Feynman Diagrams

Sometimes there are such things in the universe that even if you don't know why, that thing just is. 

For example, the sum of the interior angles of a triangle.

You can divide the angles in any other way, it doesn't matter. The sum of the interior angles of a triangle is half the angle of a circle, regardless of the shape of the triangle, that is, 180 degrees with the angle system we know.

Why is this so?

Throughout history, those who have been engaged in geometry have developed thousands of theorems and proved these theorems in thousands of ways.

There is no reason, it is just like that!

Likewise, we count numbers, one, two, three...

Numbers didn't just appear out of nowhere. They are also a fact of life. One apple is one apple is two apples.

Then we developed the subtraction process to work with the logic that if I eat one of the two apples, there will be one apple left.

Human beings have entered such strange subjects in mathematics that, for example, if you multiply a number by itself, you will get its square, and the opposite of this process is the square root process of the world of numbers.

However, when he realised that the negative numbers obtained by subtraction could not have a square root, he added the square root of "-1", symbolised by "i" in mathematics, to his calculations, saying what if I attribute a relative value to it?

He realised that this number "i", even if it has a relative value, is useful in some operations. In mathematics, we call this complex numbers. It is a number that does not exist in reality, but somehow it helps us to get out of the way in some complicated calculations.

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I have been writing articles on physics for a while, especially on the world of subatomic particles, particles of the quantum world.

From the history of the development of the event, I also go into details that are interesting to me in some articles.

I hope you are not bored.

I have not received advanced physics education, so I can convey the information in the articles to you as much as I have learnt from the sources I have read, the videos I have watched, or the online courses of some universities.

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I've been wondering for a while, these subatomic particles are not visible to the eye. They can't be seen with a microscope or anything like that.

How did scientists come up with these theories? 

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Another thing that puzzles me is that scientists work in facilities like CERN, which cost billions of dollars, or huge telescopes, which are certainly built at huge expense. 

These include huge neutrino-capturing facilities built deep in gold mines, which are extremely costly. 

We can even include the giant facility that captures gravitational waves in these huge investments.

How is it that scientists were able to persuade the world governments to make these huge investments?

In this way, they have been able to experimentally prove the theories they have put forward in these facilities!

What is the secret of this?

How could states be persuaded to allocate such huge resources to these issues?

Are the fierce financial fights of today's world worth devoting such enormous resources to these issues? 

Does the benefit from all these studies benefit the capitalist world? 

Is it worth making these huge investments?

Apparently, it is worth it, so much expense is being incurred!

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We may come back to the subject of these huge costly investments later, but at the moment I would like to mention a few more scientists who have been of great help in the development of quantum theory.

Yes, with the experiments carried out in these large facilities, all the subatomic particles mentioned in the theory, which should exist according to the theory, can now be observed in some way.

By theory I mean the standard model of quantum theory, fermions, leptons and bosons. 

Then electrons, gluons, neutrinos, muons.

And then there's the god particle! The so-called Higgs boson.

In addition to that, there are actually their antiparticles!

Fermionic antiparticles!

Anti quarks, anti leptons. Positrons, anti gluons, anti-neutrinos, anti muons...

This is a very complicated subject, I won't go into details of the standard model, I think the names of the particles are enough.

As far as I know, as far as I know, research is still going on in the facilities in case there are other particles.

Scientists now have a huge hadron accelerator in their hands.  

CERN!

Accelerate, accelerate, collide particles with each other, who's holding your hand?

Collide protons with protons, collide with electrons, collide with neutrons, collide and collide and collide atoms with each other. 

Maybe one day they will find another set of subatomic particles that have not been found so far!

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I said I wanted to talk about a few more scientists related to quantum theory.

Where were we last time in the last article?

Einstein and Bohr were arguing among themselves, and although they were scientists who laid the first building blocks of the quantum world, there was something that Albert Einstein could not get his head round. Quantum entanglement!

God doesn't play dice, Einstein said last time! But he was proved wrong.

However, in those days, when Einstein was very famous not only in the world of science, but also in the whole world, there was no standard model that we use to model the particles of the quantum world, which we call the standard model today!

