got hung into a loop it would not arrive where it was intended, but would rather be like a lost postal item, hung in limbo. If the loop idea is valid, it means that there are not that many strings out there. The estimate that sticks to mind was 10 for some reason. I'm sure that Crisp probably has some up to date info on the theory. (If you could be so kind to supply a link or info)

I have a gut feeling, the major components for an interstellar telephone device are as follows:

Super cold generator (In deep space it is coooold)
Magnetic generator (a coil)
Super conductor
Laser generator
Pure element from the periodic chart
An alloy with some special properties
A capacitor bank for high power short duration
(we may need a plasma generator but I do'nt think so)

Then we are ready to go:

Considering that the effect of gravity is considered by some to be almost instantaneous, like on the order of a billion times faster than light, I'm surprised that no one has mentioned the possibility of using it, or an aspect, to communicate vast distances.

I had indeed considered gravity before the post. I felt that not enough was known on how to make the changes to effect a message of any sort at present. Though what we discuss here is in the realm of what if and gravity communications certainly falls under that category. We do know of it's effects but not know to generate such other than by assembling a mass or by using a already assembled (conveniently I might add) mass. So how do we effect a mass sufficiently to generate the changes needed to make a message known?

My Graviton generator is broke. I can not find the parts to repair it in this timeline....hee...hee...hee.

...and I'm not going to give back the parts I stole! :eek:

Especially this interesting, shiney, little dohickey.

While I was kidding around on this topic, in a moment of clarity, I came to the following understanding:

The technology I propose works like this: The stream carries charged particles that is accelarated to light speed when piggybacked to the photon stream. Because the stream configuration is EM in nature, when enough energy is applied, it tunnels the space at the atomic level. Not all particles will tunnel the space but some will. Those atoms which are travelling in the tunnel eventually loose their energy level and drop out of the tunnel to normal space. To control the distance we may have to control the applied energy.

To test the theory, the following test should be rigged. An ordinary detector should be designed and tested first and carried on a probe and sent with a scheduled probe out of our planet. The time differential must be more than atleast 4 to 5 minutes of normal space communication.

Then from ground we can send a data pulse to the detector and receive the result on normal telemetry. The reason is that, on ground, the transmitter will be the size of a house. So it is one way high speed communication. Testing on earth with a receiver will not work because the distance is too short.

The only thing I have not figured out is how do you aim the transmitter to the receiver plate since aiming in normal space may not work. Any ideas how to solve this problem?

If anyone tries to patent this, I will really be pissed. It is now in public domain for all mankind.

Hi everybody,

Wow, I've been gone for a couple of days and all of the sudden there are like 100 messages to catch up. Neat :).

Okay, some thoughts:

Kmguru said:
Well if we can not use photons to communicate (because it is too slow). We may be able to piggyback someother particle (gluon or boson or ?) that can appear to travel FTL after getting a boost from the photons namely lasers. Another way could be to make a microscopic tunnel in space to bridge the otherside (is it same as quantum tunneling?). Can the string theory help in our quest?

The problem with other particles is that they are forced to travel in "empty space" at speeds not exceeding the speed of light. Gluons are particles that "glue" quarks together, and they have not been verified to exist separately (quarks and gluons always recombine to form couples of quark/antiquark to form a meson particle type, or 3 quarks couple to form a hadron particle type). A boson is a general classification type for particles: we divide all known particles in two categories: bosons and fermions, depending on spin. It's not a particle itself.

Quantum tunneling is a phenomenon were a particle leaks through what is called a "potential barrier". For example: an alpha particle (2 protons + 2 neutrons) can leak out of a nucleus to emit alpha-radiation. Or, if you shoot a particle at a wall, it can leak through the wall (quantum mechanics predicts that if you throw a ball at a wall, there's a slight possibility that the ball will go straight through it... However, the probability is very small). Quantum tunneling is hence the phenomenon that a particle passes an obstacle it normally can't pass; it seems that the particle found a "tunnel" connecting the two opposite sides of the barrier, making it possible for the particle to pass the barrier (while it normally can't, because it hasn't got enough energy).

The reason why I mentioned quantum tunneling is that experiments and calculations suggest that particles pass a barrier faster than the speed of light (it's a little more complicated than this, since there speed for a particle is not always speed as we think it is).

Practically speaking, I don't think you can use quantumtunneling for interstellar communication, because:

The tunneling probability lowers fast if the width of the barrier to tunnel through increases. The probability that a particle tunnels through a 4 lightyears barrier is nonexistent.
The barrier here would be the empty-space gap between transmitter and receiver, but the exact location of where the particle will pop out is unknown. So instead of tunneling to the receiver, your particle with the information might appear totally out of direction. You would need some sort of "focussing" here, and I don't think the tunneling phenomenon is understood well enough to do this.


About string theory: I am not familiar with the theory, but I do know that it is still very hypothetical. There have been a couple of experiments that can be explained if you assume string theory, but personally I think there's just not enough evidence to support string theory yet.

Links on quantum tunneling:

http://www.aei-potsdam.mpg.de/~mpoessel/Physik/FTL/tunnelingftl.html
Extensive list of literature on the subject. Technical.
http://www.biols.susx.ac.uk/home/John_Gribbin/quantum.htm#Photons
Basic explanation of what quantum tunneling and the experiments are about.

On request: some links on String theory:

http://www.physics.ucsb.edu/~jpierre/strings/index.html
Not too technical introduction to string theory.
http://superstringtheory.com
You probably know this one. The "official" homepage of string theory (even though it's only the claim that sounds prestigeous). Excellent introduction though.


Chagur, wet1:

Considering that the effect of gravity is considered by some to be almost instantaneous, like on the order of a billion times faster than light, I'm surprised that no one has mentioned the possibility of using it, or an aspect, to communicate vast distances.

So how do we effect a mass sufficiently to generate the changes needed to make a message known?

I agree with wet1 that not enough is known about gravity to be able to say something about communication techniques. I am now sure about this, but I believe gravity is also restricted to the speed of light. In general relativity, gravity waves spread out at the speed of light. In the attempts to describe a quantum theory of gravity, the graviton is probably also restricted to the speed of light (just for the sake of causality, whether the experiment confirms this is unknown to me). And even if gravity travels faster than light there's still a problem: as wet1 mentioned, how would you affect a mass to produce large enough fluctuations in gravity waves in order to make them detectable several hundreds of lightyears further ? (The waves become smaller in amplitude as they travel further).


And finally, Kmguru:
Not all particles will tunnel the space but some will. Those atoms which are travelling in the tunnel eventually loose their energy level and drop out of the tunnel to normal space. To control the distance we may have to control the applied energy.

The tunneling probability indeed depends on the energy of the incoming particles. However, we're talking about probabilities here, so even with a "fixed" energy, there is still a large spread on where a particle has a large enough probability to pop up after tunneling.

Reason is that, on ground, the transmitter will be the size of a house.

I'd make that a few hundred times larger ;). You'd have to give the particles a lot of energy, and that would require particle accelerators (and most of those don't fit in your basement).

The only thing I have not figured out is how do you aim the transmitter to the receiver plate since aiming in normal space may not work.

Hrm.... I think directional aiming is sufficient, assuming the tunnelbarrier is uniform in all directions (if the barrier is noticeably smaller in one direction, the distance for tunneling shortens, and hence the probability for emerging there increases).

Bye!

Crisp

I have a few things I need to do first like setting up a cluster of Sun microsystems E6800s. Then I may start working on this gadget.

My post re. the speed of gravity was based on the following:

www.metaresearch.org/cosmology/gravity/possiblenewpropertiesofgravity.asp

Not quite sure how reputable the site is, but there also is some stuff that seems to back it up on:

www.math.ucr.edu/home/baez/physics/grav_speed.html

Chagur

My understanding of gravity is very little. I think, gravity is the effect of mass or caused by mass. If we hold a theory that forces can be transformed from one form to another, may be someday, someone will find a gravity generator which has the effect of gravity without the required mass. My understanding is that presently we do not even have a theory as to how to accomplish this.

Several years ago a physicist wrote a paper on hypercharge theory that can in effect create artificial gravity. Whatever it is, we need either electricity or an engine to make it happen. Converting electron to graviton will be very interesting indeed.

So what do you think? 100 years or more? or never?

Hi all,

Chagur: Well, it all seems plausible ;). Once again the problem is that experimental verification is difficult for gravity, making it hard to rule out any theory (and there are plenty) at the moment.

Bye!

Crisp

kmguru,
Interested in Interstellar communication.
Saw your dialog of 07-13-01 in which you mention Int. Comm.
I can send you photographs of apparatus with this purpose.
Sincerely yours,
cyberlight13
cyberlight13@yahoo.com

Iwas kidding around about the Graviton Generator...though I have some ideas how to make a FTL communication device. While there is no restriction in physics about converting one fundamental force to another, I have not spent the time to research the development of a graviton Generator.

We are many years away from making it possible.

Take a capacitor... charge it...

then seperate the two halves....

one plate launches into deep space...

the other stays on earth...


no matter how far away the ship gets... the two plates will be connected.

then its a matter of modulating the voltage across the two plates...

such as vibrating one plate... the vibration should cause a fluctuation in the existing field... which may. may be detectable.

