The return of Bohm's pilot wave theory

I guess on the "severely unexplained phenomena" scale, surreal is higher up than just magical. At least with magically collapsed wavefunctions there is SOME predictability. Surreal is well...just crazy!

"Of the many counterintuitive features of quantum mechanics, perhaps the most challenging to our notions of common sense is that particles do not have locations until they are observed. This is exactly what the standard view of quantum mechanics, often called the Copenhagen interpretation, asks us to believe. Instead of the clear-cut positions and movements of Newtonian physics, we have a cloud of probabilities described by a mathematical structure known as a wave function. The wave function, meanwhile, evolves over time, its evolution governed by precise rules codified in something called the Schrödinger equation. The mathematics are clear enough; the actual whereabouts of particles, less so. Until a particle is observed, an act that causes the wave function to “collapse,” we can say nothing about its location. Albert Einstein, among others, objected to this idea. As his biographer Abraham Pais wrote: “We often discussed his notions on objective reality. I recall that during one walk Einstein suddenly stopped, turned to me and asked whether I really believed that the moon exists only when I look at it.”

But there’s another view — one that’s been around for almost a century — in which particles really do have precise positions at all times. This alternative view, known as pilot-wave theory or Bohmian mechanics, never became as popular as the Copenhagen view, in part because Bohmian mechanics implies that the world must be strange in other ways. In particular, a 1992 study claimed to crystalize certain bizarre consequences of Bohmian mechanics and in doing so deal it a fatal conceptual blow. The authors of that paper concluded that a particle following the laws of Bohmian mechanics would end up taking a trajectory that was so unphysical — even by the warped standards of quantum theory — that they described it as “surreal.”

Nearly a quarter-century later, a group of scientists has carried out an experiment in a Toronto laboratory that aims to test this idea. And if their results, first reported earlier this year, hold up to scrutiny, the Bohmian view of quantum mechanics — less fuzzy but in some ways more strange than the traditional view — may be poised for a comeback."----------https://www.quantamagazine.org/20160517-...l-support/

(Dec 5, 2016 01:31 AM)Magical Realist Wrote: "Nearly a quarter-century later, a group of scientists has carried out an experiment in a Toronto laboratory that aims to test this idea. And if their results, first reported earlier this year, hold up to scrutiny, the Bohmian view of quantum mechanics — less fuzzy but in some ways more strange than the traditional view — may be poised for a comeback."

I would bet money against a comeback, especially since it was never widely accepted in the first place.

Quote:The authors of that paper concluded that a particle following the laws of Bohmian mechanics would end up taking a trajectory that was so unphysical — even by the warped standards of quantum theory — that they described it as “surreal.”

Soo, im thinking quantum duality.
does the particle actually cease to exist in one position & then re-appear in another.
is it the same particle and it is just assumed that it is 2 identical particles ?

i am reminded of watching HNK news live footage of the japanese harbour just after the latest big offshore quake.
the change of the tidal flow backwards and forwards.
the interconnectedness of ther water as we expereince it.. yet are particles not interconnected in the same manner ?

butterflys are etherial efeminate creatures associated with day dreams and light mental discoarse...
ironically so associated to "the butterfly effect".
almost a mysognynistic propoganda peice to undermine the physical causality of its nature....(hhmm..)
is the modern scientific mind free of gender stereo types ? (different discussion maybe).

is spooky action infact an action or re-action ?

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(Dec 5, 2016 04:08 AM)Syne Wrote:

(Dec 5, 2016 01:31 AM)Magical Realist Wrote: "Nearly a quarter-century later, a group of scientists has carried out an experiment in a Toronto laboratory that aims to test this idea. And if their results, first reported earlier this year, hold up to scrutiny, the Bohmian view of quantum mechanics — less fuzzy but in some ways more strange than the traditional view — may be poised for a comeback."

I would bet money against a comeback, especially since it was never widely accepted in the first place.

Copernicus springs to mind.
let science not be quieted by the idle macinations of power mongers set to circle the wagons of reality around their fragile egos.

(Dec 5, 2016 09:16 AM)RainbowUnicorn Wrote:

(Dec 5, 2016 04:08 AM)Syne Wrote:

(Dec 5, 2016 01:31 AM)Magical Realist Wrote: "Nearly a quarter-century later, a group of scientists has carried out an experiment in a Toronto laboratory that aims to test this idea. And if their results, first reported earlier this year, hold up to scrutiny, the Bohmian view of quantum mechanics — less fuzzy but in some ways more strange than the traditional view — may be poised for a comeback."

