Does the Observer Affect the Superposition of Quantum Particles?

[QGary]

Hi,

I am pretty sure I am not qualified to be here. I had to look up the registration question 'what is the W in W= fx'...so if this is too ignorant a question just let me know and I will slither away

I just started poking into the general QP subject and so far have not seen an answer to two questions that keep popping into my head:

1) The act of "observing" an electron causes it to change from a possibility (anywhere in the wave) to a specific locatable particle right? What I keep wondering is, if high energy equipment is needed to do the measurement, could it not be that the measuring equipment itself is changing the equation and effecting the particle? In the discussions I have observed on this, the implication seems to be that it is the act of observation by an intelligent being that is changing wave to a specific particle/location, not the physical machinery doing the measurement..which is it? And if we say its the "observer" that is causing this, how can we be sure the measurement process is not the culprit?

2) Assuming that question one's answer is that the observer is causing the change, has this phenomenon ever been observed on larger objects?

Sorry again for my ignorance here, and let me know if this is just too simple for your discussion group.

Thanks!

 

[Dali]

Hi and welcome to PF!

In the discussions I have observed on this, the implication seems to be that it is the act of observation by an intelligent being that is changing wave to a specific particle/location, not the physical machinery doing the measurement..which is it?

It is the physical machinery. Any measurement device will have to interact in some way with the particle to be able to measure for example its position. It this interaction that disturbes the particle (or quantum system in question) in such a way that any wave-like quantum effects are destroyed. This process is nowadays understood well in terms of decoherence. Intelligent beings reading the end-result or not does not matter at all.

 

[QGary]

"It is the physical machinery. Any measurement device will have to interact in some way with the particle to be able to measure for example its position. It this interaction that disturbes the particle (or quantum system in question) in such a way that any wave-like quantum effects are destroyed. This process is nowadays understood well in terms of decoherence. Intelligent beings reading the end-result or not does not matter at all."​

OK then I am not seeing what the fuss is about the "observer" effecting the outcome of the experiment, and all the discussion about humans creating or effecting (to an extent) physical realities in the universe (IE outside our own bodies) by "mind power"?

 

[strangerep]

[...] then I am not seeing what the fuss is about the "observer" effecting the outcome of the experiment, and all the discussion about humans creating or effecting (to an extent) physical realities in the universe (IE outside our own bodies) by "mind power"?

It's utter rubbish. Lots of people latch onto a little bit of QM terminology without bothering to achieve a thorough understanding of the details, and then distort those bits into supporting their own beliefs.

Try to move past all that distraction, just as you would move past the endless babble emanating from an insane asylum.

 

[bhobba]

It's utter rubbish. Lots of people latch onto a little bit of QM terminology without bothering to achieve a thorough understanding of the details, and then distort those bits into supporting their own beliefs. Try to move past all that distraction, just as you would move past the endless babble emanating from an insane asylum.

Unfortunately true.

Genuine quantum experts like Wigner once held the view consciousness collapses the wave function. But once he heard about decoherence from some early work by Zurek abandoned it. It not that decoherence completely removes the possibility of consciousness causeing collapse, or solves the infamous measurement problem to everyones satisfaction, - its just that its very hard to see why you need such a 'mystical' position.

Thanks
Bill

 

[DiracPool]

OK then I am not seeing what the fuss is about the "observer" effecting the outcome of the experiment, and all the discussion about humans creating or effecting (to an extent) physical realities in the universe (IE outside our own bodies) by "mind power"?

I think all this crap persists because it sounds profound to say that something doesn't exist until you look at it. It's like Goldmember demonstrating how he is a swinging Dutchman and then proclaiming.."Isn't that WEIRD?" We'll, its absurd, it has nothing to do with consciousness or your soul creating some change in a quantum state or external physical reality. Any contact of one quantum system with another qualifies as an "observation." It's just that guys like Michio Kaku and Sean Carroll are pursuaded to hype this up on popular science shows to get better ratings. That's the story.

 

[DiracPool]

Oh yeah, I almost forgot, this whole fascination with "Shrodinger's cat" hasn't helped either.

 

[K^2]

Well, the fact is, absolutely anything can be an observer in the system. That's true. There is no mysticism in Quantum Mechanics. However, universe from perspective of a rock is not a terribly exciting place. The description becomes interesting only when we have an "intelligent" observer. Criterion for "intelligent" varying wildly by example. I use the term very loosely. This, of course, has nothing at all to do with QM itself; rather with psychology and how we view the world. But you can kind of see where the whole fascination starts with, and how a small misinterpretation by a layperson can cause the whole thing look like some sort of new-age power of mind type deal.

Schrodinger's Cat actually puts this whole thing right side up when you really think about it. That experiment asks you, what's the difference between a detector that measured atom's decay and observer, in this case a cat, that reacts to the measurement result, in this case by inhaling poison.

And the answer, there isn't any. A detector is a detector. Again, no mysticism. Physics doesn't care if the measurement device has degree of awareness. Superposition of the atom translates to superposition of detector, and superposition of detector to superposition of observer. Perfect symmetry. But we can discuss experience of a cat. We cannot discuss experience of a gamma radiation detector.

 

[Lino]

Superposition of the atom translates to superposition of detector, and superposition of detector to superposition of observer. Perfect symmetry. But we can discuss experience of a cat.

K^2, Can I confirm, is the cat the "observer" in your sentence?

Regards,

Noel.