In ancient Greek philosophy, particularly in the teachings of Empedocles, Earth was considered the primary element or substance from which all things were composed.

In modern physics, quarks are considered the fundamental constituents of matter, being the building blocks of protons and neutrons, which in turn make up atomic nuclei.

Materialism is a philosophical position that asserts that matter is the fundamental substance of reality, and that all phenomena, including consciousness and mental processes, are ultimately reducible to physical processes.

Mass-energy equivalence, as expressed by Einstein's equation E=mc^2, describes the fundamental relationship between mass and energy, showing that they are interchangeable and can be converted into each other.

Phenomenalism is a philosophical position that argues that the physical world is composed entirely of sense experiences or phenomena, and that matter is not an independent substance but a collection of these experiences.

Atomism is a philosophical and scientific theory that posits that matter is composed of fundamental, indivisible particles called atoms.

In the Standard Model of particle physics, matter particles are classified into three generations: quarks, leptons, and bosons.

Holism is a philosophical perspective that emphasizes the interconnectedness and interdependence of all parts of a system, viewing the whole as greater than the sum of its parts.

Heraclitean Flux is a philosophical concept that emphasizes the constant change and impermanence of matter, as expressed by the ancient Greek philosopher Heraclitus.

In quantum mechanics, the fundamental unit of matter and energy is the quantum, which is the smallest possible amount of energy that can be exchanged between two systems.

Wave-particle duality is a fundamental concept in quantum mechanics that describes the dual nature of matter, exhibiting both wave-like and particle-like properties.

Idealism is a philosophical position that asserts the primacy of consciousness or ideas over matter, arguing that reality is fundamentally mental or spiritual in nature.

Continuum Theory is a philosophical and scientific concept that posits that matter is continuous and infinitely divisible, without any fundamental units or particles.

The Big Bang theory suggests that the universe began as a hot, dense state of matter known as plasma, composed of ionized particles and radiation.

Molecular Theory is a scientific theory that explains the behavior of matter in terms of the interactions between molecules, which are composed of atoms held together by chemical bonds.