Quantum entanglement is another quantum principle with no physical equivalent, that lets quantum entities restarting at the same point unify into one system, so any physical event instantly affects them all at any distance. Thus while physical particles must be in the same locality to interact, entangled photons affect each other instantly even when light years apart.
For example, when a Cesium atom emits two photons in opposite directions, they entangle into one system with net zero spin. Both photons still spin up or down randomly, but if one is measured spin up, the other instantly becomes spin down. Experiments find it always so, but if each photon’s spin is random, how does the other instantly know to be the opposite, at any distance?
Einstein called this spooky action at a distance because it was faster-than-light, and so suggested an experiment to disprove it (Einstein, Podolsky, & Rosen, 1935). When the test was made, based on Bell’s theorem, it supported entanglement, even for photons too far apart to connect at the speed of light (Aspect, Grangier, & Roger, 1982). This was one of the most careful experiments ever done, as befits the ultimate test of quantum theory, and it found that entanglement does occur faster than light, despite Einstein’s objection.
How then can an event at one location affect another at any distance? According to particle physics, it can’t, but by the evidence, it does. If two photons heading opposite ways are separate particles that spin randomly, why can’t both spin up, or both spin down? Quantum theory insists that all the initial spin is conserved but gives no clue as to how. Nature could conserve spin by making one photon spin up and the other down from the start, but apparently this is too much trouble. Instead, it lets both photons spin either way, until one is observed, then instantly adjusts the other to be the opposite, wherever they are in the universe. Entangled states, now common in physics, have no physical explanation (Salart, Baas, Branciard, Gisin, & Zbinden, 2008).
Particles can’t entangle as quantum theory describes but processes can. We see two photon particles leaving a Cesium atom (Figure 3.23a) but what if one process runs both? When a Cesium atom emits two photons at a point, their processing can merge and then just spread as it always does, so instead of each photon going its own way, the same processing is going both ways. Just as one photon can take many paths and let a later event decide the one it took, two photons can go both ways and let a later physical event decide which went which way.
In network terms, the photon servers just share their client jobs, so the wave front going left is run by two servers, as is the one going right (Figure 3.23b). The entangled photons look and act like separate photons, but actually each is half spin-up and half spin-down.
This explains why the initial total spin is always conserved. When a network overload ends the merger by restarting server, this leaves the other to run the other photon with the opposite spin. Which server restarts is random, as it depends which one is available, but spin is always conserved because the processing before and after a physical event is always the same (Figure 3.23c).
Entanglement is then non-local for the same reason quantum collapse is, that client-server effects ignore the network transfer rate that defines the speed of light. By analogy, just as a laptop can instantly change any pixel regardless of its screen position, the photon servers are equidistant to all points on the screen of our space, so it doesn’t matter how far apart the entangled photons are.
Entangled photons adjust spin instantly because both photon servers share the work of both wave fronts, so are already connected to handle any physical event. Nothing has to go anywhere, as when either server restarts, the other just carries on running the other wavefront, so entanglement doesn’t contradict Einstein’s speed of light limit.
Super-conductivity is also based on the entanglement of many electrons, so every electron is run by their merged servers. Electricity then flows with no resistance because, in effect, no electrons move in a superconductor metal. Bose-Einstein condensates let any number of quantum entities merge in this way.