In 2005 I received the following email from a Dutch physicist:
In the Schrödinger Cat experiment at a certain moment the observer opens the door and looks inside. The observer has to test if the cat is still alive or dead.
Two weeks ago I had a Zoom conference with my granddaughter. During the call I told her that I wanted to make some tea and I also wanted to explain to her how you do that in detail.
Schrödinger's cat: the essence of this thought-experiment is
that there is a correlation between the state of the atom
(decayed or not) and the state of the cat (dead or alive);
correlations are also in classical physics, but correlations
in quantum physics have special properties which don't exist
within classical correlations; John Bell has sorted out in the
year 1960 how you can distinguish between classical from quantum
correlations; I can't say much more about this subject, helas.
Schrodinger kat: de essentie van dit gedachtenexperiment is
dat er een correlatie is tussen de toestand van het atoom
(vervallen of niet) en de toestand van de kat (dood of levend);
correlaties zijn er ook in de klassieke fysica, maar correlaties
in de quantumfysica hebben bepaalde eigenschappen die
klassieke correlaties niet hebben; John Bell heeft in de
zestiger jaren uitgezocht hoe je klassieke van quantum
correlaties kunt onderscheiden; veel meer dan dit kan ik
er niet over zeggen, helaas.
First you take a teapot. Next you fill the teapot with hot water. Then you put a teabag in the teapot. You close the lid. You wait some time and you say hocus pocus like a magician. Next you lift the lid and you look inside the teapot
I did exactly like that. After a quick visible investigation I was lucky? Yes; it looked like tea.
Next I poured the tea in a cup and it tasted delicious. Yes; it was tea.
I don't know what my granddaughter thought about this experiment, but for me this experiment, which I call the Tea Experiment, raises a lot of questions.
One of the first basic concepts to agree upon, if you want to do science, is that all terminology used should be clear. Specific if you want to do science with some-one else, both participants should make up a list of all concepts they agree upon. Some of the specific concepts will be discussed in this documents.
One of the first questions I have with the teapot experiment: is this a classical experiment or a quantum experiment?
To answer that question you much first define what classical experiment and what a quantum experiment is. This implies more or less that you assume that the answer for any specific experiment can't be: both. My own intake is that quantum experiments involve elementary particles (electrons, protons and neutrons). But I don't know if that is enough.
A different question is: why making this difference? Also here I don't have a good answer.
IMO in order to understand the processes that take place in the universe or here on earth you should try to perform as many different experiments as possible and observe how they evolve.
With different processes I mean, first try to perform one experiment and call this the standard experiment. Next repeat the standard experiment with only one change and do this as often as possible, each with a different change.
A typical example is to increase the addition of a certain compound in small steps and observe what happens.
When the observer concludes that the cat is alive he has to close the box, wait for some time and opens the box again.
The observer has to continue until the cat is dead.
Also in this experiment you can ask yourself two questions:
What is the overall importance of both experiments?
- Have the different observations anything to do with the health of the cat: staying alive or being dead.
The answer is: No. . The observations itself don't influence this process
- What is the reason that the cat will die?
In the classical experiment a poison is involved. When the poison is released the cat will die.
But the process is slightly more complicated. What is the reason that the poison is released? That is a radioactive decay of the atom.
But still the issue is more complicated: To establish this radioactive decay you have to perform '1000' experiments.
Also there is another reason which will complicate this process: how much poison should be released?
If it is not enough it can take a rather long (painful) time in between being healthy and being dead.
- You can make the experiment more complex. After the cat dies he will decay.
The most important lesson is that the results or the outcome of an experiment lies in the details of the experiment i.e. how the experiment is performed. Human observations are not important, except if humans direct influence the process.
Like all subjects you have to explain what the subject means.
Accordingly to Wikipedia https://en.wikipedia.org/wiki/Quantum_superposition superposition means:
The problem is what is a distinct state in physics. From a physical point of view you can't add states.
Quantum superposition is a fundamental principle of quantum mechanics. It states that, much like waves in classical physics, any two (or more) quantum states can be added together ("superposed") and the result will be another valid quantum state; and conversely, that every quantum state can be represented as a sum of two or more other distinct states.
If there are two sources of water waves, which each create waves in circles, the two set of circles will interfere which each other. The two waves don't add together. It looks like that, but from a physical point of view it is more that the water particles lift each other up and down. The idea that water-waves influence each other, which involve some sort of superposition (meaning something else as interference) is not clear.
In the case of the Schrödinger cat experiment it is assumed that before opening the box the cat is both simultaneous alive and dead and that when one opens the state of the cat is either alive or dead.
