Does Time Exist?

Our universe is expanding. We know this to be true because when we look out into space, we can observe the numerous galaxies drifting apart from each other. Now, when we project this drifting motion backwards in time we plot the galaxies drawing ever closer to each other, ultimately meeting at one point. This point in time is widely considered to be the moment of the so called "Big Bang" - the birth of the universe if you will. Our best estimate as to the age of the universe is 13.8 billion years, give or take. But if time doesn't exist, how can we speak of the age of the universe (or the age of anything for that matter)?

The speed of light in a vacuum is 299,792,458 metres per second. That's fast! It takes light a mere 8 minutes and 20 seconds to complete its journey from the Sun to the Earth. But if time doesn't exist, how can we speak of the speed of light (or the speed of anything for that matter)?

Time cannot be separated from space; this is why Einstein introduced the concept of spacetime. We know that spacetime is warped and curved by gravity, which is why time actually slows down in a gravitational field - a phenomenon that has been proven experimentally.

Given all of the above, the popularity of the notion that time doesn't exist intrigues and baffles me.

There is no question that time exists. Time is fundamental to the existence of everything in the universe. All events have taken place - or are yet to take place - somewhere in space, but also at some point in time.

I don't hear any debate over whether width, length, or height exist. Einstein theorised that space and time are not absolute but are relative. That is to say, things can only be measured in accordance to a frame of reference. If we don't share a common frame of reference in space-time then we can't agree on such aspects as size, distance, speed and age of things we observe. But if time doesn't even exist, then surely we're stumped from the very start. Although without time there is no start.

My point is we can have a sensible, meaningful debate over what time is. We can discuss the concept of time scientifically and philosophically. Indeed our impression of time is highly subjective. But to say that time doesn't exist at all; to say that time is an illusion? That's absurd.