Theories in Physics: Time

Have you watched the movie Inception? If you haven’t you should know that this was a movie starring Leonardo Dicaprio, and is about a group of people who are able to dream inside of their own dreams. In this universe time would slow down in the world where the main characters would be asleep in, as they ventured into another dream. Whether or not time would actually slow down if we were able to recreate dream jumping in the real world is unknown; however as seen in many science-fiction books and movies, time has always been an aspect of life that humanity has never truly been able to grasp.

So what is time? According to the Merriam-Webster Dictionary, time is “the measured or measurable period during which an action, process, or condition exists or continues”, which in many cases is true. We are currently in a different time than during the existence of the dinosaurs, and tomorrow will be a different time than last Sunday, but these comparisons rely solely on the idea of whether or not time truly exists.

Albert Einstein said in the theory of Relativity, time passes for everyone, but it may or may not pass at different rates for different people, places, or things. This theory also combined both space and time which proved the idea that time itself is in every aspect of our universe. However the problem that arises from Einstein’s proclamation was that as humans, why can we only move through space, but not time?

The Second Law of Thermodynamics states that systems will become disorganized over time. This law relies on the idea that time only moves forward and us as humans cannot move backwards through it (at least in this universe). Systems in our universe are constantly moving from order to disorder, which provides direction to the arrow of time (direction time is moving in). Since time governs systems and the state of our universe, as humans and physicists we treat time as a Fundamental property; however recently the idea that time is a Emergent property has become popular.

Emergent properties are properties that don’t exist in specific parts of a system, but the rather the system as a whole. One way to view this is like in Inception, movies are comprised of many pictures that when put together provide a video that shows time passing. Emergent properties show that if you only analyze one portion of the system then it is not evident that time exists; however if you analyze the universe as a whole time does. So if you were to go back to the overarching question that is time real? The best answer would be both yes, and no.

Is time real?

Picture Source: discovermagazine.com