In TICM, the non-local events preceding our observation of light are time symmetric or atemporal and take place outside spacetime and are therefore not observable. Cramer’s retarded waves moving backward in time are nullified by his advance waves moving forward in time leaving behind a completed transaction that an observer interprets as a single photon exchange of energy traveling from a signal source to a receiver.
"time symmetric or atemporal and take place outside spacetime and are therefore not observable."(* citation needed)
The observation of an energy exchange takes place AFTER the the non-local events are complete so measurement does not destroy non-locality. This is probably why Cramer has little or nothing to say about the measurement problem.
Once again, I assert in plain text : Cramer's entire motivation for TIQM was to address the measurement problem.
There are many interps of QM out there of different flavors. They each have a different motivation, and sometimes their motivations overlap. For example, DeBroglie-Bohm Guiding Wave was an attempt to bring trajectories back into QM.
Cramer's TIQM has a specific ontological commitment, namely that a photon's decision to reflect or transmit is not an acausal event... (what Einstein called "God throwing dice.") but is in fact
totally determined by an Advanced Wave emitted from the absorber in the future. Therefore I assert --->
TIQM is an attempt to address the Measurement Problem.The chance of light entering or being reflected by a glass surface is not 50/50 but it ranges from nearly 0 to 100 percent and it is predictable given just the wavelength of the light and depth of the glass and Feynman explained why in simple terms in QED.
You already said this, and I already addressed it. Now you are saying it again and we are going in circles. This statement is not just "wrong" , it exhibits a profound lack of understanding of even the context of what you are reading. My job on this forum is not to give you a free education in modern physics, and so every minute I waste in my life correcting you is making me increasingly frustrated.
But let's try this.
+ QED is a wonderful book that. everyone should have it on their shelf
{heap additional praise and other info about why it was written and Feynman as a science teacher blah blah blah}.+ It's fun and other should have fun with it. I read it when I was 17.
+ QED is not NOT NOT Feynman's interpretation of Quantum Mechanics.
+ QED is NOT a textbook. It is a "gentle introduction" to Quantum Field theory of the electromagnetic force, written and targeted at a lay audience. It has no equations in it. Look at your copy of it. Zero equations. When Feynman says we "add all the arrows together" he is actually referring to a path integral. But laypersons have not sat in upper level university courses on Lagrangian mechanics and the calculus of variations : so he writes "add all the arrows". Get it?
https://en.wikipedia.org/wiki/Path_integral_formulationhttps://en.wikipedia.org/wiki/Lagrangian_mechanicshttps://en.wikipedia.org/wiki/Calculus_of_variations+ QED explains how the 50/50 probability of the photon is calculated simple terms. Yes.
+ QED most assuredly
DOES NOT tell you what causal mechanism determines how a photon behaves upon measurement. If Feynman spent a single sentence describing what CAUSES that decision, he would have been writing an interpretations of QM. But QED is not not NOT
NOT an interpretation of QM.
This non-locality that you keep blabbering about is a feature of the orthodox 1939 version of QM and most of us called it "entanglement".
1.) Entanglement is not guaranteed to happen,
2.) Entanglement does not always happen maximally,
3.) Human observers can destroy non-local entanglement anytime we want by measuring a system explicitly.
4.) We have no quantum computers in our living rooms. Why? Because a noisy warm environment can destroy the fragile non-local interactions of qubits. This is not a every-once-in-a-while thing. Decoherence is the bane of all quantum computers. Even the ones they build in cryogenic labs.
These 4 items are perfectly described and explicitly predicted by the formalism. They derive from the fact that the (states of a) Schroedinger wave is expressed in a Hilbert space, and that these things called observables will either commute or not commute in that space. When two observables are totally orthogonal you get so-called "maximal" entanglement. YOu can also have "weakly" entangled systems. Long-story short : we don't need a theory of entanglement from you nor Faradave. We already have a theory.
There is unitary evolution where long-separated pieces of the same wave function affect each other across large distances. Then there is this thing variously called decoherence, or the "Collapse of the wave function" where these formally entangled pieces of a wave function become distinct, deterministic and local particles.
Why does this occur? Does it occur at all? <----- This is the Measurement Problem.
We don't have access to Richard Feynman on this forum. But very much in the manner of Susskind, I woudl presume that Feynman was averse to interps-of-QM. One of those guys who would probably say "We don't need them". This idea that we don't need interps-of-QM at all in the first place : this ideas is a sentiment that is widely shared by many people today. I'm sorry that this forum does not have any such people to come here and chime in.
Feynman had become very comfortable -- philosophically and intellectually comfortable -- in living in a universe where totally non-determined physical events happen. He was comfortable with non-local entanglement happening. He no longer felt any inner emotional need to probe deeper and find some completely deterministic mechanism "underlying" the large-scale features of the theory.
John Cramer is different. He is one of those guys feeling something is missing from the picture. He added these Advanced Waves to the formalism , which are not in the formalism. At the very least, we know he added these backwards-in-time A-waves in order to help undergrads visualize quantum processes.