Do subatomic particles like electrons really need to spin like a pendulum?
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| How electrons spin outside the nucleus! |
The answer to this question would be yes, if Rutherford’s atomic model were perfectly correct. In his model, electrons were supposed to orbit the nucleus. To maintain this rotation, an additional angular momentum was needed, which came from the electron’s rotation on its own axis. The matter may seem simple when looking at the daily motion of the Earth or the pendulum’s rotation.
The rotation of electrons
The shape of electrons is like a point.
Electrons are not the Earth or the pendulum. They are not subject to Newton’s mathematical reality. The paths of the subatomic world are blocked by the strange laws of quantum theory, where no matter how well-established common sense is, it is certain that the path will not be found.
Do electrons actually spin?
This is where the biggest mistake is made. We often think of electrons as small spheres, like tiny balls. But in reality, the electron is not a sphere. It is a point-like particle, which has no three-dimensional extension. If there is no three-dimensionality, how can there be any talk of rotation? That is, the electron does not rotate. So spin? There is spin, but it is not the rotation of the lattice. This is the internal quantum nature of the particle. For ease of understanding, we bring in the concept of rotation, but the actual phenomenon does not stand up to comparison with rotation.
French scientist Louis de Broglie showed that any moving object has a wave nature. His theory gives the electron the dual identity of wave-particle. The problem is that his equation did not explain how the electron would remain stable around the nucleus.
Schrödinger came and untangled that tangle. He showed,
The electron does not rotate in any orbit. Rather, it has the possibility of being located at different points in the energy level, somewhere more, somewhere less. Heisenberg’s uncertainty principle added another layer. If you try to determine the position of an electron, its motion becomes uncertain. As a result, the idea that electrons revolve around the nucleus is completely invalid. Since electrons do not rotate, let alone rotate on their own axis.
So where does the word spin come from?
In 1999, Scientific American showed in a famous article that it is not right to compare the spin of electrons with the daily motion of the Earth. Why? Because, the word spin came from the effect of classical electromagnetism. When a charged object rotates, a magnetic field is created around it. So when it was found that electrons also behave like tiny magnets, scientists thought that electrons must be spinning! That’s why they named it “spin”. But later, quantum theory showed that particles do not rotate, but still magnetism is seen. The name remained, the explanation has changed.
In 1922, two German physicists Otto Stern and Walther Gerlack sent a beam of silver atoms through a magnetic field. They saw that the beam was split into two parts, one bent upwards, the other downwards. If the spin of the electron was really like the rotation of a pendulum, then countless piles of directions would have been visible on the screen. But in reality, only two parts were seen. That is, only two values of spin, spin-up ↑, spin-down ↓, are established from this, the two-dimensionality of spin is established.
In 1924, Wolfgang Pauli based his famous Pauli exclusion principle on this experiment. Even if the first three quantum numbers of two electrons in an energy level are the same, the spin must be opposite. So in the case of a pair of electrons, one is spin-up, the other is spin-down. Then in 1925, Goudsmith and Uhlenbeck established the concept of spin as a full scientific theory.
Spin is an internal property of quantum particles, which is the main reason for the magnetic behavior of the particles. It is not an apparent rotation. It is a structural property inside the particle that cannot be seen with the naked eye, nor can it be fully grasped by the imagination. Not only electrons, but all fundamental particles, including protons, neutrons, mesons, and even quarks, have spin.
