+
If time is not a fundamental property of the universe, it can still “emerge” from something more fundamental (Photo: Shutterstock)
Is there time? The answer to this question may seem obvious: of course it is! Just look at the calendar or the clock. But advances in physics suggest that lack of time is an open possibility and we need to take it seriously.
learn more
like him And what does that mean? It will take time to explain it, but don’t worry – even if we don’t have time, our lives will continue as usual.
physics crisisPhysics is in crisis. In the last century, we have explained the universe with two very successful physical theories: general relativity and quantum mechanics.
Quantum mechanics describes how things work in the small realm of particles and particle interactions. General relativity describes the general picture of gravity and how objects move.
Both theories work very well on their own, but the two are believed to contradict each other. Although 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. This theory explains how the overview of gravity at the scale of miniature particles works.
Time in Quantum Gravity It turns out that producing a theory of quantum gravity is very difficult. An 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 very similar to ours, and does not make clear predictions that can be tested with experiments to see which model is correct.
learn more
In the 1980s and 1990s, many physicists became dissatisfied with string theory and proposed a number 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 interesting aspects of quantum loop gravity is that it seems to kill time completely.
The quantum gravity of the ring is not the only one to eliminate time: many other approaches seem to eliminate time as a fundamental aspect of reality.
Time of Appearance So we know that we need a new physical theory to explain the universe, and that theory may not include time. Suppose this theory is correct. Does this mean that time does not exist? It’s complex, and it depends on what we understand it to be.
Theories of physics do not include tables, chairs, or people, but we accept that there are tables, chairs, and people. Because? Because we assume that these things exist at a higher level than described in physics.
For example, currents are said to “sprout” from the fundamental physics of the particles orbiting the universe.
But while we have a pretty good idea of how to make a table with fundamental particles, we have no idea how to “make” time for something more fundamental.
Therefore, unless we can give 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 To say 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 timeless world seems disastrous.
learn more
Our whole life is built on time. We plan for the future in the light of what we know about the past. We make people morally responsible for their past actions, with the goal of 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 brings about changes in the future. But what is the point of working to achieve change in the future when, in a very real sense, there is no future to work for?
What good is a web site if it simply “blends in” with everything else out there? Discovering 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 the “causation” as it is: the idea that one thing can cause another.
Perhaps physics tells us, then, that causality, 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.
learn more
At least that’s what Kristi Miller, Jonathan Talant and I are discussing 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 though it pushes physics into a new era.
* Sam Barron is an Associate Professor at the Catholic University of Australia. This article was originally published in English in The Conversation.