Einstein's seminal paper on the theory of relativity, published in 1905, is indeed titled "On the Electrodynamics of Moving Bodies" ("Zur Elektrodynamik bewegter Körper" in German). The title emphasizes the connection between his theory and electrodynamics, which was a well-established field of physics at the time.
The theory of relativity introduced by Einstein encompasses both special relativity and general relativity. Special relativity, which is the focus of the 1905 paper, deals with the behavior of space and time in the absence of gravitational fields, while general relativity extends the theory to include gravity.
The reason for emphasizing electrodynamics in the title is that the theory of special relativity originated from Einstein's attempts to reconcile Maxwell's equations of electromagnetism with the principles of classical mechanics. Maxwell's equations describe the behavior of electric and magnetic fields and provide a comprehensive framework for understanding electromagnetism.
In his 1905 paper, Einstein proposed that the laws of physics, including electromagnetism, should be the same for all observers in uniform motion relative to each other. This principle, known as the principle of relativity, is at the heart of special relativity. By highlighting the connection to electrodynamics in the title, Einstein was emphasizing the relationship between his theory and the behavior of electromagnetic phenomena.
Regarding the speed of causality, it is related to the fundamental concept of the speed of light in vacuum, denoted by "c." In special relativity, the speed of light plays a crucial role as a cosmic speed limit, representing the maximum speed at which information or causality can travel. This cosmic speed limit is a fundamental aspect of the theory and is deeply connected to the principles of electromagnetism as described by Maxwell's equations.
In summary, the choice of title in Einstein's paper reflects the close connection between his theory of relativity and the principles of electrodynamics, while the speed of causality is intrinsically linked to the speed of light and has direct implications for the behavior of electromagnetic phenomena.