Surely you have heard, on more than one occasion, that the universe is expanding at a growing rate. That is the theory that most scientists hold. However, there is a group of Spanish scientists who argue that this is not the case. According to them, the expansion of the universe is not the one that is changing rhythm but time in itself. This would mean that time slows down and that could be decreasing .
The affirmation could come to mean something really serious. If the time slows down, could it stop? What would happen then? We will investigate what would be the consequences of a slowdown in time.
What happens if the time slows down?
To try to understand what José Senovilla is talking about at the University of the Basque Country in Bilbao and all his team, that is to say that time is slowing down, let's imagine an ambulance. Think about how that ambulance sounds when it goes down the street with its sirens on. You will have noticed, on more than one occasion, that As that ambulance moves away from you, that siren starts to fall into the tone . This is called a Doppler effect. To this effect it is known as an Austrian physicist named Christian Andreas Doppler and explains that this effect is the apparent frequency change of a wave produced by the relative movement of the source with respect to its observer.
This happens because the sound waves stretch slightly as the sound moves away from you, with which, they will reach you at a slower pace or, what is the same, at a lower frequency.
Here comes the interesting question, what would happen if the laws of physics changed when the ambulance is passing? If, instead of speed being the cause of that fall in frequency, were the passage of time, what would be the result?
If it is true that time slows down, that would also cause sound waves to store it at a lower frequency. Well, that's exactly what Senovilla and his team are suggesting: We know that the universe expands at an accelerated rate because the galaxies that are located farther from us stretch more than the closest galaxies , which means they are moving faster. But if time was slowing, that light would reach us at a lower frequency.
We know how that theory sounds, something extravagant, nevertheless it can give answer to some problems of difficult solution.
In order for the expansion of the universe to accelerate, you need to create something that causes it. That's where the so-called "dark energy" comes in. It is assumed that this mysterious force constitutes 68% of the universe , but the truth is that it has never been possible to verify. If time is slowing down, you do not need dark energy at all.
But this hypothesis may still be rarer. In the beginning, it is based on string theory. This theory holds that the universe exists on the surface of a membrane, a "brane", that exists within a space of a dimension greater than what we call volume, also known as hyperspace.
Those Branas can have a different number of dimensions, for example, ours has three spatial dimensions and one time dimension . Others may not even have time dimensions or also have multiple time dimensions.
The dimensions in those other branes they could even oscillate between different versions: space could become time, and vice versa. And that's what the team of researchers believes could be happening in our time dimension: that is becoming little by little a spatial dimension. If that is what finally happened, our universe would be frozen in time and would exist in four-dimensional space .
We would experience all this as a gradual slowing down of time; so gradual, in fact, that during the first billion years, we would only see its evidence on large scales, such as the movement of distant galaxies.
"Our calculations show that we would think that the expansion of the universe is accelerating," said Senovilla.
"Any observation of dark energy could be evidence that our brane is changing register and that time is disappearing."
But you should not worry too much, if this just happens, if time slows down, this will not be before billions of years and by that time we are not even able to imagine how it will be our planet , so it's not something that should prevent you from sleeping at night.
What do you think of our article about this discovery by Senovilla and his team that says that time slows down? Do you find it interesting? Leave us your comments about if you are interested in these topics about space! We will be happy to read you!