The Physical Nature of Electromagnetic Waves

Since Scottish physicist James Clerk Maxwell wrote his Treatise in 1873, it has been generally believed that wireless electromagnetic radiation consists of sinusoidally oscillating electric and magnetic fields, perpendicular to each other and mutually perpendicular to the direction of propagation. The reasons as to why Maxwell concluded these mutually perpendicular orientations will now be investigated, as will the issue of the relative phase in time as between these electric and magnetic disturbances.

https://www.researchgate.net/publication/348444854_The_Physical_Nature_of_Electromagnetic_Waves