Quantum Weirdness? It's all in your mind The night sky is a field of stars in Scientific American June 2013

This document contains comments about the article Quantum Weirdness? It's all in your mind by Hans Christian von Baeyer, In Scientific American of June 2013.
This article starts with the following sentence:

A new version of quantum theory sweeps away the bizarre paradoxes of the microscopic world. The cost? Quantum information exists in your imagination.

One major problem of this article is that sentences are not clear. Common understanding is that the fastest way to communicate is the speed of light. Quantum theory seems to claim that this is not the case. Whatever the case the solution has nothing to do with my imagination, nor with probabilities. The only way to demonstrate physical claims is to demonstrate those claims by performing an experiment. See also Reflection part 1
The article starts with the following sentence:

Flawlessly accounting for the behavior of matter on scales from the subatomic to astronomical, quantum mechanics is the most successful theory in all the physical sciences. It is also the weirdest.

This is a very bombastic sentence. Quantum mechanics is only successful at the level of the "Standard Model" explaining quarks etc.

In the quantum realm, particles seem to be in two places at once, information appears to travel faster than the speed of light and cats can be dead and alive at the same time.

At this level typical quantum mechanics is not very successful. Any way this sentence is not clear.

In 2001 a team of researchers began to develop a model either eliminates or etc. The model known as QBism for short, reimagines the entity that lies at the heart of quantum weirdness - the wave function.

The article does not give any detail about this wave function, the most important parameters and how these parameters are calculated.

If you want to predict how the electron will behave, you calculate how its wave function evolves in time. The result of the calculation gives you the probability that the electron will have a certain property (like being in one place and not another)

IMO this last sentence should be something like:

Like having a 50% chance of being in one place but not another

The issue is how do you demonstrate that such a sentence is correct.

But problems arise when physicists assume that the wave function is real.

The wave function does not have to be real. This is something similar as Laplace s transformation or z transformation. Even complex numbers fall in this category. The importance is that the predictions you make should be real and verifiable.

The Unreal Quantum

Consider again the electron, We know that each time we detect an electron, we find it in one particle location. But when we are not looking the electron's wave function can spread out, representing the possibility that the electron is in many different places at once.

When we measure an electron, assuming it collides with something, then after this collision the electron will ejected in a different direction unknown to the observer. But that does not mean that the electron is in many different places at once.

Now make a measurement again. According to the standard way of thinking, the observation causes the wave function to instantaneously "collapse" back to a single particular value.

How do you know that you measure the same electron again? Unfortunate the article does not mention this. All the rest of the sentence is rather "slippery science" . In dutch we say "je beweegt je op glad ijs". Translated "You move yourself on slippery ice"

Yet QBism says that there is no paradox. The wave functions collapse is just an observer suddenly discontinuously revising his or her probability assignments based on new information, in the same way that a doctor would revise a cancer patient's prognosis based on a new CT scan.

What a doctor does is based on physical facts, based on tests and experiments. You can not compare this type of science with the rather vaque form of science expressed by Schrodinger's Cat.

We can apply this way of thinking to the famous paradox of Schrodinger's Cat. etc The atom has a 50-50 chance of decaying within an hour, accordingly to the rules of quantum mechanics.

This has nothing to do with the rules of quantum mechanics. If you want to know what the 50-50 chance is that a certain atom decays you have to perform 1000 experiments. The outcome will give you the half life time. This is rock bottom science.

QBism eliminates the puzzle. The theory says that ofcourse the cat is either alive or dead (and not both). Sure its wave function represents a superposition of alive and dead, but a wave function is just a description of the observer's beliefs.

Our beliefs have nothing to do with science. If the wave function is something in our mind than it also has nothing to do with science. sorry. The outcome of a football match will not be different if you or any one else knows or does not know the outcome.

It is an absurdity, a megalomaniac's delusion, that one's personal state of makes the world come into being.

The human mind, in general all human activities, have nothing to do with the evolution of physical processes.

The Troublemaker

The book also documents Fuch's conviction, contrary to most scientist, that philosophy matters, not only in the way in which it influences physics but also in the matter in which it is informed by the profound insights of physics - or should be.

Philosophy (thinking) has nothing to do with the evolution of physical processes. Humans try to acquire insight in this evolution by performing experiments. Philosophy_of_science helps to establish the rules how these experiments have to be performed.

Possible Probables

Fuch's openness to philosophical concenrns becomes clear when you consider QBism forces us to reconsider what is meant by probability

Probabilities (statistics) are related how the outcome of experiments are documented. Probabilities have nothing to do with the evolution (and outcome) of physical processes i.e. experiments.

Sure the 50% probability of throwing heads with a fair coin implies something about 100 tosses, but how does that intuition helps to make sense of the proposition that "the probability of rain this evening is 60%"

Probabilities have nothing to do with intuition.
When you are throwing a coin and you predict always head the outcome of the experiments will be that in 50% of the cases you will be wrong.
When you know that in 50 out of 100 days it is raining and you predict always that it is raining on a certain day than you know that in 50% of the cases you are right. Of course that is not what we want. We want better weather prediction with a higher chance of succes. That is possible. It is possible to predict the weather much more accurate, specific for short periodes in the future, where 100% accuracy is possible. For longer periodes in the future season averages are the best. This makes weather prediction completely different from gambling.

Rewriting Quantum rules

In technical terms, the Born rule says that we can measure the likelihood of finding a quantum system with property X by taking the square of the magnitude of the wave function assigned to X

How does one "measure" this magnitude in the first place?

