From: Jim Choate <[EMAIL PROTECTED]> wrote: >On Sat, 4 Jan 2003, blah wrote: > Not from the photons perspective, from a photons perspective there is > -no- time.
A photon has no "perspective". Anyone that wishes to have the short version and skip the detailed corrections to misconceptions, they may note simply that an observer in special relativity compares their results with other observers through a lorentz transform. There exists no lorentz transform by which any observer may transform coordinates to a photon, because the photon has no lorentz frame. Therefore, special relativity explicitly precludes any perspective which has been suggested as necessary for a relativistically correct description. Furthermore, since any observers which differ by a lorentz transform must give equivalent descriptions which differ by a lorentz transform, for any phenomena, requiring multiple descriptions for something defeats the entire reason for the existence of special relativity. > It is clear from Relativity that as -anything- approaches the speed > of light it's mass grows larger (photons have -no- rest mass so 0 can't > get any bigger than 0) and time -slows to zero-. It's called relativity because it assumes no absolute frame against which speeds must be referenced. Clocks _always_ keep the proper time in their own rest frame, which means that time dilation, etc., are effects seen by _other_ observers. However, a photon has _no_ rest frame. You cannot attach a clock to one. In addition, no modern text would refer to "mass increase". Mass and spin are poincare invariants. An often recommended text is "Spacetime Physics", by Taylor and Wheeler. I recommend making an investment. >> A signal carries information. You can't use quantum mechanics to >> propagate a signal faster than light. > Then explain two entangled photons and how they behave. OK. And I'll even provide an example which is quite different from the usual epr cliche at the bottom. Fisrt, however, entangled photons do not propagate any _information_ faster than than light. In other words, for puposes of sending information, it's irrelevant what you think happens "faster than light", because no information is propagated between the observers faster than light. Indeed, the photons are entangled precisely because the spins are completely indeterminate prior to measurement, so that there is no information to propagate until each observer measures the spin of their photon and cannot compare their measurements faster than light. If you want to know how this is applied to quantum cryptography, look at richard huges site at lanl: http://qso.lanl.gov/qc or charles bennett's site: http://www.research.ibm.com/quantuminfo >> If you think otherwise, allow me to refer you to the last chapter in >> "Quantum Mechanics", L. Schiff, where you will find the commutation >> relations for electromagnetic fields. > I'm familiar with it, Then, you could presumably tell me what the commutation relations are and what they mean if I were to ask? Or was that merely a lead in to repeat what what you said earlier without really acknowledging the objection except as a formality? If not, don't make such claims, since I won't hesitate to ask when I think I'm being bullshitted. > however that is taken from the perspective of the > external observer, not the photon. Now, do the math -from the perspective > of a the photons-. You are confused. Relativistic quantum mechanics is manifestly lorentz covariant, i.e., it's valid anywhere special relativity applies. Special relativity tells you that you cannot perform _any_ lorentz transform to a the frame of reference of a photon, because a photon has no frame in which it is at rest. If you think otherwise, show me the lorentz transform that accomplishes what you assert must be done. If you need the lorentz trans- forms: ct' = \gamma(ct - \beta x) x' = \gamma( x - \beta ct) or in hyperbolic form: ct' = ct cosh(A) - x sinh(A) x' = x cosh(A) - ct sinh(A) The fact that you think the physics is frame dependent, means that you don't even grasp the principle behind relativity, which is that the physics is frame independent. > Let me ask you again: This would be the _first_ time since you didn't ask _me_ before. > - How big is the cosmos to a photon? > - How does time pass to a photon? Both of those are meaningless questions which may be attributed to classical bias in thinking the photon has a well-defined location from which such a perspective is possible. You can't attach a clock on something which has no point that defines a location. >> Don't be ridiculous. Relativistic quantum mechanics is not even a new >> discipline. > I am -not- saying that it is -new-. I -am- saying that QM and Relativity > have -not- been -completely combined- and that until that happens we won't > and can't understand what is going on. As I previously pointed out, special relativity and quantum mechanics are the basis of qed, which is unparalleled in its success. You apparently do not know what qed is, how it's derived or why qed itself explains the origin of the photon. For puropses related to quantum cryptography, you don't even need to understand the photon in terms of the broken electroweak symmetry and since there was no photon prior to the symmetry breaking, gravitiation is not even an issue, as it wasn't important in any quantum mechanical aspect by the time that took place. Exactly _what_ about special relativity and quantum mechanics has not been "combined"? Be specific. > In particular I -am- saying that there is a fundamental error being made > in experiments like the 2-slit and Entangled Photons, that error is that > only -one- perspective is being looked at, the non-relativistic > perspective of the mechanism, and that the -relativiistic perspective of > the photon is being completely ignored-. You are throwing information away > -a priori-. You don't understand the origin of entanglement or relativity. Relativity tells you that any observer is capable of describing any phenomenon, since two observers only differ by a lorentz transform. As for epr photons, they are entangled precisely because the information you believe is discarded, does not exist. The entanglement occurs for the very reason that the epr pair is totally _unpolarized_. Since the epr pair is unpolarized, there is no information about any polarization to be obtained. The epr pair is a _single_ quantum state. A quantum state is a _single_ quantum state and is not separable into components