Are Superluminal Neutrinos Possible?

reply to post by Arbitrageur

You mean sort of a variation of the Quantum eraser experiment?

Exactly. The thing is, one would already know its state, since it is mediating between one particle of a known state and another. Of course, it is possible that it can change its state through infinite permutations, provided that it reaches the correct state when it arrives at the other end of the entanglement. This makes it spookier.

reply to post by CLPrime


That's not what i heard...

Here's a link..

www.hep.manchester.ac.uk...

And an excerpt from a book by Brian Cox The Quantum Universe.

"It seems that we must conclude that the pair of identical electrons in two distant hydrogen atoms cannot have the same energy but we have also said that we expect the electrons to be in the lowest energy level corresponding to an idealised, perfectly isolated hydrogen atom. Both those things cannot be true and a little thought indicates that the way out of the problem is for there to be not one but two energy levels for each level in an idealised, isolated hydrogen atom. That way we can accommodate the two electrons without violating the Exclusion Principle. The difference in the two energies must be very small indeed for atoms that are far apart, so that we can pretend the atoms are oblivious to each other. But really, they are not oblivious because of the tendril-like reaches of the Pauli principle: if one of the two electrons is in one energy state then the other must be in the second, different energy state and this intimate link between the two atoms persists regardless of how far apart they are.
This logic extends to more than two atoms – if there are 24 hydrogen atoms scattered far apart across the Universe, then for every energy state in a single-atom universe there are now 24 energy states, all taking on almost but not quite the same values. When an electron in one of the atoms settles into a particular state it does so in full “knowledge” of the states of each of the other 23 electrons, regardless of their distance away. And so, every electron in the Universe knows about the state of every other electron. We need not stop there – protons and neutrons are fermions too, and so every proton knows about every other proton and every neutron knows about every other neutron. There is an intimacy between the particles that make up our Universe that extends across the entire Universe. It is ephemeral in the sense that for particles that are far apart the different energies are so close to each other as to make no discernable difference to our daily lives.

This is one of the weirdest-sounding conclusions we’ve been led to so far in the book. Saying that every atom in the Universe is connected to every other atom might seem like an orifice through which all sorts of holistic drivel can seep. But there is nothing here that we haven’t met before. Think about the square well potential we thought about in Chapter 6. The width of the well determines the allowed spectrum of energy levels, and as the size of the well is changed, the energy level spectrum changes. The same is true here in that the shape of the well inside which our electrons are sitting, and therefore the energy levels they are allowed to occupy, is determined by the positions of the protons. If there are two protons, the energy spectrum is determined by the position of both of them. And if there are 1080 protons forming a universe, then the position of every one of them affects the shape of the well within which 1080 electrons are sitting. There is only ever one set of energy levels and when anything changes (e.g. an electron changes from one energy level to another) then everything else must instantaneously adjust itself such that no two fermions are ever in the same energy level.

The idea that the electrons “know” about each other instantaneously sounds like it has the potential to violate Einstein’s Theory of Relativity. Perhaps we can build some sort of signalling apparatus that exploits this instantaneous communication to transmit information at faster-than-light speeds. This apparently paradoxical feature of quantum theory was first appreciated in 1935, by Einstein in collaboration with Boris Podolsky and Nathan Rosen; Einstein called it “spooky action at a distance” and did not like it. It took some time before people realized that, despite its spookiness, it is impossible to exploit these long-range correlations to transfer information faster than the speed of light and that means the law of cause and effect can rest safe.

This decadent multiplicity of energy levels is not just an esoteric device to evade the constraints of the Exclusion Principle. In fact, it is anything but esoteric because this is the physics behind chemical bonding. It is also the key idea in explaining why some materials conduct electricity whilst others do not and, without it, we would not understand how a transistor works."

