Hi Brandon:

Why don't you answer the question on my last post. Tom and the reference link I posted said that when they measured without looking at the results, the probabilities did not collapse. Do you think they are not telling the truth? Can you prove that?

Claudio

First, I suggest some of you to read Where Did the Weirdness Go? by David Lindley.

Claudio,

Prove? Come on man. I can tell you that most physicists believe this to be a fallacy, misinterpreted, and not even associated with physics. Misinterpreting is easily done when it comes to experiments and theories. A limited view of an observer for starters. When scientists speak of observers, we're not referring to a cognitive mind, human or other. We're simply stating that when a measurement is done, it is done via interactions of the physical world.

I read that YEARS ago, a long time ago, anything new?
Love
Bette

Brandon:

With all the respect, I don't know if you are noticing you are being close minded, like other physicists. This is not a problem of interpretation, if Tom and the reference I gave are right, then that means the observer has to be Consciousness (a conscious observer, not just a particle or a mechanical device), not what you are saying. This is not quantum any more, the probabilities are this:

1. Either you are wrong.
2. Or Tom and the reference I quoted are lying.

If you cannot prove 2., that means you are definitely wrong.

Claudio

The measurement effect. With sublime understatement, this phenomenon is referred to as "the measurement effect."

When we measure (or detect, or see, or quantify, or determine, or otherwise gain knowledge of) something at the quantum level, the very act of measurement will have an effect on the thing itself.

To all intents and purposes, the act of a sentient being in seeking a measurement will cause the thing to have a property which can be measured, and thereby produce a definite property that can be measured.

Since around 1927, the standard quantum mechanical explanation for the difference between results in the double slit experiments particularly, and for the measurement effect generally, is that in one set of experiments, we know (or more precisely, we can in principle know)[2a] which slit the electron went through; and in the other set of experiments, we don't know (i.e., we cannot know even in principle)[2a] which slit the electron went through. This conclusion is one facet of the "Copenhagen interpretation" of quantum mechanics (so named because it was developed by Niels Bohr's institute located in Copenhagen, Denmark), which represents the closest thing to a consensus among physicists for the last seventy years or so.

The difference is whether we know. The difference is whether we choose to have the information available.

Conversely, if we do not demand to know which slit the particle went through, no particle need appear at either slit; and so we have not caused there to be any particle, and now there is no particle; and if there is no particle at either slit, the system remains free to roam the universe in whatever form seems most pleasing to itself.
And all of this is determined at the time we demand the knowledge, not at the time we institute any mechanical processes for obtaining the information.

Contrast this with the initial results from sending electrons through the apparatus (p. xx).

What happened to our interference pattern? It went away. Instead of an interference pattern, with all of its problems of interpretation, we now have a straightforward particle distribution. By detecting particles at the slits, we have changed the result at the back wall. Somehow, detecting particles at the slits has had two effects: (1) it has caused there to be particles at the slits despite the fact that, based on our previous results, we were expecting something (who knows what) with a wave-like nature; and (2) it has caused the particle that we presumably started out with to behave entirely like an innocent little particle from start to finish.

Why?

We would like to think that the particle detectors at the slits are affecting the passage of the electron -- perhaps deflecting it, or modifying it's path, or in some other way influencing the experiment. We could accept such an explanation. But that does not seem to be the case. A series of experiments have been conducted to test just such a hypothesis, and the results are uniformly negative. I will quickly run through some of the more ingenious attempts to isolate and remove any possible influence stemming from the detectors located at the slits.[2]

1. Turn off the electron detectors at the slits. Suppose we take our modified double slit set up -- with electron detectors at the slits -- and leave everything intact. But, we will conduct the experiment with the electron detectors at the slits turned off, so that we will not actually detect any electrons at the slits.

The result upon analysis: an interference pattern at the back wall. So it seems that mere passage through the electron detectors at the slits does not affect the electron, so long as those electron detectors are not functioning.

2. Leave the electron detectors on, but don't gather the information. Suppose we take our modified double slit set up -- with electron detectors at the slits -- and still leave everything intact. And we will keep the electron detectors at the slits turned on, so that they will be doing whatever they do to detect electrons at the slits. But, we will not actually look at the count of electrons at the slits, nor will we record the count at the slits in any way, so that we will not be able to obtain any results from these fully-functioning electron detectors.

The result upon analysis: an interference pattern at the back wall. So it seems that the electron detectors located at the slits do not themselves affect the electron, even when the equipment is fully functioning and detecting (in a mechanical sense) the electrons, so long as we don't obtain the results of these measurements.

3. Record the measurements at the slits, but then erase it before analyzing the results at the back wall. Suppose we take our modified double slit set up -- with electron detectors at the slits -- and still leave everything intact. And we will still keep the electron detectors at the slits turned on, so that they will be doing whatever they do to detect electrons at the slits. And we will record the count at the slits, so that we will be able to obtain the results. But, we will erase the data obtained from the electron detectors at the slits before we analyze the data from the back wall.

The result upon analysis: an interference pattern at the back wall. Notice that, in this variation, the double slit experiment with detectors at the slits is completed in every respect by the time we choose to erase the recorded data. Up to that point, there is no difference in our procedure here and in our initial procedure ([pp. 15-17]), which yielded the puzzling clumping pattern. Yet, it seems that if we, in a sense, retroactively remove the electron detectors at the slits (not by going back in time to physically remove them, but only by removing the information they have gathered so that it is not available from the time of the erasure going forward into the future), we can "change" the results of what we presume is a mechanically complete experiment, so far as those results are determined by a later analysis, to produce an interference pattern instead of a clumping pattern. This is mind-boggling.