without destroying the quantum state. In the parlance of quantum mechanics, the density matrix of an epr pair is not diagonal in the basis in which the measurement takes place. > That to understand these results the experimenter -must- look at the > perspective of all participants in the experiment, especially those > who experience relativistic effects. Photons do not "experience" anything. To do so, a photon would have to be capable of collecting and storing information about what it "experiences". You are anthropomorphizing the photon from a completely and classically biased perspective. Furthermore, your idea that experiments require analysis from different perspectives to be understood, is at odds with general (special) relativity which is based upon the premise that _any_ (inertial) frame is sufficient to use for an experiment, since all (inertial) frames are equivalent. [The parens should all be associated with the "special" in the first set]. I can use any frame for my analysis. According to relativity, the photon just doesn't have one. > And a photon is -always- relativistic. So is any paricle, since spin and parity are relativistic effets. That doesn't prevent me from analyzing any phenomenon in a frame of reference of my own choosing. Requiring that an experiment be analyzed in any particular frame of referecnce would be equivalent to falsifying relativity and insisting that a photon is a valid frame of reference contradicts what special relativity tells you about photons. > Reality is -observer dependent-, the mechanism observes the photon, > the photon observes the mechanism. You have a very naive notion of what constitutes photon. It appears that you can't really accept your own criteria for describing the photon as a relativistic object. If you accepted your own criteria, you wouldn't keep insisting that relativity has to be abandoned to describe it. Insisting that one give up a covariant description to obtain additional information, not to mention requiring a frame of reference that relativity tells you doesn't exist, is abandoning special relativity. > They are -not- in the same time-space frame. So? No two objects are in the same frame. Even the molecules in you body are not in the same frame, except as an approximation. This should be obvious, since there exists a finite time interval between your brain telling your foot to move and your foot actually moving. All causally related events have timelike separations. On the other hand, the photon doesn't even have a frame, so it makes no sense to say that a photon and a set of slits aren't in the same frame. > The mechanism behaves in its classical time-space frame and the photon > behaves in its relativistic time-spacef frame (the only one it has, > excepting slowing effects in BEC's). I'll assume that you mean bose-einsten condensate, here, but don't be so lazy, since acronyms are rarely unique and if you're misunderstood through your own failure to define your terms, that's your own fault. Now, as far as bose-einstein condensates go, the reason the photon propagates at a slower speed, is because the photon acquires a mass in the condensate as a result of a broken symmetry. In a superconductor, for example, the gauge invariance is broken and as a result the photon acquires a mass of about 1eV. This is the origin of the meissner effect in which the magnetic flux is expelled from the superconductor. The broken symmetry even results in a higgs boson, otherwise known as a cooper pair. Perform a search for ginzburg-landau theory of superconductors" and/or "bogoliubov-valatin transformation". > It's no small wonder the results make little sense. While there exists some aspects of quantum mechanics that are still not well-understood regarding entanglement, you haven't really addressed those. Most of the difficulty you are encountering is due to imposing a classical bias on non-classical objects and doing so inconsitently with special relativity, despsite insisting that special relativity is required to obtain a complete description. ------ An example of entanglement -------------------------- Consider a three level system consisting of a ground state and two closely spaced excited states. (any ordinary material with the following properties will do). The energies of the two excited states will be E1 and E2 relative to the groundstate and the difference in energy between the two excited states, \Delta E, is small compared with the E1 and E2, i.e.,|E2-E1 < E1 < E2. The states can be excited in several ways. An atom in the ground state may absorb a photon of either energy, so that the atom makes a transition to E1 or E2, after which it will emit a photon, of the same energy (or cascade through other states, which we don't care about here). I can produce excitations in the material of both energies by illuminating the material with light containing both frequencues, E1 = h\nu1 and E2 = h\nu2. The transitions back to the groundstate will be completely independent, and I will have emission of light with frequencies \nu1 and \nu2. The wavefunctions will be the individual wavefunctions associated with each state, so that if both states are excited independently: \Psi(x,t> = A exp(-iw1t)|1> + B exp(-iw2t(|2> A decay from E1 produces a photon with energy E1 with a probability of: |<1|\Psi>|^2 and similarly for E2. There is another way to excite these states. One may use a laser pulse which is much shorter than the wavelengths of E1 and E2. The pulse has a finite bandwidth of 1/T, where T is the width in units of time, and the frequency of the incident photons is completely indeterminate. Since the bandwidth was chosen such that h\Delta f > E1 + E2, we may excite both levels as before, except that since a photon is a single quantum state, the levels E1 and E2 may be excited coherently as a single quantum state and decay together with a common lifetime, which depends on the total E and is different from the lifetime of either state. The wavefunction for the excitation may be written: \Psi(x,t)> = exp(-iwt)[A exp(-iw1t)|1> + B exp(-iw2)t(|2>] Since the wavefunction is a single state, the state will evolve as: |\Psi(x,t)|^2 = |A exp(-i(w-w1)t)|1> + B exp(-i(w-w2)t(|2>|^2 If you multiply this out, you will notice that in addition to the terms from the incoherent excitation, you will have cross terms. The cross terms are called "quantum beats" and result from the interference between the two components of a _single_quantum_state. The state is inseparable. --