Cosmic..

reply to post by Cosmic4life


Professor Cox seems to agree with you (or, the other way around). However, I think Cox has taken Pauli Exclusion to reductio ad absurdum. He states that all electrons in the entire universe must occupy distinct quantum states, but he fails to see that his own reasoning negates this. His reason for such a statement is that, since electron probabilities never truly go to zero, no electron can be said to belong to a given atom. This, then, implies that all electrons essentially belong to all atoms, and, therefore, must all obey Pauli exclusion. However, notice what this demands: the exchange of an electron to another atom at some large distance. For the electron to be exchanged, it must, essentially, have traversed that distance. Therefore, it's not truly an instantaneous action-at-a-distance. It's just the atom's real-time reaction to being invaded by an alien electron from a distant atom.
And then there's also the fact that Fermi-Dirac statistics apply to systems in thermal equilibrium. Can we say that of atoms separated by any significant distance?
This is what happens when we start talking about electrons. Their locations are entirely probabilistic. If you want to say that what you and Cox describe is superluminal, then you also have to say that electrons, in general, are superluminal, just because their positions are probabilistic and can, generally, have instantaneous velocities much greater than the speed of light.

Our resident expert physicist(s) may be able to correct me, or expand, on this (I'm more of an armchair Relativity/Quantum theorist than a particle physicist), but that seems to be the mistake.

reply to post by CLPrime


I don't quite know what Prof Cox is implying is the nature of the transit, i personally don't see an electron or a proton or a neutron traveling anywhere.

Rather i see it as the Higgs field being the determining factor, the electrons being absorbed and created by the Higgs field or Zero-point field or Vacuum domain whichever is the preferred term.

This is just my interpretation of what he seems to be saying, i'm just an amateur Trekkie.

Cosmic..

Originally posted by CLPrime
reply to post by Cosmic4life

 

Professor Cox seems to agree with you (or, the other way around). However, I think Cox has taken Pauli Exclusion to reductio ad absurdum. He states that all electrons in the entire universe must occupy distinct quantum states, but he fails to see that his own reasoning negates this.

There's the other side of things, the assertion that the far off electron must be in the same lowest state as an isolated electron.

If the particles are entangled, then they aren't isolated, so you can get different statistics than you would if you were isolated. If you accept quantum mechanics and entanglement, then this is a necessary conclusion. Why is this a problem? If the facts are different, the results are different.

I think the reality is that you can't ever truly isolate anything, the electrons are always interacting with vacuum and real E&M fields both here and far, and in practice this destroys the entanglement over almost all reasonable timescales without special precautions---which is just what a quantum computer is trying to do.

Originally posted by Aim64C
that time.

What precedent is there that gravitational field density (and velocity, as it is derived) alters -time-?

None.

There wasn't precedent in the laws of physics before 1905, but there is a bunch of experimental evidence.

Muons moving fast decay (in our reference frame) a bunch slower than muons moving slowly, and electromagnetic waves emerging from gravitational fields have a redshift, and GPS computations gain accuracy when you include effects from gravitational time dialation, general in additional to special relativity.

The analogy from chemical reactions isn't entirely on point. They proceed "slower"---meaning that there is a lower rate when viewed macroscopically---because of a lower probability for the individual atomic reactions to happen. Does other physics all scale "slower" as temperature goes down? Not really, say x-ray lines might get narrower (more precise) but there generally isn't a large constant shift.

That velocity in inertial reference frames & gravitation affects time in all laws of physics is the key axiom from Einstein, and had to be validated with experiment. More specifically it is the assertion that all fundamental laws of physics must have certain mathematical properties which is the real core of things.

Originally posted by mbkennel
If the particles are entangled, then they aren't isolated,

OK, fair enough. But are they entangled?

If I'm understanding Brian Cox's argument and your question correctly, is Cox assuming all the electrons in the universe are entangled, or something along those lines?

And I'm not quite sure from reading your answer...do you agree or disagree with Cox's interpretation?

I admit my understanding of the Pauli exclusion principle comes from university websites such as these:

abyss.uoregon.edu...

Pauli exclusion principle:

The Pauli exclusion principle is an assertion that no two electrons in an atom can be at the same time in the same state or configuration, proposed (1925) by the Austrian physicist Wolfgang Pauli to account for the observed patterns of light emission from atoms. The exclusion principle subsequently has been generalized to include a whole class of particles of which the electron is only one member.

www.chem.purdue.edu...

Pauli exclusion principle: no two electrons in the same atom can have the same set of four quantum numbers.

And these may be oversimplified explanations, but they don't seem to support the claims of professor Cox.

