Fundamentals of quantum physics in five experiments for dummies. Quantum physics for dummies: the essence in simple words
You've probably heard it many times about the inexplicable mysteries of quantum physics and quantum mechanics. Its laws fascinate with mysticism, and even physicists themselves admit that they do not fully understand them. On the one hand, it is interesting to understand these laws, but on the other hand, there is no time to read multi-volume and complex books on physics. I understand you very much, because I also love knowledge and the search for truth, but there is sorely not enough time for all the books. You are not alone, many curious people type in the search bar: “quantum physics for dummies, quantum mechanics for dummies, quantum physics for beginners, quantum mechanics for beginners, basics of quantum physics, basics of quantum mechanics, quantum physics for children, what is quantum Mechanics"..
This publication is exactly for you
- You will understand the basic concepts and paradoxes of quantum physics. From the article you will learn:
- What is quantum physics and quantum mechanics?
- What is interference?
- What is Quantum Entanglement (or Quantum Teleportation for Dummies)? (see article)
What is the Schrödinger's Cat thought experiment? (see article)
Quantum mechanics is a part of quantum physics.
Why is it so difficult to understand these sciences? The answer is simple: quantum physics and quantum mechanics (part of quantum physics) study the laws of the microworld. And these laws are absolutely different from the laws of our macrocosm. Therefore, it is difficult for us to imagine what happens to electrons and photons in the microcosm. An example of the difference between the laws of the macro- and microworlds
: in our macroworld, if you put a ball in one of 2 boxes, then one of them will be empty, and the other will have a ball. But in the microcosm (if there is an atom instead of a ball), an atom can be in two boxes at the same time. This has been confirmed experimentally many times. Isn't it hard to wrap your head around this? But you can't argue with the facts. One more example. You took a photograph of a fast racing red sports car and in the photo you saw a blurry horizontal stripe, as if the car was located at several points in space at the time of the photo. Despite what you see in the photo, you are still sure that the car was in one specific place in space . In the micro world, everything is different. An electron that rotates around the nucleus of an atom does not actually rotate, but around the nucleus of an atom. Like a loosely wound ball of fluffy wool. This concept in physics is called "electronic cloud" .
A short excursion into history. Scientists first thought about the quantum world when, in 1900, German physicist Max Planck tried to figure out why metals change color when heated. It was he who introduced the concept of quantum. Until then, scientists thought that light traveled continuously. The first person to take Planck's discovery seriously was the then unknown Albert Einstein. He realized that light is not just a wave. Sometimes he behaves like a particle. Einstein received the Nobel Prize for his discovery that light is emitted in portions, quanta. A quantum of light is called a photon ( photon, Wikipedia) .
To make it easier to understand the laws of quantum physicists And mechanics (Wikipedia), we must, in a sense, abstract from the laws of classical physics that are familiar to us. And imagine that you dived, like Alice, into the rabbit hole, into Wonderland.
And here is a cartoon for children and adults. Describes the fundamental experiment of quantum mechanics with 2 slits and an observer. Lasts only 5 minutes. Watch it before we dive into the fundamental questions and concepts of quantum physics.
The quantum physics for dummies video. In the cartoon, pay attention to the “eye” of the observer. It has become a serious mystery for physicists.
What is quantum physics and quantum mechanics?
At the beginning of the cartoon, using the example of a liquid, it was shown how waves behave - alternating dark and light vertical stripes appear on the screen behind a plate with slits. And in the case when discrete particles (for example, pebbles) are “shot” at the plate, they fly through 2 slits and land on the screen directly opposite the slits. And they “draw” only 2 vertical stripes on the screen.
Interference of light- This is the “wave” behavior of light, when the screen displays many alternating bright and dark vertical stripes. Also these vertical stripes called interference pattern.
In our macrocosm, we often observe that light behaves like a wave. If you place your hand in front of a candle, then on the wall there will be not a clear shadow from your hand, but with blurry contours.
So, it's not all that complicated! It is now quite clear to us that light has a wave nature and if 2 slits are illuminated with light, then on the screen behind them we will see an interference pattern.
The installation described in the cartoon was not shined with light, but “shot” with electrons (as individual particles). Then, at the beginning of the last century, physicists around the world believed that electrons are elementary particles of matter and should not have a wave nature, but the same as pebbles. After all, electrons are elementary particles of matter, right? That is, if you “throw” them into 2 slits, like pebbles, then on the screen behind the slits we should see 2 vertical stripes.
But... The result was stunning. Scientists saw an interference pattern - many vertical stripes. That is, electrons, like light, can also have a wave nature and can interfere. On the other hand, it became clear that light is not only a wave, but also a little particle - a photon (from historical information at the beginning of the article we learned that Einstein received the Nobel Prize for this discovery).
Maybe you remember, at school we were told in physics about "wave-particle duality"? It means that when we're talking about about very small particles (atoms, electrons) of the microworld, then They are both waves and particles
Today you and I are so smart and we understand that the 2 experiments described above - shooting with electrons and illuminating slits with light - are the same thing. Because we shoot quantum particles at the slits. We now know that both light and electrons are of a quantum nature, that they are both waves and particles at the same time. And at the beginning of the 20th century, the results of this experiment were a sensation.
