When we talk about atoms, we often imagine that it is a miniature solar system with a tiny and dense nucleus at its center, surrounded by electrons rotating around the nucleus at high speed. However, such a metaphor far underestimates the vastness of the space inside the atom. In fact, if you zoom in to the size of a stadium, the nucleus is only the size of a mung bean, and the electrons are so small that they are almost impossible to find in such a huge space.
More than 99.99% of the inside of the atom is empty, a figure that makes one wonder if the inside of the atom is really like nothing. But this is far from the truth. Although the clouds of electrons outside the nucleus seem to permeate the vast expanse of space, they are actually solid particles with a definite position and state of motion. Similarly, protons and neutrons, which make up the nucleus of an atom, are particles with mass and solid form. This seemingly empty space is actually full of material reality.
The nucleus: a dense treasure trove in the microcosm
When discussing the composition of the atomic nucleus, we cannot help but marvel at its complexity and compactness. The nucleus, a tiny structure that occupies the vast majority of atomic mass, is made up of two elementary particles: protons and neutrons. Protons, which carry a positive charge of one unit, are the core component in the nucleus that determines the chemical properties of the element. Neutrons, although electrically neutral externally, play the role of a stabilizer in the nucleus and are an important factor in maintaining the stability of the nucleus.
On the periodic table, the number of protons in the nucleus of each element, from hydrogen to uranium, is different, which is known as atomic number. It not only determines the type of element, but also affects the stability of the nucleus. For example, a nucleus with a proton count of less than 20 has approximately the same number of protons as neutrons, while when the number of protons is greater than 20, the nucleus needs more neutrons in order to remain stable.
However, the density of the nucleus is unimaginable, it is about 10 to the power of 17 kilograms per cubic meter, which means that if a space the size of a fingertip were filled with the nucleus, its weight would reach a staggering 100 million tons.
This compactness makes us have to re-examine the space inside the atom, which looks empty on a macroscopic scale, but on a microscopic scale it is a wonderful world of extreme accumulation of matter.
Nuclear force: a powerful glue in the microcosm
Protons and neutrons are able to bond together to form a stable nucleus because of a strong interacting force called the nuclear force. The nuclear force is an extremely powerful force that is able to overcome the electrostatic force repulsion between protons due to the same charge, pulling them tightly together. This power is much more powerful than any kind of force that we come into contact with in our daily lives.
When the two protons are close enough, the nuclear force kicks in, quickly pulling them together while releasing a huge amount of energy. This process can be observed in nature, such as the nuclear fusion reaction that takes place inside a star. In the laboratory, this process can also be simulated by the High Energy Particle Collider to study the properties of atomic nuclei.
However, it is not easy to press the protons together, and there is a Coulomb barrier made of electrostatic force between them. Protons can only bind when the energy provided by the outside world is large enough to overcome this barrier. This also explains why the nucleus is usually stable, while nuclear reactions only occur at extremely high energies.
Inside the nucleus, the combination of protons and neutrons is not arbitrary, and the combination between them follows a certain regularity. This regularity leads to the different properties of the nuclei of different elements, thus constituting a rich and colorful material world.
Quarks and gluons: the basic masonry of the microcosm
To delve into the mysteries of the atomic nucleus, we have to mention the elementary particles that make up protons and neutrons - quarks. Quarks are elementary particles smaller than atoms, and they come together in a complex way to form the nucleus we know as an atom. So far, scientists have discovered six quarks with different "tastes", including upper (u), lower (d), cane (c), odd (s), top (t), and bottom (b) quarks.
Quarks not only have mass, they also carry an electric charge. In protons, two upper quarks have a charge of +2⁄3 and one lower quark has a charge of -1⁄3, and it is this combination of charges that makes the proton as a whole display a +1 charge. The neutron is composed of one upper quark and two lower quarks, and its total charge is zero, indicating that it is electrically neutral.
The force that holds quarks together comes from another elementary particle – gluons. The gluon has no mass, but it is responsible for transferring the strong force between the quarks, allowing the quarks to be tightly bonded. This binding force is so strong that at the quark level, protons and neutrons exhibit extremely high stability.
The existence of quarks and gluons has been confirmed by scientists through experiments at the High Energy Particle Collider, which not only reveal the microstructure of matter, but also provide key clues to our understanding of the stability of atomic nuclei. From this point of view, the stability of the nucleus is actually a macroscopic representation of the interaction between quarks and gluons.
Elementary Particle Family: The microscopic building blocks of the universe
In exploring the deepest layers of matter, we discover a colorful family of elementary particles. This family includes quarks, leptons, canon-bosons, and Higgs bosons. Each elementary particle has its own unique properties and functions, and together they form the microscopic basis of the universe.
The lepton family includes electrons, μ atoms, τ ions, and three neutrinos corresponding to them. Electrons are the main components of electron clouds in atoms, while μ and τ are heavy particles produced in high-energy physical processes. Neutrinos, on the other hand, are very light particles that barely interact with any matter, making them very difficult to detect.
Gauge bosons are particles that are responsible for transmitting fundamental forces, including photons (the medium of electromagnetic interaction), gluons (the medium of strong interaction), and W and Z bosons (the medium of weak interaction). These particles play a crucial role in the theory of particle physics, and they ensure that the various fundamental interactions can be carried out in the way predicted by the theory.
The Higgs boson, on the other hand, is a recently experimentally confirmed particle that is crucial to explaining why elementary particles have mass. The presence of the Higgs boson fills the final piece of the puzzle of the Standard Model of particle physics.
These elementary particles, although we cannot directly perceive them in our daily lives, are the building blocks of everything we see on a microscopic scale. Through the study of these particles, we can not only understand the basic structure of matter, but also explore the origin and evolution of the universe.
Implications for Photon Mass: The Materiality of the Macrocosmic Universe
In physics, photons have always been regarded as elementary particles without rest mass, which are quanta of electromagnetic waves and are responsible for transmitting electromagnetic interactions. However, the latest scientific tests have shown that photons actually have mass, albeit a very tiny mass, less than 1.2×10 kilograms to the minus 51st power. This discovery has far-reaching implications for our understanding of the composition of the macrocosm.
The existence of photon mass means that all the matter that makes up the macrocosm, whether it is galaxies, stars, planets, or even us human beings, is a real three-dimensional object, not an illusory world composed of one-dimensional "strings" or pure energy. This fact provides a solid scientific basis for the reality of matter, refuting ethereal theories that are based on mathematical reasoning rather than experimental evidence.
In the field of science, any theory needs to be verified by experiments. Cutting-edge physics theories such as string theory, although mathematically attractive, have not yet been experimentally proven. Therefore, we should use experiments to test scientific theories, rather than relying solely on mathematical models to extrapolate the real world.
Through the study of microscopic particles, especially the detection of the mass of photons, we are more convinced that we live in a material, four-dimensional, real universe. Every corner of this universe is made up of real matter, which follows the laws of nature and is constantly moving and changing.