According to Physicists and Philosophers, Time Might Not Exist – And That’s OK – Revista Galileu

Is there time? The answer to this question may seem obvious: of course it is! Just look at the calendar or the clock. But developments in physics suggest that the lack of time is an open possibility and we should take it seriously.

like him? And what does that mean? It will take some time to explain this, but do not worry: even if there is no time, our lives will continue as usual.

crisis in physics
Physics is in crisis. In the last century, we explained the universe with two very successful physical theories: general relativity and quantum mechanics.

Quantum mechanics describes how things work in the tiny realm of particles and particle interactions. General relativity describes the big picture of gravity and how objects move.

Both theories work very well on their own, but the two are believed to contradict each other. While the exact nature of the conflict is controversial, scholars generally agree that both theories should be replaced by a new, more general theory.

Physicists want to produce a theory of “quantum gravity” that replaces general relativity and quantum mechanics, while achieving the extraordinary success of both. Such a theory explains how the big picture of gravity works on a particle miniature scale.

Time in quantum gravity
It turns out that producing a theory of quantum gravity is very difficult. One attempt to overcome the conflict between the two theories is string theory. String theory replaces particles with strings that vibrate up to 11 dimensions.

However, string theory faces an additional difficulty. String theory provides a variety of models that describe a universe much like our own, and it doesn’t make clear predictions that can be tested with experiments to see which model is correct.

In the 1980s and 1990s, many physicists became dissatisfied with string theory and came up with a series of new mathematical methods for quantum gravity.

One of the most notable is toroidal quantum gravity, which suggests that the fabric of space and time consists of a network of very small discrete pieces, or “rings”.

One of the cool aspects of loop quantum gravity is that it seems to completely kill time.

Ring quantum gravity is not alone in eliminating time: many other approaches seem to remove time as a fundamental aspect of reality.

Appear time
So we know that we need a new physical theory to explain the universe, and that theory may not include time. Suppose such a theory is correct. Does this mean that time does not exist? It’s complex, and it depends on what we mean by being.

Physics theories do not include tables, chairs, or people, yet we accept that there are tables, chairs, and people. Because? Because we assume that such things exist at a higher level than described in physics.

For example, streams are said to “sprout” from the fundamental physics of particles orbiting the universe.

But while we have a pretty good idea of ​​how to make a table out of fundamental particles, we have no idea how to “make” time out of something more fundamental.

So unless we can come up with a good explanation of how time appears, it is not clear that we can simply assume that time exists. There may not be time at any level.

time and agency
Saying that time does not exist at any level is like saying that there are no tables. Trying to survive in a world without tables can be difficult, but managing a world without time seems disastrous.

Our whole life is built on time. We plan for the future in light of what we know about the past. We hold people morally responsible for their past actions, with a view to reprimanding them later.

We believe that we are agents (entities that can do things) in part because we can plan to act in a way that will bring about change in the future. But what is the point of working to bring about change in the future when, in a very real sense, there is no future to work for?

What is the point of punishing someone for a past action when there is no past and therefore no action apparently? Finding out that there is no time can stop the whole world. We would have no reason to get out of bed.

work as usual

There is a way out of the confusion. While physics can eliminate time, it seems to leave “causation” as it is: the idea that one thing can cause another.

Perhaps physics tells us, then, that causation, not time, is the essential feature of our universe.

If true, the agency can still survive. Because it is possible to completely reconstruct the feeling of agency from a causal perspective.

At least, that’s what Kristi Miller, Jonathan Talant, and I discuss in our new book. [Out of Time: A Philosophical Study of Timelessnes, sem edição em português]. We suggest that the discovery that time does not exist may not have a direct impact on our lives, even as it pushes physics into a new era.

* Sam Barron is an associate professor at the Australian Catholic University. This article was originally Published in English on The Conversation.