Attention! Now let's move on to a more subtle issue.
We shine a stream of photons (electrons) onto our slits and see an interference pattern (vertical stripes) behind the slits on the screen. It is clear. But we are interested in seeing how each of the electrons flies through the slot.
Presumably, one electron flies into the left slot, the other into the right. But then 2 vertical stripes should appear on the screen directly opposite the slots. Why does an interference pattern occur? Maybe the electrons somehow interact with each other already on the screen after flying through the slits. And the result is a wave pattern like this. How can we keep track of this?
We will throw electrons not in a beam, but one at a time. Let's throw it, wait, let's throw the next one. Now that the electron is flying alone, it will no longer be able to interact with other electrons on the screen. We will register each electron on the screen after the throw. One or two, of course, will not “paint” a clear picture for us. But when we send a lot of them into the slits one at a time, we will notice... oh horror - they again “drew” an interference wave pattern!
We are slowly starting to go crazy. After all, we expected that there would be 2 vertical stripes opposite the slots! It turns out that when we threw photons one at a time, each of them passed, as it were, through 2 slits at the same time and interfered with itself.
Fantastic! Let's return to explaining this phenomenon in the next section.
What is spin and superposition?
We now know what interference is. This is the wave behavior of micro particles - photons, electrons, other micro particles (for simplicity, let's call them photons from now on).
As a result of the experiment, when we threw 1 photon into 2 slits, we realized that it seemed to fly through two slits at the same time. Otherwise, how can we explain the interference pattern on the screen?
- But how can we imagine a photon flying through two slits at the same time? There are 2 options. 1st option:
- a photon, like a wave (like water) “floats” through 2 slits at the same time 2nd option:
a photon, like a particle, flies simultaneously along 2 trajectories (not even two, but all at once)
In principle, these statements are equivalent. We arrived at the “path integral”. This is Richard Feynman's formulation of quantum mechanics. By the way, exactly Richard Feynman there is a well-known expression that
We can confidently say that no one understands quantum mechanics
But this expression of his worked at the beginning of the century. But now we are smart and know that a photon can behave both as a particle and as a wave. That he can, in some way incomprehensible to us, fly through 2 slits at the same time. Therefore, it will be easy for us to understand the following important statement of quantum mechanics:
Strictly speaking, quantum mechanics tells us that this photon behavior is the rule, not the exception. Any quantum particle is, as a rule, in several states or at several points in space simultaneously.
We just have to admit, as an axiom, that the “superposition” of a quantum object means that it can be on 2 or more trajectories at the same time, in 2 or more points at the same time
The same applies to another photon parameter – spin (its own angular momentum). Spin is a vector. A quantum object can be thought of as a microscopic magnet. We are accustomed to the fact that the magnet vector (spin) is either directed up or down. But the electron or photon again tells us: “Guys, we don’t care what you’re used to, we can be in both spin states at once (vector up, vector down), just like we can be on 2 trajectories at the same time or at 2 points at the same time!
What is "measurement" or "wavefunction collapse"?
There is little left for us to understand what “measurement” is and what “wave function collapse” is.
Wave function is a description of the state of a quantum object (our photon or electron).
Suppose we have an electron, it flies to itself in an indefinite state, its spin is directed both up and down at the same time. We need to measure his condition.
Let's measure using magnetic field: electrons whose spin was directed in the direction of the field will be deflected in one direction, and electrons whose spin was directed against the field - in the other. More photons can be directed into a polarizing filter. If the spin (polarization) of the photon is +1, it passes through the filter, but if it is -1, then it does not.
Stop! Here you will inevitably have a question: Before the measurement, the electron did not have any specific spin direction, right? He was in all states at the same time, wasn't he?
This is the trick and sensation of quantum mechanics. As long as you do not measure the state of a quantum object, it can rotate in any direction (have any direction of the vector of its own angular momentum - spin). But at the moment when you measured his state, he seems to be making a decision which spin vector to accept.
This quantum object is so cool - it makes decisions about its state. And we cannot predict in advance what decision it will make when it flies into the magnetic field in which we measure it. The probability that he will decide to have a spin vector “up” or “down” is 50 to 50%. But as soon as he decides, he is in a certain state with a specific spin direction. The reason for his decision is our “dimension”!
This is called " collapse of the wave function". The wave function before the measurement was uncertain, i.e. the electron spin vector was simultaneously in all directions; after the measurement, the electron recorded a certain direction of its spin vector.
Attention! An excellent example for understanding is an association from our macrocosm:
Spin a coin on the table like a spinning top. While the coin is spinning, it does not have a specific meaning - heads or tails. But as soon as you decide to “measure” this value and slam the coin with your hand, that’s when you get the specific state of the coin - heads or tails. Now imagine that this coin decides which value to “show” you - heads or tails. The electron behaves in approximately the same way.
Now remember the experiment shown at the end of the cartoon. When photons were passed through the slits, they behaved like a wave and showed an interference pattern on the screen. And when scientists wanted to record (measure) the moment of photons flying through the slit and placed an “observer” behind the screen, the photons began to behave not like waves, but like particles. And they “drew” 2 vertical stripes on the screen. Those. at the moment of measurement or observation, quantum objects themselves choose what state they should be in.
Fantastic! Is not it?