-MT

Mosheh Thezion,
Take a capacitor... charge it... then seperate the two halves.... one plate launches into deep space... the other stays on earth... no matter how far away the ship gets... the two plates will be connected.
What's the science behind this?

Kmguru,
The stream carries charged particles that is accelarated to light speed when piggybacked to the photon stream. Because the stream configuration is EM in nature, when enough energy is applied, it tunnels the space at the atomic level.
And this?

Chagur,
the effect of gravity is considered by some to be almost instantaneous
I was under the impression that the general consensus among active researchers is that gravity waves propagate at the speed of light. (As reported in New Scientist (http://www.newscientist.com/article.ns?id=dn3232).)

I am also under the impression that instantaneous communication will violate relativity. There are two things that I know of which act across space instantaneously: probability wave collapse and the effects of entanglement. One may not exist as a real phenomenon (rather than as a human aid to calculation); the other cannot transmit information. Seems to leave the prospects for interstellar communication limited to purely subluminal velocities.

Why can't quantum entanglement (http://en.wikipedia.org/wiki/Quantum_entanglement) transmit information?

Say, for instance, that two entangled photons are produced in a subatomic event. They speed off in opposite directions until many light-years separate them. Then imagine that you come along and attempt to measure the spin of one of them. Because of quantum uncertainty (which I am gradually and reluctantly coming to accept is a genuine limit to knowledge) the photon did not possess a definite spin value until you interacted with it. However, now that you have 'forced' it to assume one particular value, should its distant partner also be measured it will possess the exact same value (or the exact opposite - I'm not sure). "Spooky action at a distance" has been demonstrated, though no information has been communicated.

Einstein and some others apparently tried to argue that all this showed was that the photons both share the same value for spin from the moment they are created. However, (fairly) recent experimentation has shown that this is not the case, and that both photons do genuinely assume a common value only when they are forced to interact with the environment (observer). I think that it was a statistical argument which has convinced physicists of this.

Zephyr: The quantum phenomena involved are controlled by probability. You cannot decide in advance what state will be measured. You merely know what result will occur at a distance site after you have made a local measurment.

Imagine that two pairs of dice could be entangled. I throw one pair here on Earth and you throw the other pair on a planet in the Alpha Centauri system. When I see my result, I know yours and vice versa.

It seems hard to believe that such a phenomena could occur, but that is what the quantum theory boys say is so.

BTW: I suspect that this thread belongs in the SciFi Forum, although is is probably not as far out as some others accepted here as science.

Wow Dinosaur, you said it so much more succinctly than I could.

Yah I was just going to say, what about "spooky action at a distance"...

Here is something I found very interesting from a few years ago. When it comes to interstellar communication, everyone automatically starts thinking about EM radiation. Here’s something to think about……!

(I have posted only the abstract of the paper)

<blockquote>Inscribed matter as an energy-efficient means of communication with an extraterrestrial civilization

Christopher Rose and Gregory Wright

<I><B>Nature</B></I> 431, 47-49 (2 September 2004)

It is well known that electromagnetic radiation—radio waves—can in principle be used to communicate over interstellar distances. By contrast, sending physical artefacts has seemed extravagantly wasteful of energy, and imagining human travel between the stars even more so. The key consideration in earlier work, however, was the perceived need for haste. If extraterrestrial civilizations existed within a few tens of light years, radio could be used for two-way communication on timescales comparable to human lifetimes (or at least the longevities of human institutions). Here we show that if haste is unimportant, sending messages inscribed on some material can be strikingly more energy efficient than communicating by electromagnetic waves. Because messages require protection from cosmic radiation and small messages could be difficult to find among the material clutter near a recipient, 'inscribed matter' is most effective for long archival messages (as opposed to potentially short "we exist" announcements). The results suggest that our initial contact with extraterrestrial civilizations may be more likely to occur through physical artefacts—essentially messages in a bottle—than via electromagnetic communication.</blockquote><P>

Only a bit of food for thought. I am well aware that supporters of relativity reject particle entanglement violates relativity by the assertion that information has not be transmitted.

That frankly is a bit "post ad hoc CYA" as far as I am concerned.

It would appear that regardless of our current or even ever future inabiity to transmit information that we can use by particle entanglement, the fact that information is being sent seems most obvious.

If these particles are not communicating as to their status and changes then the particle entanglement phenomena is "Spooky" indeed. :D

It would seem without arguement that such particles are infact communicating by some instantaneous means. Their respective quantum condition and changes "IS Information" regardless of how others would like to argue to the contrary.

It is important to note that no temporal conflict occurs when nature communicates FTL.

MacM,

I suppose that you could claim that information has been passed between the two entangled particles. But the 'knowledge' of this information is strictly restricted to the particles themselves. Imagine that you and I, separated by light-years, each possess a mutually entangled photon. By measuring the spin of yours you cannot ascertain that I have or have not done the same. The most you can deduct is that if I did measure it I would obtain the same (or opposite?) value. To you (and to me) the result of measurement will still suggest that the photon has only 'opted' for one value or another at the moment of interaction. After this interaction has occurred the entanglement is lost.

Hercules Rockefeller,

That's an interesting idea - it's got old-school appeal. While still ignorant of the figures I think only the most parsimonious of civilisations would begrudge the extra energy required for a narrow beam EM transmission. But then who's to say just how miserly ET is with its energy?

MacM,

I suppose that you could claim that information has been passed between the two entangled particles. But the 'knowledge' of this information is strictly restricted to the particles themselves. Imagine that you and I, separated by light-years, each possess a mutually entangled photon. By measuring the spin of yours you cannot ascertain that I have or have not done the same. The most you can deduct is that if I did measure it I would obtain the same (or opposite?) value. To you (and to me) the result of measurement will still suggest that the photon has only 'opted' for one value or another at the moment of interaction. After this interaction has occurred the entanglement is lost.

Oh, I agree nature has one up on us in this regard but I do object to those that claim information has not been transmitted FTL. I think the particles would disagree (as should any reasonable thinking individual not married to the prohibition of FTL by relativity).

Hercules Rockefeller: You have an interesting name implying incredible strength combined with incredible wealth. If such is the case, I congratulate you: Unlike some who make disparaging remarks due to jealousy.

Tight beam radiation & the sending of physical artifacts do not seem worthwhile due to the low probability of either method ever reaching an intelligent civilization. A bottle with a note tossed into the Pacific Ocean is many orders of magnitude more likely to be found than a tight beam message or a physical artifact sent out into the universe.

At the risk of starting a flurry of posts claiming otherwise, I would like to point out that there is little reason to expect more than one intelligent civilization per galaxy at any given point in time. It is quite possible than some (perhaps most) galaxies contain no intelligent civilizations. While there is good reason to expect life to exist whenever the conditions are suitable, intelligent life is a very low probability occurrence.

MacM: If you accept the analogy of entangled dice, can you describe a mechanism whereby you could transmit useful information using such dice?

If you do not accept the dice analogy, might you describe how you would transmit useful information via entangled quantum entities? Since the Quantum Theory experts admit to not knowing how to do it, I do not expect you to have a useful method.

Others: John Gribbin (See Schrodinger’s Kittens & the Search for Reality) claims that the Von Neumann hidden variable proof is invalid (Id est: Hidden variables are possible contrary to Von Neumann). Gribbin claims that this was asserted by Grete Hermann in 1935, but ignored. Gribbin states that Bell refuted the proof in about 1966, later claiming that it was not only invalid, but silly.

If the Von Neumann proof is invalid (this is likely due to the work of Bell & Aspect), then entangled particles need not rely on lack of local causality. They could be an indication that objective reality is sometimes a valid concept.

The quantum world is really weird. Some experiments involving entangled particles seem explainable assuming objective reality, thus retaining local causality as valid. Other experiments involving entangled particles (EG: Polarization phenomena) refute objective reality.

The two slit experiments indicate that certain quantum particles (including atoms) sometimes act like waves and sometimes act like particles. Entangled particles experiments (perhaps only thought experiments) indicate that sometimes objective reality is valid and sometimes it is not.

Perhaps, the best interpretation of quantum phenomena requires admitting that some of our intuitive concepts are not applicable to the world of quantum phenomena. Id est: Perhaps we should give up the quest for an understandable model and be content with the predictive value of the equations.

The above view seems no worse that accepting the mathematics of 4D & higher spaces without being able to visualize the geometric objects described by the mathematics. For example consider the following.A 4D hyper-cube has vertices at which 4 lines are mutually perpendicular. Worse yet: In general, an nD hyper-cube has vertices at which n lines are mutually perpendicular.


The diagonal of a unit nD hyper-cube is SquareRoot(n). This implies that a 441D unit hype-cube has a one unit side & a 21 unit diagonal.


Consider a unit 16D hyper-cube with an inscribed 16D hyper-sphere. You can fit 256 hyper-spheres in the corners, tangent to the faces and to the inscribed sphere. Each of those 256 hyper-spheres are significantly larger than the central inscribed hyper-sphere.The above and various other claims relating to nD geometry can be proven mathematically, but are impossible to visualize or model in our minds.

Is it a crime to give up on being able to visualize some Quantum World concepts which are provably valid?

MacM: If you accept the analogy of entangled dice, can you describe a mechanism whereby you could transmit useful information using such dice?