Yes, electrons were discovered during Einstein's lifetime, it was already known that the atom has a nucleus, it was also known that there are protons and neutrons in the nucleus, and it was also known that there is a lot of space between the nucleus and electron orbits.

Einstein was the first to calculate the dimensions of an atom, but the atom consists of a vacuum!

The atomic model thought at that time was that electrons revolve around the nucleus at certain energy levels, just like the planets revolve around the sun, and when they gain energy with photons or lose energy by emitting photons, they make a quantum leap from one orbit to another.

This is the model of the atom.

This is what we were taught in physics classes in high school, if any of you are my age and remember physics classes.

Later on, in chemistry classes, maybe it was in chemistry classes in university years, we learnt that electrons are not in circular orbits around the nucleus of the atom, but that they rotate at different energy levels, it would be wrong to say that they even rotate, that they exist in a cloud of possibilities. 

I remember they told us that each energy level can contain a certain amount of electrons.

Again, we were analysing chemical reactions with quite complicated formulas. I liked chemistry class too.

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Yes, today we know that the quantum world consists of lower particles under the name of the standard model.

The particles I have just mentioned, which are thought to be present in this model, can now be observed and proved to be correct through various experiments.

So what happened after Einstein and Bohr? How did we get to this level?

How was it decided that the atomic nucleus is composed of smaller particles?

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It all boils down to maths.

The results of the mathematical calculations somehow indicated that these particles must exist.

However, this was not so easy.

Many scientists, who were working on many formulae, calculated that the results of the formulae always led to inextricable results, and finally they came to the conclusion that there could not be more sub-particles of the atom.

However, some things still did not fit into the formulae.

Until one day in 1927, Paul Dirac, who is today considered to be the greatest scientist in physics after Isaac Newton, adapted Albert Einstein's theory of relativity to the subatomic quantum world and came up with a complicated formula.

The Dirac equation, which was named after him, revolutionised the quantum world of particles, but no scientist, including himself, could fully understand his equation.

Even Einstein did not have a favourable opinion about Paul Adrian Maurice Dirac, who was considerably younger than him and was actually a mathematician.

In fact, what Dirac did was to rearrange the quantum equations developed by Bohr and others, which did not give accurate results because electrons move around the nucleus at almost the speed of light, with Einstein's general theory of relativity on space-time, which was developed by taking into account the speed of light.

The results obtained from the formula correspond exactly with the experimental observations of electron motions.

However, Einstein also objected that there must be an antimatter in addition to the matter we know from the formula that the universe is made of!

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At this point, an issue I mentioned at the beginning of this article gains importance.

Although the results of the calculations showed that some particles that do not normally exist in nature should also exist in the quantum world, no one, including Dirac himself, wanted to believe in this absurd theory in those days.

Just like in mathematics, can a negative number have a square root? But if you add the concept of complex numbers to mathematics, it does! It doesn't exist in reality, but suppose it does! 

Matter, antimatter! 

Anti particles! The electron, the anti-electron, the positron!

Normally, it is impossible for them to exist, but according to the calculations, they must exist!

Here is the beauty of mathematics.

Those were the days of Einstein and Bohr, but Dirac shared the 1933 Nobel Prize in Physics with Erwin Schrödinger for his work.

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Dmitri Vladimirovich Skobeltsyn was a Soviet academic and physicist. In 1929, he studied ionising radiation entering the atmosphere from space with a particle detector using water vapour. 

In his studies, he observed that ionising radiation particles were not only deflected in the direction they should normally be, but also deflected in the opposite direction.

In 1932, the American physicist Carl David Anderson used Skobeltsyn's work to prove the existence of the positron and was awarded the Nobel Prize in Physics in 1936.

Paul Dirac's formula, which even he could not believe, was exactly right!

The positron exists! Antimatter exists!

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Dirac's formula is correct, but there is a problem. The formula was developed on a single electron!

Atoms, on the other hand, have more than one electron, and even though the formula has been tried to be organised as a multi-electron formula for a period of 30 years since these years, no result has been obtained.

Because the movements of electrons around the atomic nucleus are affected by each other, and the mystery of how this effect occurs cannot be solved.

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Another scientist, the American physicist Richard Philips Feynman, has an answer to this interaction. 

