Does the Future Exist? | Unveiled

Does the Future Exist?

We spend a lot of our lives thinking about, looking forward to, and planning for… the future. A mystical, far off place that often takes up more of our energy than even the present does. But is the future ever really there?

This is Unveiled, and today we’re answering the extraordinary question; does the future exist?

In general, most people are eternalists. Most mainstream representations of time are eternalist in nature. They follow the fairly uncomplicated notion of eternalism, which says that the past, present, and future are all separate parts of time, and each has its own unique traits. It’s an intuitive approach. We know things have happened, are happening, and will happen, so presumably, there is a past, present, and future to speak of. But there are some theories and philosophical approaches that turn this on its head.

As humanity has consistently found across history, it’s unusually difficult to talk about time and how it functions. Eternalism, however, is also the philosophy behind the Block Universe Theory, arguably one of the simpler models out there. It’s rooted in Albert Einstein’s work defining spacetime as being made up of four dimensions: three spatial and one temporal. In the Block Universe model, we have points across space and time that all technically exist always… it’s just that we can’t get to all those other points in time (besides the present).

This is a problem, though, because how can we possibly prove that all points in time - particularly future points in time - always exist? A number of physicists have therefore grown to be unsatisfied with eternalism and the Block Universe as a valid explanation. And a number of alternative models have emerged; many of which appear pretty weird at first but could make even more sense.

At the heart of the problem, physicists are grappling with the fact that while we can technically move in any direction in space that we want to, we can only go forwards in time. Bit by bit, and never backwards. We can only ever perceive the present moment or remember past moments (moments which, at the time, were also in the present). This conundrum has led to the development of the Growing Block Universe Theory, instead.

The Growing Block Theory says that spacetime is always growing as time passes, with new slices being added as the present continues and then slips into the past forever. Crucially, because in the Growing Block the slices of the future haven’t been created yet (and will only be created when they become the present) the future doesn’t actually exist. It’s emerging with every passing second, but we can’t say at any one moment that the future is already there. It’s as though we’re on a runaway train but the track is only being laid as soon as we pass over it.

The Growing Block Universe Theory has grown more and more popular in recent years, but it does still have some problems of its own. It explains the past fairly well, arguing that we have clear enough proof the past exists because of causation, where past events influence and directly affect the present. But its depiction of the present can be questioned. We certainly know the present exists because it’s the state we perpetually occupy, but how exactly do we define the present moment? And then, how do we measure these so-called slices of spacetime? Is the present a second? A minute? An entire day? Or is it far smaller than any of those? The smallest unit of time ever recorded is the zeptosecond, defined as being a trillionth of a billionth of a second. Could the present be this minuscule, then, or smaller? So small that, despite it being our constant reality, we can’t actually perceive it? Unfortunately, this question doesn’t have an answer… but if we were to consider ourselves as living just zeptosecond to zeptosecond, then the present suddenly becomes an extremely fragile thing.

But maybe you’re not convinced by either the Block Universe or the Growing Block Universe theories? In that case, you may prefer presentism. For a presentist, we only ever perceive and exist in the present. Every single moment you’ve ever experienced has been in the present… so therefore that’s the only thing, the only aspect of time, we can ever truly recognise. Presentism goes further than Growing Block Theory, though, because it bluntly declares that the past doesn’t exist, either. Yes, this in the face of archaeological and historical evidence that the past is real… but to the presentist, because the dinosaurs don’t exist now, they don’t exist at all. Presentism hasn’t taken off quite like the Growing Block Universe has done, however, mostly because this unusual belief doesn’t stand up to even light scrutiny from other temporal philosophers. No matter how we perceive time, we know that dinosaurs existed, or that yesterday happened, and presentism can’t account for that.

Regardless of which of these beliefs you personally subscribe to, or if you believe something else entirely about the nature of time, we do at least have some scientific dogma to help us understand the strange ways in which time can behave. We can again look at Einstein’s work, for example, to show that the present moment isn’t actually the same for everyone. If you’re travelling, you experience the passage of time differently compared to someone standing still - depending on how quickly you’re moving. This aspect of special relativity is known as time dilation, and it’s vital to consider when it comes to our future plans for space travel.

Time dilation says that the faster you travel through space, the slower you travel in time, relative to a stationary observer. So, if you travel through space fast enough and then return to Earth, less time could have passed for you than for everyone else on this planet. You (and everyone else) still exist in the present, but you reached this present moment at different speeds… which doesn’t seem like it should be possible, but it’s a reality for many astronauts returning from the ISS. A phenomenon otherwise known as the “loss of simultaneity”. This blurring of the boundaries isn’t something that will affect anybody in their day-to-day lives, but it does pose a pretty sizeable problem for both the presentists and the growing block theorists. If two sets of people can reach the same moment at different speeds, then one must have been in front of the other… all of which seems to scientifically prove that the future does, in fact, exist.

A less scientific example of the loss of simultaneity is simply that we all perceive time in different ways on different days. Time seems to fly by when we’re enjoying ourselves, but if we’re waiting for something it can seem to take forever. For two people, at the same moment, time can feel as though it’s passing differently, and the future can feel as though it’s near or far. Is time actually passing at a different rate here? Is it far more fluid than most models would have us believe? Or perhaps it’s that those slices of the present, the ones constantly added in the Growing Block Universe, are in some way not uniform? Perhaps we each experience different-sized slices of spacetime, dictated by any number of variables - like mood, or past experience, or age. Again, at the moment, we can’t possibly quantify how these units take shape.

But, to take the problem of time to its extreme, there are places in the universe where it doesn’t even seem to exist at all: inside black holes. Black holes don’t just distort the space around them, they also distort time itself… all the way down to their singularities. According to some theories, if you were to fall into a singularity, you would witness the entire history of that specific point in space and time. The future would be laid out before you, potentially all the way up until the end of the universe. Sure, if you ever did find yourself in this position, you’d never be able to escape to tell anyone about it. And you wouldn’t need to see the past or the future to know that you, yourself, were already dead. But, from a purely hypothetical point of view, the experience would once again imply that the future does exist.

And yet, the true nature of the future remains something which neither science nor philosophy can really nail down. What we do know is that the future will, at least, happen. We can plan for it and predict it. We know that, tomorrow, the sun will rise. And it will also rise a week from now, a month from now, and every day for billions of years. We’re also confident that the sun will eventually become a red giant and burn the Earth up… so, if we accept the Growing Block Theory, then those particular slices of the present will be very significant indeed!

Ultimately, no belief or model or theory has bearing on the fact that tomorrow will come. Or that what we do in the present affects what will happen next. There are plenty of interpretations on whether or not the future exists, but it is always just around the corner.