Posted on 11/26/2016 6:19:48 PM PST by TigerLikesRooster
Why quantum mechanics might need an overhaul
by Tom Siegfried 3:37pm, November 4, 2016
Nobel laureate Steven Weinberg says current debates suggest need for new approach to comprehend reality
SAN ANTONIO ? Quantum mechanics is sciences equivalent of political polarization.
Voters either take sides and argue with each other endlessly, or stay home and accept politics as it is. Physicists either just accept quantum mechanics and do their calculations, or take sides in the never-ending debate over what quantum mechanics is actually saying about reality.
Steven Weinberg used to be happy with quantum mechanics as it is and didnt worry about the debates. But as he has thought about it over the years, the 83-year-old Nobel laureate has reassessed.
Now Im not so sure, he declared October 30 in San Antonio at a session for science writers organized by the Council for the Advancement of Science Writing. (Disclosure: I am a member of the CASW board.) Im not as happy about quantum mechanics as I used to be, and not as dismissive of its critics.
One reason Weinberg thinks theres a need for a new chapter in the quantum story is that those who think everything is fine with quantum mechanics take different sides in the debates about it.
Its a bad sign in particular that those physicists who are happy about quantum mechanics, and see nothing wrong with it, dont agree with each other about what it means, Weinberg says.
Quantum mechanics stirred up consternation from its beginnings. More than a century ago, physicists such as Max Planck, Albert Einstein and Niels Bohr showed that standard 19th century physics was inadequate for explaining various features of heat, light and atoms. By the 1920s, other physicists, including Werner Heisenberg, Erwin Schrodinger, Paul Dirac and Max Born, developed those early realizations into the full-fledged quantum mechanical math that today lies at the foundation of physical understanding of just about everything. Quantum mechanics, Weinberg noted, is the basis of our understanding of not only atoms, but also atomic nuclei, electrical conduction, magnetism, electromagnetic radiation, semiconductors, superconductors, white dwarf stars, neutron stars, nuclear forces and elementary particles.
But quantum theorys explanatory power has come at a substantial price: the need to accept counterintuitive weirdness about reality that many physicists, including such pioneers as Einstein and Schrodinger, refused to accept.
One such objectionable aspect was the quantum rejection of Newtonian determinism, the belief that all events are fully determined by preceding circumstances. You can calculate exactly where a baseball will land, for instance, if you know its velocity and direction when it gets hit by a bat. Quantum mechanics, to the contrary, imposes a probabilistic element into the description of natural processes. When an electron bounces off an atom, no one can predict exactly which direction the electron will go; quantum mechanics just permits you to calculate the odds that it will go one direction or another. A mathematical formula called the wave function provides the instructions for calculating where an electron is likely to be ? when you make a measurement of the electron, you are most likely to find it where its probability wave is most intense. Repeated measurements would find a range of results corresponding to the probabilities that the quantum math specifies.
Einstein objected, saying God does not play dice. He further objected to another weird aspect of quantum mechanics, involving its description of pairs of particles separated at birth. Two photons emerging from a single atom, for instance, could fly very far apart yet share a single quantum description; making a measurement on one can reveal something about the other, no matter how far away it is.
Attempts to explain these conundrums fall into two broad categories, Weinberg said: instrumentalist and realist. Instrumentalists contend that the wave function is merely a tool for calculating the results of experiments ? theres no way to know anything more about reality. Devotees of the realist approach contend that the wave function is a real thing out in the world, evolving over time, and at a fundamental level it is responsible for whats really happening.
Weinberg finds the instrumentalist view unattractive. Its so ugly to imagine that we have no knowledge of anything out there ? we can only say what happens when we make a measurement, he says. The instrumentalist approach takes the attitude that we just dont know whats going on out there.
On the other hand, the realist view does say whats going on out there, but at the cost of enormous complexity, in the form of a countless number of independent streams of reality. Whats going on out there is a wave function that is progressing with time in a perfectly deterministic but incredibly complicated way, Weinberg says. In this view, all possible outcomes of quantum processes (that is, everything) come to pass in one stream or another (even though nobody is aware of any of the other streams, or histories).
Weinberg would prefer a reality with one history. But apart from that preference, the realist approach does not explain why measurement results observe the rules of quantum probabilities. If everything actually does happen in the various histories, there seems to be no reason why the quantum rules for probability would apply inside any one stream.
So Weinberg thinks there might be something beyond quantum mechanics, a deeper theory that introduces probabilities at a fundamental level, rather than requiring a human to make measurements to get the probabilities to show up. And there is a line of research attempting to generalize quantum mechanics along those lines. But so far a compelling theory that succeeds in generalizing quantum mechanics does not exist.
