Imagine you have a small mirror in which you can only see the reflection of your eyes. Then take a larger one where you can see your entire face. Then you find another place where you can see yourself at full length.
The most common picture we have of the Big Bang is that from the point where a universe originated, it was expanding.
But what if this universe is just Twins from another world that formed at the same time at that point and is expanding in the opposite direction?
This is a bold proposal recently published by a group of cosmologists at the Perimeter Institute for Theoretical Physics in Canada.
And they go further.
In this against the universe which they suggest, because it is moving in the opposite direction from our direction, time also passes in the opposite direction.
This hypothesis, as complicated as it may sound, is an attempt by its authors to explain a more simple and “economic“, many secrets of the universe, among them the mysterious dark matter.
There are two basic concepts to understanding the idea of an anti-universe.
The first relates to the . extension Standard Model of Particle PhysicsThe theory that describes the fundamental particles that make up the universe and the forces that cause them to interact with each other.
According to the Standard Model, whenever a particle of matter appears, it also happens isotope of antimatterwhich is an identical particle but with a different charge.
This means that during the Big Bang the same amount of matter and antimatter were produced.
The second concept is symmetry.
In cosmology, this principle indicates that any physical process remains the same even if time is regressing, if inverse space Or if the particles are replaced by antiparticles.
Based on these two principles, the analogy that can be made is that just as the universe exists, one can expect the universe to exist. symmetric anti-universe Who do we know?
In a recent study by the Perimeter Institute for Theoretical Physics, the authors analyzed a type of symmetry called CPT, the initials for charge, valence, and time.
This symmetry indicates that if they are reversed Loads, image and time From the particle interaction, this interaction will behave the same way.
Therefore, this symmetry that applies to particles, according to the study authors, can also be applied to the universe as a whole, opening up the possibility of a symmetric universe.
“The universe as a whole is symmetric CPT”the authors write in their research.
Under this hypothesis, the Big Bang is the starting point in which the universe arose and its existence image reflection.
“We propose that the universe before the Big Bang is the ‘anti-universe’ of the universe after the Big Bang,” the authors say.
Latham Boyle, one of the study’s co-authors, cautions against this He has no certainty on the anti-universe hypothesis and that his proposals must be empirically verified.
But he thinks his calculations give him some clues.
“So far, we believe that the anti-universe is a true mirror image that is reflected in time Exchange of particles and antiparticlesBoyle says in a conversation with BBC Mundo.
According to that vision, this anti universe It is not an independent universebut just a reflection of our universe.
“We have an ‘anti-self’ in the other universe, but it’s not independent,” Boyle says.
“If you choose to eat eggs for breakfast, your anti-variety version can’t choose to eat bacon for breakfast.”
“If you had eggs for breakfast, he would have to have breakfast. anti egg“.
As Boyle and colleagues suggested, the Big Bang is like a mirror that not only inverts the image, but also reflects it time direction.
Time moves on both sides of the universe Stay away from the Big Bangonly on one side the time arrow goes to the right, and on the other hand it goes to the left.
“Every aspect of the universe thinks it’s perfectly normal,” Boyle says. They both think their time is moving forward.”
“From our point of view, in the opposite universe Time is moving backwardBut for them we are the ones going in the opposite direction.”
Boyle’s idea holds another mind-boggling possibility: Maybe we are the ones in the opposite universe And we don’t know.
And another question you may ask yourself: Is it possible to travel to this anti-universe?
“We can’t cross over to the other side of the glass,” Boyle says. “So it must be possible travel to the past“.
This means that you will have to travel through space-time, crossing the singularity of Big Bang and It comes out from the other side.
But beyond these sci-fi-like ideas, Boyle and colleagues’ work also suggests solutions to them. More practical problems Physics and Cosmology.
His proposal offers challenging insights into three basic concepts of cosmology: Dark matter, inflation after the Big Bang and gravitational waves
Dark matter is a mysterious ingredient This makes up 25% of the universe, but until now no one has been able to notice what it is or what it is made of.
However, dark matter can be observed by gravity effect exercised on the universe.
For years, scientists have proposed various theories to explain what dark matter is, but still Nobody has a convincing answer.
Some possible answers hold that dark matter is made of a particle we don’t know yet, That is, it is outside the standard form.
However, Boyle’s study provides a “cheaper” answer to the dark matter puzzle.
His suggestion is that to explain dark matter it is not necessary to imagine new particles.
Instead, Boyle thinks the answer may be that dark matter is made of “Right neutrinos”a variety of neutrinos, which are not part of the Standard Model.
It has not yet been proven that there is “Right neutrinos” But according to Boyle, many scientists agree that it may be part of the Standard Model.
In this way, Boyle saves himself the effort of speculating on new molecules and finds the answer in laws The physics we already know.
So far, known neutrinos are “left-handed,” referring to the direction in which they are spinning.
But in a symmetric universe, a right-handed neutrino is also expected, i.e. A antineutrinoAccording to astrophysicist Paul Sutter, in an article on the portal life Where he reviews Boyle’s study.
These right-hand neutrinos will be so Mostly invisible Its presence can only be detected through gravity.
An invisible particle that dominates the universe and interacts only through gravity It’s very similar to dark matter.”Sutter explains.
Joseph Formaggio, a physicist who researches the role of neutrinos in cosmology, says he finds Boyle’s proposal to explain dark matter intriguing.
I love your model minimum‘,” says BBC Mundo Formaggio, who was not involved in the investigation.
“Usually in particle physics many phenomena can be explained by introducing new particles, interactions and fields, through which Easy to get lost“.
“But this research has another approach, they don’t add anything beyond what we’ve already observed,” concludes Formaggio, who directs the Department of Experimental Nuclear and Particle Physics at MIT.
Formaggio refers to the idea of right-handed neutrinos It’s very popularalthough it is not known if they exist.
“It’s a new particle,” he says with a laugh, “but it really isn’t.”
Finally, the study questions the existence of cosmic inflation and primordial gravitational waves.
Boyle’s model wonders if there is a period when the universe will exist after the Big Bang rapidly expandeda concept known as inflation.
This inflation, in turn, may have created primordial gravitational waveswhich are ripples that travel in the fabric of space-time, like the ripples caused by throwing a stone into a lake.
Boyle’s proposal holds that instead of inflation, matter in the universe expands with less force, without the need for “Burning Time”.
Therefore, according to this model, if there was no inflation, then there would also be no primitive gravitational waves.
In 2015 gravitational waves were first detected, however, Boyle cautions that these events correspond to events much later than the Big Bang, and therefore are not primitive gravitational waves.