Matter - Definition of matter

What is matter

Matter is defined as any entity that can be found in the universe that has mass and occupies space. This classic definition of matter has evolved as time goes on and scientific advances developed in the area of quantum physics and the theory of relativity, so we can define from a point of view of modern physics that matter as any type of entity that has mass and an macroscopically level occupies and curved a region of space-time and a microscopic level can behave like a wave, we will explain in detail each of these concepts involved in the definition.

We can say that we are surrounded by matter, we ourselves are matter, the screen by you are reading this web, the water we drink, the air we breathe, the sun that shines ... Our world is full of it but if we move into its fundamental structure on a microscopic scale we understand that the matter world is practically empty inside and if we see the immensity of the universe we understand that the matter we can identify occupies only 4% of its volume.

Today we know that matter is formed of tiny particles called atoms, which is composed of electrons moving around a tiny nucleus, to give us an idea the volume occupied by the electrons and the nucleus in an atom corresponds to 0,00001% it means that the atom is almost empty, then what is it that makes the steel is hard and compact? The answer lies in the links that originate inside the atoms and the bonds with other atoms.

Thanks to the chemical bonds and atomic interactions matter acquires "consistency", chemical bonds hold the world without them there would only loose atoms and there would be none of the substances that make up our universe including ourselves. These bonds are responsible for the different states in which matter can be presented:

• Solid - Atoms that component these states are strongly entangledin predefined forms restricting the movement of the particles in a vibrating or oscillating movement.

• Liquid - The bonding forces of the liquid are less than the forces that holds the atoms of the solid, allowing free movement of the particles within the volume occupied by the liquid.

• Gaseous - The movement of the atoms is free due the forces that produce the joints between the atoms are weak.

• Plasma - In this state atoms and molecules are split into ions, electrons, and molecular fragments electrically charged but as a whole is a neutral state.

Recent discoveries demonstrate the existence of a fifth state of matter known as BEC (Bose-Einstein condensate) in honour of the scientists who predicted the possible existence, in this state the atoms are cooled to temperatures near of the absolute zero doing that the atomic motions are null and materials acquire amazing properties similar of quantum physics where the atoms transform in waves that overlapping each other and leaving existas individual atoms to become a single super atom. In 1995 physicists Eric Cornell and Carl Wiemman synthesized in the laboratory the first BEC giving them the Nobel Prize for physics in 2001.

Dark matter, dark energy and antimatter

Thanks to the physics studies in the early twentieth century as well as scientific advances in the field of astronomy and cosmology now we know that there is not only matter in the universe but also there is dark matter, antimatter and dark energy. Within the observable universe matter occupies only 4% while dark matter occupies 23% and dark energy 73%.

Dark matter is the amount of matter that we know exists in the universe but can not identify it through the current identification techniques, we know exist due that it has mass generates gravitational effects visible by telescopes and space probes, but we can not identify because they can not see their electromagnetic radiation may be because their internal composition does not have any electrical charge.

Furthermore thanks to the discoveries of the astronomer Edwin Hubble now we know that the universe is constantly expanding, in this aspect dark energy corresponds to a hypothetical type of matter present in the universe that we can not observe or measure but we know that there is due which is the precursor of the repulsive force that makes the universe expand faster and faster over time.

The remaining 4% of matter that exists corresponds to 3.6% intergalactic gas while only 0.4% corresponds to the matter found in stars, planets, comets and other celestial bodies.

We know that matter is made of atoms that in turn are composed of particles such as electrons, protons and neutrons, the physicist Paul Dirac in 1928 predicted the existence of antiparticles and hence the existence of antimatter formed by anti-electrons (positrons) and antiprotons. In 1932 the positron was identified validating the theory of antiparticles and the possible existence of antimatter, then in 1995 the European laboratory CERN managed to create nine antihydrogen atoms.

When the matter comes into contact with antimatter both destroy becoming energy in a process whose efficiency is 100%, a property can be used by humans to produce efficient and clean energy, with only 100 grams of antimatter could supply all global consumption of electricity demand for 1 year, on the other hand the use of antiparticles like positrons is currently used for medical applications as identification of tumoursby tomography it would be possible its use as fight of cancer cells.

Intrinsic properties of matter

Considering the above definition of matter we know that has mass, energy and occupies a volume, the matter involves these three intrinsic properties.

Mass - In order that matter can exist it is necessary that it has mass and we can measure, mass defines the amount of matter that has an entity, we know that at the microscopic level the mass of any particle is defined by the degree of interaction that takes with the Higgs field and at macroscopic level we know the gravitational effects exerted by the masses.

Energy - The matter has energy corresponding to the movement of subatomic particles as well as the energy stored in the bonds that exist between the atoms and subatomic particles themselves, that energy can be released and detected by the electromagnetic spectrum, on the other hand thanks to Einstein and his famous equation E = mc² we know that energy can be converted into matter and viceversa helping us to explain the birth of the universe after a huge explosion of energy.

Space - Matter occupies a volume and therefore space, from the point of view of relativity theory we can affirm that any body that has mass it produces a curvature in spacetime fabric being directly responsible of the gravitational forces, thereby introducing time with the concept of matter.

Finally at the microscopic level the behaviour of matter enters in the world of quantum mechanics where the double slit experiment demonstrate his duality in that matter as an electron behaves as both a wave and a particle energy being material together.