But that is not all. Finally we We got to the most interesting part.
But... it seems to me that there will be an overload of information, so we will consider these 2 concepts in separate posts:
- What's happened ?
- What is a thought experiment?
Now, do you want the information to be sorted out? Watch the documentary produced by the Canadian Institute of Theoretical Physics. In 20 minutes it is very brief and chronological order You will be told about all the discoveries of quantum physics, starting with Planck's discovery in 1900. And then they will tell you what practical developments are currently being carried out on the basis of knowledge in quantum physics: from the most precise atomic clock to super-fast quantum computer calculations. I highly recommend watching this film.
See you!
I wish everyone inspiration for all their plans and projects!
P.S.2 Write your questions and thoughts in the comments. Write, what other questions on quantum physics are you interested in?
P.S.3 Subscribe to the blog - the subscription form is under the article.
Quantum physics has radically changed our understanding of the world. According to quantum physics, we can influence the rejuvenation process with our consciousness!
Why is this possible?From the point of view of quantum physics, our reality is a source of pure potential, a source of raw materials from which our body, our mind and the entire Universe are composed. The universal energy and information field never ceases to change and transform, turning into something new every second.
In the 20th century, during physics experiments with subatomic particles and photons, it was discovered that the fact of observing the experiment changes its results. What we focus our attention on can react.
This fact is confirmed by a classic experiment that surprises scientists every time. It was repeated in many laboratories and the same results were always obtained.
For this experiment, a light source and a screen with two slits were prepared. The light source was a device that “shot” photons in the form of single pulses.
The progress of the experiment was monitored. After the end of the experiment, two vertical stripes were visible on the photographic paper that was located behind the slits. These are traces of photons that passed through the cracks and illuminated the photographic paper.
When this experiment was repeated automatically, without human intervention, the picture on the photographic paper changed:
If the researcher turned on the device and left, and after 20 minutes the photographic paper was developed, then not two, but many vertical stripes were found on it. These were traces of radiation. But the drawing was different.
The structure of the trace on photographic paper resembled the trace of a wave that passed through the slits. Light can exhibit the properties of a wave or a particle.
As a result of the simple fact of observation, the wave disappears and turns into particles. If you do not observe, a trace of the wave appears on the photographic paper. This physical phenomenon is called the “Observer Effect”.
The same results were obtained with other particles. The experiments were repeated many times, but each time they surprised scientists. Thus, it was discovered that at the quantum level, matter reacts to human attention. This was new in physics.
According to the concepts of modern physics, everything materializes from the void. This emptiness is called the “quantum field”, “zero field” or “matrix”. The void contains energy that can be converted into matter.
Matter consists of concentrated energy - this is a fundamental discovery of 20th century physics.
There are no solid parts in an atom. Objects are made of atoms. But why are objects solid? Finger attached to brick wall doesn't go through it. Why? This is due to differences in the frequency characteristics of atoms and electric charges. Each type of atom has its own vibration frequency. This determines the differences in the physical properties of objects. If it were possible to change the vibration frequency of the atoms that make up the body, then a person would be able to walk through walls. But the vibrational frequencies of the atoms of the hand and the atoms of the wall are close. Therefore, the finger rests against the wall.
For any type of interaction, frequency resonance is necessary.
This is easy to understand with a simple example. If illuminated stone wall flashlight, the light will be blocked by the wall. However, cell phone radiation will easily pass through this wall. It's all about the differences in frequencies between the radiation of a flashlight and a mobile phone. While you are reading this text, streams of a wide variety of radiation are passing through your body. This is cosmic radiation, radio signals, signals from millions of mobile phones, radiation coming from the earth, solar radiation, radiation generated by household appliances, etc.
You don't feel it because you can only see light and hear only sound. Even if you sit in silence with your eyes closed, millions are passing through your head. telephone conversations, pictures of television news and radio messages. You do not perceive this, because there is no frequency resonance between the atoms that make up your body and the radiation. But if there is resonance, then you react immediately. For example, when you remember a loved one who just thought about you. Everything in the universe obeys the laws of resonance.
The world consists of energy and information. Einstein, after much thought about the structure of the world, said: “The only reality existing in the universe is the field.” Just as waves are a creation of the sea, all manifestations of matter: organisms, planets, stars, galaxies are creations of the field.
The question arises: how is matter created from a field? What force controls the movement of matter?
The scientists' research led them to an unexpected answer. The creator of quantum physics, Max Planck, said the following during his acceptance speech for the Nobel Prize:
“Everything in the Universe is created and exists thanks to force. We must assume that behind this force there is a conscious mind, which is the matrix of all matter."
MATTER IS CONTROLLED BY CONSCIOUSNESS
At the turn of the 20th and 21st centuries, new ideas appeared in theoretical physics that make it possible to explain the strange properties elementary particles. Particles can appear from the void and suddenly disappear. Scientists admit the possibility of the existence of parallel universes. Perhaps particles move from one layer of the universe to another. Celebrities such as Stephen Hawking, Edward Witten, Juan Maldacena, Leonard Susskind are involved in the development of these ideas.
According to the concepts of theoretical physics, the Universe resembles a nesting doll, which consists of many nesting dolls - layers. These are variants of universes - parallel worlds. The ones next to each other are very similar.
