Albert Einstein has been rightly claimed to be the most influential contributor in the field of Pure and Applied Physics in the twentieth century (Pais and Penrose 3). Through his intellectual thinking and experimentation Albert Einstein managed to develop various scientific theories as well as discoveries. Among his outstanding discoveries is the law of photoelectric effect (Naik). Just to be appreciated is the fact that he was awarded the 1921 Nobel Prize in Physics following this discovery (Naik). In 1926, Einstein co-invented the Einstein refrigerator with one of his former students (Naik). This was termed as one of the most revolutionary refrigerators of the time as it lacked any moving parts.Through his numerous theories on general relativity, Einstein asserted that gravitation is a distortional force on the structures of space and time by matter, which impact inertia forces of motion on another matter (Born 23). Indeed, this has been praised by many as one of the greatest expressions of the human mind and is still applied by scientists up to date. Other theories by Einstein are the Theory of critical opalescence and the Unified field theory (Pais, and Penrose 143). To qualify his principles, Albert Einstein engaged in various experimental research works. This essay is written as a discussion of the theories, experiments, and discoveries by Albert Einstein.First is a discussion on the theories by Albert Einstein. Einstein established the Theory of critical opalescence, which served to explain the variation of density in a fluid at the critical point (Pais, and Penrose 143). According to this theory, thermodynamic fluctuations are due to density fluctuations in a fluid, which are typically controlled by the second derivative of the free energy equation (Pais, and Penrose 143). Based on this reasoning, Einstein claimed that at the critical point, the second derivative is zero, a factor, which should explain why there is a large density fluctuation at this point. Since light of any wavelength scatters due to density fluctuations, Einstein claimed that fluctuations much smaller than wavelength can sufficiently explain why the sky is blue (Pais, and Penrose 144).Another theory by Einstein is the Modern quantum theory (Havas, Einstein and Beck 67). This theory states that the there should be a stimulated emission for the maser and laser to occur. According to him, Planck’s distribution law on absorption and emission of light can only hold true if such emission in a mode with photons can increase exponentially as compared emissions in an empty mode (Havas, Einstein and Beck 67). This meant that stimulated emission of light is only possible in the presence of photons. It is asserted that this theory forms the basis of the quantum mechanics in the modern society. This claim is based on the fact that it is only this theory that gives acceptable and simple laws for explaining atomic transitions (Havas, Einstein and Beck 68).The third important theory by Einstein was Einstein–Cartan theory (Pais, and Penrose 161). According to him, the general relativity theory was insufficient to explain spin angular momentum. In this theory, it is asserted that to explain spin angular momentum, the general relativity equation should be modified to accommodate non-zero torsion (Pais, and Penrose 161).. However, the derivation of the theory follows the same Hilbert-Einstein action with the only exception that the connections rather than the metrics are taken as the dynamic variables. Although the theory has not been technically proved due to technological limitation, scientists believe of its possible truth.Secondly is a discussion on experiments of Einstein. Einstein is believed to have conducted numerous experiments in his quest to explain the physical nature and behavior of matter (Havas, Einstein, and Beck 73). One of the experiments was on quantized atomic vibrations. During this experiment, Einstein wanted to find a solution to the problem of specific heat anomaly in solids. He identified that solid motions are quantized (Havas, Einstein, and Beck 73). By making calculations from his collected data, the results matched those by Planck. This followed the conclusion that at freezing temperatures specific heat of solid drop to zero (Havas, Einstein, and Beck 74).Another experiment by Einstein was on photoelectric effect (Naik). During the experiment, he decomposed light at a particular temperature in to low and high frequency components. He found out that the number of states of light in a box is exactly equal to the number of states of mobile particles in the same box (Havas, Einstein, and Beck 91). This led to his conclusion that light is indeed made up of localizable particles (Havas, Einstein, and Beck 91). Based on this therefore, photoelectric effect was a direct result of having each wave of a particular frequency made up of photons whose energy is the product of the wave frequency and the Planck’s constant.Einstein also conducted