4. Arrange the experiment so that we can make an arbitrary choice at some later time, after the experiment is "complete," whether or not to use the information gathered by the electron detectors at the slits. Suppose we take our modified double slit set up -- with electron detectors at the slits -- and still leave everything intact. And we will still keep the electron detectors at the slits turned on, so that they will be doing whatever they do to detect electrons at the slits. And we will record the count at the slits, so that we will be able to obtain the results. But (this gets a little complicated), we will
(1) mix the data from the slits with additional, irrelevant garbage data, and record the combined (and incomprehensible) data;
(2) design a program to analyze data coming from the slits in one of two ways, either
(a) filtering out the garbage data so that we will be able to obtain clean results of electrons going through the slits, or
(b) analyzing the mixed-up data so that we will not be able to obtain the results of electrons going through the slits; and
(3) leave it up to a visiting politician which way we actually analyze the data from the slits.

The result upon final analysis by method (2)(a): a particle clumping pattern appears from the data.
The result upon final analysis by method (2)(b): an interference pattern appears from the data.

So it seems that an arbitrary choice (represented by the politician who has no personal interest in the experiment) made hours, days, months, or even years after the experiment is "complete," will change the result of that completed experiment. And, by changing the result, we mean that this arbitrary, delayed choice will affect the actual location of the electron hits as recorded by the electron detector at the back wall, representing an event that was supposed to have happened days, months, or even years in the past. An event that we suppose has taken place in the past (impingement of the electron on the detector) will turn out to be correlated to a choice that we make in the present. Imagine that.

The proverbial tree has already fallen in the forest, and we can later choose whether or not to listen. And if we choose to listen then the falling tree will have made a noise, and if we choose not to listen then the falling tree will not have made a noise.

What is the difference? It turns out that, so far as experimentalists have been able to determine, the difference is not whether electrons were run through an electron detector at the slits. It turns out that, so far as experimentalists have been able to determine, the difference is whether the analysis of the results at the back wall is conducted when information about the electrons' positions at the slits is available, or not.

In searching for the wave-like phenomenon that must, it simply must be taking place in the unmodified electron double slit experiment, the theorists are left with the equivalent of a parent's worst nightmare: you hear the screaming and pounding and crashing of broken lamps from the child's room; but every time you open the door . . . there sits the innocent little darling like an angel, eyelashes batting, smiling beatifically (probably reading the Bible), "Yes, Mother/Father, can I help you with something?" You close the door in bewilderment, and immediately the racket starts up again. Well, the theorists know that there is something wave-like going on. They can see the indisputable evidence of waves in the interference pattern and in their extraordinarily precise predictions based on a wave model. But, every time they look for the wave itself -- there is no wave, only a particle. And, perversely, all evidence of waves simultaneously disappears!

It is because the particle interacted with the detector (a photon or whatever) that its wave collapsed.

In this note, we discussed the delayed choice experiments.
Specifically, we focussed on the role of conditional probabilities for measurements on entangled particles.
The (well-known) point stated in the introduction was
to distinguish correlation from causation. The lesson we
draw here is that this very correlation between distant
measurements does not feel their relative time ordering:
it does not distinguish between future and past. This implies backwards correlation but still precludes backwards
causation or any other tension with relativity, effectively
demystifying the delayed choice experiments.
It is important to note that arriving at our conclusions did not require introducing new physics. We only
relied on elementary quantum mechanics: not on novel
‘backwards time’ concepts, nor on any particular interpretation: we only used the Born rule ‘as is’. And it
better be so, since a careful quantum optical analysis of
any of the delayed choice experiments is in perfect concordance with experimental results - without any auxiliary/new input. Only, these quantum optical analyses
are slightly less transparent, and may leave some conceptual issues unclear and confusing. It is precisely this gap
that we intended to fill with this note. With the remarks
and intuition presented here, there really is no mystery
whatsoever in any of the discussed experiments.

I come back to the idea that you can pretty much say anything, and so long as if you have enough supporting evidence - regardless of where this evidence came from - you can get another person to believe it, too.

1. Either you are wrong.
2. Or Tom and the reference I quoted are lying.

Since every other prediction ever made by quantum theory has proved correct, we have little choice but to accept this prediction, too, as correct.

I don't think these are the only two options.

While, indeed, the person you are referencing being wrong is a possibility, Tom could also be wrong. Of course, Tom could be lying, but this set of options seems to be a setup for a false dilemma, rather than the only two options available: They could both be wrong; BrandonHedberg could be lying; Claudio could be lying...

While I do not remember Tom ever saying he was always correct, assuming he had, we could only take such a claim on faith. An open-minded skeptic would accept Tom's data and the other other data and reserve judgment until sufficient evidence had been gathered. Perhaps Claudio has done that: Or, perhaps BrandonHedberg has done that. Based on what I see here, I am unwilling to form a firm opinion on who knows what.

The long quote from bottomlayer.com is fine and interesting, but I don't understand what it proves in an empirical sense without a bunch "if" statements footnoted. Perhaps I'm missing something, but I'm not an expert on this topic. However I do have a problem with the author's logic:



On a final note (please forgive me if I have missed some of the finer points of this post) we must also expand the traditional idea of conscious observer, within the MBT crowd, to include non-human conscious observation, such as TBC. Using PMR concepts when doing Big Picture analysis of research is a tricky endeavor.