[troutman]

The Order of Time - Carlo Rovelli

https://blog.12min.com/the-order-of-time-pdf-summary/

In the course of time, the events of the universe succeed each other in an orderly way: pasts, presents, futures. The past is fixed, the future open… And yet all of this has turned out to be false. One after another, the characteristic features of time have proved to be approximations, mistakes determined by our perspective, just like the flatness of the Earth or the revolving of the sun.

Let’s start with perhaps the most fundamental aspect of time: it, we believe, passes everywhere at the very same speed. This is, however, completely wrong.

Gravity is just a side-effect of large bodies modifying the structure of space-time between them.

The difference between past and future, between cause and effect, between memory and hope, between regret and intention… in the elementary laws that describe the mechanisms of the world, there is no such difference.

The only law which distinguishes the past from the future is the Second law of thermodynamics, which states that the total entropy of a system can never decrease over time. In plainer words, if nothing else changes, heat cannot pass from a cold body to a hot one. In essence, this means that time is fundamentally interrelated with heat.

The word “now” means nothing beyond your approximate surroundings: in universal terms, now is a non-existent concept.