Non-matter in physics
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Non-Matter Concepts in Physics: Definitions and Context
In physics, "non-matter" typically refers to entities or phenomena that do not fit the traditional definition of matter—substances with mass and volume. This includes fields, forces, spacetime properties, and certain theoretical constructs that influence the universe but are not made of atoms or particles in the usual sense.
Non-Baryonic and Non-Exotic Matter: Dark Matter and Energy
A major area of research involves non-baryonic dark matter, which is matter that does not consist of protons, neutrons, or electrons. This form of matter is necessary to explain the structure and evolution of the universe, as baryonic matter alone cannot account for observed phenomena. Some models propose new types of quarks as candidates for non-baryonic dark matter, suggesting that these particles could have been produced in the early universe and remain as cold dark matter today . Other theories suggest that dark matter and dark energy might not be forms of matter at all, but rather manifestations of spacetime properties such as nonmetricity or non-Newtonian mathematics, which could mimic the effects attributed to dark matter and energy without requiring new particles 586.
Nonlocal and Non-Relativistic Theories: Spacetime and Gravity
Nonlocal field theories and non-relativistic expansions of general relativity explore how gravity and spacetime might behave differently from standard models, especially in the presence or absence of matter. These approaches maintain consistency with known solutions of Einstein's theory and suggest that the stability and properties of spacetime are closely linked to the presence of matter, but can also be described in frameworks where matter is not the primary actor 179. Some models even allow for the existence of wormholes without requiring exotic (non-standard) matter, by modifying the energy-momentum tensor in the equations of gravity .
Non-Abelian States and Quasiparticles: Beyond Fermions and Bosons
In quantum mechanics, all known particles are classified as either fermions or bosons. However, in certain two-dimensional systems, interactions can give rise to quasiparticles that do not fit this dichotomy. These "non-Abelian" states of matter have ground states that are degenerate and can be shifted by exchanging identical quasiparticles. While these are still forms of matter, their properties challenge the traditional understanding of particle classification and may have applications in quantum computation .
Non-Metric Properties of Spacetime: Simulating Matter and Energy
Some theories propose that properties of spacetime itself, such as nonmetricity and torsion, can act as sources of gravity and mimic the effects of matter and energy. In these models, the non-metric aspects of spacetime are described mathematically as stress-energy tensors, which can be interpreted as a specific form of (possibly dark) matter and energy. These properties interact with standard matter only through gravity and may provide alternative explanations for dark matter and dark energy .
Conclusion
The concept of non-matter in physics encompasses a wide range of ideas, from non-baryonic dark matter and non-Abelian quasiparticles to nonlocal gravity and non-metric properties of spacetime. These theories challenge and expand the traditional boundaries of what is considered matter, offering new ways to understand the universe's structure, the nature of dark matter and energy, and the fundamental behavior of spacetime itself 12345678+1 MORE.
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