Measure for Measure: How Does Familiar Experience Emerge From Quantum Reality?

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The audience at the Skirball Center was treated to a quadruple-header of competing physics theories on Thursday night at “Measure for Measure: Quantum Physics and Reality,” part of the Big Ideas Series at the 2014 World Science Festival. A lineup of renowned physicists met to weigh various competing interpretations of quantum mechanics, and proclaim which ones they found wanting.

The lingering debate is intriguing, given that, as panel moderator and Festival co-founder Brian Greene noted, quantum mechanics is hardly a new arrival; the basic framework was set in place by the 1930s. “Yet 80 years later, there are still questions that are ripe for discussion at the foundation of the subject—questions that are still controversial,” Greene said.

To panelist and Caltech physicist Sean Carroll, the quick and near-universal acceptance of quantum mechanics is an intellectual marvel. “Every part of it seemed to violate some cherished notion that we had clung to,” he said. “Quantum mechanics comes along and just changes all of the rules.”

But there is still the “measurement problem”; the fact that, despite the fact that the elegant equations of quantum mechanics give rise to probability waves describing the likelihood of a particle’s position, we still experience reality, and the particles in it, as defined points. Does the wave function of a particle really collapse when we look at it? Or is there some other kind of relationship between wave and particle?

The four panelists and Greene sifted through four proposed solutions to the measurement problem: the De Broglie-Bohm theory, the many worlds interpretation (also known as the Everett formulation), dynamical collapse theories, and a new arrival on the scene called Quantum Bayesianism, nicknamed QBism.

Under the Bohmian interpretation of quantum mechanics, it’s not that the wave function collapses into a position; both wave and particle exist, with the former is a guiding force for the latter.

“You’ve always got waves, you’ve always got particles,” says Rutgers University physicist and mathematician Sheldon Goldstein.

But Carroll wasn’t a fan.

“Faced with the measurement problem, the philosophers instantly want to add new physics; the physicists are like, we just need better philosophy,” Caroll said (borrowing the words of University of Oxford philosopher of physics David Wallace). For Carroll, the fact that Bohmian theory has to add more equations and concepts into the mix is a sign of weakness. “I believe in a much leaner and meaner version of quantum mechanics, so I just think that none of this is necessary,” Carroll said.

His preferred interpretation is the many worlds theory, in which there are various branching realities that account for all predictions on the probability wave. This approach, Carroll says, basically just trusts the current equations that we have are accurate.

But Ruediger Shack, a Royal Holloway, University of London mathematician, was skeptical: “My worry is that in a theory in which anything happens, we are not saying anything about the world we are in.”

The third possible solution to the measurement problem, dynamical collapse, posits that wave functions really do collapse unpredictably. On the subatomic level, this collapse happens rarely enough to be negligible, but when you get to the macroscopic level (things we see with our naked eyes), the sum of all those wave function collapses adds up to our superficially stable reality.

“This approach is more or less the most pedestrian, straight-forward” approach, Columbia University philosopher and physicist David Albert said. When solving equations yields the puzzling problems that don’t quite line up with observations, “the obvious thing to do is to think about modifying these equations.”

Carroll said spontaneous collapse came along with too many weird and unnecessary consequences for his taste: “If it turned out to be true, I would probably retire.”

In QBism, a lot of the mess in quantum mechanics can be solved by accounting for the presence of the observer him or herself. As mentioned before, the ‘B’ in QBism stands for Bayesian, referring to a branch of statistics that, although it’s come into greater use in recent years, remains a little controversial. This is because it adds a somewhat subjective element to science; Bayesian analysis factors in “prior probability,” or a guess at what the outcome of an experiment’s result will be, based on previous data.

When you apply Bayesian principles to quantum mechanics, interesting principles arise. In this interpretation, the wave function is not independently, objectively real; it is the mathematical tool a scientist uses to bet on where the particle is located. A single particle may have several different wave functions if it is observed by several different observers.

Once a scientist measures a particle’s position, “there is no collapse problem,” Shack said. “The probability becomes useless; it has done its job, and we don’t need it any longer.” It’s not hard to see why this idea spooks some scientists.