The problem is that when you make a video of the physical state of the cat from inside the box, you will observe after opening the box, that the cat is never in a sort of simultaneous state. It is a 'simple' physical experiment and depending how set up, after the release of the poison the time that the cat is dying can be long and painful. That means, if you wait long enough the cat is always dead. To consider, that just before the operator looks inside the box, the state of the cat involves superposition, does not make sense. As I already mentioned, the process of opening the box, does not involve any physical change, specific in the state of the cat.
The concept of "opening the box" is called "the collapse of the wave function", but IMO this concept is not clear.
In the case of the teapot experiment the conclusion can be exactly the same: Looking into the teapot does not change the quality of the tea in the teapot. No superposition is involved. No collapse of the wave function is involved.
A special type of processes can be considered as collision experiments. In those type of experiments you have a target and a bullet. The target is supposed at be rest and the bullet should have a large speed and hit the target. After hitting, the target is supposed to break down and release an avalanche of smaller particles including photons.
From a physical point of view I assume that the experiments can be repeated, implying approximate the same avalanche of smaller particles including photons.
Around the target there will be a sphere with measurement devices. These devices will be able to detect the particles and establish what type of particles this are.
Now here we have the first issue: When is the full characteristic or properties of a particle physical decided?
When the reader thinks that this is when bullet hits the target and when the particle is created, that seems the most logical explanation. Because, suppose, when the particle is an electron and when there is a magnetic field, its trajectory will be bended accordingly, before it hits the detector. This assumption, should be
demonstrated by means of an actual experiment.
When the reader thinks that this is when the particle collides with the detector than he or she is in favour of the "opening the box" situation, which explains the physical characteristics of the cat or a particle, when the cat or the particle is observed.
- At the moment when the bullet collides with the target?
- or thereafter when the particle collides with the detector?
Next consider that as part of the collision two photons are created, which move in opposite directions. Both these photons can be detected.
Suppose the photon moves in the x direction than the plane in which the photon vibrates is the yz plane
Consider that the photon can only be measured in one direction, than the result will be either (+z or -z) or (+y or -y).
That means the 6 measurements, in vertical direction each, at different instances, are not correlated.
The first result is (+z,+z). The second result is (+z,-z). The final one is (-z,-z)
When there are two photons and both move along the x axis in opposite directions, and you repeat that 6 times, then you can get the following results in time (going from left to right):
+z +z -z -z +z -z
+z -z -z +z -z -z
That means the 6 measurements, in vertical direction, at different instances, are correlated
With a different target, and you repeat the same experiment, you also can get the get
following results (going from left to right):
+z +z -z -z +z -z
-z -z +z +z -z +z
What is the explanation?
The explanation is two-fold:
Anyway, and that is the most important thing, the two photons are not entangled. Neither when the results show that they are not correlated, nor when the results show that they are correlated.
- The primary reason is inside the reaction and most probably in the target, which should be different.
- It is not in the moment when the photons are detected and the direction in the z direction is measured.
The directions of the photons are decided as part of the reaction.
- There is also no (instantaneous) communication involved between the two photons when they are measured.
6. Space and Time and Space-Time
Like all subjects you have to explain what the subject means.
With space, in this paragraph, we mean a certain area and all the objects it contains. We can also use the concept empty space, which particular means the area outside the physical objects.
To define time is a much more difficult subject.
In 2. Physics in General the subject is evolution of the Universe and understanding of physical processes. What that means is that all these processes change. What I mean is that all these processes
exist and change in time 'simultaneous'. Here on earth and in all the stars in the Sagittarius galaxy.
As I mentioned time is a difficult subject. Time is not something that exist. When you read on your clock and it shows 10:35, than that number does not show 'time' but a clock reading which we call time.
We can draw a coordinate system starting from a point O, draw dots along each axis and define that the distance between each is 1 km. Next we can draw an object at coordinate (1,1,1) and claim that the distance from the origin is square root(3) or 1.732 km.
When you write down 10:35 near the origin than the distance from the origin is 1.732 km at 10:35.
How we know that the object at 10:35 is at (1,1,1) I leaf an open question. The point I want to made is that the concept 'time' is a very difficult.
It is much more a human issue than a physical issue. It is a human issue because we have a brain and we observe that we are becoming physical older, in the future, that we physical change, now, and that we were younger in the past. Those are the events we remember.
It is a physical issue, because we use clocks to 'measure' something what we call 'time'. Normally identical clocks show the same time. However that it is not always the case. When you have two identical clocks and you move them 'apart' and bring them 'together' there is a high chance that their clock count is different.
