If you allow a tennis ball to fall on a hard surface like a table, you can be sure it will bounce back. If you were to do the same experiment with a quantum particle, you would find that this classic path was only one of the possible results, with less than 100% probability. Surprisingly, there is a limited chance that the quantum particle will pass through the tunnel to the other side of the table and go through the barrier as if it were no obstacle at all. Wikimedia comments on user MichaelMaggs and (edited by) Richard Bartz [19659003] If we lived in a completely classic, non-quantum universe, it would be easy to feel things. When we split things into smaller and smaller pieces, we would never reach a limit. There would be no basic, indivisible building blocks in the universe. Instead, our cosmos would be made of continuous material, where if we built a word-like sharper knife, we could always cut something in smaller and smaller pieces. That dream went dinosaur's way in the early 20th century. Experiments by Planck, Einstein, Rutherford and others showed that matter and energy could not be made of a continuous substance but rather divided into discrete pieces, known as quantum today. The original idea of quantum theory had too much experimental support: The universe was not basically classic. Going to smaller and smaller distance scales reveals more basic nature views, which means that we can understand and describe the smallest waves, We…
Wikimedia comments on user MichaelMaggs and (edited by) Richard Bartz [19659003]
If we lived in a completely classic, non-quantum universe, it would be easy to feel things. When we split things into smaller and smaller pieces, we would never reach a limit. There would be no basic, indivisible building blocks in the universe. Instead, our cosmos would be made of continuous material, where if we built a word-like sharper knife, we could always cut something in smaller and smaller pieces.
That dream went dinosaur’s way in the early 20th century. Experiments by Planck, Einstein, Rutherford and others showed that matter and energy could not be made of a continuous substance but rather divided into discrete pieces, known as quantum today. The original idea of quantum theory had too much experimental support: The universe was not basically classic.
Perhaps the first three decades of the 20th century, physicists struggled to develop and understand the nature of the universe on these small, puzzling scales. New rules were needed, and to describe them, new and contra-intuitive equations and descriptions. The idea of an objective reality went out of the window, replaced by terms such as: probability distributions rather than predictable results
The particles describing reality can no longer be described solely as particle-like. Instead, they had elements of both waves and particles and behaved according to a new set of rules.
Originally, these descriptions concerned a large part of the physicists. These problems did not arise simply because of the philosophical difficulties associated with accepting a non-deterministic universe or a changed definition of reality, although there were certainly many who were disturbed by these aspects.
Instead, the difficulties were more robust. The theory of special relativity was well understood, but quantum mechanics, which was originally developed, only worked for non-relativistic systems. By converting quantities as position and momentum from physical properties to quantum mechanics & nbsp; – A specific class of mathematical function & nbsp; – These bizarre aspects of reality can be incorporated into our equations.
But the way you allowed your system to develop depends on time, and the term time is different for different observers. It was the first existential crisis that faced quantum physics.
We say that a theory is relativist invariant if its laws do not change for different observers: for two people move at different speeds or in different directions. The formulation of a relativist invariant version of quantum mechanics was a challenge that took the greatest thoughts in physics many years to overcome, and was finally achieved by Paul Dirac in the late 1920s.
The result of his efforts gave what is now called Dirac equation which describes realistic particles like the electron and also stands for:
This was a big step forward and the Dirac equation did an excellent job of describing many of the earliest known basic particles, including the electron, positron, muon, and even (to some extent) proton, neutron and neutrino.
But it could not “I do not take everything into account. Photons, for example, could not be fully described by the Dirac equation, because they had error particle properties. Photon interactions were not, explain phenomena such as radioactive decay were completely impossible within Dirac’s framework of relativistic quantum mechanics, even with this huge progress, an important part of history was missing.
The major problem was that quantum mechanics, even relativistic quantum mechanics, was not large enough to describe everything in our universe.
Think about what happens if you place two electrons close together. If you think classically, you think of these electrons, each of which generates an electric field, and also a magnetic field if they are moving. Then, the second electron will see the field generated by the first, experiencing a force because it interacts with the outer field. This works both ways, and thus a force is exchanged.