Yes, I am talking about Feynman, who was also involved in the construction of the atomic bombs dropped on Japan during World War II.

The theory developed by Feynman is known as "quantum electrodynamic theory". Richard Feynman put forward the diagrams known today as Feynman diagrams on the interaction of electrons in the electromagnetic field.

The results obtained from the calculations made using the diagrams are so consistent with the results obtained in experiments that the error rates can be said to be as low as the thickness of a strand of hair in a thousand kilometres.

Feynman was able to produce these diagrams, but no one, including his students and even himself, could understand this theory.

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Another conclusion from Feynman's diagrams is that what we call a vacuum is not really a vacuum. 

The void in a vacuum is actually something that is empty on average.

(There is a famous computer-generated video on this subject, the fluctuating vacuum imitation video, which symbolises the transformation of a matter into an antimatter in the form of fluctuations in a cube, the enthusiasts will immediately remember this video!)

Of course, this is unbelievable!

As I mentioned at the beginning of the article, in mathematics, the square root of a negative number does not exist in reality, but complex numbers symbolised by "i" can be used hypothetically in some formulas in order for the calculations to give proper results, the same thing, what we call the void is a medium in which matter and antimatter constantly exist and disappear, and the average result is empty according to Feynman diagrams!

Feynman himself cannot believe this result!

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Feynman had to show the electron interactions in diagrams because the formulae he put forward to explain the interactions became so complicated that no mathematician could solve them.

In order to share his ideas with the scientific world, Feynman planned to open the subject to other scientists at a scientific congress held on Shelter Island in 1947.

Niels Bohr, who laid the foundations of quantum mechanics, Paul Dirac, who formulated the antimatter theory, and Robert Oppenheimer, who was responsible for the construction of the atomic bomb, were present at the conference.

Almost all scientists, especially Niels Bohr, objected to Feynman, who explained his ideas with some diagrams instead of formulae as these scientists were used to. Bohr was the first to object that it was not possible for the quantum world to consist of such hypothetical particles, because Feynman's ideas were contrary to all the ideas he had devoted his life to until this age.

How ruthless people can be, even if they are scientists, when it goes against their interests, isn't it?

Moreover, if someone expresses ideas that are contrary to the subject they have devoted their lives to!

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Paul Dirac also said that there was no need to listen to Feynman, that his ideas had nothing to do with reality, and even denounced him as an idiot who understood nothing of quantum mechanics.

Feynman knew that his diagrams were correct, but he could not convince the scientific world.

Except for a scientist of his own age, Julian Schwinger, Schwinger, like Feynman, had been working on this subject and the results they both found were similar, albeit in different ways.

Over the next few years, Feynman and Schwinger's work together attracted the attention of non-conservative scientists such as Bohr and Dirac, and by the late 1950s, innovators in quantum mechanics began to adopt Feyman and Schwinger's ideas.

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This is a whole new way of looking at quantum mechanics.

As physicists work on the theory with Feynman diagrams, they calculate that new and new particles may exist.

It turns out that not only matter-antimatter, neutron-anti-neutron, electron-positron, electron-positron, but also the atomic nucleus may consist of lower particles. 

The possibility of muons, for example, astonishes scientists even more.

The quantum world is now in turmoil!

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It will be another scientist who picks up the pieces.

Murray Gell-Mann, another American physicist, winner of the 1969 Nobel Prize in Physics.

Gell-Mann is the physicist who brought order to the chaotic world of transatomic particles.

He grouped particles and named the fundamental particles "quarks".

With his experiments in an electron accelerator building, Gell-Mann succeeded in splitting the proton, and the first version of the standard model was now available.

Matter consists of electrons and quarks, antimatter consists of positrons and antiquarks.

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Today, quantum theory has been sufficiently analysed and proven experimentally.

Nevertheless, there is still so much to be worked on that today it is even possible to produce brand new substances using the rules of the quantum world.

Yes, dealing with subatomic particles may be a method for developing brand new substances that the capitalist world can use. 

Who knows what will come to the market in the coming years in this way.

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Yes, it was quite a long article today. But at least for me, the historical development in the quantum world has settled in my mind a little more.

I hope it was useful.

As always, let me end this article by saying stay with science.

Love and respect to everyone from Moscow