It's always interesting to question what is considered our standard point of view even when it works so well. Special Relativity is common sense in my opinion and is why I would never give it up. However, what always bugged me was time and using it as a 4th dimension. One of the concepts of space-time that is the stuff of SCI-FI, is you could warp space-time in such a way that the fabric of Space-Time could fold allowing for fast-than-light travel (FLT). The warping of space-time does require extreme bending but in places like black holes, the event horizon provides a great conceptual model of zero time. It's what gives rise to concepts like the Holographic Universe.
I recall on a thought experiment (exploring common sense) I was looking at the concept of fractional dimensions. Like the Mandlebrot, but the question I asked myself was, what would a fractional dimension look like if we experienced one? There has been a movie of the flat world (a 2D universe) experiencing its interaction with a 3D world. You know the circle forming when viewing a 3d sphere interesting a plane. So my thought experiment was what if one and only one of the dimensions was fractional? Normally we think of dimensions as X,Y,Z and t, which act like a 4D index into space (X,Y,Z) and time (t). If you pick a space dimension like X, we can envision it as a horizontal position in space. What would it look like if X was fractional? Common sense would say that it would have a boundary that is no longer an integer but could be limited to only a direction forward (note forward is a reference to time). However, from the Flatworld POV, such a clipping of a dimension would be a dimension that can only progress forward. What if time was in reality a fraction dimension incapable of time reversal? Time as a fraction dimension could not move backward. From our perspective, time is an arrow, a ray, but what if that is what the 4th dimension is? A fractional dimension. When you look at special relativity from that perspective, things make a little more sense conceptually. It really makes the Holographic Universe concept seem even more profound.
