Single Photon Double Slit Diffraction

There are many different ways to show that a single photon is actually a superposition of both slits in the double slit experiment and this was a particular good one.

Double slit single photon with microscope

The author has done a really good job with his double-slit microscope with a HeNe laser and a CCD to image the diffraction pattern. He only missed a few details in his experiment, which also showed excellent single-slit as well as double slit-diffraction. It was very clever to simply lower the beam intensity in order to show single photon behavior and so this is an experiment that I could do with my microscope and laser as well.

In his explanation, he described a dipole source as spherical source in all directions, but of course a dipole is a planar and not a spherical source. This does not really change any of his conclusions.

He did not talk about the fact that the emitter and detector were in resonance for the lifetime of the emitter, which was about 1 ns or so for a 632.8 nm HeNe at 0.3 mW with a 1 GHz bandwidth. Each single photon has a 1/e coherence length of 300 mm and so the emitter and detector are close enough for quantum phase correlation. His diagrams incorrectly show very short photons while the actual HeNe photon is in fact much longer, especially as an amplitude, which is sqrt of the intensity length.

The single photon width corresponds to the 1.5 mm HeNe beam width and so a single photon always goes through both slits as long as the beam diameter covers both slits. Therefore, this is not a mystery at all and the true mystery is why does anything ever behave like a classical particle at all. The simple answer is that it is the decay of the quantum photon resonance that makes a photon classical. That is, it is the decay of this source-detector quantum resonance at the detector that makes the quantum photon a classical particle.

Finally, he mentions that the single slit diffraction also means that the single photon interferes with itself and this is true. He suggests that the single slit acts like a resonant chamber and this is exactly correct. In fact, there is a short and quite measurable delay in the photon transit through a slit because a photon lives longer in the slit.

All in all, a very nice demo!

Quantum Gravity Black Holes

Quantum matter action results in a causal set universe where space and time emerge from a sprinkle of random quantum photon resonant paths. The quantum gravity of matter action is Lorentz invariant and therefore completely consistent with the measurements of Science. However, matter-action interpretations of those measurements are quite different from spacetime interpretations.

This is especially true for the gravity black hole singularity of Science since gravity black hole singularities do not have a basis in quantum gravity until now. This is largely due to the nature of the black-hole singularity and the sprinkled photon resonances from which spacetime emerges do not have any singularities.

Gravity relativity is a body centered force in spacetime that curves or warps spacetime around that body. Thus, bodies follow the straight-line geodesics in warped spacetime and so there is no spacetime gravity force, just gravity warping of spacetime.

In matter action, quantum gravity is a result of the random photon geodesic resonances that complement the quantum geodesic resonances that bind charge matter. The matter-action causal set shows not only the photon geodesic resonances that bind quantum charge, matter action also shows those photon geodesic resonances that bind each body to the universe. Instead of gravity relativity warping spacetime, quantum gravity is the result of bodies shadowing each other's universe geodesic bonds. Thus quantum gravity force occurs along body centerlines and so quantum gravity is then a center-of-mass force and not actually a body-centered force. 

A quantum black hole is then consistent with all measurements of black holes, but a quantum black hole is much more interesting than the singularity of a spacetime black hole. Photon geodesic resonances deflect around black holes because of the gravitational red shift and constant speed of light. However, there are still quantum resonances that occur between a black hole and an emitter and absorber of light. 

A quantum black hole still has the very slow decay of cosmic time as a spiral decay, which has no meaning in spacetime relativity. The spiral decay in cosmic time of a quantum black hole is very reminiscent of the interpretation of a black hole as an eternal collapsing object without an event horizon. Thus, quantum black holes are the natural outcome of a all collapsing matter in the matter-action universe.

The quantum black hole is really not black at all and, just like any quantum body, not only absorbs light as heat, but also reflects and transmits light to emitters as well as other black holes. The Ricci tensor of relativity shows the effect of matter on spacetime, but the random red shifts of photon geodesic resonances sprinkled into spacetime correspondingly reveal the presence of matter. Photon resonance geodesics are simply causal links between bodies that are the underlying structure of matter action from which space and time emerge as gravity relativity.

The quantum causal set of a black hole incorporates the same causal set emitter pair geodesics as does all of reality. Of course, the emitter superposition only decays with quantum black hole absorption and it is only then that there is an arrow of time.

Quantum black holes, just like all matter, have both reversible quantum resonances as well as irreversible quantum decays. While reversible quantum resonances represent superpositions that are the basis of reversible atomic events without time's arrow, irreversible quantum decay is the basis for the very slow cosmic time arrow for universe decay. Black holes absorption are a universal heat sink that ultimately determines the irreversible atomic time arrow for each photon geodesic.