If I could I can assure you I woudn't be writting my views on this forum. :D

If you do not accept the dice analogy, might you describe how you would transmit useful information via entangled quantum entities? Since the Quantum Theory experts admit to not knowing how to do it, I do not expect you to have a useful method.

Show where I claimed I could. Then tell us if you subscribe to the arguement that the particles are NOT commmunicating any information when they are changing state.

The two slit experiments indicate that certain quantum particles (including atoms) sometimes act like waves and sometimes act like particles.

I see no conflict in that in that matter is nothing but compacted energy. Energy seems to be in the form of waves.

The above view seems no worse that accepting the mathematics of 4D & higher spaces without being able to visualize the geometric objects described by the mathematics.

Consideration of anything greater than 3D is a waste of time. Pun intended.

Is it a crime to give up on being able to visualize some Quantum World concepts which are provably valid?

Yep.

MacM: You asked the following.Then tell us if you subscribe to the arguement that the particles are NOT commmunicating any information when they are changing state.Yes I do subscribe to that argument.

Suppose I send a simple question to an astronaut who is a few light hours distant. He need only answer yes or no, requiring the transmission of a single bit of meaningful information (Id est: One for yes & zero for no). To the best of my knowledge, there is no way for him to transmit that single bit of information using particle entanglement, even if we are allowed to set up the entangled particles in advance of transmitting the question.

Until somebody describes a mechanism for transmitting a single bit of information, I will continue to subscribe to the argument.

BTW: I assume that you are aware that quantum particles obey probabilistic laws, not controllable deterministic laws.

MacM: You asked the following.Yes I do subscribe to that argument.

Until somebody describes a mechanism for transmitting a single bit of information, I will continue to subscribe to the argument.

Then you are applying an incorrect standard to the terms:

WEBSTER:

Communication - (1) the act of transmitting. (2a) - a giving or exchanging information,....

"Or" is an important two letter word here. Communication need not be a system of back and forth replies. It can be and in the case of particle entanglment IS one way communication and is "giving" information, not exchanging information.

BTW: I assume that you are aware that quantum particles obey probabilistic laws, not controllable deterministic laws.

Certainly. But that doesn't change the fact that the particle being measured communicates, "gives" information, to the other particle.

MacM: You are either nit picking or ignorant of what the Quantum Theory boys mean when they say that no informnation can be transmited via the use of entangled particles.

In case you are ignorant of their claim, I will state my understanding of it.The Quantum theory boys state that I cannot use any entangled particle phenomena to send a message FTL to a distant observer. For example, I cannot inform the distant observer of the current temperature in my apartment using entangled particle activities.I think that they do acknowledge FTL action (Id est: Spooky action at a distance), but they deny that any useful informtion is transmitted FTL or otherwise via entangled particle phenomena. I concur with the latter claim, but am not sure about the former.

I am not sure exactly what the Quantum Theory boys are claiming with respect to entangled particles. They obviously claim that a local measurement provides a knowledge of the result of a distant measurement. I do not know if they are claiming a cause effect relationship acting FTL. I have no idea of what they claim if no measurement is ever made at the distant location.

As indicated by a previous post, I am not quite willing to acknowledge FTL interaction between entangled particles. Einstein favored a hidden variable explanation for the spooky action at a distance. Due to Von Neumann (and perhaps others), hidden variables were considered to be impossible until Bell and Aspect showed that the Von Neumann proof was flawed.

When the Von Neumann proof was refuted, FTL activity need not be used as an explanation for entangled particle weirdities. At least that is my interpretation of the implications of rejecting the Von Neumann proof.

Frankly, I do much confidence in my opinions on this or any other Quantum phenomena. I have even less confidence in your opinions on this or any subject involving SR, GR, or QT. I think we have an argument between sombody with poor eyesight and another who is almost blind.

BTW: It is naive to use a dictionary definition in the discussion of a complex subject.

I see. I thought that you could change the spin of one of the particles and the other would change to reflect that, like forcing one of the entangled dice, but since you can't ... that doesn't really help.

Certainly. But that doesn't change the fact that the particle being measured communicates, "gives" information, to the other particle.

Taking the hidden variable explanation, you can do the same without entanglement - if a planet flashes either a red or blue light in all directions, then two people an equal but opposite displacement away will see the light and deduce that the other person is seeing the same colour.

The only difference engtanglement makes is that there's no 'middle man' choosing the colour.

Zephyr: Your red & blue light flashing is a pertinent analogy. I wish I had thought of it.

T=CR... TIME equals capacity times resistance...


and if the resistance is low.... as in zero..... then... instantanious communication across what can be called subspace can occur... in the electrostatic realm.....

dont ANY of you study electronics???

-MT

MacM: You are either nit picking or ignorant of what the Quantum Theory boys mean when they say that no informnation can be transmited via the use of entangled particles.

If you understood english you would know I have not commentedon what the QM boys have said. Nor have I claimed we can communicate using particle entanglement.

I have said and repeat that the claim no information has been sent FTL is outrageously false. The mere quantum status of a particle is information and the change of state is information. The arguement put forth is BS and only used as a eans of ignoring the failure of SR.

BTW: It is naive to use a dictionary definition in the discussion of a complex subject.

Only with respect to very specific technical or scientific terms. It is even more naive to be unable to converse in absence of some supporting relavistic formula and suggests the person is ignorant of basic physics.

Messages can be exchanged instantaneously through particle entanglement. It is easy to figure out how to do it using the Bell-state Quantum Eraser. I'll give a cut & paste explaining the Bell-state eraser, then explain further if some of you can't see how a message can be sent by using the eraser.

"Figure 6.5. Experiment 4 - Bell-state Quantum Eraser.


The Bell-state quantum eraser has one more feature: each slit is covered by a substance that changes the polarization of a photon. Consequently, the left-hand slit will receive photons with a counter-clockwise polarization, and the right-hand slit will pass photons with a clockwise polarization.

Note: Polarization does not affect interference patterns.

Initially, neither detector shows an interference pattern. Since we control the polarization of photons passing through the slits and we know the polarization accepted by each slit, we can deduce which way the photons travelled (counter-clockwise through the left; clockwise through the right). Thus no interference patterns are detected.

However, if we rotate the polarizing filter in front of detector A so that the polarizations of the photons that hit the detector are the same (that is, we can no longer distinguish between clockwise and counter-clockwise polarizations), then the interference pattern appears at both detectors!

How do the photons arriving at detector B know that the polarizations have been "erased" at detector A?"
http://www.joot.com/dave/writings/articles/entanglement/spookiness.shtml

All that needs to be done is to use two fiber optic cables of the same length, then transmit a stream of entangled photons from a laser through the cables. One photon from each entangled pair through each of the two cables, as explained above. Locate the observers at the far ends of the cables with the polarizing filters. If neither observer is polarizing the light at his end of the cables, an interference pattern is shown on both screens. When one observer begins to polarize the light at his end, the interference pattern will disappear at the other observer's location, replaced by the circle pattern. This happens instantly, regardless of the length of the fiber optic cables. All one observer needs to do to send a message to the other observer is to use a Morris code by varying the time he reverses from polarized to non-polarized states at his end. The identical code will be shown instantly at the other location. Note that the laser at the beginning of the experiment has to continously send entangled photons through the cables, since they do not travel faster than light, but the observers at the other ends can communicate instantaneously by using the entangled photons that arrive through the exact same lengths of cables. I am not commenting on how useful such a method may be, only that information can be exchanged faster than light.

... I am not sure exactly what the Quantum Theory boys are claiming with respect to entangled particles. ...I have no idea of what they claim if no measurement is ever made at the distant location. ....I try to answer - see below.
I have said and repeat that the claim no information has been sent FTL is outrageously false. The mere quantum status of a particle is information and the change of state is information. The arguement put forth is BS and only used as a eans of ignoring the failure of SR.....Like Dinosaur, I am not completely sure of myself (been a long time since I went thru Bell's math, which I encourage all interested to do as it is not as difficult as calculus.) but I think I know what the "QT boys" would say if NO measurement is ever made at the distant location and even what can happen there, "later."

A correct understanding of this is why I dislike Zephyr's red and blue flashing planet analogy. True, it makes a simple classical analog of how it is possible to instantly know what is being observed at some distant location, but it misses the main point of QT. It helps promote the type of miss-understanding (or ignorance) displayed by MacM precisely because IT IS CLASSICAL, NOT QUANTUM.

The thing that often gets MacM into trouble is that QT violently disagrees with common classical experience. (So does SRT, but that is another story.) The essence of QT entanglement, if forced into Zephyr's model, is that the planet is on each flash is emitting BOTH red and blue flashes yet when A observes red, distant B observes only blue. I.e. until "an observation" is made, somewhere, the system is in a "mixed state."

Any observation on either will do to force the system into a "pure state" or "eigen state” to keep the original German word, still used in most English QT courses. (Eigen is a math term, in use long before QT was known.)

To be general, if the "mixed state" of “object” (particle or photon) is A + B with state A and state B each being 50% or equal in "strength," then observation on either separate object, will make it a pure eigen state, either A or B and the other, still unobserved object, is at the same time forced into the other state.