For Fuchs, the new expression of the Born rule provides another hint that the wave function is just a tool that tells observers how to calculate their personal beliefs or probabilities about the quantum world around them.

My personal beliefs have nothing to do with science. The way the world evolves is independent of human activities. That does not mean that there are limits to our understanding of how the world evolves. That is the case and some of those limits are based on human limited capabilities.

A new reality

In the last paragraph of this document we read:

Before the speed or position of an electron is measured, the electron does not have a speed or a position. The measurement brings the property in question into being.

A measurement performed on an electron is nothing but a process which changes the properties of the electron measured. Before the measurement at each instant and after the measurement the electron has properties unknown to the experimenter. Only at the moment of the measurement certain properties come into being, relevant only at the instant of the measurement.
Next is written:

As Fuchs put it: "With every measurement set by an experimenter's free will, the world is shaped just a little as it participants in a kind of moment of birth." In this way, we become active contributors to the ongoing creation of the universe

The meaning of this sentence (unfortunate like so many sentences) is not clear. Free will (for example) has nothing to do with quantum mechanics.

Reflection Part 1

The article tries to solve the problem in the Quantum realm (Also called Quantum Absurdity) that the cat is in a superposition of both "alive" and "dead". The QBism solution is that the wave function is just a description of the observer's beliefs. Secondly states that the cat is either alive or dead (but not both).
That may be true, but what is the physical meaning of this proposition? What are the physical consequences of the concept of superposition. And more important what have my beliefs to do with the physical reality. To describe the physical reality, the evolution of processes and the outcome of experiments (in general) have nothing to do with my beliefs nor with any human involvment.
One of the issues of the quantum theory is the concept of faster than light communication. Unfortunate the article does not address this issue nor if faster than light communication is possible. In fact the central issue is to demonstrate that faster than light communication is possible.

To demonstrate the issue consider the reception of the bank. Behind the wall of the reception there are in many cases different clocks to show the time of the countries with which the bank is supposed to do business. Suppose we are in Amsterdam and we see different clocks which show the names New York, Tokyo and Sidney. All the clocks are identical, show the same time in minutes but the time in hours is different. All the clocks move at the same rate.
When it is 12 o'clock in Amsterdam the time in Japan will be 8 o'clock. You assume that in your mind because the clock which shows the time in Tokyo shows 8 o'clock. The question is is that the actual time in Tokyo.
To do that you go the reception of a bank in Tokyo which has the same four clocks against the wall. Next you take a camera and you transmit a signal to Amsterdam. In Amsterdam you now have 4 o'clocks and a TV screen which shows the time in Tokyo. A simple investigation will show that the time lacks behind. This is communication line 1.
Next you take a camera in Amsterdam. You make a picture of Amsterdam time. Transmit this image to Tokyo and show the Amsterdam time on a TV screen in Tokyo. Next you take a picture of that screen and transmit it back to Amsterdam. This is communication line 2.
In Amsterdam you now have 4 clocks and two TV screens: One with Tokyo time and one with Amsterdam time. Tokyo time lacks behind, Amsterdam time lacks behind with a factor 2. This is all in agreement with the concept that the (maximum) speed of communication is the speed of light. Until now there are no paradoxes.

Something weird would be observed if the clock which shows Amstrdam time and the clock on the TV screen which shows Amsterdam time would indicate exactly the same time

In that case both clocks show the same time simultaneous which implies faster than light communication. However this is not the case.

Next we modify this experiment slightly. First we go to Tokyo. In Tokyo we place a painting in a room and we use two camera's. One camera shows the front and one the back. The light in the room is OFF. Next we go to Amsterdam and we observe the two TV screens which are black. In Tokyo we turn the light in room ON. In Amsterdam TV screen 1 will show the front and TV screen 2 the back of the painting. Both pictures will appear simultaneous.
In Tokyo we turn the light OFF, we turn the painting front to back, but we keep the camera's fixed. We turn the light ON.
In Amsterdam when the light is turned ON TV screen 2 will show the front and TV screen the back. Again both pictures will appear simultaneous.
However and that is important no communication faster than the speed of light is involved. Nothing weirds has happened.

In Tokyo when you turn on the light you immediate know the outcome of the experiment. You know in Tokyo what is shown on screen 1 and what is shown on TV screen 2 (after a time delay) in Amsterdam. The problem is that knowledge does not include any communication transfer. In fact faster then light cummunication has nothing to do with what we know but only what is observed.

• In the case of the experiments with the painting both images change simultaneous in Amsterdam but no information exchange takes place between the two observers in front of each TV screen involved.
• In the case of the clocks there is information exchange between the observer in front of the clock on the wall which shows Amsterdam time and in front of the TV screen which shows Amsterdam time, but this information exchange is not simultaneous.

In short both experiments in the Quantum realm do not show any weird behaviour

It is up to the QBism community to demonstrate with an experiment some weird behaviour. Unfortunate (?) the article does not give any hint that such an experiment exists nor in which "direction" we should search to find this experiment.

Reflection Part 2

The same subject of this document is also discussed in the usenet newsgroup sci.physics.reasearch Quantum weirdness? It's all in your mind.
In one of posts in that discussion an article by David Mermin is discussed. For comments about that article read this: Is the moon there when nobody looks? Reality and the quantum theory In the article the concept of Quantum Bayesianism is not used in order to explain quantum mechanics

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