But the further the layers are from each other, the less similarity there is between them. Theoretically, in order to move from one universe to another, spaceships are not required. All possible options are located one within the other. These ideas were first expressed by scientists in the mid-20th century. At the turn of the 20th and 21st centuries, they received mathematical confirmation. Today, such information is easily accepted by the public. However, a couple of hundred years ago, for such statements one could be burned at the stake or declared crazy. Everything arises from emptiness. Everything is in motion. Objects are an illusion. Matter is made up of energy. Everything is created by thought.These discoveries of quantum physics contain nothing new. All this was known to the ancient sages. Many mystical teachings, which were considered secret and were accessible only to initiates, said that there is no difference between thoughts and objects. Everything in the world is filled with energy. The universe reacts to thought.
Energy follows attention. What you focus your attention on begins to change. These thoughts are given in various formulations in the Bible, ancient Gnostic texts, in mystical teachings that arose in India and South America
. The builders of the ancient pyramids guessed this. This knowledge is the key to new technologies that are used today to control reality.
Our body is a field of energy, information and intelligence, in a state of constant dynamic exchange with the environment. The impulses of the mind constantly, every second, give the body new forms to adapt to the changing demands of life. From the point of view of quantum physics, our physical body
under the influence of our mind, it is capable of making a quantum leap from one biological age to another, without passing through all the intermediate ages. published
Physics is the most mysterious of all sciences. Physics gives us an understanding of the world around us. The laws of physics are absolute and apply to everyone without exception, regardless of person or social status.
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Fundamental discoveries in the field of quantum physics
Isaac Newton, Nikola Tesla, Albert Einstein and many others are the great guides of humanity in the wonderful world of physics, who, like prophets, revealed to humanity the greatest secrets of the universe and the possibilities of controlling physical phenomena. Their bright heads cut through the darkness of ignorance of the unreasonable majority and likewise guiding star showed the way to humanity in the darkness of the night. One of such guides in the world of physics was Max Planck, the father of quantum physics.
Max Planck is not only the founder of quantum physics, but also the author of the world famous quantum theory. Quantum theory is the most important component of quantum physics. In simple words, this theory describes the movement, behavior and interaction of microparticles. The founder of quantum physics also brought us many other scientific works, which became the cornerstones of modern physics:
- theory of thermal radiation;
- special theory of relativity;
- research in thermodynamics;
- research in the field of optics.
Quantum physics' theories about the behavior and interactions of microparticles became the basis for condensed matter physics, particle physics, and high-energy physics. Quantum theory explains to us the essence of many phenomena in our world - from the functioning of electronic computers to the structure and behavior of celestial bodies. Max Planck, the creator of this theory, thanks to his discovery, allowed us to comprehend the true essence of many things at the level of elementary particles. But the creation of this theory is far from the only merit of the scientist. He became the first to discover the fundamental law of the Universe - the law of conservation of energy. Max Planck's contribution to science is difficult to overestimate. In short, his discoveries are invaluable for physics, chemistry, history, methodology and philosophy.
Quantum field theory
In a nutshell, quantum field theory is a theory for describing microparticles, as well as their behavior in space, interaction with each other and interconversion. This theory studies the behavior of quantum systems within the so-called degrees of freedom. This beautiful and romantic name doesn’t really mean anything to many of us. For dummies, degrees of freedom are the number of independent coordinates that are needed to indicate motion mechanical system. In simple terms, degrees of freedom are characteristics of motion. Interesting discoveries in the field of interaction of elementary particles were made by Steven Weinberg. He discovered the so-called neutral current - the principle of interaction between quarks and leptons, for which he received the Nobel Prize in 1979.
Max Planck's quantum theory
In the nineties of the eighteenth century, the German physicist Max Planck began studying thermal radiation and eventually obtained a formula for the distribution of energy. The quantum hypothesis, which was born in the course of these studies, laid the foundation for quantum physics, as well as quantum field theory, discovered in 1900. Planck's quantum theory is that in thermal radiation the energy produced is not emitted and absorbed constantly, but episodically, quantumly. The year 1900, thanks to this discovery made by Max Planck, became the year of the birth of quantum mechanics. It is also worth mentioning Planck's formula. In short, its essence is as follows - it is based on the relationship between body temperature and its radiation.
Quantum mechanical theory of atomic structure
The quantum mechanical theory of atomic structure is one of the basic theories of concepts in quantum physics, and in physics in general. This theory allows us to understand the structure of all material things and lifts the veil of secrecy over what things actually consist of. And the conclusions based on this theory are quite unexpected. Let us briefly consider the structure of the atom. So, what is an atom actually made of? An atom consists of a nucleus and a cloud of electrons. The basis of an atom, its nucleus, contains almost the entire mass of the atom itself - more than 99 percent. The kernel always has positive charge, and it defines chemical element, of which the atom is a part. The most interesting thing about the nucleus of an atom is that it contains almost the entire mass of the atom, but at the same time occupies only one ten-thousandth of its volume. What follows from this? And the conclusion that emerges is quite unexpected. This means that there is only one ten-thousandth of the dense substance in an atom. And what takes up everything else? And everything else in the atom is an electron cloud.