Perhaps a replacement for todays quantum theory will come together any time now. Or perhaps not. Maybe its just the way we express the theory is bad, Weinberg says, and the theory itself is right.
Or possibly a surprise is in store.
Theres always a third possibility, Weinberg said, thats theres something else entirely, that were going to have a revolution in science which is as much of a break with the past as quantum mechanics is a break from classical physics. Thats a possibility. It may be that a paper from a graduate student tomorrow morning will lay it out. By definition I dont know what that would be.
In any case, Weinberg observed, theres a danger in evaluating any theory in terms of contemporary philosophical prejudices. Newtonian gravity, Weinberg noted, was itself regarded as unacceptable by many scientists of his era.
Newtons theory seemed unpalatable to his contemporaries, Weinberg said. Newtonian gravity was action at a distance, with no tangible pushing or pulling guiding the planets in their orbits. That seemed like the introduction of an occult element into science, and was rejected for that reason by the followers of Descartes, Weinberg said. Furthermore, the force of gravitation was something that couldnt be deduced from fundamental philosophical considerations and was rejected in part for that reason by the followers of Leibniz. And Newton also did away with the dreams of Kepler and others to deduce the size of planetary orbits from fundamental principles.
Yet over time, Newtons theory compiled an impressive list of successes (much like quantum mechanics has).
By the end of the 18th century, it was perfectly clear to everyone that Newtons theory was correct, or at least a spectacularly successful approximation, Weinberg said. We can take the lesson that its not really a good idea to hold new physical theories too strictly up to some preexisting philosophical standard. We have to go with it and see where it takes us ? and see whether or not perhaps we have to change our philosophical standards.
No, they claim it can be in two places at the same time.
how can you be in two places at once when your really nowhere at all- Firesign Theater
Quantum mechanics and its predecessor theories will forever need to be updated by man as more and more is learned.
Weinberg appears to be leaning to the latter. We could be subconsciously trapped in some preconceived notion, even a certain deep-rooted philosophical view.
Quantum physics works — statistically. I have always thought it was a sign of mental infirmity to claim this statistical representation is somehow the real reality. That is like saying all of the mass of a planet is REALLY at its center of mass. After all, that’s the way Newton’s equations work.
Heisenberg was caught speeding in town in his BMW. A cop pulled him over.
‘’Sir, do you know how fast you were going?”
“No, but I know where I am.”
It’s too bad that we cannot trust any of the ‘science’ coming from ‘Science News.’ There are a wholly owned subsidiary of the Global Cooling, Global Warming, Global Climate Change, Global Climate Disruption, Globull Gloaming crowd. I used to love reading all kinds of publications, but since there is no $$$$$$ in spreading the truth of the coming Ice Age, there is no point in real science. The Great Cold will return, and there is nothing we can do but prepare.
You make a point, but the trend has been that the more experiments are done, the more quantum theory is confirmed.
There is a great deal of disagreement about the interpretation of QM and how it relates to the everyday world, but experiments aren’t helping us much there (and that’s why there is so much disagreement).
electron-ic discovery
I’ll let myself out.
God DOES play dice and His dice are loaded.
One should have expected the appearance of probability, for in pseudo-randomness, God instead of man is free to determine all outcomes.
They infiltrated most of science communities. They love to undermine their opposition from inside. By now, probably most of scientific media was taken over.
Scientists are now virtually prohibited from challenging reigning theory and find an alternative to better explain observed data, if it does not fit liberal political agendas.
A couple of years ago, the theme of International Congress of Mathematicians was "women in mathematics." Gender politics was inserted into the mathematics community.
They will stay there like leeches until they get too old and their agendas become slowly irrelevant, like old Communism. However, it will take a long time and do severe damage.
The death of communism as a live ideology led to the birth of another pernicious virus, which went onto the quest for bringing down the West from within.
Schrödinger's cat, right? I'm going with 'space/time's a solid and all exist simultaneously.
“The death of communism as a live ideology led to the birth of another pernicious virus, which went onto the quest for bringing down the West from within. “
What’s ironic about that it could very well be two former communist countries, Russia and/or China who will bring back sanity and reality back to science, and in doing so will become the new superpowers.
Today they are the least infected by cultural Marxism.
“They dont even know if quantum mechanics is feasible, or can be utilized. But they are talking about an overhaul?”
Quantum Mechanics is both feasible and utilized. Designers of today’s computer chips that I’m using to write this use quantum mechanics as part of the design process and it works.
#37 That would explain all the Windows weirdness from time to time!
It's certain all quantum models are wrong, but some are useful. Similarly all religions are wrong (including global warming); some religions are useful.
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