Just how long will physicists refuse to agree? Will one of the four solutions to the measurement problem presented here eventually reign supreme? The outlook is far from certain: Goldstein thought that, in another century or so, quantum mechanics might be replaced by something entirely different. Carroll predicted that 50 years from now, 97 percent of working philosophers/physicists will have settled on an interpretation of QM.

“Come back to the World Science Festival 2100 to see if the predictions are borne out!” Greene joked.

Photo Credit: Greg Kessler

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2014_quantum_275
Date: Thursday May 29, 2014
Time: 08:00 PM-09:30 PM
Venue: NYU Skirball Center for the Performing Arts
Moderator: Brian Greene
Participants: David Z. Albert, Sean Carroll, Sheldon Goldstein, Ruediger Schack

Throw a baseball and you can track its arc across the sky without disturbing it. Scientists don’t have that luxury with quantum particles. When no one is looking, a particle has near limitless potential: it can be nearly anywhere. But measure it, and the particle snaps to one position. This transition from the fuzzy quantum world to the sharp reality of common experience is as vital as it is controversial. How do objects shed their quantum weirdness when measured? Join a debate of current theories, including tales...[Read more]

17 comments
eltodesukane
eltodesukane

My preferred interpretation is the many worlds theory.

But I don't see much difference between
- the Born rule interpretation: collapse of the wave function,
 (random collapse, according to some probabilities)
- the many-worlds interpretation: branching of the wave function,
 (random branch selection, according to some probabilities)

In both case we have a deterministic theory with a probabilistic measurement.
The measurement problem is present in both cases,
(random collapse or random branch selection)

Many say the meaning of probabilities is unclear in the many-worlds interpretation.
But I don't see a problem, it is the probability we go down some branch.

KSeanProudler
KSeanProudler

I find it mind boggling that today's physicists have not figured this all out as of yet. They all are currently viewed as being intelligent people but either they do not agree with each other or at the very least they do not find the answers, thus they are on the wrong track. If you follow the track of truth, you can't go wrong. Nothing can stop you.

Thus, what exactly are these tracks that they are currently following ?
Where do they lead ?

It is sad to say, but still to this day, most people choose to be no more intelligent than their eyeballs and their ears. Thus they believe what they see, and they also accept what they hear.

In turn they miss the obviousness that it is absolutely impossible for a car to stop ( zero motion ), then start ( be in motion ), and stop again ( back to zero motion ). How the heck can they miss the obviousness that all cars are always moving at the speed of light within that 4 dimensional environment known as Space-Time. All that can be done is change the direction of travel of that cars constant motion within the 4 dimensional environment known as Space-Time.

If you examine motion properly, by following the path of truth, you soon end up with a full understanding of Albert Einstein's Theory of Special Relativity along with creating all of the mathematical equations which are related to Albert Einstein's Theory of Special Relativity. No education in physics is required at all to do so. When you complete your analysis of motion you then investigate the world of physics, and it is then that you surprisingly discover that your work produces the exact same outcome as Albert Einstein's.

After that you encounter 4 dimensional events and the laws of physics that govern them. Then you scratch your head and wonder why these laws of physics are not in today's physics books since they resolve all current questions concerning Quantum mechanics. Instead you only find the laws of physics which relate to 3 dimensional events.

RonaldPatrickMarriott
RonaldPatrickMarriott

The Quantum world "Dark energy" Telsa "Cosmic energy"  is made from a high energy photon created by a lightning product named Relativistic Perturbation Mantle, I made a discovery in Lightning physics that revealed the very centerpiece in the reproduction cycle for many things in the universe...Dark matter producing Dark energy and earths biosphere...
"Relativistic Perturbation "Mantle".

The explanation is not all here but the generality. Paper is on the way. 