An electronic cloud is not a permanent and, in fact, not even a material substance. An electron cloud is just the probability of electrons appearing in an atom. That is, the nucleus occupies only one ten thousandth in the atom, and the rest is emptiness. And if we consider that all the objects around us, from specks of dust to celestial bodies, planets and stars, are made of atoms, then it turns out that everything material is actually more than 99 percent composed of emptiness. This theory seems completely incredible, and its author, at the very least, is a mistaken person, because the things that exist around have a solid consistency, have weight and can be touched. How can it consist of emptiness? Has an error crept into this theory of the structure of matter? But there is no mistake here.
All material things appear dense only due to the interaction between atoms. Things have a solid and dense consistency only due to attraction or repulsion between atoms. This ensures the density and hardness of the crystal lattice of chemical substances, from which everything material consists. But, interesting point, when, for example, environmental temperature conditions change, the bonds between atoms, that is, their attraction and repulsion can weaken, which leads to a weakening of the crystal lattice and even its destruction. This explains the change in the physical properties of substances when heated. For example, when iron is heated, it becomes liquid and can be shaped into any shape. And when ice melts, the destruction of the crystal lattice leads to a change in the state of the substance, and from solid it turns into liquid. These are clear examples of weakening bonds between atoms and, as a result, weakening or destruction of the crystal lattice, and allow the substance to become amorphous. And the reason for such mysterious metamorphoses is precisely that substances consist of only one ten-thousandth of dense matter, and the rest is emptiness.
And substances seem solid only because of strong bonds between atoms, when they weaken, the substance changes. Thus, the quantum theory of atomic structure allows us to look at the world around us in a completely different way.
The founder of atomic theory, Niels Bohr, put forward an interesting concept that electrons in an atom do not emit energy constantly, but only at the moment of transition between the trajectories of their movement. Bohr's theory helped explain many intra-atomic processes, and also made breakthroughs in the field of science such as chemistry, explaining the boundaries of the table created by Mendeleev. According to , the last element capable of existing in time and space has a serial number of one hundred thirty-seven, and elements starting from one hundred and thirty-eight cannot exist, since their existence contradicts the theory of relativity. Also, Bohr's theory explained the nature of such physical phenomena as atomic spectra.
These are the interaction spectra of free atoms that arise when energy is emitted between them. Such phenomena are characteristic of gaseous, vaporous substances and substances in the plasma state. Thus, quantum theory made a revolution in the world of physics and allowed scientists to advance not only in the field of this science, but also in the field of many related sciences: chemistry, thermodynamics, optics and philosophy. And also allowed humanity to penetrate into the secrets of the nature of things.
There is still a lot that humanity needs to turn over in its consciousness in order to realize the nature of atoms and understand the principles of their behavior and interaction. Having understood this, we will be able to understand the nature of the world around us, because everything that surrounds us, from specks of dust to the sun itself, and we ourselves, all consists of atoms, the nature of which is mysterious and amazing and conceals a lot of secrets.
Nobody in this world understands what quantum mechanics is. This is perhaps the most important thing you need to know about her. Of course, many physicists have learned to use laws and even predict phenomena based on quantum computing. But it is still unclear why the observer of the experiment determines the behavior of the system and forces it to accept one of two states.
Here are several examples of experiments with results that will inevitably change under the influence of the observer. They show that quantum mechanics practically deals with the intervention of conscious thought into material reality.
There are many interpretations of quantum mechanics today, but the Copenhagen interpretation is perhaps the most famous. In the 1920s, its general postulates were formulated by Niels Bohr and Werner Heisenberg.
The Copenhagen interpretation is based on the wave function. This is a mathematical function containing information about all possible states of a quantum system in which it exists simultaneously. According to the Copenhagen Interpretation, the state of a system and its position relative to other states can only be determined by observation (the wave function is used only to mathematically calculate the probability of the system being in one state or another).
We can say that after observation, a quantum system becomes classical and immediately ceases to exist in states other than the one in which it was observed. This conclusion found its opponents (remember Einstein’s famous “God does not play dice”), but the accuracy of the calculations and predictions still had their effect.
However, the number of supporters of the Copenhagen Interpretation is declining, and main reason This is due to the mysterious instantaneous collapse of the wave function during the experiment. Erwin Schrödinger's famous thought experiment with the poor cat should demonstrate the absurdity of this phenomenon. Let's remember the details.
Inside the black box sits a black cat, along with a vial of poison and a mechanism that can release the poison randomly. For example, a radioactive atom may break a bubble during decay. Exact time atomic decay is unknown. Only the half-life is known, during which decay occurs with a probability of 50%.
Obviously, to an outside observer, the cat inside the box is in two states: it is either alive, if everything went well, or dead, if decay has occurred and the bottle has broken. Both of these states are described by the cat's wave function, which changes over time.
The more time has passed, the more likely that radioactive decay has occurred. But as soon as we open the box, the wave function collapses, and we immediately see the results of this inhumane experiment.
In fact, until the observer opens the box, the cat will endlessly balance between life and death, or be both alive and dead. Its fate can only be determined by the actions of the observer. Schrödinger pointed out this absurdity.
According to a survey of famous physicists conducted by The New York Times, the electron diffraction experiment is one of the most amazing studies in the history of science. What is its nature? There is a source that emits a beam of electrons onto a light-sensitive screen. And there is an obstacle in the way of these electrons, a copper plate with two slits.