This isn't the first case where I've seen Brian Cox take something which looks like a sound principle of physics, and apply an interpretation to it which doesn't make sense, at least to me. I can't recall what the other case is right now, but what I do remember is that it made me question if I can believe everything Brian Cox says. I'm not convinced that I can.

reply to post by Arbitrageur


What Cox is describing is definitely entanglement. He says electrons in separate atoms are forced to exist in unique quantum states, because, as he states, electron probabilities never truly go to zero and, therefore, electrons cannot be said to "belong" to a given atom. This would require that every electron in the universe follow the Pauli exclusion principle mutually with every other electron. His solution to this is to theorize that the energy (n) states of different atoms are slightly out of phase, so-to-speak. This results in electrons having ever-so-slightly different n-numbers relative to each other. So he says.

Originally posted by CLPrime
reply to post by Arbitrageur

 

What Cox is describing is definitely entanglement. He says electrons in separate atoms are forced to exist in unique quantum states, because, as he states, electron probabilities never truly go to zero and, therefore, electrons cannot be said to "belong" to a given atom. This would require that every electron in the universe follow the Pauli exclusion principle mutually with every other electron. His solution to this is to theorize that the energy (n) states of different atoms are slightly out of phase, so-to-speak. This results in electrons having ever-so-slightly different n-numbers relative to each other. So he says

My understanding is this:
a) technically Cox is correct
b) this correctness is in no way superior to saying that a very distant star (make a pick, some billion light years away) exerts some gravity pull on each and every ATS member, thus forming a bound and correlated system. And it's true, isn't it?

Look, muons detected in experiments at CERN have their trajectories bent by the gravitational pull of Phobos. Do we account for it? Do we need to?

If we look at the wave functions, and the distances involved in Cox' example, we'll quickly find out that well, the "effect" is vanishingly small. There are just so many correction you will need to make if you want to be really @nal that this one does not stand out at all.

Thanks for replying buddhasystem.

I wasn't quite sure what to make about Cox's argument, that helps put it in perspective.

reply to post by DJW001

Of course, there is observational proof that velocity alters time. Short lived particles produced in a quantum interaction traveling at relativistic velocities last much longer to an "outside" observer than they should. Even at the macroscopic level, at non-relativistic velocities, time dilation can be observed, albeit measured in nanoseconds.

You are confusing 'rate' and 'time.'

Time as a causal structure is different than time as a rate of state transitions.

A refrigerator does not alter time. It alters the rate of molecular activity.

Demonstrate that velocity and/or gravity have the ability to affect causal time structure any more than a refrigerator does.

Are you catching on to this simple concept, yet?

In order to understand why time "slows down," perhaps you should go back to the "elevator experiment."

Child.

Perhaps you should actually pay attention to relativity.

Gravity propagates at the speed of light. Accelerating to the speed of light means you begin to 'ride' your own 'gravity wave' - which is exactly why you see an increase in mass. This also explains time dilation for massive objects at velocity.

www.desy.de...

In general relativity, on the other hand, gravity propagates at the speed of light; that is, the motion of a massive object creates a distortion in the curvature of spacetime that moves outward at light speed. This might seem to contradict the Solar System observations described above, but remember that general relativity is conceptually very different from newtonian gravity, so a direct comparison is not so simple. Strictly speaking, gravity is not a "force" in general relativity, and a description in terms of speed and direction can be tricky. For weak fields, though, one can describe the theory in a sort of newtonian language. In that case, one finds that the "force" in GR is not quite central—it does not point directly towards the source of the gravitational field—and that it depends on velocity as well as position.

General Relativity -is- Special Relativity; simply an extrapolated situation that is further elaborated upon. The entire principle of Special Relativity naturally follows the baseline concepts established in General Relativity.

I figured this out when I first read the theory of General and Special relativity. The two are one in the same.

In sum, there is no reason to believe that things cannot travel faster than light, provided that it is possible to travel "backwards" in time. Objecting to this possibility based on concepts like causality is a philosophical objection.

I've already described how this is not really an issue.

There are two problems. First - the presumption that time exists. This is incorrect. Only quantum states exist. From a given set of states, only a possible number of previous states could have existed, and a possible number of future states. It is impossible to determine exactly which state one came from, or which one you will be going to. Thus - the universe, even, has limited 'knowledge' of its own past and future (a factor Relativity does not account for).

As such - causality is a moot point to begin with.