This would work just as well for an electric field as it would for any other type of field: as a gravity field. Electrons have mass as well as charge, so if you place them in a gravity field, they would respond based on their mass in the same way their electric charge would force them to respond to an electric field. Even in general relativity, where mass and energy curve space, the curved space is continuous, just like any other field.
The problem with this type of formulation is that the fields are in the same way as position and momentum is during a classical treatment. Fields press particles that are in certain positions and change their momentum. But in a universe where positions and moments are uncertain, and need to be treated as operators rather than a physical quantity with a value, we change ourselves by letting our treatment of fields be classic.
It was the great advance of the idea of quantum field theory or its related theoretical advances: second quantization . If we treat the field itself as quantum, it will also become a quantum mechanical operator. Sudden processes that were not predicted (but observed) in the universe, such as:
Although physicists typically think of quantum field theory in particle exchange and Feynman charts, this is just a computational and visual tool that we use to try to add some intuitive feeling to this concept. . The Feynman charts are incredibly useful, but they are a perturbative (ie approximate) method of calculating, and quantum field theory often provides fascinating, unique results when you take a non-perturbative approach.
But the motivation for quantifying the field is more fundamental than the argument between those who favor disturbing or non-interfering methods. You need a quantum field theory to successfully describe the interactions between & nbsp; not just particles and particles or particles and fields, but also between fields and fields as well. With quantum field theory and further advances in their applications, everything from photon photo spreading to the strong nuclear power was now explained.
At the same time, it immediately became clear why Einstein’s way of uniting would never work. Motivated by Theodr Kaluza’s work, Einstein became fond of the idea of unifying general relativity and electromagnetism in a single frame. But general relativity has a fundamental limitation: it is a classical theory that is the core, with its perception of continuous, non-quantized space and time.
If you refuse to quantify your fields, you make yourself lack the important, inherent universe characteristics. This was Einstein’s fatal error in his unity attempt, and the reason why his attitude toward a more fundamental theory has been completely (and rightly) abandoned.
The universe has proven time and again to be quantum in nature. These quantum properties occur in applications ranging from transistors to LED screens to the Hawking radiation that cause black holes to decompose. The reason why quantum mechanics is fundamentally flawed on its own is not because of the strange nuclear that the new rules adopted, but because it did not go far enough. Particles have quantum properties, but they also interact through fields that are quantum themselves and all exist in a relativist invariant way.
Perhaps we will really achieve a theory of everything, where every particle and interaction is & nbsp; relativistic and quantized. But this quantum leap must be part of every aspect of it, even those parts that we have not yet successfully quantified. In Haldane’s immortal words, “my own suspicion that the universe is not only more alien than we suppose but alien to we can assume.”
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If you wanted to answer the question of what is really fundamental in this universe, you need to examine matter and energy on the smallest scale, if you tried to divide particles into smaller ones and smaller elements, you would start to notice some extremely funny things when you walked less than a distance of a few nanometers, where physical physics The rules still apply.
On even smaller scales, reality begins to work in strange, contra-intuitive ways. We can no longer describe reality as made up of individual particles with well-defined properties such as position and momentum. Instead, we go into the quantum kingdom: where basic indeterminism regulates, and we need a whole new description of how nature works. But even the quantum mechanics have their failures here. They condemned Einstein’s greatest dream – from a complete, deterministic description of reality – from the beginning. Here’s why.
The particles describing reality can no longer be described solely as particle-like. Instead, they had elements of both waves and particles, and behaved according to a new set of rules.
Originally, these descriptions concerned a large part of the physicists. These problems did not arise simply because of the philosophical difficulties associated with accepting a non-deterministic universe or a changed definition of reality, although there were certainly many who were disturbed by these aspects.
Instead, the difficulties were more robust. The theory of special relativity was well understood, but quantum mechanics, which was originally developed, only worked for non-relativistic systems. By converting quantities as position and momentum from physical properties to quantum mechanics – a specific class of mathematical function – these bizarre aspects of reality can be incorporated into our equations.
