I am sitting here, on a Sunday (I think it’s a Sunday but days are all becoming the same) morning, looking out of the window, watching the world go by. Time may feel like it’s standing still amongst all the Coronavirus chaos, but it is still going on, forever moving constantly forward. But why?
As fundamental as time may seem, there isn’t a universal law dictating that it should move forward. There is no scientific law telling time what to do. It’s all down to dumb luck and entropy.
If you tip a jigsaw puzzle out of the box onto the floor, there is an infinitesimally small chance that the pieces will all fall into place. Apart from that one, unique arrangement of pieces where the picture is clear, there are countless other ways which result in a mess, with pieces all over the floor, some lost forever under the sofa. The universe is drawn in the direction of chaos. Think about your headphones always coming out of your pocket tangled, or how milk and tea mix together rather than stay separated. Things naturally become more chaotic with time, and the chance that things randomly naturally order themselves are very low.
The level of disorder is known as entropy, the greater the randomness of a system the greater the entropy. Well, in the field of thermodynamics there is a little more to it, let me explain it briefly. The energy in molecular bonds is more likely to be equally spread out throughout the atoms, rather than clumped together. But, this is not important to us in the “real” world. In other words, the universe is drawn towards a system with greater entropy, what we perceive as time moving forwards, or our future. As we travel forward in time, the entropy in the universe increases.
Entropy may seem hard to quantify from a personal viewpoint, life is all ups and downs. Cosmically there is a definite trend towards higher entropy or disorder, all starting with the Big Bang. In the beginning there was order, and ever since the universe has been racing towards chaos. The universe expands, particles spread and then clump together and then explode in supernovae, forming galaxies, solar systems, planets, creating life and the messiness of human existence.
We are currently living in a universe that is gaining entropy and expanding, but what is left when the universe finally gets what it wants: pure chaos? Well at that point we will be left with an effectively empty universe, and time can go whichever way, but with nothing for it to act on and nothing to observe it. Scientists call this state Heat Death, energy will be equal everywhere and nothing will happen, probably forever (but that’s a blog for another time).
As I continue staring out of my window, these reflections make me want to experience the moment. It may seem like there’s disorder all around, with viral pandemics ripping across the world, but that just shows us that we are still here, watching, waiting, for time to pass this particular chaotic instant, and on to the next (hopefully less scary) cosmic mess. This too shall pass!
A version of this article feature on https://sciculture.eu/time-and-chaos/