Light as matter

As the photons enter the cloud of cold atoms, Lukin said, its energy excites atoms along its path, causing the photon to slow dramatically. As the photon moves through the cloud, that energy is handed off from atom to atom, and eventually exits the cloud with the photon.

"When the photon exits the medium, its identity is preserved," Lukin said. "It's the same effect we see with refraction of light in a water glass. The light enters the water, it hands off part of its energy to the medium, and inside it exists as light and matter coupled together, but when it exits, it's still light. The process that takes place is the same it's just a bit more extreme - the light is slowed considerably, and a lot more energy is given away than during refraction."

When Lukin and colleagues fired two photons into the cloud, they were surprised to see them exit together, as a single molecule.

The reason they form the never-before-seen molecules?

An effect called a Rydberg blockade, Lukin said, which states that when an atom is excited, nearby atoms cannot be excited to the same degree. In practice, the effect means that as two photons enter the atomic cloud, the first excites an atom, but must move forward before the second photon can excite nearby atoms.

The result, he said, is that the two photons push and pull each other through the cloud as their energy is handed off from one atom to the next.

"It's a photonic interaction that's mediated by the atomic interaction," Lukin said. "That makes these two photons behave like a molecule, and when they exit the medium they're much more likely to do so together than as single photons."

Read more at: http://phys.org/news/2013-09-scientists-never-before-seen.html#jCp

    " ... as Newton put it, 'For every action, there is an equal and opposite reaction.' That relativity tends to be reactive."

    While it's an unexpected pleasure to be talking about some actual physics in this dialogue, quoting from Newton's second law of motion doesn't obviate Newton's first law of motion.

    "What is the larger context; Does it balance and if so, wouldn't that balance be a universal state?"

    John, didn't I ask you to look up "equivalence principle" a while back? It would save you from a whole lot of speculation.

    Best,

    Tom

    Tom,

    I know it is heresy, but I think spacetime is model, not mechanism. It is no more causal than giant cosmic gear wheels explaining epicycles. So the question is as to what underlaying factor is being overlooked. Now I know you don't give Carver Mead much credence, but just bear with me a little and think through some of the implications of the following:

    "A ten-foot electron! Amazing!

    It could be a mile. The electrons in my superconducting magnet are that long.

    A mile-long electron! That alters our picture of the world--most people's minds think about atoms as tiny solar systems.

    Right, that's what I was brought up on-this little grain of something. Now it's true that if you take a proton and you put it together with an electron, you get something that we call a hydrogen atom. But what that is, in fact, is a self-consistent solution of the two waves interacting with each other. They want to be close together because one's positive and the other is negative, and when they get closer that makes the energy lower. But if they get too close they wiggle too much and that makes the energy higher. So there's a place where they are just right, and that's what determines the size of the hydrogen atom. And that optimum is a self-consistent solution of the Schrodinger equation."

    So what happens to the space being defined by this energy, as it contracts into atomic structure? It shrinks. It's not a force in itself, but is an effect of these quanta contracting.

    It may not be acceptable to your beliefs as to how reality functions, but it does seem more likely to me and in all our discussions, you haven't yet convinced me that spacetime geometry offers an actual, physical solution, so I find this more reasonable. Maybe I am wrong and someone will come along to point out my error, but just making the same points over and over again on the assumption I didn't hear you the first time is not a sufficient proof.

    Regards,

    John M

    John,

    I don't hold anything against Carver Mead that I don't hold against any believer in a discontinuous reality, such as Vongehr and his followers.

    The reason is right there at the top of your source: "Things on a very small scale behave like nothing you have direct experience about. They do not behave like waves. They do not behave like particles ...or like anything you have ever seen. Get used to it."

    All believers in a quantum reality independent of the classical wave function take this view. It amounts to an invitation to just believe, and click the heels of your ruby slippers.

    Even were an electron of infinite length -- (which is what the Wheeler-Feynman one-electron universe amounts to) -- the continuous uncollapsed wave function that is the Schroedinger equation would define the shape of space in a scale invariant coordinate-free continuum that is made only of space and time. One is not compelled to believe in it; its structure is complete. One is only compelled to believe things that one imagines are separate from a unitary reality.

    I am not the believer in this dialogue.