That is, the amount of A and B states in the universe is statistically* unchanged by the observation. (Counting the two "joined" or "entangled" particles in the mixed state as one A and one B because BOTH are "half A" and "half B")

Now that the distant object has been forced into a pure state it can be changed, or naturally evolve** into other possible states, even interacting with another object to form a new mixed state. (It has been liberated - no longer tied to its original partner, who most likely no longer exist as “observation“ killed it.) For example, if the distant object is a photon and the local observation forced the distant photon into pure vertical polarization and it is not destroyed by a simultaneous distant observation, then it could enter an "optically active" crystal, such as ADP, and emerge as a horizontally polarized photon.

Hope this helped.
_________________________________________
*I think this word required as the original mixed state could have been 40/60 % of A & B respectively. (At least in principle. - I do not know if any unequal mixed entangled state has ever been made, but see no reason why it could not exist.) I am not absolutely sure, but think that in this case, on 1/5 of many identical repetitions of simultaneous*** local and distant measurements, the results of both measurements will both be "state B." I.e. You get: A&B results+ A&B results+ A&B results+ A&B results+ B&B results on average to be still a 40/60 mix favoring B after the mixed state has been forced into two pure eigen states. (I have never seen this “statistical state conservation law” -It just occurred to me as I was writing this, but I think it true, and unfortunately for me, probably already well known. - If not, please refer to it as the “BT rule.“)
Note also, in Zephyr's red&blue light emitting planet with unequal intensity in the lights, sometimes, both observes "see blue" if blue was dominante light emitted. Also, even if the above 40/60 % in favor of state B exists in the original mixed state, then very rarely the result can be, I think, A&A. (I am very uncertain about this, but I suspect that this is possible, but rare, even if blue or B is dominant. I am certainly getting in over my head for sure now. This would mean, if true, that in the 50/50 mixed state, one can not be sure that the result is A&B every time.)

**It is ironic that the evolution is completely deterministic!
Only an “observation” can make a random outcome. What is the essential nature of an “observation”? - Answer that and go straight to Stockholm for your prize.

***All in one frame, of course. (Reference frames are “universe wide.”)

A refinement of the Bell-state Quantum Eraser exercise I outlined above would be the following.

Launch a detector/double slit device along with a crew for a future Mars mission. Launch a laser to emitt the entangled photons to a location mid-way between the Earth and Mars. The entangled photons do not need to be emitted through a fiber optic cable in this exercise, only one stream of the entangled photons toward Mars and their counterparts emitted towards Earth. Same as above, by measuring the photons arriving at the Earth with the polarizer, the pattern will change from the interference pattern to the non-interfered pattern at the Mars location. If the laser emitting the photons is not exactly midway between Earth and Mars, the communication will not be exactly instantaneous, but still much faster than a radio signal beamed from Earth to Mars at the speed of light. Remember, you are measuring members of the entangled pairs that have arrived on Earth at approximately the same time their counterparts have arrived on Mars. Why could this not work if the laser were powerful enough to emitt enough entangled photons so the pattern could be ascertained at each location (Mars and Earth)?

...I have said and repeat that the claim no information has been sent FTL is outrageously false. ...The least amount of sure information is called a "bit" - For example, I have written either a one or a zero on the paper before me. Your knowing which gives you have one bit of information.

Please tell me how (operational details) you can use QT entanglement to send even one bit from point A to point B. A lot of people, me included, say you can not do this via QT entanglement.

For example, you write a one or zero on your paper, and tell me which it is via QT entanglement experiments.

...Why could this not work if the laser were powerful enough to emitt enough entangled photons so the pattern could be ascertained at each location (Mars and Earth)?Each photon only interfers with its self, not with any other.

Very low intensity, long photographic exposures still show the inteference pattern (proving the above) even when there is essentially zero chance that two exist at the same time.

Each photon only interfers with its self, not with any other.

Very low intensity, long photographic exposures still show the inteference pattern (proving the above) even when there is essentially zero chance that two exist at the same time.

Better read the information at the link I gave, Billy T. Or, are you stating that the information is incorrect? Are you familiar with Bell-state erasers? Again:

"Initially, neither detector shows an interference pattern. Since we control the polarization of photons passing through the slits and we know the polarization accepted by each slit, we can deduce which way the photons travelled (counter-clockwise through the left; clockwise through the right). Thus no interference patterns are detected.

However, if we rotate the polarizing filter in front of detector A so that the polarizations of the photons that hit the detector are the same (that is, we can no longer distinguish between clockwise and counter-clockwise polarizations), then the interference pattern appears at both detectors!"
http://www.joot.com/dave/writings/articles/entanglement/spookiness.shtml

Better read the information at the link I gave, Billy T. Or, are you stating that the information is incorrect? Are you familiar with Bell-state erasers? ...No. Wife says I must eat dinner now, so I will try to look later. But please tell me if there are always photons passing thru your two slits.

If yes, then there is alway the inteference pattern on screen as each interfers with itself and thus of course has its own polarization, not matter how you force that polarization to be at some distant point.

The least amount of sure information is called a "bit" - For example, I have written either a one or a zero on the paper before me. Your knowing which gives you have one bit of information.

Please tell me how (operational details) you can use QT entanglement to send even one bit from point A to point B. A lot of people, me included, say you can not do this via QT entanglement.

I never said you could asshole. I use that friendly adjective because you saw fit to referance my name once again above and comment about my ignorance even about a subject for which I have had little comment.

You would do well to give specific examples of my ignorance rather than your shotgun techniques. Keeping in mind "Ignorance" means lack of knowledge, not what is my case which is rejection of what you call knowledge. That sir is not ignorance. You seem ignorant of the meaning of ignorance.

All your huff and puff has not addressed the issue of information being transmitted by the entangled particles. This has nothing to do with mankind developing a communication system using particle entanglement but only the fact that these particles must be sharing information FTL.

Address that issue since it is the only one I have commented on.

Question: "Do you argue that entangled particles DO NOT transmit information to the other particle when it changes state"?

If not by what mechanisim do you suggest the other particle knows to also change?

BTW: Be sure to read my post above regarding the definition of communication.

No. Wife says I must eat dinner now, so I will try to look later. But please tell me if there are always photons passing thru your two slits.

If yes, then there is alway the inteference pattern on screen as each interfers with itself and thus of course has its own polarization, not matter how you force that polarization to be at some distant point.

Yes, there are always ENTANGLED photons passing through the slits at both locations. That's the whole point. You are speaking of regular photons, Billy T, not entangled photons at both locations.

2inquisitive,

Could you post a diagram or a sketch? I'm having difficulty envisaging it.
Are all of the entangled photons polarized, with the orientations of the polarizing filters determining whether the photons' true paths are known and an interference pattern produced?

If so, I don't see how the presence or absence of an interference pattern on Earth will dictate whether or not one occurs on Mars. Can't photons reaching Earth's receiver build up an interference pattern (because their paths through the slits are unknown) while their entangled counterparts at Mars do not (because their paths are determined)?

Yes, when the photons are split by the crystal, the entangled photons will have opposite polarizations. There are plenty of illustrations at the link provided.
Oh, and when the polarizations of the photons are determined at one location, it causes the interference pattern to disappear at the OTHER location as well. That is how my example works, by detecting the changing patterns at the other location. By turning the polarizing filter at one location, the pattern at the other location can be monitored for a sequence, like short-long-short-short-long, etc. by altering the rate at which the polarizing filter at one end is rotated.

Ok, but how will determining photon paths (thus cancelling the interference pattern) at one detector force a result at the distant receiver?

This has nothing to do with the path of the photons, only polarizations which do not destroy the photons.

If the polarizing filter is not used, the photons can be thought of as passing through both slits, causing an interference pattern. If you force the photon to 'opt' for one or the other by using a polarizing filter, interference does not occur. I thought that this was the basis for your communication system.

By BLOCKING one slit, the photon can be thought of as passing through only one slit. Polarizing the slits does not block the slits, the photon can still pass. Read the link, please. These types of questions are answered. You have to know something about the Bell-state eraser before you can understand my proposed experiment.
http://www.joot.com/dave/writings/articles/entanglement/spookiness.shtml

I'm out of my depth but I don't see how an interference pattern is produced at all at detector A if there is no double slit there.

OK, I have now had time to read your reference:
http://www.joot.com/dave/writings/articles/entanglement/spookiness.shtml

but either I do not understand of it has some errors. (I was glad to see it also told you that each photon interfers only with itself.) It states:

"Note: Polarization does not affect interference patterns.
Initially, neither detector shows an interference pattern. "

First sentence is true as one normally understands it to be polarization of the incident stream of photons, but the second sententence is also true as they have reversed polarizing filters separately covering only one slit each. The electric fileds of photons passing thru one slit when reaching the screen is orthogonal to that same photon traveling via the other slit (orhogonal electic fields can not add to zero. (no interference, so in their case, the first sentence is false.)

If strength of the E field of one photon was 2 before coming to the slits and 1 each while passing thru the two slits, then the orthogonal E fields at the screen add to square root of two, which when squared (intensity of light is porportional to the square of the field) is 2. The original intenensity was 4 (the square of field strength 2) so as expected, half of the intensity has been lost in passing thru the two reversed slits.

