Energy: theoretical and experimental incompatibility Hossein Javadi Independent researcher and founder of CPH theory, Tehran, Iran [email protected] July 6 2018 Abstract: In this article, four issues have reviewed and analyzed: What is the physical nature of energy? Does energy have mass? What was the mass-energy equivalence before relativity? According to the work-energy theorem, what is the physical nature of force, when force is displacing, energy is produced? Finally, the theoretical and empirical approach to the photon mass is compared. Keywords: energy, electromagnetic wave, massless, photon, limit speed, heat, relativity Highlights of Energy History The word "energy" was first used by Aristotle. [1] Energy is one of the most basic physical concepts, but its simple yet precise definition is difficult, usually, it defines energy as the ability to do work. In the seventeenth century, Leibniz, "had developed concepts that correspond to our current understanding of kinetic and potential mechanical energy". [1] "Antoine Lavoisier described the law of conservation of mass (or the principle of mass/matter conservation) as a fundamental principle of physics in 1789". [2] Energy: theoretical and experimental incompatibility Caloric theory of heat, "according to this theory, heat was a fluid substance called caloric. This caloric was assumed to be invisible and weightless fluid that could neither be created nor destroyed". [3] "Count Rumford rejected the caloric theory by doing an experiment in 1798 and he proved that heat could be produced by friction or by doing mechanical work. Thus, caloric was being released, though the subdivision of matter was not occurring. Therefore, Rumford rejected the idea that an object contains a definite amount of caloric in it". [3] "In 1800, Thomas Young first introduced the word “energy” to the field of physics in 1800, but the word did not gain popularity. He later established the wave nature of light through interference experiments". [1] “Sadi Carnot was a French military engineer and physicist, often described as the "father of thermodynamics". He published only one book, the Reflections on the Motive Power of Fire (Paris, 1824), in which he expressed, at the age of 27 years, the first successful theory of the maximum efficiency of heat engines. In this work he laid the foundations of an entirely new discipline, thermodynamics. Carnot's work attracted little attention during his lifetime, but it was later used by Rudolf Clausius and Lord Kelvin to formalize the second law of thermodynamics and define the concept of entropy”. [4] "The related term “work” was defined in 1828/29 by Gustave Gaspard de Coriolis and Jean-Victor Poncelet". [1] "The principle of work and kinetic energy (also known as the work-energy principle) states that the work done by all forces acting on a particle (the work of the resultant force) equals the change in the kinetic energy of the particle". [5] "Between 1842 and 1847, Julius Robert von Mayer, James Prescott Joule, and Hermann Ludwig Ferdinand von Helmholtz discovered and formulated the basics of what we refer to today as the law of conservation of energy: Energy cannot be created or destroyed; it can only be transformed from one form to another. Instead of the word “energy”, however, they used the terms “living force”, “tensional force” or “fall-force”. In 1851 − 1852, William Thomson (Lord Kelvin) and William J. M. Rankine began to use the word “energy” to denote any kind of “force” across all branches of science. Finally, in 1905, Albert Einstein established the general equivalence of energy and mass with his theory of relativity. From there, the concept of “energy” was generalized into the form used today." [1] That, is the famous equation in physics. Although it did not prove, the two separate conservation laws the energy conservation law and the mass conservation law was unified into a mass-energy conservation law. Kinds of energy Although there are different kinds of energy, including kinetic energy, potential energy, electromagnetic energy, thermal energy, chemical energy, acoustic energy, etc., they can be converted to each other. We can use the convertible property of energies to each other, to consider and analyze the most important common energies property. To know more about energy, the best kind of energy is electromagnetic energy and the mass-energy equation . Does energy have mass? As previously stated, in 1798, Benjamin Thompson rejected the theory of calories, but in the case of energy mass, there was no new word for energy. If we consider this claim to be the relation . not only is it not easy at the time of Thompson, even today, to prove that energy has mass or not. But technological advances have allowed empirical observations in the last century to be investigated and analyzed in different ways. In this regard, Einstein has presented two very important propositions, one in classical mechanics and the other one in relativity. 