an experiment for determining the idea that the principle of relativity can be used to explain the effects of gravitational fields (Born 26). During the experiment, he timed the rate of a clock both when accelerated upwards and downwards. From his findings, it was clear that the rate of the clock was dependent on its position in the gravitational field (Born 28). Based on this conclusion, Einstein asserted that the deflection of light by gravity cannot be zero (Born 28). This was because, from his experience, just like other forms of matter, light was particulate in nature and particulate material were affected by gravitational fields.Thirdly is a discussion on the discoveries which were made by Einstein. The first discovery was on the fact that light is particulate in nature (Born 43). Just to be appreciated here is the fact that prior to Einstein’s explanation that light was not a continuous phenomenon; scientists believed that light used to travel in a straight line. This was the reason that none of the scientists could explain the science behind photoelectric effects effect. However, with the explanation of Einstein on the phenomenon, scientists have since then developed various models based on the quantum mechanism of light (Born 46). Therefore, it is worthy asserting that shading light on the fact light is quantized remains a crucial scientific discovery by Einstein.Through his experiment on the relationship between principle of relativity and gravitational fields, Einstein sufficiently managed to ascertain that light is affected by gravity (Havas, Einstein, and Beck 103). By basing his argument on the probable deflection of light by gravitational fields, Einstein was able to challenge scientists around the world. In particular, the discovery that light was evidently affected by gravitational shift was later proved by scientists after detecting deflection of light following a solar eclipse (Havas, Einstein, and Beck 104). It is worthy noting that necessity is the mother of invention. This means that this discovery by Einstein was the result of devotion by scientists to challenge or qualify it.The last and most important discovery by Einstein is when he proved Planck wrong on oscillator energies (Havas, Einstein, and Beck 126). According to him it was clear that oscillator energy should have a zero point energy value. From his explanations, the zero point value should be at half the maximum energy of the oscillator (Havas, Einstein, and Beck 126). This was simply because Einstein had founded out that splitting of joined atoms leaves each individual atom with an equal but opposing share of their collective energy. Just to be emphasized is the fact that this discovery has stood the test of time. Therefore, this discovery on the ultimate value of zero point for an oscillator served as a critical solution to the problem of designing efficient oscillators (Havas, Einstein, and Beck 129).From the above discussion, it is evidently clear that Einstein deserves to be recognized as a scientific hero by the global community. This is because of his resourceful contribution to the ultimate understanding of the particulate nature of matter. It is claimed that most of his claims have not stood to test of the modern technological advancements in the society. Still cited by opponents of the genius nature of Einstein is the fact that during his intuitions, he failed to appreciate numerous underlying scientific principles (Naik). However, given the valuable insight he brought in the scientific world, it contradicts reality to deny Einstein praise. Also, even any force claim he made triggered the quest by the scientific community to search for the true, a factor that has no doubt brought physics were it is today.Also to be appreciated by all is that Einstein made other valuable contribution through his unique philosophical approach to issues affecting the political, social, and academic fronts of the human community. He believed in finding a lasting solution to problems affecting the community rather than repairing damages (Pais, and Penrose 3). This meant that by taking his approach, the community could ultimately realize sustainable social and economic prosperity. Indeed, this is the reason that he has been identified by many professionals as the man of the twentieth century. Therefore, it is logical to conclude that Einstein deserve to be called a hero.Works citedBorn Max. Einstein’s Theory of Relativity. Ontario: Dover Publications, 1962.Havas, Peter, Einstein, Albert, and Beck, Anna. The Collected Papers of Albert Einstein: The Swiss Years, Writings, 1900-1909. West Sussex: Princeton University Press, 1987.Naik, Abhijit. “What Did Albert Einstein Invent.” What Did Albert Einstein Invent. 22 Jan. 2010. 30 Apr. 2010. <http://www.buzzle.com/articles/what-did-albert-einstein-invent.html>Pais, Abraham, and Penrose, Roger. Subtle is the Lord: The Science and the Life of Albert Einstein. New York: Oxford University Press, 1982.