Of all the ideas and concepts that I have encountered, nothing confused and enthuses me more than time. It is a concept I have trouble understanding, so explaining my views will be difficult. I will try anyway.
For the day-to-day experience of life, it seems that time is an Inherent force like gravity or electromagnetism. For me at least it was somewhat unintuitive to find out that it is not. It is a man-made system to keep track of things that are important such as how long until it gets dark, and how long until it is winter, so we can stockpile a sufficient amount of food. I wonder what a world would look like where clocks or time were not invented? If clocks were not invented or any other measure to standardise the processes that occur in the expanding universe, you would still age as ageing is just the sum of all the processes that occur within your body, but there would be nothing to compare it against.
It just so happens that these processes occur over a period which we have standardised as time, in the UK it is 30,660 rotations of the earth on average (84 years). The thing is, if the universe stopped moving and therefore, the standard by which we measure time stopped, we would still age, and ‘time’ would still tick by. If you’re anything like me, time is one of those subjects that you find hard to grasp. If you’re unlike me you’re either an expert when it comes to physics, or you do not think about time at all, and due to common sense, most people are in the latter group.
We, humans, change our standards of time depending on the seasons. We do not age a negative hour when the turn the clocks back, the results if that were true, would be very interesting. So the concept of time is quite fluid as it stands.
There are many phrases and quotes related to time, here are a few I like.
Time is the most valuable thing a man can spend – Theophrastus.
The future is something which everyone reaches at the rate of sixty minutes an hour, whatever he does, whoever he is – C.S. Lewis.
Men talk of killing time, while time quietly kills them – Dion Boucicault.
The only reason for time is so that everything doesn’t happen at once – Albert Einstein.
Here is a thought of my own. If time = distance / speed. If you have no reference points to measure speed or distance by – say you’re in a void – does time pass? My answer would be that time doesn’t exist in this question, but you will still age…over ti…
It is this last quote by Einstein that both disturbs and enthrals me. I know from reading, not from understanding, that time is relative; meaning that it changes at different rates depending on the observer. Once you divorce the idea of time being absolute, which I find difficult, it is easier to understand how clocks travelling at different speeds can tick at different times relative to the observer; just as a ball will have different relative speeds when thrown at two different starting speeds. Imagine you’re standing next to a road you see a car drive past, and the kid sat in the back throws a ball to the front of the car and you measure the speed. The speed will be whatever the boy can throw it at, say five mph plus the speed of the car say 70 mph, so the speed of the ball will be 75 mph relative to you the outside observer. Whereas, inside the car, the boy will only see the ball travel at five mph as he and the ball are already travelling at 70 mph, so the ball will travel at five mph relative to the boy, which is much slower than you see it. Time works the same way in a relativistic universe, and therefore, two people can have different views of time.
Here is a cool video of an interesting time-related paradox.