A Recent Discovery Transforms Our Understanding of Light Through Fusion of Photons With Maxwell’s Fields

Our understanding of light gets transformed almost every century! Newton’s conjecture in 1704, that light consists of particles was replaced by Young’s experiments, around a century later, which proved that light is a wave. It found support from Maxwell’s comprehensive theory that light is an electromagnetic wave. However, Einstein in 1905, postulated that light is made of particles called photons, with energy proportional to its frequency. He used it to explain photoelectric effect, where current is generated when light falls on a metal. Einstein was awarded the 1921 Nobel Prize in physics, mainly for this and it forms the basis of our broader understanding of the nature of light which assumes that light can behave like waves as well as particles depending on the nature of experiments. For over a century, we have believed that light’s particle and wave nature have a phenomenological disconnect.

Recently, Dr. Dhiraj Sinha, a faculty member at Plaksha University, Mohali, India, has published a research article in the journal, Annals of Physics, where he has established a mathematical correlation between the wave nature of light defined through its electromagnetic field and its particle nature expressed in terms of photons. His focus of attention has been the role of magnetic field of light whose temporal variation induces an electric potential within a region of space. From a mathematical perspective, the magnetic flux of light j, generates a voltage defined by dj/dt, over a differentially small variation in time t. He has argued that the energy transfer to an electron of charge e is, E= edj/dt and its frequency or phasor domain representation is ejw, where w is the angular frequency of radiation. This expression, Dr. Sinha notes, is similar to the Einstein’s expression on the energy of a photon, ħw, where ħ is the reduced Planck’s constant and w is the angular frequency of light. In other words, Dr. Sinha has postulated that it is the temporal variation of magnetic flux of radiation field, which energises the electrons in a metal, in accordance with the Faraday law of electromagnetic induction. Thus, he has discovered a special and a hitherto unexplored aspect of light matter interaction, which has largely remained neglected for more than a century.

The theoretical framework offers the missing link between Maxwell’s electromagnetic fields which define light and Einstein’s quantum mechanical concept of a photon.  Currently, the energy of a photon is considered to be an experimental fact which does not have any formal connection to light’s wave nature. Quantisation of magnetic flux has been observed in two-dimensional electron systems as well as superconducting loops, which supports Sinha’s viewpoint. Maxwell's equations are about fields, they are silent on quantisation, but they do not oppose it. Thus, by using the concepts of magnetic flux and charge quantisation in an integrated manner, Dr. Sinha has argued that Maxwell's equations can be used to explain light matter interaction.

Another unresolved mystery of light is associated with experiments where a single photon is sent through two slits resulting in interference patterns similar to waves. It is impossible to tell the exact slit through which the photon has passed. Measurement devices, integrated with the slits can records the arrival of a photon, but this process of measurement, destroys the interference pattern. Thus, any measurement on identification of the photon trajectory, destroys the wave like properties of a photon. Dr. Sinha’s work also sheds light on this mystery of light. He has argued that light propagates as a wave in free space and as soon as it encounters measuring devices at the slits, which are polarisers with opposite polarity, the direction of electric field of light is influenced and it destroys the original two-slit interference pattern. Removal of the measuring devices restores the original pattern. Thus, looking at light from the perspective of radiation field resolves the famous, ‘which way problem’ of photonic experiments.

A number of leading physicists have expressed support for the idea including, Jorge Hirsch, Professor of Physics at University of California, San Diego. He was the first to note that the mathematical approach of Dr. Sinha is flawless and wrote a letter of support for the journal editors. Steven Verrall, former faculty member at University of Wisconsin La Crosse and Lawrence Horwitz, Professor Emeritus at the University of Tel Aviv are also highly supportive of Dr. Sinha’s ideas. A leading physicist after reviewing the work wrote to the author, “We learned from Einstein that Maxwell's equations were relativistic forty years before relativity. Now we know that they were already quantum, sixty years before quantum mechanics! I find this amazing.” Richard Muller, Professor of Physics at University of California Berkeley and Faculty Senior Scientist at Lawrence Berkeley Laboratory, commented, “The ideas are intriguing and they address the most fundamental of the non-understood issues of quantum physics including the particle/wave duality and the meaning of measurement.”

To conclude, Dr. Sinha’s work fuses Einstein’s photons with Maxwell’s electromagnetic fields. Defining the energy of photoelectrons through the frequency domain representation of interaction energy between radiation field and  electrons while using electromagnetic field theory, is a major scientific breakthrough.

Additional Information

Sinha, Dhiraj, “Electrodynamic excitation of electrons. Annals of Physics”, 473, 169893 (2025).

(https://www.sciencedirect.com/science/article/abs/pii/S0003491624003002)