When hydrogen sits at an high altitude weightless environment of lightning, it allows a disc of antihydrogen fusion to be created. In the construction process this fusion creates rings of Carbon, Liquid oxygen cooling the fusion back to carbon sealing and surrounding a 2 dimensional 12 foot disc of fused negative energy (anti-hydrogen fusion). This combination traps the energy allowing for the conversion of the first carbon ring to high energy photons "dark energy" and then disappears "dark matter" only to reappear (as seen on NASA video) when the fusion is cooled back to our dimension as a Sprite. The photons produced is considered our Aether and allows the "Spooky" qualities for quantum physics and Compton Scattering, When Mantle consumes the first carbon ring it allows the paramagnetic Liquid Oxygen to rush in producing a Sprite above storms. This witnessed event is documented and backed by current sciences. Mantle for short produces Gamma rays found by NASA's FERMI satellite during Sprite production. PAMELA satellite found the anti-protons around the Van Allen belt produced by Mantle's energetics discharge. Mantle's reproduction will lend efforts to traveling as dark energy exceeding light speed "Warp" travel, wormhole production and dimension technology. The release of charged liquid Oxygen is converting to Air/water for the atmosphere and electrons for the Ionosphere. This will supply us with clean water and energy any place on earth or space.
These advancements of the human race in the areas of Food production, Computer storage using Dark energy, battery tech., Transportation, Infrastructure, Medical, Space Travel and Dimension Building using high energy particle physics from my discoveries.

Ellen Tabor
Ellen Tabor

My brain turned to scrambled eggs during this presentation...thank you, WSF!

eltodesukane
eltodesukane

@KSeanProudler  SR (Special relativity) and GR (general relativity) certainly do not "resolve all current questions concerning Quantum mechanics".

As far as we know, Quantum mechanics seems far more fundamental than GR, and incompatible with GR.

somewheresouth
somewheresouth

@KSeanProudler What do you mean, it is impossible for a car to stop? Perhaps you are just using the wrong frame of reference...


What evidence do you present for the statement that "If you follow the track of truth, you can't go wrong."?


If you have resolved "all current questions concerning Quantum mechanics" I would like to see your mathematical proofs. And while you're at it, you could prove the existence of solutions to the Navier-Stokes equations. I hear the prize for that is a million dollars.

Bill Vintage 1948
Bill Vintage 1948

@KSeanProudler Regardless of that, light is made up of wavicles. If you set up an experiment to determine whether you are dealing with particles or waves, the experiment will agreeably give you both. 
..
Thus, it is problematic to try to claim that one answer is "the truth." 
..
The smaller the universe you examine, the stranger and more ambiguous
it seems to be.
..
Shows like "Sliders" explore speculative experiences which probably cannot
and never will arise. It is fun to play with, though. "Quantum Leap" was
another fun series. Yes, it would be neat if I could jump back into my 
own body at the age of ten and then live my life forward from that point
with all of my memories from my previous run-through intact. What would
I do with that knowledge?  Obviously, I would make quite a bit of money
and have a more pleasant adolescence. Then, eventually, I would arrive
at my present age. In the new reality, though, I would have no motivation
to leap back to the age of ten again, so what would balance the "me" 
that disappeared from the old reality?  I don't think people ... their souls,
or whatever we are .. can just vanish. Equations need to balance. 
..
Most people I hear talking about Quantum Mechanics are just speculating
based on no information at all. The discipline does not seem to teach you
much of use about the universe but it does seem to reveal quite a bit about
the people who are speculating about it.



CedeBooflawkr
CedeBooflawkr

That a million bucks for one episode pretending to be smart is proof he is smart.

KSeanProudler
KSeanProudler

@somewheresouth @KSeanProudler  Sorry but math is not a specialty of mine.

The first step I take is to figured something out, and it is only then that I convert it into an equation. For example my analysis of motion produced a complete understanding of Einstein's theory of Special Relativity and produced all of its equations. The equations were simply an outcome. See my videos 1 -> 9 ( approximately 1 1/2 hour long total ) at  https://www.youtube.com/watch?v=KKAwpEetJ-Q&list=PL3zkZRUI2IyBFAowlUivFbeBh-Mq7HdoQ


(Mod Note: Please do not use URL shorteners. See the community guidelines for more details.)


Here, you will note that a car, or a spaceship for instance, is constantly in motion at the speed of light. All that can be altered is the direction of which it is traveling, within the 4 dimensional environment know as Space-Time.

CedeBooflawkr
CedeBooflawkr

Without a clear understanding and use if QM we would not have this digital age. Without understanding this mechanics neither the lasers nor the transistors that make this email feasible.

Was not sure what to make of your Back to Future scenario. It relates to relativity not QM. As to speculating, there is a lot of that by celebrity scientists like Carroll and yes by others who -because they get their beliefs from such celebrities and tabloids that they are featured in - are wrong.

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