Second - nothing can move, classically, faster than the speed of light.

However - there are several potential ways around this. First - presuming classical motion, a 'barrier' will form at a certain energy state (this will actually differ for each massive particle in the system). At such a point, additional energy added to the mass will result in quantum tunneling or Cerenkov Radiation. Spin-0 particles will tunnel to the other side of the barrier at super-luminous speeds, before resuming a sub-light velocity. Others will simply rebound off of the barrier in a burst of Cerenkov Radiation.

Second - in non-classical movement, one simply 'shifts' to a separate location. IE - one ceases to exist at one location, and simply resumes existing at another within the next available frame of time. Exactly how one would do this is a civilization-changing question. However, causality does not preclude this from happening in either quantum or relativistic terms.

phys.educ.ksu.edu...

www.sciencedaily.com...

Quantum tunnelling (or tunneling) is the quantum-mechanical effect of transitioning through a classically-forbidden energy state.

"Aim... you're talking about quantum mechanics in a discussion about relativity. You really don't know what you're talking about, do you?"

The world is not exclusively relativistic or quantum mechanical. Both must hold relevant. In fact - Relativity must derive from Quantum Mechanics. Failure to explain how is merely a failure on our part.

reply to post by CLPrime

The Pauli Exclusion Principle says that no two fermions can occupy the same quantum state. It says nothing about atoms in the universe occupying the same energy state.

To be anal, as you put it:

Every possible region of space is unique as it exists relative to various influences (it could indeed be argued that mass, and the separation thereof, creates space; though that is approaching a philosophical debate that would be very difficult to design an experiment to demonstrate).

Thus - the Pauli Exclusion Principle inherently applies to all fermions (which would include atoms and that which they comprise).

We may not account for it in our experiments or our metric systems - but it does, indeed, matter when discussing such topics.

Though, I suppose it could be, theoretically, possible to manipulate objects in the universe in such a way as to create two identical regions of space. Though the complexity of such an endeavor and the amount of absolute knowledge and ability it would require is so implausible as to place it out of the range of consideration.

Anyway - the point is, if you want to get right down to it - each region of space represents a unique energy state in and of itself.

reply to post by Aim64C

You are confusing 'rate' and 'time.'

Time as a causal structure is different than time as a rate of state transitions.

A refrigerator does not alter time. It alters the rate of molecular activity.

Demonstrate that velocity and/or gravity have the ability to affect causal time structure any more than a refrigerator does.

Are you catching on to this simple concept, yet?

No. Please provide your definition of the word "rate."

Originally posted by Aim64C

reply to post by DJW001

Of course, there is observational proof that velocity alters time. Short lived particles produced in a quantum interaction traveling at relativistic velocities last much longer to an "outside" observer than they should. Even at the macroscopic level, at non-relativistic velocities, time dilation can be observed, albeit measured in nanoseconds.

You are confusing 'rate' and 'time.'

Time as a causal structure is different than time as a rate of state transitions.

Verbiage aside, do you agree or do you not, that the observed rate of decay depends on the velocity of the particle moving in the reference frame where such measurement is done?

reply to post by DJW001

No. Please provide your definition of the word "rate."

Time (as a causal string of events) and rate (one cyclic activity as compared to another) are two different things.

As I have said, multiple times - time can be kept with chemical reactions utilizing a number of different principles of chemistry. These are highly dependent upon temperature. Altering the temperature changes the number of cycles that will transpire during another activity it is compared against.

This, however, is not an instance of time manipulation.

Making the assumption that velocity and/or gravitational fields have the capacity to alter causal time is as logically flawed as assuming temperature alteration has that capability.

reply to post by buddhasystem

Verbiage aside, do you agree or do you not, that the observed rate of decay depends on the velocity of the particle moving in the reference frame where such measurement is done?

You're smarter than this, Buddha.

What evidence is there that suggests relativistic distortion is a distortion of causal time?

We can play word games all day long. The only difference between a chemical clock and an atomic clock is the cyclic mechanism used to derive the metric of time. Atomic clocks are less susceptible to changes in temperature, because they measure subatomic phenomena within the nucleus of decaying atoms.

How is a decaying atom any more or less of causal relevance than shifting covalent chemical bonds?