But the way you got your system to develop was due to the time, and the term time is different for different observers. It was the first existential crisis that faced quantum physics.
We say that a theory is relativist invariant if its laws do not change for different observers: for two people move at different speeds or in different directions. The formulation of a relativist invariant version of quantum mechanics was a challenge that took the greatest thoughts in physics for many years to overcome, and finally achieved by Paul Dirac in the late 1920s.
The result of his efforts gave what is now called Dirac equation which describes realistic particles like the electron and also stands for:
This was a big step forward and the Dirac equation did an excellent job of describing many of the earliest known basic particles, including the electron, positron, muon, and even (to some extent) proton, neutron and neutrino.
But it could not “I do not take everything into account. Photons, for example, could not be fully described by the Dirac equation, because they had error particle properties. Photon interactions were not, explain phenomena such as radioactive decay were completely impossible within Dirac’s framework of relativistic quantum mechanics, even with this huge progress, an important part of history was missing.
The major problem was that quantum mechanics, even relativistic quantum mechanics, was not large enough to describe everything in our universe.
Think about what happens if you place two electrons close together. If you think classically, you think of these electrons, each of which generates an electric field, and also a magnetic field if they are moving. Then, the second electron will see the field generated by the first, experiencing a force because it interacts with the outer field. This works both ways, and thus a force is exchanged.
This would work just as well for an electric field as it would for any other type of field: as a gravity field. Electrons have mass as well as charge, so if you place them in a gravity field, they would respond based on their mass in the same way their electric charge would force them to respond to an electric field. Even in general relativity, where mass and energy curve space, the curved space is continuous, just like any other field.
The problem with this type of formulation is that the fields are in the same way as position and momentum is during a classical treatment. Fields press particles that are in certain positions and change their momentum. But in a universe where positions and moments are uncertain, and need to be treated as operators rather than a physical quantity with a value, we change ourselves by letting our treatment of fields be classic.
It was the great advance of the idea of quantum field theory or its related theoretical advances: second quantization. If we treat the field itself as quantum, it will also become a quantum mechanical operator. Sudden processes that were not predicted (but observed) in the universe, such as:
Although physicists typically think of quantum field theory in particle exchange and Feynman charts, this is just a computational and visual tool that we use to try to add some intuitive feeling to this concept. . The Feynman charts are incredibly useful, but they are a perturbative (ie approximate) method of calculating, and quantum field theory often provides fascinating, unique results when you take a non-perturbative approach.
But the motivation for quantifying the field is more fundamental than the argument between those who favor disturbing or non-interfering methods. You need a quantum field theory to successfully describe the interaction between not only particles and particles or particles and fields, but also between fields and fields. Med kvantfältteori och ytterligare framsteg i deras tillämpningar var allt från fotonfotonspridning till den starka kärnkraften nu förklarlig.
At the same time, it became immediately clear why Einstein's approach to unification would never work. Motivated by Theodr Kaluza's work, Einstein became enamored with the idea of unifying General Relativity and electromagnetism into a single framework. But General Relativity has a fundamental limitation: it's a classical theory at its core, with its notion of continuous, non-quantized space and time.
If you refuse to quantize your fields, you doom yourself to missing out on important, intrinsic properties of the Universe. This was Einstein's fatal flaw in his unification attempts, and the reason why his approach towards a more fundamental theory has been entirely (and justifiably) abandoned.
The Universe has shown itself time and time again to be quantum in nature. Those quantum properties show up in applications ranging from transistors to LED screens to the Hawking radiation that causes black holes to decay. The reason quantum mechanics is fundamentally flawed on its own isn't because of the weirdness that the novel rules brought in, but because it didn't go far enough. Particles do have quantum properties, but they also interact through fields that are quantum themselves, and all of it exists in a relativistically-invariant fashion.
Perhaps we will truly achieve a theory of everything, where every particle and interaction is relativistic and quantized. But this quantum weirdness must be a part of every aspect of it, even the parts we have not yet successfully quantized. In the immortal words of Haldane, “my own suspicion is that the Universe is not only queerer than we suppose, but queerer than we can suppose.”