ISSN (Online) : 2348 - 2001 International Refereed Journal of Reviews and Research Volume 6 Issue 1 January - February 2018 International Manuscript ID : 23482001V6I1012018-03 (Approved and Registered with Govt. of India) Some Facts for Relating Electromagnetic Field and Gravitational Field - A Review Rampada Misra Ex-Reader, Department of Physics (UG&PG) P.K.College, Contai, West Bengal, India E-mail: [email protected] Mukul Chandra Das Satmile High School, Satmile Contai, West Bengal, India E-mail: [email protected] Abstract and gravitational. In electromagnetic theory Maxwell unified electricity, magnetism and Characteristics of some physical entities like light. Similarly in general theory of relativity gravity, mass, charge, energy etc. have been Einstein unified space-time and gravitation. But, discussed. It has been clarified that these lead to what about the unification of electromagnetism the interrelation between electromagnetic field and gravitation? and gravitational field in some way or other. It is shown that on the basis of this interrelationship For a long time several workers tried to unify gravitoelectromagnetic equations could be electromagnetic field and gravitational field. So- proposed. many papers were published on “gravitoelectromagnetism”. But, no satisfactory Introduction result , based on experiments, have come out. It In early days when the theory of quantum is to be mentioned that this sort of trial for mechanics was not fully developed, there were unification was stopped for about 60 years. This two classical field theories – electromagnetic type of work, again, revived around 1980. Registered with Council of Scientific and Industrial Research, Govt. of India Listed in the UGC Approved List of International Journals Serial Number : 64038 43 ISSN (Online) : 2348 - 2001 International Refereed Journal of Reviews and Research Volume 6 Issue 1 January - February 2018 International Manuscript ID : 23482001V6I1012018-03 (Approved and Registered with Govt. of India) It should be pointed out that there is the grand According to Einstein’s theory of general unified theory which dealt with the fundamental relativity gravity is the curvature of space-time fields ( electromagnetic field, strong field and that is produced due to a massive object. weak field ). But gravity has not been included Basically, it is a stress energy tensor. Gravity is in it due to the fact that strength of gravitational related to Big-Bang [ 1 ]. field is too small. Einstein’s opinion is that [ 2 ] all forces of Since 1980, several workers tried to unify nature are rooted to gravity. Gravitation exists electromagnetism and gravity considering everywhere where there is some space [ 3 ] and different aspects of the two. gets over any substance. It is impossible to imagine space and gravitation separately. The In this work trial would be made to discuss some space surrounds us since the whole matter fundamental physical entities. The line of carries gravitational charge of only one sign. discussion would be to make clear the facts – This leads to the relation between gravitational how these entities interrelate electromagnetism charge and gravity. and gravity. These discussions have been presented lucidly in this dissertation. From these 2. Concept of gravitational charge discussions one may find in which way the mentioned physical entities interrelates We know that the sum potential of the electric electromagnetism and gravitation. field in our space is zero. So, all bodies and space-time as a whole are electrically neutral It should be mentioned that this review may be showing relation between space and electric thought of as a step towards interrelationship charge. This is based on two unique properties— between electromagnetism and gravity. i) Values of electric charge of different signs of Some fundamental physical entities elementary particles are exactly equal, Let us discuss some preliminary physical entities ii) The number of elementary particles which related to the problem which shows the relation carries electrical charges of different signs are between electromagnetic field and gravitational equal. field. This shows relation between space and electric 1. Concept of gravity charge. A long standing question is—what is gravity and 3. Concept of charge and mass where does it come from? Let us discuss some characteristics of charge and The answer is –Gravity is the 4-dimensional mass as well as their interrelationship. interaction. Registered with Council of Scientific and Industrial Research, Govt. of India Listed in the UGC Approved List of International Journals Serial Number : 64038 44 ISSN (Online) : 2348 - 2001 International Refereed Journal of Reviews and Research Volume 6 Issue 1 January - February 2018 International Manuscript ID : 23482001V6I1012018-03 (Approved and Registered with Govt. of India) What are charge and mass? Newton’s law of gravitation and Coulomb’s law. Since, the force fields are derived from gradient We know that charge is an electric phenomenon of potentials, hence and mass is gravitational effect. General Theory of Relativity implies that gravity and E = −∇ ϕe and g = −∇ ϕg electromagnetics affect each other. Again, ( 1 ) charge itself is an effect of 3-D space and the basic mathematical rule of vectors [ 4 ]. It is So, Poisson’s equation for the two cases become created by the polarization of the neutral vacuum energy by the force of a vector cross product ρ ∇2ϕ = − and ∇2ϕ = 4 πG ρ from the intersection of two waves. Similar to e g c m ε0 the creation of charge, the creation of mass is a ( 2 ) clear example of E= m c2. So, mass is nothing but energy. When energy is confined to a If there be no source term (i.e. for vacuum or particle, we detect it as mass. paired charges) these potentials obey Laplace’s equation ∇2ϕ = 0 . 