That is to say - how is it any more relevant to claim measuring a change in the rate of atomic decay as being evidence of time alteration than it is to claim a refrigerator does the same?

If I place an atomic clock next to a black hole, how is that any different - in terms of causality - than putting a piece of meat in the refrigerator? (on that note - putting meat in a refrigerator, then placing it next to a gravitational singularity would make for an interesting long-term storage solution... millenia of storage with no freezer burn... Maybe that's how Wendy's does their never-frozen beef...)

Of course - since everything we know to exist functions based off of subatomic activity - developing an experiment to test whether or not the effects of relativity extend to causality is nearly impossible (or, at least, well beyond my knowledge). It's like trying to lick your elbow, or observe the outside of a box that you cannot escape.... or reach the event horizon (presuming such a thing exists - I'm mildly skeptical, as Relativity assumes a space that is infinitely divisible; which is not the case; and the prospect has some interesting implications for the extreme ends of Relativistic mathematics - such as my earlier descriptions of what happens when a massive object approaches the speed of light).

To be honest - I'm starting to wonder if you all are deliberately being obtuse in this matter. It's... really... not that complicated of a subject. I had Relativity down pat within a week of researching it in my spare time in sixth grade. The problem is that Relativity is, and always has been, incomplete.

Einstein never really finished the theory, and recognized it as misrepresenting reality at the extreme ends of its mathematics (black holes, near-C moving objects, etc). This was even more apparent when "spooky action at a distance" (entanglement) indicated there could be such a thing as non-local information and/or material transfer. This is absolutely unacceptable in strict General and Special Relativity - where causal violations can potentially occur.

The potential for causal violations would appear to be an artifact of our own construction brought about by our extrapolations on an incomplete theory that, knowingly, does not accurately describe behavior at extreme metrics.

"Aim, black holes exist."

Very large, dense masses that do not radiate much in terms of energy exist. Whether or not they are a singularity is yet to be seen. I believe it was Bose, or Bohr, who had a theory on what was, essentially, a black hole as being a bose-einstein condensate from hell. Ah, yes: iopscience.iop.org...

Anyway - I digress, considerably.

reply to post by Aim64C

Time (as a causal string of events) and rate (one cyclic activity as compared to another) are two different things.

As I have said, multiple times - time can be kept with chemical reactions utilizing a number of different principles of chemistry. These are highly dependent upon temperature. Altering the temperature changes the number of cycles that will transpire during another activity it is compared against.

This, however, is not an instance of time manipulation.

Making the assumption that velocity and/or gravitational fields have the capacity to alter causal time is as logically flawed as assuming temperature alteration has that capability.

You still haven't explained what you mean by "rate." Now you have to explain what you mean by "cycle." Incidentally, where did I ever use the expression "causal time?" If you have bothered to read and understand what I have been posting, you would know that I consider time to be just another axis, interconvertable with the three we habitually conceive. I think you are the one who is being obtuse, and suspect you are desperately trying to use semantics to "prove" that quantum foam is an absolute, universal frame of reference; the aether.

reply to post by DJW001

You still haven't explained what you mean by "rate." Now you have to explain what you mean by "cycle."

I must admit, this is a trial of my patience.

Look. How do we measure time?

We don't measure time. We can't. We compare one cyclic event to another. This can be a pendulum, the charging and discharging of an inductor, capacitor, or both. It can be the vibrations of a piezoelectric crystal, or the decay of an atomic nucleus. Or it can be the number of times we play ring-around-the-rozie with the other planets. It really doesn't matter.

The point is - we don't actually measure time. It is an arbitrary concept we have established based on the events that occur within the reference of another event.

We base our concept of time around the relative activity of the world around us.

Incidentally, where did I ever use the expression "causal time?"

I apologize. I will not over-estimate you again.

Causal time is exactly what the term implies. Time as it relates to causality. "Absolute time" - if you will. IE - the time that, if you could navigate, would allow you to be your own grandfather, or whatever.

All other metrics of time are relative and derived from the former description of how we measure time.

If you have bothered to read and understand what I have been posting, you would know that I consider time to be just another axis, interconvertable with the three we habitually conceive.

What you consider time to be is irrelevant to what time actually is.