I will leave it as an exercise for you to show that if a vertically polarized beam is split into two parts, still vertical polarized, an one part passes thru a polarizor inclined at angle alpha and the other thru polarizer orthogonal to first, then they are recombinded that half the intensity is lost, regardless of angle alpha. Point being that with orthogonal polarizers separately covering the two slits, half the intensity is lost and there is no interference in what remains.

There is more confusion as the article progresses.

...Question: "Do you argue that entangled particles DO NOT transmit information to the other particle when it changes state"?
If not by what mechanisim do you suggest the other particle knows to also change?
BTW: Be sure to read my post above regarding the definition of communication.No information has been transimitted, not even one bit.
Part of this is the dificulty of comunicating with you as you have little experience with QT state functions. They need not be localized in 3D space and are one thing. if for any reasons (natural deterministic evolution under Schroedinger equation of by "Observational interference" a ramdom change is made in this one thing, this one thing is everywhere changed. - no signal sent any where. No "commuication" of informations. You simply are ignorant of the the details of QT and i agree that this is not an insult, only a statement about your state of knowledge which make it hard for you to appreaciate that no infomation has been sent anywhere. Nor can it be, via entanglement.)

If you want to invent some new definitions (Not those developed by Shannon, years ago) and nonconventional ideas about communication (does not require the abillity to send even one of Shannon's bits etc., feel free, but do not expect the world to get into step with you. instead expect lot of problems speaking to people who are not ignorant about these standard terms and definitions.) - I will try to get to rest of your post if it merit reply later. A lot appeared while eating my dinner and I want to read first.

Yes, there are always ENTANGLED photons passing through the slits at both locations. That's the whole point. You are speaking of regular photons, Billy T, not entangled photons at both locations.No I am speaking about ANY photon. It will interfer with its self if the part of it passing thru only one slit is not "twisted" (repolarized) wrt the part of it pass thru the othe slit. Regardless of of the state of polarization or any changes in the state of polarization (be they by a local ADP crystal or a observation of its entangled partnern on other side of universe) made prior to passing thru both slits, that one photon will (Normal condition): interfer withitself. (abnormal condition with reversed polarizer covering only one slit each: not interfer with its self.)

PS - I have mentioned ADP crystals as they are very optically active, but not very non-linerar so unlike the crystals of BO, which are non - linear in the induced fields created by the passing photons, ADP is not used to make to phase and polarization locked sub harmonic photons out of one.

ADP is good for rotating plane of polarization and particular interesting because they can be switched by appling an external electric field (I worked briefly with them years ago. wonderfully fun to grow - I made a few nearly perfect single crystals big as my thumb.)

No information has been transimitted, not even one bit.

Your claimed solution is BS pure and simple. Frankly I really don't care what others say or have said. Nor do I care what you say. YOU are speaking from ignornace of how it actually transpires physically so your arguement is based on ignorance.

You now suggest some wave function exists everywhere in the universe simultaneously and collpasing the wave, or what ever has the affect of change everywhere simultaneously.

What a load of double talk crap. If that is the best they can do they should find other occupations.

Hi kmguru, wet1,

As far as theory is concerned, lightspeed is the fastest possible way to transmit information over a given distance. So if that is too slow for you, there are two options:


Either you shorten the distance the information has to travel. There are plenty of theories ranging from wormholes, warping of spacetime, ... to shorten distances in space, but they are rather hypothetical.
Or you resort to FTL particles such as tachyons, which are even more hypothetical and above all, now generally assumed not to exist.


Perhaps you could use some not-too-well documented effect from one of the theories at hand. For example: quantum tunneling. Recent measurements indicate that particles seem to tunnel barriers at speeds exceeding the speed of light. I do not believe this experiment has been verified, but perhaps its usuably somehow.

So it seems we're stuck with lightspeed just for a few decades now.

Bye!

Crisp


tunneling is how some pieces of solid state electronics works. not only as it been vefiryied, it is taught in first class quantum mechanics and has daily application. What asnt been reproduced is tunneling over insterstellar distance and probably wont ever be, but ive been known to be wrong before

BT, thanks for the enlightening post. 2 questions:

1. What you are describing sounds reminiscent of the double-slit experiment where in certain cases the photon appears to "know" ahead of time which slit it will pass through and whether it will be measured. Is this some kind of quantum entanglement being acheived through the time dimension instead of the spacial dimension?

2. What are the current theories on the nature of an "observation?" Are particles really assumed to have half states? Or could be it that neither state exists until observation forces "state-potentials" into measurable "reality." Given the so called spooky action of quantum entanglement, would it seem more appropriate to assume either that the act of observation (which adds energy to the system, which itself would have random input) has an impact on the particle or space-time (which then precipitates from potential to particle state) or there is some form of communication in the opposite time direction.

Edit: one more question.

Is there a concise way to explain the relationship between quantum tunneling, quantum entanglement, and the slit experiments (if any)?

Your claimed solution is BS pure and simple....Not my "solution." Just the best I can do to try to get some standard QT across to you in words. Perhaps it will help you understand if I ask you where on the xy palne is function sin(x)? Is it not at both ends of the universe? if it evolves into cos(x) have not both ends of the universe been changed? It really is hard to talk to you in your state of ignorance, but perhaps you get from this some idea how the wave function can be not localized yet changed eveywhere at the same time with out signals being sent to the other side of the universe.

Some things just do not make common sense, but the math describing them is very well confirmed to agree with nature, but not with your common sense. One photon does go thru two different slits, just like the QT math says it does. etc. in violation of your common sense. If you really want to understand physics you will need to drop some of your "common sense."

I'm out of my depth but I don't see how an interference pattern is produced at all at detector A if there is no double slit there.Agreed. that was one of the confusions in article I was referring to.

BT, thanks for the enlightening post. 2 questions:

1. What you are describing sounds reminiscent of the double-slit experiment where in certain cases the photon appears to "know" ahead of time which slit it will pass through and whether it will be measured. Is this some kind of quantum entanglement being acheived through the time dimension instead of the spacial dimension?

2. What are the current theories on the nature of an "observation?" Are particles really assumed to have half states? Or could be it that neither state exists until observation forces "state-potentials" into measurable "reality." Given the so called spooky action of quantum entanglement, it would seem more appropriate to assume either that the act of observation (which adds energy to the system, which itself would have random input) has an impact on the particle or space-time (which then precipitates from potential to particle state) or there is some form of communication in the opposite time direction.
On 1:
I think it could be viewed as such, if you sort of think of it as "self entanglement." Photons have a length. Very stable excited states, which can nonetheless still radiatively decay to lower state sort of take a long time to do it. In the uncertainty principle view, their "delta t" is big (do not have a well-defined time of emission) so their delta E is very small or well-defined energy. (They product being fixed to less than small value. If their energy is very well defined and you know energy is proportional to frequency and that Fourier analysis of a well-defined frequency is quite a long sin wave etc. then the photons that come from Meta stable state can be very long (several meters). I said "can be" as the collisions during emission can change the energy levels etc and make the energy less well-defined etc.)
Summary: In some sense, the photon can simultaneously "feel" the full extent of the space /environment for its full length. It is not sending information from it head to its tail etc. If you like, you may think of it a FTL effects, much like entanglement, but it is limited to separations as long as the photon. The two-path interferometer (Mack Zelner name for it I vaguely remember) can have the length of one path slowly increased. I have done this. the interference pattern just fades away as the "head part" of each photon going the long way round over laps less and less with the "tail" of the part going the shorter path. (Of course this "head and tail" nonsense is just to keep me slightly in touch with what QT actually is - not understandable in human terms, only via math.)

On (2)
I do not know. QT is incomplete until we do. It requires something outside of the theory, which is completely deterministic in and of itself, called and observation, at least in the generally accepted “Copenhagen interpretations.”
Bohm has a very attractive alternative, but after reading one of his books on it, I fear he has a fatal flaw. Cannot go into details but he needs each of his "guiding waves" to recognize the particle it is guiding. I set a thought experiment in my mind where two electrons were in space of same guiding wave (Using device much like the two unequal path interferometer above). They also, like photons, interfere only with them selves. thus the guiding wave must somehow know which of the two electrons to "guide" I.e. all electrons can not be identical and the Pauli principle, which basically explains the shell structure of all atoms, hence all chemistry etc, goes out the window. I was really sad the day I convinced my self that Bohm's near classical theory can not be fact and reverted back to the Copenhagen school's view. Like MacM, I wish physics were more like classical experience tells us things are, but nature apparently does not care about our wishes.

PS good nite all - my bed time and may be away a few days.

for sleeper 555:
On your "
Is there a concise way to explain the relationship between quantum tunneling, quantum entanglement, and the slit experiments (if any)?"

I do not think they have much in common, exceptof course being part of the strange world of QT.

Tunneling always has quanitiy of the wave function some how (very clear in the math how, and fun to watch) leaking thru a barier that classical physics can not cross. One object can tunnel and part be in two different "wells" but it alway remains one object, in sense that if it dies it all dies.

Entanglement has two objects, somewhat like simese twins, each "knows" all about the other and has since the instant they were born together, always from a single parent, as far as i know, but do not know if this is necessary. they can be separated and only one die.

Interference slit etc can process single items (of any QT kind at least in priciple) to produce interference pattern, but if you interfer, force change, make "observation" after the single object enters the slit region, that destroys the interference (unless both get the same transformation without you getting any knowledge of where they are, their separated energies, etc.)

hope that helps.