2 Energy: theoretical and experimental incompatibility 1 - Heat in classical mechanics: “Latent heat is temporarily hidden, like money put away in a safe, but available for use if one knows the lock combination. But heat is certainly not a substance in the same sense as mass. Mass can be detected by means of scales, but what of heat? Does a piece of iron weigh more when red- hot than when ice-cold? Experiment shows that it does not. If heat is a substance at all, it is a weightless one. The "heat-substance" was usually called caloric and is our first acquaintance among a whole family of weightless substances. Later we shall have occasion to follow the history of the family, its rise and fall. It is sufficient now to note the birth of this particular member. The purpose of any physical theory is to explain as wide a range of phenomena as possible. It is justified in so far as it does make events understandable. We have seen that the substance theory explains many of the heat phenomena. It will soon become apparent, however, that this again is a false clue, that heat cannot be regarded as a substance, even weightless. This is clear if we think about some simple experiments which marked the beginning of civilization”. (page 43, [6]) 2 - Heat in relativity: “Energy, at any rate kinetic energy, resists motion in the same way as ponderable masses. Is this also true of all kinds of energy? The theory of relativity deduces, from its fundamental assumption, a clear and convincing answer to this question, an answer again of a quantitative character: all energy resists change of motion; all energy behaves like matter; a piece of iron weighs more when red-hot than when cool; radiation traveling through space and emitted from the sun contains energy and therefore has mass; the sun and all radiating stars lose mass by emitting radiation. This conclusion, quite general in character, is an important achievement of the theory of relativity and fits all facts upon which it has been tested". (page 208, [6]) When Einstein was two years old, "in 1881 J. J. Thomson, later a discoverer of the electron, made the first attempt to demonstrate how this might come about by explicitly calculating the magnetic field generated by a moving charged sphere and showing that the field in turn induced a mass into the sphere itself". [7] “Thomson’s slightly complicated result depended on the object’s charge, radius and magnetic permeability, but in 1889 English physicist Oliver Heaviside simplified his work to show that the effective 4 2 mass should be m = ( ⁄3) E / c , where E is the energy of the sphere’s electric field. German physicists Wilhelm Wien, famous for his investigations into blackbody radiation, and Max Abraham got the same result, which became known as the “electromagnetic mass” of the classical electron (which was nothing more than a tiny, charged sphere). Although electromagnetic mass required that the object be charged and moving, and so clearly does not apply to all matter, it was nonetheless the first serious attempt to connect mass with energy”. [7] One of the more plausible precursors to is attributed to Fritz Hasenöhrl, a physics professor at the University of Vienna. In a 1904 paper Hasenöhrl clearly wrote down the equation 3/8 . [8] Probably the title of Einstein's article, which in 1905, titled "DOES THE INERTIA OF A BODY DEPEND UPON ITS ENERGY‐CONTENT?" [9], speaking about the equivalence of mass and energy, is the best document to accept that Einstein believed that energy has a mass under all circumstances. But why he assumed the rest mass of the photon is zero? Mysteries zero rest mass and speed of the photon By limiting the speed limit to the speed of light c and accepting relativistic mass at the beginning of the twentieth century, only one way seemed to be, assuming that the photon rest mass is zero. Given this assumption let’s focus on energy and momentum of photon. After 1906 Einstein have derived the second postulate of special relativity the constancy of the speed of light by assuming that the light quanta that he proposed in 1905 were massless particles. Relativistic energy and momentum is given by; 3 Energy: theoretical and experimental incompatibility (1) It is just possible that we could allow 0 provided the particle always travels at the speed of light c. [11] In this case above equations will not serve to define and so that for massless particle given by; || (2) As it follows from the Einstein relativistic mass formula: (3) What does determine the momentum and energy of a massless particle? Not the mass (that is zero by assumption) not the speed (that is always ). Relativity offers no answer to this question, but curiously enough, quantum mechanics does, in the form of Plank's formula: ⇒ (4) Only moving photon has mass as follows from the Einstein formula .