Paradoxical Time

From "Reality is Not What It Seems: The Journey to Quantum Gravity" by Carlo Rovelli. This point he made was so interesting :D

There is no true time. Suppose we calibrate our clock using a pendulum. How do we know if that pendulum swings in regular intervals? If we try to confirm that by counting the oscillations using our pulse, for example, but how then do we know our pulse is regular? We might compare my pulse to another pendulum, and this just gets all circular.

You might ask, well I can count the seconds on my watch (which depends on pendulums) and it seems regular to me! But our senses could be fooled or proceed in a non-regular way, and that, is as hard to find as tricks played on us by our own brain.

You might argue, Newton's laws of motion declares that the pendulum swings in regular intervals. However that law is only true when each second is uniformly long aka time flows regularly. If, for example, each second is twice as the sencond before it, then according to Newton's laws, the pendulum does not swing regularly!

Additionally, our clocks might not tick in the same rhythm. And the worst thing is, I'm always fixed in my set of senses, so I can't investigate your set of senses and confirm that our clock rhythms are(not) the same. This scenario is similar to another scenario: imagine three people. One sees blue and green in reverse, another see blue and red in reverse, but they don't know anything about it. The third person is you. When you three switch eyes (thus switch sight), you three would all agree that the other is colour-blind. So see, there is no "definite" green, blue, or red, but universally calling the sky "blue" is just easier for everyone. Likewise, hanging a clock on the wall is just easier for everyone.

We really don't know, it just seems to be useful assuming such regular & universal "t" exists. It functions as a nice dummy variable (probability generating functions: "that's true.") that links one function to another. For example, we express velocity in terms of t and then acceleration in terms of t. Why don't we simply express acceleration in terms of velocity?

But why rid the dummy variable that the pink clock above represents? It might not mean anything, but it makes our calculation easier. In fact, the concept of time makes everything easier.

Oh, apart from help sorting our calculations, time is useful with respect to something else: time heals everything. Heard it before?