I would bet money against a comeback, especially since it was never widely accepted in the first place.

Copernicus springs to mind.
let science not be quieted by the idle macinations of power mongers set to circle the wagons of reality around their fragile egos.

Has nothing to do with ego and everything to do with Bell's theorem, the experimental completeness of QM, etc.. There are also inherent problems with: "Each indirect measurement yields only an approximate value, but the scientists could average large numbers of measurements to reconstruct the trajectory of the first photon."

Quote:Until a particle is observed, an act that causes the wave function to “collapse,” 

Why is it said like that? You'd almost think they're saying you'll first see the particle as a wave. Can't recall ever noticing that.  I can't see the other side of my pc monitor, what's it like back there?

(Dec 5, 2016 11:17 PM)Zinjanthropos Wrote:

Quote:Until a particle is observed, an act that causes the wave function to “collapse,” 

Why is it said like that? You'd almost think they're saying you'll first see the particle as a wave. Can't recall ever noticing that.  I can't see the other side of my pc monitor, what's it like back there?

It's important to keep in mind that the wave function is an expression of what we can know about a system, as probabilities. So there may be a spider on the back of your PC monitor, but once you look, that probability becomes either 100% spider or 100% no spider. You no longer need a probability spread to help guess at what you will find.

(Dec 5, 2016 11:42 PM)Syne Wrote:

(Dec 5, 2016 11:17 PM)Zinjanthropos Wrote:

Quote:Until a particle is observed, an act that causes the wave function to “collapse,” 

Why is it said like that? You'd almost think they're saying you'll first see the particle as a wave. Can't recall ever noticing that.  I can't see the other side of my pc monitor, what's it like back there?

It's important to keep in mind that the wave function is an expression of what we can know about a system, as probabilities. So there may be a spider on the back of your PC monitor, but once you look, that probability becomes either 100% spider or 100% no spider. You no longer need a probability spread to help guess at what you will find.

Do I need to observe the back of my monitor to know that there is actually anything behind the screen (such as a back cover, internal wiring etc)? Or do I need/not need a probability spread to help confirm everything connected with the monitor is behind the screen without actual observation?

(Dec 6, 2016 07:08 PM)Zinjanthropos Wrote:

(Dec 5, 2016 11:42 PM)Syne Wrote: It's important to keep in mind that the wave function is an expression of what we can know about a system, as probabilities. So there may be a spider on the back of your PC monitor, but once you look, that probability becomes either 100% spider or 100% no spider. You no longer need a probability spread to help guess at what you will find.

Do I need to observe the back of my monitor to know that there is actually anything behind the screen (such as a back cover, internal wiring etc)? Or do I need/not need a probability spread to help confirm everything connected with the monitor is behind the screen without actual observation?

Well, the back of your monitor is governed by classical mechanics, not quantum mechanics, so it's state of existence isn't inherently probable in nature. As we move from the quantum to classical domains, quantum decoherence makes things less probable and more concrete. My above example was only an analogy. Rest assured, the back of your monitor is actually there, even when no one looks at it.

If we have two entangled photons and spin one so its twin at the other side of the universe spins opposite then I take it the problem lies on how does the info get from to the other instantaneously. But is it really instantaneous? I read where some Chinese scientist claim that quantum particle interaction can take place upwards to 10,000 times the speed of light. Now I'm no quantum particle physicist but if were able to travel FTL than wouldn't the fastest way for me to convey information be to go there myself?

If I were able to go there myself and return FTL then would an observer from my original position actually know if I left and returned? Would time taken, if any, be noticeable for a stationary observer?

(Dec 6, 2016 11:05 PM)Zinjanthropos Wrote: If we have two entangled photons and spin one so its twin at the other side of the universe spins opposite then I take it the problem lies on how does the info get from to the other instantaneously. But is it really instantaneous? I read where some Chinese scientist claim that quantum particle interaction can take place upwards to 10,000 times the speed of light. Now I'm no quantum particle physicist but if were able to travel FTL than wouldn't the fastest way for me to convey information be to go there myself?

If I were able to go there myself and return FTL then would an observer from my original position actually know if I left and returned? Would time taken, if any, be noticeable for a stationary observer?

The difference is that the observer at one photon cannot use the information about the other to learn what their own observation will be any faster than light can travel between the two. The observer can only use QM to calculate the probability of what they will find, and only find out how that correlates to the other photon through normal communication. So in practice, the speed of light is never violated.