    Best,

    Tom

    Tom,

    I'm no more standing by everything someone says, whom I find a particular insight interesting. As I said, I could well be wrong. There are real physical reasons why things like length compression and time dilation are real, but I don't think it arises from the geometry, rather the geometry models it. So when these physical causes are ignored and the geometry alone is used, resulting in ideas like expanding space, but then ignoring the need for time to increase to match it in order to be relativistic, I start to think important factors are being overlooked. This is not politics to me. I'd like to think I know what is happening, but I understand my ability to know will always be finite and am willing to accept the word of the experts, but when the experts start saying things that don't even make sense on their own terms, let alone mine, then it all is open to question. To go back to a previous impasse, what is the difference between the vacuum and empty space? This is not intended as a gotcha question, but a genuine problem. I just can't walk across a bridge that doesn't exist.

    Regards,

    John M

    John,

    Push 2 gyroscopes when one's spinning and one not. You'll discover where the power is in the IQbit in my essay, and why 'unmoving' is wrong. Inertia IS momentum, but orbital angular momentum (OAM), and symmetrically balanced in a toroid (two opposing 'vortices') not a sphere. Particles 'spin' or do not exist at all!

    And I agree. 'Higgs', 'Marjorana fermions', 'Cooper Pairs', electrons/positrons, whatever condenses from the QV background does so, and due to relative motion.

    The 3D gyroscope is the 'Sagnac ring' which is a toroid. They're essential on spacecraft as they can sense 'yaw' as well as the basics. They work on a principle consistent with the DFM and the postulates of SR, NOT the 'interpretation' of SR now embedded is Tom's and so many psyche's. That seems to be the true trouble with physics'.

    Peter.

    PS; Applause for your 'space-time' definition. It's an effect not a cause.

    Therefore it behooves me to figure out another way to cross that river.

    " ... what is the difference between the vacuum and empty space?"

    What is the difference between the ether and the vacuum? If we are speaking of physical, i.e., measurable, phenomena, things that are not differentiable are identical.

    An ether does not measurably affect the propagation and transmission of electromagnetic waves. What measurable effect would one or the other -- vacuum or empty space -- produce, if they are not the same thing?

    Best,

    Tom

    Tom,

    " What measurable effect would one or the other -- vacuum or empty space -- produce, if they are not the same thing?"

    Yes, but according to the expanding universe model, empty space is expanding, while the vacuum, as measured by the speed of light, is constant. I don't see any difference, but this Big Bang cosmology is based on it. Presumably the "fabric of space" is expanding, but not the dimension of time.

    Regards,

    John M

    As it is argued, lightyears are the denominator and expansion is the numerator. To illustrate the problem, turning it around to say the expansion is the denominator would mean one is arguing, not that space is expanding, but that the speed of light is slowing down, since what took x lightyears to cross, now takes 2x lightyears to cross.

    The denominator is the unit of measure, the ruler. The numerator is how many units of that measure are described. So if we denominate the distance in lightyears, that is space. The numerator is how much of that space is in question. This is not expanding space, but an increasing amount of the measure of space, ie. distance.

    Here is the intro and first chapter of a book on ancient Egypt, that while it is a lot of anthropology, gives a very interesting exposition of the origins of formal math and organized religion, as the mutual search for and explanation of order in the cosmos. It shows on a very primitive level, the tendency to assign agency to pattern, which, in the present context, is what "the fabric of spacetime" amounts to.

    On a further note the various deities amount to the various fields/mediums/concepts, such as sky, earth, fire, etc. and how they interact, ie. relate. Consider that while monotheism replaced such forms of polytheism, it has no properties, other than agency, because there can be no other fields for it to relate. At best it is described as absolute and infinite. The variations on this theme do tend to assign some features, such as the Christian Trinity, which might possibly be construed as an analogy for past, present and future, since the Father is the prior incarnation, the Son the current and the Holy Ghost as amorphous potential to those still suffering.

    The search for order(in pattern) continues.

    Regards,

    John M

      " ... this Big Bang cosmology is based on it."

      No it isn't, John. The big bang solution to general relativity only says that at some distant history, all the particles of matter (quarks and leptons) in the universe were very close together.

      Because it is presumed that nothing lies outside the universe, spacetime points were also assumed infinitely close at that period. That is no problem -- in a massless universe, Bose-Einstein statistics allow any number of bosons to occupy a common point. In order for a universe with more than one massive particle in it to smoothly connect on every scale, spacetime and matter would have to expand uniformly -- and this can't happen, due to two sound quantum mechanical principles: Heisenberg uncertainty and the Pauli exclusion principle.

      These two principles forbid unification of quantum mechanics (Fermi-Dirac statistics) with Bose-Einstein statistics. So the theories are cosmologically incompatible.

