Science upends our everyday understanding of time. Since Albert Einstein developed his theory of special relativity no physicist speaks dogmatically of yesterday, today and tomorrow.
Under special relativity, and its sister theory general relativity, there is no time other than spacetime – all time is dependent on the location of the observer. This has somewhat mindbending implications, impugning among other things one’s sense of identity. Your life does not play out in a “start, middle and end” fashion; traditional narrative is scientific fiction.
Alison Fernandes, assistant professor in the Department of Philosophy at Trinity College Dublin, is fascinated by such contradictions, and in her research on "temporal asymmetries, physics and agency" she explores how human experience can be reconciled with scientific fact.
The now does have a very slippery character. Philosophers have worried about how 'long' the now might be.
Fernandes tests hypotheses surrounding time travel to better understand the nature of causation and chance – and while this may, at first glance, seem to lack practical application – it can help to explain, among other things, whether we should value past and future events differently.
There are big implications here for the self-help industry, especially that strand which advocates “living in the now”.
While “we can typically interact more with events that are nearby us in time,” scientifically speaking “no particular moment in time is privileged as being ‘the present’, or as having any particular significance”, Fernandes - this week’s ‘Unthinkable’ guest - explains.
What does science tell us about the nature of time, and how does it conflict with our experience of time?
Alison Fernandes: “When we think of time, we often think of it as something which itself changes: time flows, or passes by. We also tend to think that the moment we occupy, ‘now’, is special – that it’s somehow more real or ‘privileged’ than other times.
“And we also think of the future as having very different properties from the past. While future events have yet to happen – and are therefore ‘open’ or unfixed – past events have already happened, and are therefore settled.
“But science doesn’t suggest time has any of these features. According to how science conceives of time, time itself doesn’t change. Sure, different things happen at different points in time. But time itself isn’t passing or flowing or anything like that. Nor is the present special.
“Many candidate laws of fundamental science don’t even distinguish between past and future directions in time. They look the same and work equally well in both temporal directions.
“The picture from science gets even more strange when we look to sciences like special and general relativity, as well as quantum mechanics. We’re not even sure how the finished picture of time will look. But from what we’ve seen so far, the broad lesson will remain - there’s a big gap between time as conceived by science, and time that we take ourselves to experience.”
Is this conflict philosophically problematic?
“I would say it’s philosophically productive. It means philosophy has a lot of work to do to explain what’s going on with the conflict. How can experience, or science, be so wrong about the nature of time, or how can these points of view be reconciled?
“Some philosophers have argued that science is getting it wrong – we should revise sciences like special relativity because they don’t fit with our intuitive view of time.
“One of the big conflicts is that special relativity suggests there aren’t event facts about what events are simultaneous with one another. If there can’t be facts about what events are happening at the same time, then there certainly can’t be facts about which moment in time is the privileged present. So some have thought special relativity must be wrong.
“But as scientific theories have proved so successful, philosophers have been less likely to dismiss them. They’ve been more likely to argue that our ordinary experience of time is wrong, or that our ordinary view and the scientific view should be reconciled in some way.
“My own preferred route is towards reconciliation. I think we should accept what science tells us about time, but then go on to scientifically explain why we nevertheless experience time as we do. This is a project that draws on work from lots of areas of science, including physics, biology, psychology and other cognitive sciences. It’s a way of using science at the very heart of philosophy.”
What practical wisdom can we gain from thought experiments about time travel?
“In our world, we don’t have a choice about what moment we experience when. We’re ‘stuck’ in the present-and perhaps we can begin to feel trapped by it too.
“But imagine if you could travel to other parts of time, and choose what time to experience next. Perhaps you would then begin to think of the past and the future as just as real as the present – you would adopt a more ‘scientific’ view of time. And that might be a way to appreciate that all parts of your life are equally as important as each other.
“Here you are, right now. But look at where you’ve been and where you’ll go next – they’re just as much a part of your life too.
“Sometimes we lose this long vision of our lives. We want it to be all good right now. But sometimes we make better choices by taking the long view, and seeing all parts of time as equally real.”
Mindfulness advocates tell us to “live in the moment”. But is it possible to locate the now?
“The now does have a very slippery character. Philosophers have worried about how ‘long’ the now might be. If you make it too short, it’s always already slipped away. But if you make it too long, it doesn’t seem that special any more.
“This is one of the ways you can get into a tangle if you take how we experience time to be a literal guide to how time is.
“In fact, what seems to be going on is that our brain is doing a lot of work to integrate a certain temporal window of information. When you watch someone shout from far away, you experience the sound and sight of their shouting together, even though the visual information arrives first. But when it comes to thunder and lightening, we don’t integrate - so we experience the thunder after the lightening.
“It turns out that what we experience as happening ‘now’ is flexible and a lot of science is needed to explain why we experience certain events together.”
* Alison Fernandes will deliver a lecture on "Is time travel possible?" as part of Trinity College Dublin's 11-part public lecture series Big Questions in Philosophy, on Tuesday evenings (7.30pm-9pm) starting January 22nd in the Thomas Davis Theatre. Cost €100 or €50 concession. https://www.tcd.ie/Philosophy/events/public-lecture-series/index.php
Ask a sage:
Question: What's the time?
Answer (courtesy of Segal's law): "A man with a watch knows what time it is. A man with two watches is never sure."