Unlike Newton, Ernst Mach did not believe in Absolute Time.
Said Newton… “Absolute, True, and Mathematical Time, of itself and by its own nature, flows uniformly on, without regard to anything external.” The problem with this conjecture, Newton himself acknowledged, is that “it may be that there is no equable motion by which Time can be accurately measured.”
Regardless, Newton felt that motion, itself, did not effect Time… “The persistent existence of things” he said, “is always the same whether motions be swift or slow or null.”
Mach believed that Time was ONLY knowable through motions. And since all motions are relative, there can be no “absolute” Time. Time is “an idle metaphysical conception,” he states.
Mach feels that humans experience something we label as the passage of Time. And when we look for a way to measure this subtle perception, we look for some motion which moves “in almost parallel correspondence with our sensation of Time.” Not so dissimilar, says Mach, from how we seek to measure our sensation of Heat… the thing that we choose as a “thermometer” is the thing which most closely moves in parallel to our own perception of the rising and falling amount of Heat.
For Mach, our concept of Time depends on motion, and motion depends on change… therefore, there can be no Time without Change. Of course, when looking at the Cosmos as a whole, that change comes in the form of a growing amount of Entropy or Chaos.
In fact, the great unwinding of the Universe is about the only clock Mach can imagine capable– just maybe– of keeping correct time.
“The Entropy of the Universe, if it could ever possibly be determined,” says Mach, “would actually represent a species of the absolute measure of Time.”
Well, that’s a relief. I’d hate to be late to Armageddon.