(ORDO NEWS) — Does time exist? The answer to this question may seem obvious: of course! Just look at the calendar or clock.
But the development of physics suggests that the existence of time is an open discussion, and we should take it seriously.
How can this be and what would it mean? It will take some time to explain, but don’t worry: even if time doesn’t exist, our life will go on as usual.
Crisis in physics
Physics in crisis. In the past century, we have explained the universe in terms of two extremely successful physical theories: general relativity and quantum mechanics.
Quantum mechanics describes how everything works in an incredibly small world of particles and their interactions. General relativity describes the big picture of gravity and how objects move.
Both theories work very well on their own, but they are thought to contradict each other. While the exact nature of the conflict is debatable, scholars generally agree that both theories need to be replaced by a new, more general theory.
Physicists want to create a theory of “quantum gravity” that will replace general relativity and quantum mechanics, while at the same time recording their exceptional success. Such a theory would explain how the overall picture of gravity works on a miniature particle scale.
Time in quantum gravity
It turns out that creating a theory of quantum gravity is extremely difficult.
One attempt to overcome the conflict between the two theories is string theory. String theory replaces particles with strings vibrating in 11 dimensions.
However, string theory faces another difficulty. String theories offer a number of models that describe the universe in broad terms like ours, and they don’t really make any clear predictions that can be tested experimentally to find out which model is correct.
In the 1980s and 1990s, many physicists became disillusioned with string theory and proposed a number of new mathematical approaches to quantum gravity.
One of the best known of these is loop quantum gravity, which proposes that the fabric of space and time is made up of a network of very small discrete fragments or “loops”.
One of the great aspects of loop quantum gravity is that it completely eliminates time.
Loop quantum gravity is not the only one that abolishes time: a number of other approaches also seem to abolish time as a fundamental aspect of reality.
Time of occurrence
So we know that we need a new physical theory to explain the universe, and that there may not be time for that theory.
Let us assume that such a theory turns out to be correct. Does it follow from this that time does not exist?
It’s complicated, and it depends on what we mean by existence.
The theories of physics do not include any tables, chairs, or people, and yet we still accept that tables, chairs, and people exist.
Why? Because we assume that such things exist at a higher level than the level described by physics.
We say, for example, that tables “emerge” from the underlying physics of particles flying through the universe.
But while we have a pretty good idea of how a table can be made from fundamental particles, we have no idea how time can be “made” from something more fundamental.
Thus, until we can give a clear explanation of how time comes into existence, it is unclear whether we can simply assume that time exists.
Time does not exist on any level
To say that time does not exist on any level is like saying that there are no tables at all.
Trying to live in a world without tables can be challenging, but managing a world without time feels like a disaster.
Our whole life is built around time. We plan for the future in the light of what we know about the past. We think of ourselves as humans (entities that can do things) in part because we can plan actions that will lead to change in the future.
But what is the point of acting to bring about change in the future when there is, in the most direct sense, no future to act for?
What is the point of punishing someone for a past act when there is no past, and therefore, apparently, there is no such act?
The discovery that time does not exist would seem to bring the whole world to a standstill. We would have no reason to get out of bed.
There is a way out of the impasse.
While physics can eliminate time, it seems to leave intact causality: the way in which one thing can lead to another.
Perhaps then physics tells us that causality, not time, is the fundamental characteristic of our universe.
We assume that the discovery that time does not exist may not have a direct impact on our lives, even if it advances physics into a new era.
—
Online:
Contact us: [email protected]
Our Standards, Terms of Use: Standard Terms And Conditions.