What kind of picture can we expect on the screen if electrons usually appear to us as small charged balls? Two stripes opposite the slots in the copper plate. But in fact, a much more complex pattern of alternating white and black stripes appears on the screen. This is due to the fact that when passing through a slit, electrons begin to behave not only as particles, but also as waves (photons or other light particles that can be a wave at the same time behave in the same way).
These waves interact in space, colliding and reinforcing each other, and as a result, a complex pattern of alternating light and dark stripes is displayed on the screen. At the same time, the result of this experiment does not change even if the electrons pass one after another - even one particle can be a wave and pass through two slits simultaneously. This postulate was one of the main ones in the Copenhagen interpretation of quantum mechanics, when particles can simultaneously demonstrate their “ordinary” physical properties and exotic properties like wave.
But what about the observer? It is he who makes this confusing story even more confusing. When physicists, during similar experiments, tried to determine with the help of instruments which slit the electron actually passed through, the picture on the screen changed dramatically and became “classical”: with two illuminated sections exactly opposite the slits, without any alternating stripes.
The electrons seemed reluctant to reveal their wave nature to the watchful eye of observers. It looks like a mystery shrouded in darkness. But there is a simpler explanation: observation of the system cannot be carried out without physical influence on it. We will discuss this later.
2. Heated fullerenes
Experiments on particle diffraction were carried out not only with electrons, but also with other, much larger objects. For example, fullerenes, large and closed molecules consisting of several dozen carbon atoms, were used. Recently, a group of scientists from the University of Vienna, led by Professor Zeilinger, tried to incorporate an element of observation into these experiments. To do this, they irradiated moving fullerene molecules with laser beams. Then, heated by an external source, the molecules began to glow and inevitably display their presence to the observer.
Along with this innovation, the behavior of molecules also changed. Before such comprehensive observations began, fullerenes were quite successful in avoiding obstacles (exhibiting wave properties), similar to the previous example with electrons hitting the screen. But with the presence of an observer, fullerenes began to behave like completely law-abiding physical particles.
3. Cooling dimension
One of the most famous laws in the world of quantum physics is the Heisenberg uncertainty principle, according to which it is impossible to determine the speed and position of a quantum object at the same time. The more accurately we measure a particle's momentum, the less accurately we can measure its position. However, in our macroscopic real world, the validity of quantum laws acting on tiny particles usually goes unnoticed.
The recent experiments of Professor Schwab from the USA make a very valuable contribution to this field. Quantum effects in these experiments were demonstrated not at the level of electrons or fullerene molecules (the approximate diameter of which is 1 nm), but on larger objects, a tiny aluminum strip. This tape was fixed on both sides so that its middle was suspended and could vibrate under external influence. In addition, a device was placed nearby that could accurately record the position of the tape. The experiment revealed several interesting things. First, any measurement related to the position of the object and observation of the tape influenced it; after each measurement, the position of the tape changed.
The experimenters determined the coordinates of the tape with high accuracy, and thus, in accordance with the Heisenberg principle, changed its speed, and therefore its subsequent position. Secondly, and quite unexpectedly, some measurements led to cooling of the tape. So the observer can change physical characteristics objects by their mere presence.
4. Freezing particles
As is known, unstable radioactive particles decay not only in experiments with cats, but also on their own. Each particle has an average lifespan, which, as it turns out, can increase under the watchful eye of an observer. This quantum effect was predicted back in the 60s, and its brilliant experimental proof appeared in a paper published by a team led by Nobel laureate physicist Wolfgang Ketterle from the Massachusetts Institute of Technology.
In this work, the decay of unstable excited rubidium atoms was studied. Immediately after preparing the system, the atoms were excited using a laser beam. The observation took place in two modes: continuous (the system was constantly exposed to small light pulses) and pulsed (the system was irradiated from time to time with more powerful pulses).
The results obtained were fully consistent with theoretical predictions. External light effects slow down the decay of particles, returning them to their original state, which is far from the state of decay. The magnitude of this effect was also consistent with predictions. The maximum lifetime of unstable excited rubidium atoms increased by 30 times.
5. Quantum mechanics and consciousness
Electrons and fullerenes cease to show their wave properties, aluminum plates cool down, and unstable particles slow down their decay. The watchful eye of the observer literally changes the world. Why can't this be proof of the involvement of our minds in the workings of the world? Perhaps Carl Jung and Wolfgang Pauli (Austrian physicist, Nobel Prize winner, pioneer of quantum mechanics) were right, after all, when they said that the laws of physics and consciousness should be seen as complementary to each other?
We are one step away from recognizing that the world around us is simply an illusory product of our mind. The idea is scary and tempting. Let's try to turn to physicists again. Especially in last years, when fewer and fewer people believe the Copenhagen interpretation of quantum mechanics with its mysterious wave function collapses, turning to the more mundane and reliable decoherence.
The point is that in all these observational experiments, the experimenters inevitably influenced the system. They lit it with a laser and installed it measuring instruments. They shared an important principle: you cannot observe a system or measure its properties without interacting with it. Any interaction is a process of modification of properties. Especially when a tiny quantum system is exposed to colossal quantum objects. Some eternally neutral Buddhist observer is impossible in principle. This is where the term “decoherence” comes into play, which is irreversible from a thermodynamic point of view: the quantum properties of a system change when it interacts with another large system.