Some things just do not make common sense, but the math describing them is very well confirmed to agree with nature, but not with your common sense. One photon does go thru two different slits, just like the QT math says it does. etc. in violation of your common sense.

Funny. It doesn't violate my common sense at all. Perhaps it is you that are ignorant after all.

If you really want to understand physics you will need to drop some of your "common sense."

No what you are saying is if you want to become a conformist, follow the herd and don't think.

in post by Billy T:

“ Originally Posted by Laika
I'm out of my depth but I don't see how an interference pattern is produced at all at detector A if there is no double slit there. ”

Agreed. that was one of the confusions in article I was referring to.
================================================== ==============

I agree that no double slit was at the detector A location. I guess I assumed there was because of the statement about interference patterns at each location. If the double slits are set up as shown in the diagrams, then only one-way communication can be achieved instantaneously.

I have another website, a graduate level QM course, that explains the Bell-state eraser in more detail. There is also a link to the published paper at the site. The experiment I listed above should still work, but the communication would be one-way according to where the double slit were located. A nonlinear beta-barium borate crystal is used to create the entangled photons. A 351.1nm photon from an argon ion pump laser is converted to TWO longer wavelength (702.2nm) photons. Yes, a single photon that is supposed to be indivisible is split. From the website:

"It is peculiar then, that the presence of the quarter wave plates causes the s photons to so drastically change their behavior. One can't help but ask, how do these photons know that we could know which slit they went through?

Quantum Erasure



Increasing the strangeness of this scenario, the next step is to bring back the interference without doing anything to the s beam. A polarizer is placed in the p beam, oriented so that it will pass light that is a combination of x and y. It is no longer possible to determine with certainty the polarization of s before the quarter wave plates and therefore we cannot know which slit an s photon has passed through. The s photons are no longer marked. The potential to gain which-way information has been erased."
http://grad.physics.sunysb.edu/~amarch/

Notice that the state of interference or non-interference at the double slit location CAN BE CHANGED FROM THE OTHER LOCATION. Same as I said before, rotate the polarizer in a Morris Code type pattern at one location, and the same code will show up as a sequence of changes from interference to non-interference AT THE OTHER LOCATION.

...
1) Either you shorten the distance the information has to travel. There are plenty of theories ranging from wormholes, warping of spacetime, ... to shorten distances in space, but they are rather hypothetical.
2) Or you resort to FTL particles such as tachyons, which are even more hypothetical and above all, now generally assumed not to exist.
...

3) U can just prove that light speed barrier is a hoax and get fundings to break the barriers.

Considering that the effect of gravity is considered by some to be almost instantaneous, like on the order of a billion times faster than light, I'm surprised that no one has mentioned the possibility of using it, or an aspect, to communicate vast distances.http://sciforums.com/showthread.php?p=640978#post640978

2inquisitive: I only have a vague understanding of the Quantum Eraser apparatus, but I think I understand the basic concept.

I strongly suspect that the system cannot be used for FTL transmission of meaningful messages, but do not understand it well enough to analyze the effects possible due to alternating between one & two slits with entangled particles.

BTW: The two slit experiment has been performed using particles other than photons According to John Gribbin, it has been done with atoms.

A single photon going though a two slit experiment does not create any pattern. It neither creates an interference pattern when both slits are open nor a circular pattern when only one slit is open. It merely results in a spot on the recording film (or other sensing device).

The patterns can be generated either by sending a lot of particles through the apparatus in a short time period, or by sending a lot of particles through one at a time over a longer time period. In neither of these cases does it seem possible to alternate the patterns in extremely short time intervals, as is required to accomplish FTL transmission of meaningful information.

I suspect that a thorough analysis would result in showing that FTL transmission of a message would not result. It certainly does not seem possible to switch from one pattern to the other instantaneously (or even close to instantaneously), even though entangled particles seem to transmit their state instantaneously (or at least FTL).

BTW: Is there any experiment which shows that entangled particles actually transmit their state information instantaneously? An experiment capable of doing so would have to establish that two spatially separated events occurred simultaneously. This seems more difficult than an experiment showing FTL transmission of the information.

Thanks for your input, Dinosaur. I was thinking of generating the patterns by using lots of particles over a short period of time. I would have to google to find if an experiment has been performed to confirm the instantaneous change of state, but that is what is always stated in QM theory, of course. I have very little knowledge of QM, its just that the stated example of instantaneous communication hit me when I read of the Bell-state quantum eraser. By altering polarization detection at one location of the entangled photons, it is stated that the pattern will change from circle to interference pattern at the OTHER location using the Bell-state eraser procedure. My idea is so simple, I know many others should have thought of it if it would work, but I was wondering WHY it would not work. Yes, it would take a good bit of time to transmit a lengthy message by Morris Code, but radio signal travel times to Mars is very long. I was thinking of a way a warning could be issued to a Mars astronaut in the event of an impending danger, like a sudden increase in deadly radiation from the sun headed their way. Besides, I know technology could greatly improve on my 'Morris Code' example, I was just wondering if the basic idea is sound.

If you can, please give a web link to a less confused, more error free discussion of the "Bell quantum erraser" You said:

"I have another website, a graduate level QM course, that explains the Bell-state eraser in more detail."

Give it.

I note that your speaking recently of "quarter wave plates" only adds to my confusion. They are used to convert circular polarization into linear (or conversely) not for blocking each other when set orthonagonally to each other.

I would like to be able to follow your arguement that FTL communication is possible, but as it is so confused, even in your prior references, this is impossible. (I have no doubt the arguement is flawed and I would like to tell you specifically where and how, but as I can not even follow it with all the confusion and errors, I can not do this.)

As I stated in the post, here is a link to a graduate-level educational site that also has a link to the original pdf version of the published paper:
http://grad.physics.sunysb.edu/~amarch/

As I stated in the post, here is a link to a graduate-level educational site that also has a link to the original pdf version of the published paper:
http://grad.physics.sunysb.edu/~amarch/Thanks for reference. The main paragraph of the abstract and the next to last “summary paraagraph” are fine, but again confusion and error in between:

For example:
“In the case at hand, the single photon has a fifty percent chance of going through the left slit and a fifty percent chance of going through the right slit.” -No. This is a classical view. It is wrong to speak this way, but if you must, then say just the opposite. I.e. Each photon (as wave) always goes thru BOTH slits.

“It seems reasonable to assume that the photon has to pick one slit to go through. Quantum mechanics must just be inadequate at providing us with all the available information.” The essence of this logic is: My ordinary classical view is correct, therefore quantum mechanics is wrong or at least “inadequate.”

“It is not possible to observe the which-way information and the interference pattern at the same time. This is an example of quantum mechanics' principle of complementarity. There are pairs of quantities which can be measured and obtained individually, but never at the same time. You can know one precisely, but then you will know nothing about the other and vice versa. - Name not tôo important but that is the “uncertainity principle” not the “principle of compemetarity” While errors like this are not of great importance, they sure do not aid creditability. BTW they do use correctly the complementary principle in the abstract as related to the wave particle duality, not measurement uncertainity.

“Photon p must be able to communicate to s through some means that is unknown to us. -- Assuming what you are trying to show is always a good idea to insure success. :rolleyes:

PS If this student were in my class, his grade would have been C- He obviouly knew (from the abstract) what he was to show, but did not understand or intentionally tried to defend the opposite, a classical view, as correct.

Well, the paper was not from a student in a class. It was published in a respected peer-reviewed Journal, Physical Review A by several authors on Feb. 20, 2002.

Double-slit quantum eraser
S. P. Walborn,1 M. O. Terra Cunha,1,2 S. Pa´dua,1 and C. H. Monken1
1Departamento de Fı´sica, Universidade Federal de Minas Gerais, Caixa Postal 702, Belo Horizonte, MG 30123-970, Brazil
2Departamento de Matema´tica, Universidade Federal de Minas Gerais, Caixa Postal 702, Belo Horizonte, MG 30123-970, Brazil
~Received 17 November 2000; published 20 February 2002!
We report a quantum eraser experiment which actually uses a Young double slit to create interference. The
experiment can be considered an optical analogy of an experiment proposed by Scully, Englert, and Walther
@Nature ~London! 351, 111 ~1991!#. One photon of an entangled pair is incident on a Young double slit of
appropriate dimensions to create an interference pattern in a distant detection region. Quarter-wave plates,
oriented so that their fast axes are orthogonal, are placed in front of each slit to serve as which-path markers.
The quarter-wave plates mark the polarization of the interfering photon and thus destroy the interference
pattern. To recover interference, we measure the polarization of the other entangled photon. In addition, we
perform the experiment under ‘‘delayed erasure’’ circumstances.
DOI: 10.1103/PhysRevA.65.033818 PACS number~s!: 42.50.Dv, 03.65.Ta, 42.50.Ar, 42.25.Kb
PHYSICAL REVIEW A, VOLUME 65, 033818"
http://grad.physics.sunysb.edu/~amarch/Walborn.pdf

Well, the paper was not from a student in a class. It was published in a respected peer-reviewed Journal, Physical Review A by several authors on Feb. 20, 2002....The reference you gave me, in your post of 27 after the hour, when I asked for a clear, error free one was:
http://grad.physics.sunysb.edu/~amarch/
It begins by stating:
"This web-page was created as an assignment for PHY 566, taught by Prof. Luis Orozco at Stony Brook University in the fall semester of 2002."
That is why I think a student made it.
I will try to look at the original paper that student was working from. Thanks for the new reference, to it.