      General relativity cosmology, however, has the advantage of being complete to within a very tiny distance of the first moment, t = 0. A unification energy is assumed.

      Time is inseparable from the fabric of space -- the best hope for a continuum theory is that nothing except time and space is required for a complete coordinate-free description of reality at all times and all scales.

      Best,

      Tom

      Tom,

      How do you go about defining "close" if the very nature of space is the question at issue?

      If these points simply expand away from each other at some stable speed of light, that is an expansion in space, ie. increasing distance, not of space. Where does the "vacuum" come from, if it's not the "expanding space" and if the expanding space is truly relativistic, why doesn't the speed of light increase, since it always goes the same rate in a vacuum?

      Regards,

      John M

      Peter,

      (two opposing 'vortices')

      It's not conveniently measurable, but doesn't the possibility of a neutral state fit in there somewhere? What is zero? Physics treats it as a point, but wouldn't it logically be the blank paper/empty space/the vacuum? Space does seem defined by its content, but the opposite is true as well, the content is defined by the space it occupies.

      Regards,

      John M

      "How do you go about defining 'close' if the very nature of space is the question at issue?"

      Now you're asking the right questions, John. If the nature of space is topologically continuous, such as the parallelized 3-sphere of Joy Christian's framework, "close" and "far" are artifacts of the measure criteria, not the measure space, because the topology breaks down the distinction between local and global points.

      "If these points simply expand away from each other at some stable speed of light, that is an expansion in space, ie. increasing distance, not of space."

      The only way we know that distance between bodies is increasing, is by measuring the rate of change in relations between mass points. We never measure changes in distance between spatial points -- nor could we in a relativistic model, because there is no privileged reference frame.

      "Where does the 'vacuum' come from, if it's not the 'expanding space' and if the expanding space is truly relativistic, why doesn't the speed of light increase, since it always goes the same rate in a vacuum?"

      Don't confuse the idea of "empty space" which is not actually empty ("There is no space empty of the field" as Einstein and Descartes acknowledged), with the energy of the quantum vacuum.

      Spacetime (Minkowski space) has no role to play in a quantum vacuum; any energy that is borrowed from the quantum vacuum is continuous with the spacetime field -- which supports Hawking's claim that "black holes ain't so black," meaning that they radiate energy away. A proof that all singularities of general relativity are radiated away in finite time, would prove that there is no boundary between quantum and classical domains -- just as Einstein, Bell, Joy Christian, I and countless others who reject quantum mysticism expect is the true foundation of physics.

      Best,

      Tom

      Tom,

      Remember I'm not getting the term "vacuum" from the quantum vacuum, but from "C is the speed of light in a vacuum."

      Now if this vacuum is empty space, then if that space expands, the rate of propagation of the light has to increase proportionally, in order for C to remain constant to this dimension of space/vacuum. Otherwise, it's not a relativistic situation, only an increasing distance, as measured in units derived from C. In other words, x lightyears to 2x lightyears is increasing distance, not expanding space.

      "The only way we know that distance between bodies is increasing, is by measuring the rate of change in relations between mass points."

      Exactly. What is proposed is increasing distance, not expanding space.

      Regards,

      John M

      "Now if this vacuum is empty space, then if that space expands, the rate of propagation of the light has to increase proportionally, in order for C to remain constant to this dimension of space/vacuum."

      No it doesn't.

      Tom

      John,

      As Einstein taught us, all physics is local. Locality is that which is restricted by the speed of light; i.e., a limit on the speed (and therefore the distance in a continuous spacetime) at which bodies can influence each other's motion.

      The value of this limit does not affect the global expansion of space. With no privileged frame of reference, local physics at what one imagines is the edge of the universe (though the universe has no edge) will look just like the physics in the center (though the center of the universe is any point one wishes to choose in the 4-dimensional continuum).

      We say space is expanding, because we observe mass points all moving in a general direction away from each other (thus the "center" is everywhere).

      More than that, though, the universe is accelerating. When Einstein realized (because of Hubble's result) that gravity was insufficient to halt the expansion, he accepted the solution to general relativity that sets the cosmological constant to zero -- now theorists are looking at a nonzero or even negative cosmological constant to keep the picture coherent. In spite of all that, though, local physical influences and measurements are still governed by the finite speed of light, and by the principle of uniformity this should apply to the entire universe; the range of both gravitation and electromagnetic radiation is infinite.

      Best,

      Tom