Quantum physics study shows future events can affect the past.

[Achwienichtig]

http://secondnexus.com/technology-a...-backward-and-the-future-can-affect-the-past/

Interesting read. Essentially, they beefed up the split screen test to include two screens. The second screen was put into place only after the particle (in this case a helium atom) had passed through the first screen. Depending on whether or not the second screen was put into place, the particle exhibited different behaviors while passing through the first screen, despite the second screen's placement taking place after the fact.

Of course, we will all need to wait a while to see the verdict of the scientific community with repeated testing, but it seems to corroborate with quantum physics in general.

 

[fromderinside]

Since observing is after the fact inserting the second filter could move the filter from it particle observable attribute by the second grid into a wave function. As I see it the problem with this study is that the single filter always produces result A and the double filter always produces result B. Now if one could get either A or B with a single filter then always get B or A depending on the the first filter state (can't happen since it takes place much too rapidly). I'm probably wrong in my understanding since I'm not a physicist.

 

[barbos]

Is it Delayed Choice Quantum Eraser?
I was under impression that experiment was actually done already.

And no, you can't affect the past.

 

[Achwienichtig]

This article does a better job at explaining it.

Professor Truscott's team first trapped a collection of helium atoms in a suspended state known as a Bose-Einstein condensate, and then ejected them until there was only a single atom left.

The single atom was then dropped through a pair of counter-propagating laser beams, which formed a grating pattern that acted as crossroads in the same way a solid grating would scatter light.

A second light grating to recombine the paths was randomly added, which led to constructive or destructive interference as if the atom had travelled both paths. When the second light grating was not added, no interference was observed as if the atom chose only one path.

However, the random number determining whether the grating was added was only generated after the atom had passed through the crossroads.

If one chooses to believe that the atom really did take a particular path or paths then one has to accept that a future measurement is affecting the atom's past, said Truscott.

So, with only one laser grid in place, the particle would select one path. However, when the second laser grid recombined the two paths, after the moment when the particle should have already selected one path, the measurements indicated that the particle had in fact traveled both paths.

In short, the addition of the second grid at t2 determined the behavior of the particle at t=1.

 

[ronburgundy]

So what exactly are the various assumptions being made to infer that T2 affects T1?

And how definitively certain do we have reason to be in these assumptions? For example, the quote implies that we must assume the "the atom really did take a particular path". Also, Achweinichtig's interpretation assumes that we can be certain about "when the particle should have already selected one path".

Is it more probably that one of these or another required assumption is mistaken, or that T2 really impacts T1?

 

[fromderinside]

This article does a better job at explaining it.

Professor Truscott's team first trapped a collection of helium atoms in a suspended state known as a Bose-Einstein condensate, and then ejected them until there was only a single atom left.

The single atom was then dropped through a pair of counter-propagating laser beams, which formed a grating pattern that acted as crossroads in the same way a solid grating would scatter light.

A second light grating to recombine the paths was randomly added, which led to constructive or destructive interference as if the atom had travelled both paths. When the second light grating was not added, no interference was observed as if the atom chose only one path.

However, the random number determining whether the grating was added was only generated after the atom had passed through the crossroads.

If one chooses to believe that the atom really did take a particular path or paths then one has to accept that a future measurement is affecting the atom's past, said Truscott.

So, with only one laser grid in place, the particle would select one path. However, when the second laser grid recombined the two paths, after the moment when the particle should have already selected one path, the measurements indicated that the particle had in fact traveled both paths.

In short, the addition of the second grid at t2 determined the behavior of the particle at t=1.

My problem is with the consistency with which the particle select the same path whenever it the test is run. That being true it matters not whether the second grid is inserted randomly it will always result in the two path 'selection'.

 

[Speakpigeon]

Is it Delayed Choice Quantum Eraser?
I was under impression that experiment was actually done already.

And no, you can't affect the past.

Of course you can affect the past.
EB

 

[barbos]

Is it Delayed Choice Quantum Eraser?
I was under impression that experiment was actually done already.

And no, you can't affect the past.

Of course you can affect the past.
EB

Please demonstrate.

 

[Achwienichtig]

Of course you can affect the past.
EB

Please demonstrate.

That's what the article is about. Supposedly researchers have demonstrated just that. They created a cause linked to an event that happened prior to the cause. They reversed the order of cause and effect on an infinitesimal level. Nobody's arguing we're going to develop time travel machines from this.

 

[Achwienichtig]

So what exactly are the various assumptions being made to infer that T2 affects T1?

And how definitively certain do we have reason to be in these assumptions? For example, the quote implies that we must assume the "the atom really did take a particular path". Also, Achweinichtig's interpretation assumes that we can be certain about "when the particle should have already selected one path".

Is it more probably that one of these or another required assumption is mistaken, or that T2 really impacts T1?

I'm trying my best not to interpret the article, only to summarize. Could there be a faulty assumption being made somewhere? I'm sure there could be. I'll leave it up to science to determine.

 

[PyramidHead]

Please demonstrate.