4. Similarity between charge and mass We know that the charges are the sources and Above discussion shows that charge and mass sinks of electrostatic fields, where the electric behave similarly. field lines emanate from positive charges and 5. Quantum Mechanical Description terminate at the negative charges. Similarly, in Newton’s gravitation masses are the sources of Attempts were made to compute electromagnetic fields so that field lines terminate at objects that mass in quantum theory of electrons [ 5 ] using ρ the field reaction. Now, “the electron having a have mass. Poisson’s equation ∇2ϕ = − is charge, produces an electromagnetic field ε0 around itself. The field, in turn, interacts with valid for electrostatic fields where the fields are the electron.” This is termed as “ field produced by gradient of scalars. We have reaction” [ 6 ]. Again, because of the field formalized Gauss’s law for electrostatic fields to reaction the apparent mass of the electron differs q ρ be ∫∫ E.d S = e which gives ∇.E = e and from the original mass. The excess mass due to ε0 ε0 this field reaction is called the electromagnetic for masses g.d S = − 4 π G m which leads to mass of the electron and the experimentally ∫∫ c observed mass is the sum of the original mass where and are the ∇.g = − 4 πGc ρ m ρe ρm and the electromagnetic mass. The first general charge and mass densities respectively. This electromagnetic approach towards arises from the similarity of the form of electromagnetic mass was due to Einstein [ 7 ]. Registered with Council of Scientific and Industrial Research, Govt. of India Listed in the UGC Approved List of International Journals Serial Number : 64038 45 ISSN (Online) : 2348 - 2001 International Refereed Journal of Reviews and Research Volume 6 Issue 1 January - February 2018 International Manuscript ID : 23482001V6I1012018-03 (Approved and Registered with Govt. of India) He strongly believed that an electromagnetic 99% mass to the ordinary matter through their mass was possible [ 8 ] and that field is in the quasi-stable equilibrium states. Similarly, the form of energy-momentum tensor. Here, mass of electron is due to the excitation of an stability of electron was considered to be due to electron field in an infinite ocean of zero-point gravitational forces and the contribution to mass energy of vacuum. Perhaps the huge dark energy comes from it which speaks about the relation which provides repulsive gravitation and has between mass and charge i.e. between some underlying relationship with that of electromagnetics and gravity. vacuum energy of space [ 10 ] is responsible for the present acceleration in the expanding 6. Correction to mass universe. Since, excitation of an electron field By considering vacuum fluctuations of the fields produces mass, so mass and charge are a correction [ 9 ] to the mechanical mass has interrelated which means the interrelationship been introduced in quantum electrodynamics or between gravitation and electromagnetism. quantum field theory [ 10 ]. The observed mass 8. Classical Theory of Electromagnetic Mass has been expressed as m= m0 + δ m , where Model m is the non-electromagnetic and δ m , the 0 Lorentz termed electron mass as electromagnetic electromagnetic mass. Here the radiation mass which does not possess any “material reaction of a charged particle or the self-energy mass” and , thus, thought about a relationship of the particle is normally known as the between gravitation and electromagnetism. electromagnetic mass of the particle. Classical theory of stochastic electrodynamics believes According to Lorentz theory of electromagnetic that the fluctuations of zero-point energy are fields we come across mass depending on responsible for the existence of electromagnetic electric field ( actually the rest mass ) as mass of the charged particle. So, the zero-point energy associated with the particle is assumed to e2 4 U give the correction to the mass of the particle. m = = This reveals that charged particles have em 6π ac2 3 c 2 electromagnetic mass meaning the relation ( 3 ) between mass and charge i.e. between gravity and electromagnetism. e2 where U = is the electrostatic energy. 8π a 7. Quantum Mechanical World View This relation unifies gravitation with Quarks and gluons are thought to be the electromagnetism.