During this interaction, the quantum system loses its original properties and becomes classical, as if “submitting” to the larger system. This also explains the paradox of Schrödinger's cat: a cat is too big a system, so it cannot be isolated from the rest of the world. The very design of this thought experiment is not entirely correct.
In any case, if we assume the reality of the act of creation by consciousness, decoherence seems to be a much more convenient approach. Perhaps even too convenient. With this approach, the entire classical world becomes one big consequence of decoherence. And as the author of one of the most famous books in this field stated, this approach logically leads to statements like “there are no particles in the world” or “there is no time at a fundamental level.”
What is the truth: the creator-observer or powerful decoherence? We need to choose between two evils. Nevertheless, scientists are increasingly convinced that quantum effects are a manifestation of our mental processes. And where observation ends and reality begins depends on each of us.
Classical physics, which existed before the invention of quantum mechanics, describes nature on an ordinary (macroscopic) scale. Most theories in classical physics can be derived as approximations operating on scales that are familiar to us. Quantum physics (also known as quantum mechanics) differs from classical science in that the energy, momentum, angular momentum and other quantities of a coupled system are limited to discrete values (quantization). Objects have special characteristics as both particles and waves (wave particle duality). Also in this science there are limits to the accuracy with which quantities can be measured (the uncertainty principle).
We can say that after the emergence of quantum physics, a kind of revolution took place in the exact sciences, which made it possible to reconsider and analyze all the old laws that were previously considered immutable truths. Is it good or bad? Perhaps it’s good, because true science should never stand still.
However, the “quantum revolution” was a kind of blow to old-school physicists, who had to come to terms with the fact that what they had previously believed in turned out to be just a set of erroneous and archaic theories that needed urgent revision and adaptation to the new reality. Most physicists enthusiastically accepted these new ideas about a well-known science, making their contribution to its study, development and implementation. Today, quantum physics sets the dynamics for all science as a whole. Advanced experimental projects (like the Large Hadron Collider) arose precisely thanks to her.
Opening
What can be said about the foundations of quantum physics? It gradually arose from various theories designed to explain phenomena that could not be reconciled with classical physics, for example, Max Planck's solution in 1900 and his approach to the problem of radiation of many scientific problems, as well as the correspondence between energy and frequency in Albert Einstein's 1905 paper explaining photoelectric effects. The early theory of quantum physics was thoroughly revised in the mid-1920s by Werner Heisenberg, Max Born and others. The modern theory is formulated in various specially developed mathematical concepts. In one of them, the arithmetic function (or wave function) gives us comprehensive information about the amplitude of the probability of the location of the pulse.
Scientific research wave essence of light began more than 200 years ago, when the great and recognized scientists of that time they proposed, developed and proved the theory of light based on their own experimental observations. They called it wave.
In 1803, the famous English scientist Thomas Young conducted his famous double experiment, as a result of which he wrote the famous work “On the Nature of Light and Color,” which played a huge role in the formation of modern ideas about these phenomena familiar to us all. This experiment played a vital role in the general acceptance of this theory.
Such experiments are often described in various books, for example, “Fundamentals of Quantum Physics for Dummies.” Modern experiments with the acceleration of elementary particles, for example, the search for the Higgs boson in the Large Hadron Collider (abbreviated as LHC), are carried out precisely in order to find practical confirmation of many purely theoretical quantum theories.
Story
In 1838, Michael Faraday discovered cathode rays to the delight of the whole world. These sensational studies were followed by a statement about the problem of so-called “black body” radiation (1859), made by Gustav Kirchhoff, as well as the famous assumption of Ludwig Boltzmann that the energy states of any physical system can also be discrete (1877 ). Only then did the quantum hypothesis appear, developed by Max Planck (1900). It is considered one of the foundations of quantum physics. The bold idea that energy can be both emitted and absorbed in discrete "quanta" (or packets of energy) matches exactly the observed patterns of black body radiation.
Albert Einstein, famous throughout the world, made a great contribution to quantum physics. Impressed by quantum theories, he developed his own. General theory relativity - that's what it's called. Discoveries in quantum physics also influenced the development of the special theory of relativity. Many scientists in the first half of the last century began to study this science at the suggestion of Einstein. At that time she was advanced, everyone liked her, everyone was interested in her. Not surprising, since it closed so many “holes” in classical physical science (although it also created new ones), and offered a scientific basis for time travel, telekinesis, telepathy and parallel worlds.
The role of the observer
Any event or state depends directly on the observer. This is usually how the basics of quantum physics are briefly explained to people far from the exact sciences. However, in reality everything is much more complicated.
This fits perfectly with many occult and religious traditions, which from time immemorial have insisted on the ability of people to influence the events around them. In a way, this is also the basis for a scientific explanation of extrasensory perception, because now the statement that a person (observer) is able to influence physical events with the power of thought does not seem absurd.
Each eigenstate of an observed event or object corresponds to an eigenvector of the observer. If the spectrum of the operator (observer) is discrete, the observed object can only achieve discrete eigenvalues. That is, the object of observation, as well as its characteristics, is completely determined by this very operator.
