How does matter exist

This creates a puzzle: why is matter in the form of protons and electrons dominant in the universe, when the interactions acting in the hot dense early stages of the Big Bang should have produced equal quantities of matter and antimatter?

What process made all of the matter around us? This is one of the major unanswered questions of contemporary physics and cosmology. Suppose that early interactions of the Big Bang did produce equal amounts of matter and antimatter. Later, in the hot dense "soup" of the early universe during the later stages of expansion, most of the protons and antiprotons and most of the electrons and positrons should have found each other, combined, and annihilated, leaving behind a matter-less universe that would be only thinly populated by photons, with perhaps a few neutrinos and antineutrinos and a few electrons and positrons.

How and why did this dominance of matter over antimatter occur? What broke the expected overall matter-antimatter symmetry? Until recently, the only exception to the almost universal matter-antimatter symmetry present in particle physics was found in the weak-interaction decays of a few peculiar mesons. One of these is the K 0 meson, which is made of a down quark and an antimatter strange quark. Its antimatter twin, the anti-K 0 or K 0 -bar, is made of a strange quark and an anti-down quark.

Both the K 0 and the K 0 -bar have the same zero electrical charge, zero spin, negative parity spatial mirror image symmetry , and both have the same mass about half a proton mass. Therefore, on the basis of all the observables they cannot be told apart. Quantum mechanics tells us that when two quantum states cannot be distinguished, a peculiar thing happens: they "mix". The two indistinguishable states mix to form two new states that are distinguishable.

In the case of neutral kaons, the K 0 and K 0 -bar combine in two different ways to make the K S particle K-short , which decays in about 10 seconds, and the K L particle K-long , which decays times more slowly. The decay of the K L meson shows what is called a "CP violation", a preference for matter over antimatter together with a preference for one space-symmetry or "handedness" over the other. The CP-violation of the K L means that systems composed of matter and of antimatter do not behave in precisely the same way.

Its decay can favor matter over antimatter. It suggests a way in which the universe's preference for matter over antimatter might have come about. The CP-violation in the K 0 meson is related to the fact that it contains a second-generation strange quark as one of its component parts. The third-generation cousin of the strange quark is the bottom quark. However, none of these CP-violating decays could have caused the universe's matter excess because the CP violations observed in these systems are too weak in magnitude and therefore too improbable to account for the amount of matter that is present in the universe.

One question that might be asked in the context of CP violations is: Why do the processes of the early Big Bang seem to have produced roughly equal numbers of protons and electrons? Were there two matched CP violations going on, one producing the excess of protons over antiprotons and the other producing the excess of electrons over positrons?

The answer to this question is: No, we do not need two separate CP violations. The CP violation that produced the proton excess made an equal number of some other electrically negative particles that were not antiprotons. When the change of state occurs in stages the intermediate steps are called mesophases. Such phases have been exploited by the introduction of liquid crystal technology.

The state or phase of a given set of matter can change depending on pressure and temperature conditions, transitioning to other phases as these conditions change to favor their existence; for example, solid transitions to liquid with an increase in temperature. Near absolute zero, a substance exists as a solid. As heat is added to this substance it melts into a liquid at its melting point, boils into a gas at its boiling point, and if heated high enough would enter a plasma state in which the electrons are so energized that they leave their parent atoms.

Forms of matter that are not composed of molecules and are organized by different forces can also be considered different states of matter. Superfluids like Fermionic condensate and the quark—gluon plasma are examples.

In a chemical equation, the state of matter of the chemicals may be shown as s for solid, l for liquid, and g for gas. An aqueous solution is denoted aq. Matter in the plasma state is seldom used if at all in chemical equations, so there is no standard symbol to denote it. In the rare equations that plasma is used in plasma is symbolized as p. Glass is a non-crystalline or amorphous solid material that exhibits a glass transition when heated towards the liquid state.

Glasses can be made of quite different classes of materials: inorganic networks such as window glass, made of silicate plus additives , metallic alloys, ionic melts, aqueous solutions, molecular liquids, and polymers. Thermodynamically, a glass is in a metastable state with respect to its crystalline counterpart.

The conversion rate, however, is practically zero. A plastic crystal is a molecular solid with long-range positional order but with constituent molecules retaining rotational freedom; in an orientational glass this degree of freedom is frozen in a quenched disordered state.

Liquid crystal states have properties intermediate between mobile liquids and ordered solids. Generally, they are able to flow like a liquid, but exhibiting long-range order. Other types of liquid crystals are described in the main article on these states.

Several types have technological importance, for example, in liquid crystal displays. Transition metal atoms often have magnetic moments due to the net spin of electrons that remain unpaired and do not form chemical bonds.

In some solids the magnetic moments on different atoms are ordered and can form a ferromagnet, an antiferromagnet or a ferrimagnet. In a ferromagnet—for instance, solid iron—the magnetic moment on each atom is aligned in the same direction within a magnetic domain. If the domains are also aligned, the solid is a permanent magnet, which is magnetic even in the absence of an external magnetic field. An antiferromagnet has two networks of equal and opposite magnetic moments, which cancel each other out so that the net magnetization is zero.

For example, in nickel II oxide NiO , half the nickel atoms have moments aligned in one direction and half in the opposite direction. In a ferrimagnet, the two networks of magnetic moments are opposite but unequal, so that cancellation is incomplete and there is a non-zero net magnetization. Skip to main content. Search for:. States of Matter A state of matter is one of the distinct forms that different phases of matter take on. Schematic representation of a random-network glassy form left and ordered crystalline lattice right of identical chemical composition.

See, for example, D. Gurnett, A. Bhattacharjee ISBN Berlin: Springer. Essentially, all of the visible light from space comes from stars, which are plasmas with a temperature such that they radiate strongly at visible wavelengths. This conundrum is one of the central open questions in fundamental science, and one way to search for the answer is to bring the power of precision atomic physics to bear upon antimatter. It has long been established that any excited atom will reach its lowest state by emitting photons, and the spectrum of light and microwaves emitted from them represents a kind of atomic fingerprint and it is a unique identifier.

The most familiar everyday example is the orange of the sodium streetlights. Hydrogen has its own spectrum and, as the simplest and most abundant atom in the Universe, it holds a special place in physics.