T=cr

-mt

Q= kz

-sl

time = capacitance x resistance .................. T = CR

-MT

Oh wait... I get it. You are equating the RC time constant in exponential functions directly to time? Is that it?

HUMMM... AS I THOUGHT... anyway...

its a well known formula.... i didnt invent it... and if you knew electronics.. you would know what it means....


a small capacity.. as would exist between a space ship and a satalite at earth...

with small resistances in play.. would allow for the faster than light communication, which the thread starter was seeking...

what is subspace.? or wormholes..? if not one dimesional passageways??

and what is a line of electric flux?? a line of force???

a one dimensional line of force.......

we all ready have the means... we just dont know how to use it.

im just pointing the way.

-MT

HUMMM... AS I THOUGHT... anyway...

its a well known formula.... i didnt invent it... and if you knew electronics.. you would know what it means....

Hmmm... I suppose then that after 21 years as an electronics design engineer I know exactly what the RC time constant represents in the exponential describing the time domain response of an RC circuit, and that your statements below are...


a small capacity.. as would exist between a space ship and a satalite at earth...

with small resistances in play.. would allow for the faster than light communication, which the thread starter was seeking...

what is subspace.? or wormholes..? if not one dimesional passageways??

and what is a line of electric flux?? a line of force???

a one dimensional line of force.......

we all ready have the means... we just dont know how to use it.

im just pointing the way.

-MT

...complete and utter nonsense. I'm just trying to prevent rampant pseudoscience and ignorance.

Hmmm... I suppose then that after 21 years as an electronics design engineer I know exactly what the RC time constant represents in the exponential describing the time domain response of an RC circuit, and that your statements below are...



...complete and utter nonsense. I'm just trying to prevent rampant pseudoscience and ignorance.

I agree. I, too, have done a fair amount of work with RC circuits as well as tank (LC) circuits in filters and other applications.

This MT guy realy doesn't have a single clue as to what he's talking about. It's pure garbage through and through.

(P.S. Ignorance can be a wonderful thing for people like that. It allows them to think they know something when they actually know nothing at all. And everything would be fine - it they just kept it to themselves.)

MT seems typical of someone who wants certain things to be true or possible and uses scientific jargon (incorrectly) to support their hopes and "theories". The capacitance and resistance between ships in space somehow allowing FTL sounds cool, until you run into people who actually know what these quantities really mean.

Hi MT, When I took my first linear circuits course the lumped-circuit assumptions were covered on day one. Somehow I don't think an interstellar circuit counts as "small". Plus, reducing the impedance of free space is going to be somewhat challenging. But good luck anyway!

-Dale

i didnt say it works... and it is morons such as superluminal that likes to make statements about others in order for himself to seem larger.

it requires a completely new form of technology... technology where in we have the means to modulate the voltage of specific individual lines of force..

something we cannot do, not at this time.

people can say what they like.. i am not so insecure that i am afraid to propose things which i know full well dont work... but i know why... and so it is a matter of overcoming that which is apposing us...

morons like superluminal, would rest on whatever degrees they have and tell the 'wright' brothers that they cant fly.. and or tell 'nasa' that getting to the moon is ridiculous..

its sad really...

im just sharing ideas for your consideration... and mental enjoyment.

superluminal seems to think this is a contest... and as if he can win..

so sad.

-MT

...
morons like superluminal, would rest on whatever degrees they have and tell the 'wright' brothers that they cant fly.. and or tell 'nasa' that getting to the moon is ridiculous..

its sad really...

im just sharing ideas for your consideration... and mental enjoyment.

superluminal seems to think this is a contest... and as if he can win..

so sad.

-MT superluminal should watch the movie "Around the world in 80 days"

...

we all ready have the means... we just dont know how to use it.

im just pointing the way.

-MT Clearly stated but they cant see,

all they want to prove is that the things they wasted studying all their life was worth enough for considering them as the best to be reproduced with.

i didnt say it works... and it is morons such as superluminal that likes to make statements about others in order for himself to seem larger.

it requires a completely new form of technology... technology where in we have the means to modulate the voltage of specific individual lines of force..

something we cannot do, not at this time.

people can say what they like.. i am not so insecure that i am afraid to propose things which i know full well dont work... but i know why... and so it is a matter of overcoming that which is apposing us...

morons like superluminal, would rest on whatever degrees they have and tell the 'wright' brothers that they cant fly.. and or tell 'nasa' that getting to the moon is ridiculous..

its sad really...

im just sharing ideas for your consideration... and mental enjoyment.

superluminal seems to think this is a contest... and as if he can win..

so sad.

-MT

Insecurity has nothing to do with it. You are simply fantasizing and using terms that apparently you don't even understand. To "...modulate the voltage of specific individual lines of force.." is pure nonsense. Perhaps a phrase you picked up from some work of fiction? It sure isn't a scientific concept even in the least.

MT, Anom,

You guys make me laugh. It's people like myself who were the Wright brothers, and NASA engineers, and the people who still make the findings of science into reality! If interstellar flight is ever to be a reality, it's practical, intelligent scientists and engineers who will make it happen. Not jibbering fools who go on about "modulating the voltage of specific individual lines of force.." without a clue as to what that might even mean. If you're just a layperson fiddling with ideas, say so. I encourage that. But don't try to come off as a sage of the impending development of FTL by talking about field lines and voltage modulation.

Try learning a bit about what your describing before yammering about it.

MT, Anom,

You guys make me laugh. It's people like myself who were the Wright brothers, and NASA engineers, and the people who still make the findings of science into reality! If interstellar flight is ever to be a reality, it's practical, intelligent scientists and engineers who will make it happen. Not jibbering fools who go on about "modulating the voltage of specific individual lines of force.." without a clue as to what that might even mean. If you're just a layperson fiddling with ideas, say so. I encourage that. But don't try to come off as a sage of the impending development of FTL by talking about field lines and voltage modulation.

Try learning a bit about what your describing before yammering about it.

Good advice!!

And it just points out that there are more fools around than there are truly intelligent people. Guys like that are the very ones that claim an education actually stands in the way of progress. Most likely, that's because they were too lazy to get one themselves.

I just don't get the whole anti-science thing. It's the fucking magic wand of the modern world. People have no concept of what it's done for them. Do they understand how they would be living their (very short and generally miserable) lives without it? Clearly not. Welcome to 15th century England. Have fun!

People fear what they don't understand, even if it benefits them. Savages.

I just don't get the whole anti-science thing. It's the fucking magic wand of the modern world. People have no concept of what it's done for them. Do they understand how they would be living their (very short and generally miserable) lives without it? Clearly not. Welcome to 15th century England. Have fun!

People fear what they don't understand, even if it benefits them. Savages.

Well, I think the anti-science thing is pretty simple, really. Again, it comes from those who were too lazy to get a decent education (and from those too young to have completed one). To all of that group science IS pure magic. As you say, they don't understand it - and actually don't want to because it takes too much personal effort to study and attempt to reason rationally. Long ago it was said that "ignorance is bliss" and I cannot help but think that statement was intended to describe this particular group of know-nothings.

I also believe they actually enjoy their ignorance because it relieves them of any responsibility and allows them to spout any nonsense that pops into their tiny little minds. It also lets them ignore real facts without feeling the slightest bit of remorse. To condense the whole thing down into two common words, "they're loosers."

AMAZING... seriously... please continue... if it makes you guys feel better about yourselves...

so sad.

-MT

AMAZING... seriously... please continue... if it makes you guys feel better about yourselves...

so sad.

-MT

There's nothing amazing about it. And it is in no way intended to make the educated "feel better about themselves." What is sad is stupidity for it's own sake.

Just You Right?

-mt

it requires a completely new form of technology... technology where in we have the means to modulate the voltage of specific individual lines of force..

-MT
what is this? individual lines of force?
these "lines" do not exist in reality.
they are a graphical representation to help people better understand the subject matter

time=rc? no mosheh. impedence=rc. it also=lc

maybe you are thinking that it takes time to charge a capacitor?

Just You Right?

-mt

Sorry, but that's not enough of a question to get an answer. Want to try again a little harder, maybe?

what is this? individual lines of force?
these "lines" do not exist in reality.
they are a graphical representation to help people better understand the subject matter

time=rc? no mosheh. impedence=rc. it also=lc

maybe you are thinking that it takes time to charge a capacitor?

it does take time to charge a capacitor..

t = cr... tells you how long it takes to charge 70% of it.

and if the lines do not exist... then please tell us what electric field is..

please...

tell us what holds the electron to the proton... and why.

-MT

http://sciforums.com/showthread.php?p=957874&posted=1#post957874

HUMMM... AS I THOUGHT... anyway...

its a well known formula.... i didnt invent it... and if you knew electronics.. you would know what it means....


a small capacity.. as would exist between a space ship and a satalite at earth...

with small resistances in play.. would allow for the faster than light communication, which the thread starter was seeking...

what is subspace.? or wormholes..? if not one dimesional passageways??

and what is a line of electric flux?? a line of force???

a one dimensional line of force.......

we all ready have the means... we just dont know how to use it.

im just pointing the way.

