When Marty slammed the DeLorean into overdrive and fired up the flux capacity as he raced away from the bad guys at 88 mile per hour, he was given an opportunity none of us will ever get. Back in the past, he could change things that would make his future better. He had the benefit of knowing how things will turn out if he made no changes, but once he made a change in his now present, the future he was trying to get back to was unknown to him. The ancients Greeks thought of themselves as having their backs to the future. They conceived of time as moving on them from behind where they couldn’t see what was coming, and with the past laid out in front of them with all their mistake to see.
Nowadays, we tend to think of time the other way round, with the future in front of us but still unknown. Despite millennia of thinking, incredible scientific advances, and numerous sci-fi films, the future remains unknowable. And always will.
We can only experience time as flowing one way, that’s all our brains are capable of. But that experience isn’t the same for all of us and we aren’t all affected by time in the same ways.
Susan Schneider, writing in Scientific American magazine, claimed that the flow of time is such an inherent part of experience that we can’t experience anything without a sense of time about it. That sense of time changes depending on how we feel. Neuroscience recognises the integral role that happiness, sadness, fear, and other emotions play in the way we feel about the passing of seconds and minutes. Pursuing rewards changes our perception of time. Novel experiences and new situations make time feel like it’s going slower. Getting absorbed in a flow state makes time pass unnoticed and when we look up from what had us absorbed we wonder where the hours have gone.
We all experience our time differently, and uniquely to us. Which is fine when we’re on our own, doing our own thing, and not having to rely on other people. But as soon as we need to work together, things change.
Regular time keeping is a modern invention. As society became more connected, with, for example, trains travelling between cities, we needed a means of coordinating ourselves. Time was the obvious way to do it. But it wasn’t simple to start with. The non-mechanical way we understood what the time is, was to look at the sun. When it’s highest in the sky, that’s midday. But midday is different depending on where you are on the planet. Midday in London doesn’t happen at the same time a midday in Glasgow. So, train drivers setting their clocks to London time would arrive in Glasgow at a different time to when the people of Glasgow were expecting. The big step in that coordination was everyone agreeing a single time that all clocks and timetables could be based upon. That agreement shifted us away from an experience of time and towards agreed convention about time.
Since then, we’ve found increasingly more accurate ways to measure time and use it to coordinate a complicated and interconnected society. Global positioning satellites factor time into their calculations to show us where we are on Google Maps. Stock markets conduct transactions in mere milliseconds. And the most accurate Strontium Atomic clocks only lose 1 second every 15 billion years. That’s pretty accurate, and with this accuracy we’re better able to coordinate ourselves.
So we have these two experiences of time, but they feel intertwined. We have our personal sense of time, boredom when we’re waiting for something, or a sense of flow when we’re absorbed. And we feel the effects of the agreed convention of coordinated time as we try not to be late, and check our calendars for where we need to go tomorrow. And mixed up in this experience is the desire to make the most of our time, to not waste our present or to look back on our past with regret.
Back to the future is a hopeful film. It tells a story of someone who can change the past to make their future better. But without a time machine, we’re left with only our present to do that. Maybe being more aware of, and intentionally changing how we experience time, could help us make the most of our present. Maybe choosing when we should be paying attention to our own sense of time and when we should be complying with the convention of coordinated time can help us shape the future.
As Ptahhotep, the ancient Egyptian thinker, said, “Follow your desire as long as you live, and do not perform more than is ordered, do not lessen the time of the following desire, for the wasting of time is an abomination to the spirit...”