What is Time and Will It Ever End?

On the face of it, time is just a measurement – a duration, a score, a point in the day. However, when you take a step deeper and try to think of time as a concept, things can get a bit tricky. Time is a lot more than just a clock, the length of a film, or a target time for a marathon.

One thing we know about time is that it goes in one direction – or at least there is no evidence to suggest otherwise. Whilst theoretically time can move in both directions, because of universal symmetry in physics, time as we know it goes from past to present.

Conceptualising Time

Time is a temporal progression through existence, but it’s hard to conceptualise and actually think about what that means. One way to think about time is as a fourth dimension. Space and time combine to make up the space-time continuum.

Einstein’s theory of relativity takes this approach, with time on a par with the three spatial dimensions.

Space is fundamentally linked to time because everything spatial, with whatever spatial dimensions, must also constantly progress through time – so it has an imaginary fourth co-ordinate for time, if it were plotted on a graph.

Will Time Ever End?

Time began at the point of the big bang. This was when all matter was created and so the progression of that matter and its existence began. The question of whether or not it will end will depend on the progression of the universe that has been created.

Dark energy is currently causing the universe to expand at an ever-increasing rate. If this continues, one theory suggests that there will be a ‘Big Rip’. The scale of increase and proportion of dark energy would cause gravity to weaken. Galaxies would be separated, solar systems would become unbound, stars, planets and eventually all atoms would be destroyed.

Otherwise, the universe may continue to expand, or dark energy could decrease, causing the universe to eventually implode. Without further information on dark energy, we cannot be sure of the fate of the universe and time.

The universe provides endless potential research for scientists. ‘Bright Lights, Big Science: The physical phenomenon that has helped to shape human history and open up our world’ explores the role of light, not only in developing our planet and its inhabitants, but also how it has helped us discover more about the universe around us, and can continue to help us in future.