Physical cosmology is the scientific study of the Universe on large-scale structures and forces and is primarily concerned with questions concerning its origins, composition, structure, evolution and ultimate destiny.
It can be compared to Physics with respect to large scale structure since it studies the behavior of space and time as well as matter on a very large scale. Physicists studying cosmology are interested in answering questions concerning the laws of formation, composition, and evolution of the Universe. They also study the relationship between the cosmos and human beings. Some cosmologists try to solve mysteries such as those concerning the Big Bang Theory or the speed of light, the structure of space-time and the future of the universe.
Albert Einstein is generally credited with developing the most common theory of general relativity or gravity.
His special theory of relativity revolutionized the theories of mechanics and science. Though not a new theory, it is a modification of old concepts and was first put forward in 1900. The uniqueness of this theory is that it has a universal value, including space, time, matter and energy. Albert Einstein’s special theory of relativity is still used today as a standard model for predicting the effects of celestial objects, especially Planck’s Constant, on human beings on Earth.
Isaac Newton developed his concept of universal gravitation as a way of modeling the cosmos on a large scale.
According to Newton, all the planets in the solar system are moving with respect to the velocity of earth, as observed by satellites. According to Newton, the solar system, including earth, is a part of a larger unending flow of matter that is going on at an uncontrollable but steady pace. Newton’s universal law of gravitation, however, could not predict the motions of individual heavenly bodies such as the planets.
On the other hand, the physical cosmology of old conceived of a universe which was not governed by General Relativity.
The theory of relativity came into being after quantum mechanics and general relativity. From these concepts, Einstein drew many theories on how the universe works. Among these theories, his special theory of relativity developed the idea that light has a definite wavelength, which can be measured. Thus, general relativity can be said to be a physical theory which predates quantum mechanics and general relativity by several years.
A major feature of general physical cosmology deals with the nature of light elements.
Light elements constitute a majority of the elements present in the universe, and they vibrate according to a set pattern, which can be deciphered by scientists. The wavelength of a photon, for instance, is determined by observing how fast the light elements are traveling through a medium. When the properties of a photon are understood, it is found that it contains two different amounts of energy, which are known as electromagnetic waves and particles of light.
Einstein’s special theory of relativity established that space and time do not exist, but only an electromagnetic field.
Thus, general relativity established that the physical cosmology of the universe is nothing but the vibration of matter that can be measured. Einstein’s theory of relativity further explained that each matter has a corresponding virtual particle, which has a different frequency compared to all other particles. This gave rise to the new concept of a field that is a combination of different wavelengths or waves of energy, which can be measured with the help of satellites. These measurements are done in order to study the properties of the virtual particles.
A number of theories have been developed on the subject of the relations between space, time and the universe.
Though these theories remain popular, no precise definition of physical cosmology has been developed so far. Particle physicists like Albert Einstein, Erwin Pohl and others have proposed different models on how the universe and the nature of space and time works. Most of these models have been rejected by mainstream scientists because they contradict the predictions of general relativity.
However, there are some who feel that general relativity is incomplete, thus leading to the creation of a new science, quantum mechanics. Though these theories still depend on a big unanswered question, there are many theories that explain cosmology that are still in practice in today’s world.
Though there are a lot of unanswered questions regarding physical cosmology, the most accepted model is quantum mechanics.
A number of experiments conducted using very sensitive instruments have proved that the laws of classical mechanics and quantum mechanics are compatible with each other. Though there are critics of this theory, there are still a lot of enthusiasts who believe in its accuracy.