Out of all the pressures we face in our everyday lives, there’s no denying that the nature of time has the most profound effect. As our days, weeks, months, and years go by, time moves from past to present to future, and never the other way around.

But according to the physics that govern our Universe, the same things will occur regardless of what direction time is travelling in. And now physicists suggest that gravity isn’t strong enough to force every object in the Universe into a forward-moving direction anyway.

So does time as we know it actually exist, or is it all in our heads? First off, let’s run through a little refresher about the so-called arrow of time.