-MT Faster than light did U mention,
http://sciforums.com/showthread.php?p=957727#post957727

it does take time to charge a capacitor..

t = cr... tells you how long it takes to charge 70% of it.

and if the lines do not exist... then please tell us what electric field is..

please...

tell us what holds the electron to the proton... and why.

-MT
If you really do know a little bit about electrical/electronic theory, Mosheh, here's an easy one for you. What are E and H fields and how are they related?

it does take time to charge a capacitor..

t = cr... tells you how long it takes to charge 70% of it.

and if the lines do not exist... then please tell us what electric field is..

please...

tell us what holds the electron to the proton... and why.

-MT
first of all, how much education do you have in electronics?

the lines do not exist. a "field" has no individual "lines"
like i said, they exist as a graphical representation, not in reality

i am not in a contest with you people...


you seem to be...

i have studied... in fact i have 7000 pages in notes i have taken during that study..

i do not have to prove anything to any of you...

some of you.. seem hell bent on proving how smart you are...

its funny really.

you like to believe lines of force dont exist... ok..

next..

i suppose youll be saying magnetic lines of flux dont exist...

seriously people.. i wonder why i waste my time.

-MT

i do not have to prove anything to any of you...

-MT
with an attitude like that, there is only one thing to say

go fuck yourself

AH... but if you dont believe in lines of electric force...


do you believe then... in lines of magnetic force???

a simple question... yes or no.??

-MT

i am not in a contest with you people...


you seem to be...

i have studied... in fact i have 7000 pages in notes i have taken during that study..

i do not have to prove anything to any of you...

some of you.. seem hell bent on proving how smart you are...

its funny really.

you like to believe lines of force dont exist... ok..

next..

i suppose youll be saying magnetic lines of flux dont exist...

seriously people.. i wonder why i waste my time.

-MT

No, it's not any kind of contest. And he's correct - the "lines" do NOT exist - they are simple representations so that one can visualize what's going on.

Apparently, you're "wasting" your time because you're getting real information form people who actually know what they're talking about. It's very clear that you don't know.

AND SO DO YOU LIGHT??? believe that lines of magnetic flux exist???

or is that my imagination as well.???

-MT

AND SO DO YOU LIGHT??? believe that lines of magnetic flux exist???

or is that my imagination as well.???

-MT
Oh, no - no bait and switch. No more answers from me until you answer the question I asked of you. Why are you avoiding it?

Your questions can be answered with a dictionary.... and so are meaningless.

i ask if you believe in magnetic lines of flux???

its a yes or no question....

are you afraid to answer it??

will it lead to a delema ... ? with the fact that you choose..... choose... not to believe in lines of electric force???

-MT

Your questions can be answered with a dictionary.... and so are meaningless.

i ask if you believe in magnetic lines of flux???

its a yes or no question....

are you afraid to answer it??

will it lead to a delema ... ? with the fact that you choose..... choose... not to believe in lines of electric force???

-MT
No, Mosheh,

Since you chose not to answer a very simple question you've made it plain that you do NOT know the answer. Now just please go away and leave the adults alone. Aren't you missing your your little wooden toys?

your wish for me to tell you what E AND h represent will not take away from the ideals of one dimensional lines of force...


no matter what you say....


you dont want to admit that you believe in magnetic lines of flux....

for to do so... leaves you open to the challenge about electric fields...

and you arent up to the task....

and google isnt helping you is it.??

ha ha... i just laugh.... its ok..

say what you like...

you dont want to face the real challenge.

-MT

your wish for me to tell you what E AND h represent will not take away from the ideals of one dimensional lines of force...


no matter what you say....


you dont want to admit that you believe in magnetic lines of flux....

for to do so... leaves you open to the challenge about electric fields...

and you arent up to the task....

and google isnt helping you is it.??

ha ha... i just laugh.... its ok..

say what you like...

you dont want to face the real challenge.

-MT
Dont do it, Dont answer them, let them remain morons.

Dont do it, Dont answer them, let them remain morons.

Ha! The little twerp just proved he's the moron by talking about lines of force yet could not answer my simple question which is related. I'm through bothering with him.

Ha! The little twerp just proved he's the moron by talking about lines of force yet could not answer my simple question which is related. I'm through bothering with him.Yeah, And I am more happy that U could not answer his question being so educated, shame on U. :p

Yeah, And I am more happy that U could not answer his question being so educated, shame on U. :p
Oh, I can answer HIS question easy enough - I'm just not going to discuss it with him personally - he's an incompetent.

The answer is NO.

Another question: are you as incompetent as he is?

Oh, I can answer HIS question easy enough - I'm just not going to discuss it with him personally - he's an incompetent.

The answer is NO.

Another question: are you as incompetent as he is?

Personally speaking, I have seen your incompetency, U call yourself Light but U ran away like a sissy after couple of post from all the questions about Light
http://sciforums.com/showthread.php?t=51619

so much so for the boost of your pathetic EGO.

U r an insult of Photons.

U r an insult of Photons.
your so dense you can absorb neutrons

this isn't even worth the post
but why do you do the things you do anomalous?

this isn't even worth the post
but why do you do the things you do anomalous?Because things that are obvious to me are oblivious to humans, in my personal life this has made me a loner so I come here to test things out, I come here to find out if someone can prove me wrong. But most of the time no one proves me wrong and that gives me a moral boost to be who I am and ignore humans and use my capacities to achive what no human could achieve before.

Thanks for asking this devious question.

After unexpectedly and unintentionally finding myself in far too many unwanted arguements in these forums, I do not want to start another one now.

However, I do want to present my humble opinion re reality of lines of force. The concept has been of great convenience to some of our most respected theoreticians in fields ( unplanned pun ) of electric and magnetic forces. I myself find the concept often very helpful when trying to understand interaction of forces and their geometric relationships in a new field theory or in a new invention.

We simply have no way of knowing if the field line concept is a true representaion of reality. Just as we cannot see them and so may say that they cannot exist because they have never been seen, we also may say that they could exist because we have never seen their absence.

In fact, the terribly complicated and convoluted quantum physics description of electric field attraction and repulsion and its reliance upon ( virtual ) photon exchange provides a shred of support for field lines being a representation of the path of said photons, from one point of view.

I personally do not care in the slightest whether existence or absence of field lines is someday proved. When amusing myself with work on theories or inventions, I use whatever visualization aid seems to help me understand how they work ( or, on rare occaisions, don't ). ;)

I urge any interested party to apply their energies to projects which are feasible and useful. Perhaps arguing about things which cannot be proved should be left to people who need some way to dissipate excess personal energies but can think of no useful way to do so.

Personally speaking, I have seen your incompetency, U call yourself Light but U ran away like a sissy after couple of post from all the questions about Light
http://sciforums.com/showthread.php?t=51619

so much so for the boost of your pathetic EGO.

U r an insult of Photons.

I have no ego issues (unlike you and the other jerk) at all. And I most certainly did NOT run away from that thread, you dummy. I treated you very kindly there and attempted to answer your questions. In fact, I made a LOT more than just a couple of posts. I also carefully explained to you how we could tell when the light was red-shifted (spectral analysis, remember?).

Your trying to label me as incompetent is very amusing - seeing clearly how little YOU actually know. And neither am I a loner like you admitted to yourself, looser! You are the one here (among others) with an openly displayed bruised ego. Go home now and see if your mommy will warm you another bottle of milk.

Hey hey hey now wait a minute.

I have no ego issues (unlike you and the other jerk) at all. And I most certainly did NOT run away from that thread,

most but not entirely right, couple of post long time back, right.

you dummy. Sure Dumbo.

I treated you very kindly there and attempted to answer your questions. In fact, I made a LOT more than just a couple of posts. Hope U counted them, I admit your contributions to the thread but then that was it, no more ego tonic, so zoom up up and away.

I also carefully explained to you how we could tell when the light was red-shifted (spectral analysis, remember?). but U failed to notice this post no. http://sciforums.com/showthread.php?p=958141#post958141
for that destroys everything your EGO needs from your past.

Your trying to label me as incompetent is very amusing - seeing clearly how little YOU actually know. Thats my point U r here to see how tall U r, but that doesnt make U any better in terms of being good.

I And neither am I a loner like you admitted to yourself, looser! Newton was a loner, so was he looser whats the relation between loner and looser, Oh I see U want to be in the pack so U dont care whats out there but what matters is how good U look in the pack. Well I aint U dear and thats not why I live.

You are the one here (among others) with an openly displayed bruised ego. Go home now and see if your mommy will warm you another bottle of milk. Yeah right, Now whos bruised.

We simply have no way of knowing if the field line concept is a true representaion of reality. Just as we cannot see them and so may say that they cannot exist because they have never been seen, we also may say that they could exist because we have never seen their absence.

when dealing with electric feilds i have not seen any evidence of "lines of force"
granted when dealing with radio waves you get "hot spots"
but that is not "lines of force"

Because things that are obvious to me are oblivious to humans, in my personal life this has made me a loner so I come here to test things out, I come here to find out if someone can prove me wrong. But most of the time no one proves me wrong and that gives me a moral boost to be who I am and ignore humans and use my capacitie