Back in Bedrock, we used mechanical stop watches to time ourselves. Now for daily use I use my stop watch function on my phone. In the past I imagined myself moving from one place to another through empty space filled with solid things. Gravity didn't bother me much, young and springy I was. Now I consider that I move at relativistic speed through spacetime on the surface of a massive object that warps the spacetime I navigate. Gravity is more complicated now, and more of an issue. But relativity rocks. For some reason, this particular stop watch is called a particle collider watch. Perhaps this is acknowledgement that reality has always laughed at me behind my perceptual back.