Typhoon wrote: ↑Sun Feb 05, 2023 3:19 am
Doc wrote: ↑Sat Feb 04, 2023 8:57 pm
Typhoon wrote: ↑Sat Feb 04, 2023 3:18 am
Requiem for a string: Charting the rise and fall of a theory of everything
String theory was supposed to explain all of [fundamental] physics. What went wrong?
This article, uncharacteristically, pulls no punches
Four years later, the Higgs was found. Supersymmetry was not. It’s now 15 years later, and there are still no signs of supersymmetry.
In fact, all the “easy” versions of supersymmetry have been ruled out, and many of the more complicated ones, too. The dearth of evidence has slaughtered so many members of the supersymmetric family that the whole idea is on very shaky ground, with physicists beginning to have conferences with titles like “Beyond Supersymmetry” and “Oh My God, I Think I Wasted My Career.”
stating the part that is not be be spoken out load.
One question that bugs me that I have never seen anyone talk about After decoherence is there recoherence? IE does the wave function come back from collapse ? And if so how long does it take? And if it doesn't, does that mean our understanding of "wave particle duality" is very different than what is imagined by Schrodinger's cat?
Decoherence explains why we do not observed QM effects at the large, everyday, scale.
https://www.youtube.com/watch?v=igsuIuI_HAQ
igsuIuI_HAQ
This is a different aspect of QM to making a measurement of a quantum system - the collapse of the wavefunction [or in my preferred understanding, the projection of the linear superposition of states onto one of its basis states].
Schrödinger's cat is probably the most misunderstood meme in popular culture.
You are the only contemporary physicist, besides Laue, who sees that one cannot get around the assumption of reality, if only one is honest. Most of them simply do not see what sort of risky game they are playing with reality—reality as something independent of what is experimentally established. Their interpretation is, however, refuted most elegantly by your system of radioactive atom + amplifier + charge of gun powder + cat in a box, in which the psi-function of the system contains both the cat alive and blown to bits. Nobody really doubts that the presence or absence of the cat is something independent of the act of observation.[9]
That presumes the cat does not observe whether or not it is alive or dead.
As I remember Quantum decoherence has been observed in Bose-Einstein condensate in the act of decohering.
As to my question I think I am doing a bad job expressing it so let me write exactly how it was a came to the question.
Thought experiment: A double slit experiment is run. There is s detector on the slits to measure which slit the photon passed through. Which of course causes the Wave function to decohere. However instead of recording this on a screen a few feet away from the slits the imaginary screen is placed one light year away(Or some large distance away ) from the double slits. Which leads to my question: When the photon is detected far far away from the slits will it still be in a state of decoherence?
It seems to me that the sum of uncertainty of Heisenberg uncertainty principle over distance/time would determine the wave functions expansion. Or alternately, once decohered is there no going back?
This is the question I have never seen addressed. I have other nagging thoughts that depend on the answer to the question. But if I am "Not even wrong", please don't spare my feelings. ;p