Unlike conventional classical mechanics (or physics), simultaneous predictions of conjugate variables such as position and momentum cannot be made. For example, electrons may (with a certain probability) be located approximately in a certain region of space, but their mathematically precise location is actually unknown.
Constant probability density contours, often called "clouds", can be drawn around the nucleus of an atom to conceptualize where an electron is most likely to be located. The Heisenberg Uncertainty Principle proves the inability to accurately locate a particle given its conjugate momentum. Some models in this theory are of a purely abstract computational nature and do not imply practical significance. However, they are often used to calculate complex interactions at the level of other subtle matters. In addition, this branch of physics allowed scientists to assume the possibility of the real existence of many worlds. Perhaps we will be able to see them soon.
Wave functions
The laws of quantum physics are very extensive and varied. They overlap with the idea of wave functions. Some special ones create a spread of probabilities that is inherently constant or independent of time, for example, when in a stationary position of energy time seems to disappear in relation to the wave function. This is one of the effects of quantum physics, which is fundamental to it. An interesting fact is that the phenomenon of time has been radically revised in this unusual science.
Perturbation theory
However, there are several reliable ways to develop the solutions needed to work with the formulas and theories in quantum physics. One such method, commonly known as “perturbation theory,” uses an analytical result for an elementary quantum mechanical model. It was created to gain results from experiments to develop an even more complex model that is related to a simpler model. This is how recursion turns out.
This approach is especially important in quantum chaos theory, which is extremely popular for treating various events in microscopic reality.
Rules and laws
The rules of quantum mechanics are fundamental. They argue that the deployment space of a system is absolutely fundamental (it has a dot product). Another statement is that the effects observed by this system are at the same time unique operators influencing vectors in this very environment. However, they do not tell us which Hilbert space or which operators currently exist. They can be chosen appropriately to obtain a quantitative description of the quantum system.
Meaning and influence
Since the inception of this unusual science, many counter-intuitive aspects and results of the study of quantum mechanics have provoked much philosophical debate and many interpretations. Even fundamental questions, such as the rules for calculating various amplitudes and probability distributions, deserve respect from the public and many leading scientists.
For example, he once sadly noted that he was not at all sure that any scientist even understood quantum mechanics. According to Steven Weinberg, at the moment there is no interpretation of quantum mechanics that would suit everyone. This suggests that scientists have created a “monster” whose existence they themselves are unable to fully understand and explain. However, this does not in any way harm the relevance and popularity of this science, but attracts young specialists to it who want to solve truly complex and incomprehensible problems.
In addition, quantum mechanics has forced us to completely reconsider the objective physical laws of the Universe, which is good news.
Copenhagen interpretation
According to this interpretation, the standard definition of causality that we know from classical physics is no longer needed. According to quantum theories, causality in our usual understanding does not exist at all. All physical phenomena are explained in them from the point of view of the interaction of the smallest elementary particles at the subatomic level. This area, despite its apparent improbability, is extremely promising.
Quantum psychology
What can be said about the relationship between quantum physics and human consciousness? This is beautifully written about in a book written by Robert Anton Wilson in 1990 called Quantum Psychology.
According to the theory outlined in the book, all processes occurring in our brain are determined by the laws described in this article. That is, this is a kind of attempt to adapt the theory of quantum physics to psychology. This theory is considered parascientific and is not recognized by the academic community.
Wilson's book is notable for the fact that he provides a set of various techniques and practitioners who, to one degree or another, prove his hypothesis. One way or another, the reader must decide for himself whether he believes or not the validity of such attempts to apply mathematical and physical models to the humanities.
Wilson's book was seen by some as an attempt to justify mystical thinking and tie it to scientifically proven newfangled physics formulations. This very non-trivial and brilliant work has remained in demand for more than 100 years. The book is published, translated and read all over the world. Who knows, perhaps with the development of quantum mechanics, the attitude of the scientific community towards quantum psychology will change.
Conclusion
Thanks to this remarkable theory, which soon became a separate science, we were able to explore the surrounding reality at the level of subatomic particles. This is the smallest level of all possible, completely inaccessible to our perception. What physicists previously knew about our world needs urgent revision. Absolutely everyone agrees with this. It became obvious that different particles can interact with each other at completely unimaginable distances, which we can only measure using complex mathematical formulas.
In addition, quantum mechanics (and quantum physics) have proven the possibility of multiple parallel realities, time travel, and other things that throughout history were considered only the province of science fiction. This is undoubtedly a huge contribution not only to science, but also to the future of humanity.
For lovers scientific picture world, this science can be both a friend and an enemy. The fact is that quantum theory opens up wide possibilities for various speculations on parascientific topics, as has already been shown in the example of one of the alternative psychological theories. Some modern occultists, esotericists and supporters of alternative religious and spiritual movements (most often psychocults) turn to the theoretical constructs of this science in order to substantiate the rationality and truth of their mystical theories, beliefs and practices.
This is an unprecedented case when simple speculations of theorists and abstract mathematical formulas led to a real scientific revolution and created a new science that crossed out everything that was previously known. To some extent, quantum physics refuted the laws of Aristotelian logic, because it showed that when choosing “either-or” there is one more (and possibly several) alternative option.
