The Logic of Simultaneity – Relativity without Inertial Frames
Special Relativity, although mathematically simple, cannot be explained in words. The theory is ambiguous because it can only describe physical phenomena through the eyes of a participating observer. This essay tries to lift the blindfold from our abstract eye. It presents an observer independent relativistic view of the universe. More
A theory of how the universe works requires two things. We need to give our understanding a context, and limit, in some way, the environment that gives us our existence. And, we must explain relativity.
In Special Relativity, the context in which the laws of physics are universally described is the inertial frame of reference. It is the Galilean inertial frame extended to the size of the universe. This natural idea allows us to universally apply the logic of inertial frames – if we accept the consequence. The spatial equality between a frame and the universe comes at the expense of time and simultaneity that now lose their universal meaning and become specific to a frame. As a result, inertial frames themselves have no common context. Only two of them can be compared at a time from each other's perspective.
Rather than asking whether this makes sense let us ask whether there is an alternative. Special Relativity bets on the well-definedness of space within a frame and cancels the common context between the frames. Can we turn the equation around and ask whether it makes sense the other way? What if there are no inertial frames?
This essay explores the idea that inertial frames are fiction and, instead, we have well defined time and simultaneity. We lose the conventional definition of space as a three-dimensional coordinate system, but this is a good thing. Spatial ambiguity is the name of quantum physics, it naturally explains the constancy of the speed of light, includes acceleration into the picture, and may even answer some perplexing cosmological questions of today. The logic goes into detail and tries to eliminate grey areas. Eight diagrams explicitly visualize questions relating to movement between observers.
Due to the predominance of logical reasoning this book can be a hard read. It is very condensed and to the point. The author's hope is that, even if reading is not easy, and paragraphs may require revisiting, the ideas come across and a consistent world view emerges from the effort.