Sticking a piece of chicken in the refrigerator keeps it, chemically, from aging at the same rate as a warmer piece of chicken. No matter how extreme the effects (even with imaginary mathematical situations), this will never result in a causal violation because we know time does not really slow or stop with the slowing and/or stopping of molecules.

Because we have nuclear decay and electronic circuitry that will continue to produce a reliable metric of time even though other sources indicate it has stopped.

Now, we suddenly want to say that: "well.. atomic clocks slow down when we start speeding up... so it must be time that is slowing down."

It's a senseless leap of logic.

I think you are the one who is being obtuse, and suspect you are desperately trying to use semantics to "prove" that quantum foam is an absolute, universal frame of reference; the aether.

Relativity doesn't work without a universal frame of reference.

Two objects collide at a combined relative velocity of 1.2C.

Resolve that without assuming a universal frame of reference. You can't, without selecting an arbitrary region of space to set as your reference frame (logically, the point of impact.) The 'problem' is that each object will appear to collide at the same velocity (0.6C, respectively). However - if one object is traveling 0.9C, and the other 0.3C - the energy released from the impact is going to be far greater than two 0.6C objects colliding (presuming equal mass of the two bodies).

For the speed of light to be constant - there must be a universal frame of reference. What is it moving constant to? Everything. Our perception of time slows in such a way as to negate the effects relative velocity to light. Traveling at 0.99C will still have you watching light zip past you at the same speed it always does.

An object can, also, never move faster than the speed of light. That inherent speed maximum establishes an absolute minimum. Having an absolute minimum more or less means there is always an arbitrary point of immobility.

There doesn't have to be an aether. It exists as a virtual and logical construct that can be derived, if by no other means, through interaction with massive objects.

Whether it exists in the form of a real construct, or it is simply the extrapolation of the data contained within each particle about its mass is a philosophical debate; much like the debate over virtual particles (and... in some cases, whether or not particles considered to be real are, in fact, virtual).

reply to post by Aim64C

Relativity doesn't work without a universal frame of reference.

Two objects collide at a combined relative velocity of 1.2C.

Resolve that without assuming a universal frame of reference. You can't, without selecting an arbitrary region of space to set as your reference frame (logically, the point of impact.) The 'problem' is that each object will appear to collide at the same velocity (0.6C, respectively). However - if one object is traveling 0.9C, and the other 0.3C - the energy released from the impact is going to be far greater than two 0.6C objects colliding (presuming equal mass of the two bodies).

Two objects cannot collide with a combined velocity of 1.2 c. All velocities are relative, hence, "Theory of Relativity." I suggest you re-read Einstein, paying careful attention to the implications of the Lorentz Transformations.

reply to post by Arbitrageur


I have yet to grasp how superluminal communication causes causality problems. I find the explanations on Wikipedia a bit vague. The article there sais "From this it is argued that, statistically, Bob cannot tell the difference between what Alice did and a random measurement (or whether she did anything at all).". The critique made sense to me, which is that the proofs seem to be circular. Interestingly, I had a similar idea as the opponents of the no-communication theorem, which is using ensembles of entangled particle pairs. This seems to solves the statistics issue. Though I could not find any experimental results.

So for me the jury is still out. Its too bad that, at least according to Wiki, this isn't being experimented on that much, with the reason that it is in violation with theory.

Originally posted by Aim64C
reply to post by buddhasystem

 

Verbiage aside, do you agree or do you not, that the observed rate of decay depends on the velocity of the particle moving in the reference frame where such measurement is done?

You're smarter than this, Buddha.

I know. But it's always good to revisit the basics.

How is a decaying atom any more or less of causal relevance than shifting covalent chemical bonds?

I couldn't care less about "casual relevance". I would observe that decay of a nucleus is just another case of a transition, and in broad sense is not different from a chemical process.

That is to say - how is it any more relevant to claim measuring a change in the rate of atomic decay as being evidence of time alteration than it is to claim a refrigerator does the same?

The fridge will alter the parameters of chemical reactions even for an observer in the same fridge. And incidentally it won't affect nuclear processes. I just don't see the relevance of the fridge analogy. I posit that it's not relevant at all.

If I place an atomic clock next to a black hole, how is that any different - in terms of causality - than putting a piece of meat in the refrigerator?

On many levels. For example, carbon dating of the pieces of beef will show different reading after they finish their storage cycle.

Your point