The question is what is the physical reason. To explain that you must understand what is the process that takes place inside the clock that explains that a clock ticks and what influences this ticking 'in time'.
Space-Time is an even more difficult concept. Space-Time is not a something physical. It is a mathematical concept. You can't measure space-time. You can only calculate space-time.
Remember that velocity is also a mathematical concept. You need a 'fixed' distance and two watches.
7. The laws of physics
Like all subjects you have to explain what the subject means.
The laws of physics are human descriptions of almost identical physical processes. The emphasis with these descriptions are the differences between these physical processes and what these differences mean. Often these differences are established by performing almost the same experiments.
For example in Newtons Law one of the differences are the number of objects involved and the mass of each object.
It is very important to understand that there is a difference between the evolution of the processes that take place in the universe and the laws of physics. Generally speaking we humans have no influence on how the evolution the universe evolves, here on earth, nor every where else. Except when directly try to influence these processes.
As mentioned the laws of nature are descriptions of identical experiments, performed by humans and by making observations.
One specific law is the Uncertainty principle which involves the problems related when performing measurements. The problem is that in the universe there is not such a thing as the uncertainty principle. The evolution of trajectories of all the stars, all the galaxies are all 'controlled' by the forces in between these objects and have nothing to do with as the uncertainty principle.
A complete different law is the "Pauli exclusion Principle" which generally speaking claims that certain particles cannot be in two positions at once.
The problem is that humans don't have the right to make this claim, nor any other claim, how the Universe evolves in time, nor how any process behaves.
What humans only can do is to try to understand these processes, what the relations are between individual processes, to see if certain processes 'follow' certain rules etc.
8. complex numbers
A complex number is the square root of -1. This is the letter i. i^2=-1
In mathematical world, in mathematics we can use positive numbers, the number zero, negative numbers and complex numbers.
In the mathematics you can use complex numbers and the results of the calculations can also be a complex number.
In our world, a line segment represented as x+iy cannot physical exist.
The question is, if you want to understand the physical universe i.e. all the processes that take place in the universe, if complex numbers are required?
Understanding the universe means to be able to predict the future. That only can work if you assume a clear distinction between space and time. It means that at each instant each object has a specific position in space. It also means that throughout the whole universe the same time exists implying the same clock-reading.
Using that concept you can draw two lines on a piece of paper. A horizontal line which is called time and a vertical line called x.
The points at are identified as x,t. The origin is identified as the point (0,0). At the time line we draw at equal distance small vertical lines. Next we are going to draw 3 lines. Each line is better described as a line of dots.
"Figure 1" represents an image of the of the universe, subdivided in roughly 20 time events. At each instant the position of 3 points is indicated.
(3)- ' ' . . ' ' .(3)
- ' ' .(2)
- . '
(1)- . . . . . . . . . . . . . ' . . .(1)
- . '
- . '
- ' . ' '
- . ' . .
- . ' ' '
(2)- . '
0,0 | | | | | | | | | | | | | | | | | time
- The first line at (5,0) is a line of horizontal dots. This line represents a point A at rest in the frame.
- The second line at (0,0) is a straight tilted-line. This line represents a point B which moves in the +x direction.
- The third line is at (9,0) is part of a circle. This line represents a point C which moves around point A in the x,y frame.
Point 1 is a point at rest. Point 2 moving away in the +x direction. Point 3 moving around Point 1.
Figure 1 shows the movement of the 3 points in the x direction. There exists also a figure 1 in the y direction and in the z direction for the same time events.
But now what happens if you are an observer situated at Point 3. How does each figure 1 looks?
The answer is: This should exactly be the same. The same for an observer at point 2. The reason is that the points which identifies the positions the objects in the universe 'now' should be independent of the position of the observer.
Consider Point 1 is the Sun, Point 2 is the Earth and Point 4 (not drawn) is the planet Jupiter. The dotted line, which shows the movement of Jupiter, will have the same shape as line 3, but with a much larger 'radius' and a much longer wave length.
Also in that case you can ask the same question: How does Figure 1 looks when the observer is situated at Point 4. Answer: The same.
The philosophy behind this view is that at each instant there exists only one now and one world view. That means at instant 13 in figure 1 the two lines 1 and 2 'collide' in the x,y and z direction. This should be the same in figure 1 (x,y and z) as observed from point 3, as from point 4.
It is also the same if those 4 points (The Sun and 2 planets) are observed from a nearby star or from a different galaxy.
However there is one more hurdle to take. In figure 1 the speed of light is not included. The assumption is that the time is measured with a clock at rest in figure 1, to be more specific at rest within the whole universe.
Created: 23 February 2022
Back to my home page Index