That's what the article is about. Supposedly researchers have demonstrated just that. They created a cause linked to an event that happened prior to the cause. They reversed the order of cause and effect on an infinitesimal level. Nobody's arguing we're going to develop time travel machines from this.

I know so little about any of this, but how much can they extend the window between the first and second screens? At this point, the photon is only causing something to happen a tiny fraction of a second ago (after passing through one screen but before the other one randomly is inserted), right? So, what if they made a very large version of the apparatus with enough of a delay between the screens that the causation would be detectable on a macroscopic level? Or maybe that makes no sense?

 

[skepticalbip]

So what exactly are the various assumptions being made to infer that T2 affects T1?

And how definitively certain do we have reason to be in these assumptions? For example, the quote implies that we must assume the "the atom really did take a particular path". Also, Achweinichtig's interpretation assumes that we can be certain about "when the particle should have already selected one path".

Is it more probably that one of these or another required assumption is mistaken, or that T2 really impacts T1?

I'm trying my best not to interpret the article, only to summarize. Could there be a faulty assumption being made somewhere? I'm sure there could be. I'll leave it up to science to determine.

So far, anyone describing quantum events begin with a faulty assumption. Their descriptions assume the event has to do with either particles or waves because we understand both from our macro world but don't understand the physical nature of the micro world. Electrons are neither particles nor waves but treating them as one or the other, depending on the application, is useful. However, we don't have an understanding of their true physical nature. If we did understand then the double slit experiment may be self evident rather than as mind blowing as it currently is.

I would wait a while before considering this release significant. Such articles generally turn out to be the result of over zealous (sloppy) researchers and/or reporters writing on something they don't understand. Just remember that a couple years ago Indian researchers announced that they had found FTL neutrinos? It turned out to be a bad connection in their test equipment.

 

[Juma]

Electrons are neither particles nor waves but treating them as one or the other, depending on the application, is useful. However, we don't have an understanding of their true physical nature. If we did understand then the double slit experiment may be self evident rather than as mind blowing as it currently is.

On the contrary. We have an extremely good understanding of particle physics today. There is nothing mind blowing as soon as you stop force macroscopic concept unto microcosmos.

 

[bilby]

I would wait a while before considering this release significant. Such articles generally turn out to be the result of over zealous (sloppy) researchers and/or reporters writing on something they don't understand. Just remember that a couple years ago Indian researchers announced that they had found FTL neutrinos? It turned out to be a bad connection in their test equipment.

Yeah, I knew that result had to be wrong, even before I read their paper.

Wait, what?

 

[barbos]

Please demonstrate.

That's what the article is about. Supposedly researchers have demonstrated just that. They created a cause linked to an event that happened prior to the cause. They reversed the order of cause and effect on an infinitesimal level. Nobody's arguing we're going to develop time travel machines from this.

No, they did not. They merely repeated what was done before, the same mis-interpretation of QM.

 

[Achwienichtig]

That's what the article is about. Supposedly researchers have demonstrated just that. They created a cause linked to an event that happened prior to the cause. They reversed the order of cause and effect on an infinitesimal level. Nobody's arguing we're going to develop time travel machines from this.

No, they did not. They merely repeated what was done before, the same mis-interpretation of QM.

So when the article says the test has never been done before, I assume you have evidence to show that it has been done before?

Enlighten us.

 

[Achwienichtig]

I would wait a while before considering this release significant. Such articles generally turn out to be the result of over zealous (sloppy) researchers and/or reporters writing on something they don't understand. Just remember that a couple years ago Indian researchers announced that they had found FTL neutrinos? It turned out to be a bad connection in their test equipment.

That is the way with all research. Tests need to be repeatable, and other explanations need to be explored.

The paper at least got through one peer-reviewed journal. It is, at the very least, news.

 

[barbos]

No, they did not. They merely repeated what was done before, the same mis-interpretation of QM.

So when the article says the test has never been done before,

They always say that.

I assume you have evidence to show that it has been done before?

Enlighten us.

you can enlighten yourself using wikipedia

 

[barbos]

In general all these experiments are results of a faulty assumptions about nature of particle-wave duality.
They assume that particle "decides" to behave one way or another at certain time, for example when it passes through apparatus arranged certain way, but in reality "decision" is done at the latest possible moment so to speak.
So nothing is "decided" until everything is actually measured.
Basically they ask the same wrong question and get amused every time by weird (in their interpretation) results.
Another interesting aspect to all these experiments is that if you treat all these experiments classically (photon is an electromagnetic wave) then nothing remarkable is happening. As I said, trouble starts when you try to attach QM in there.

 

[Achwienichtig]

Barbos, this is an actual excerpt from the study's synopsis.

Our experiment confirms Bohr’s view that it does not make sense to ascribe the wave or particle behaviour to a massive particle before the measurement takes place.

Source: http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys3343.html

Hmmm . . . Sounds exactly like what you said.

I know. I'm just as surprised as you to find out that peer-review published researchers are just as smart as a wikipedia learned intellectual like yourself!