(ORDO NEWS) — Modern physics is going through hard times. On one side lies quantum theory, which describes the structure of the universe at the atomic level, and on the other, Einstein’s General Theory of Relativity (GR), according to which space and time can be curved under the influence of gravity.
The problem is that separately both GR and quantum mechanics work fine, but they contradict each other’s postulates. For this reason, physicists have been working to create a unified “theory of everything” for the past 90 years.
But with each new discovery, there are more and more questions, but researchers do not stop trying to get to the bottom of the truth – the results of the first experiment of its kind showed that in a curved and expanding universe, pairs of particles appear from empty space.
The result obtained during the simulation again brings us back to the question of how something can arise from nothing. In other words, one step forward and two steps back.
A first-of-its-kind experiment simulating space with ultracold potassium atoms suggests that in a warped, expanding universe, pairs of particles emerge from empty space.
Where do particles come from?
A first-of-its-kind experiment simulating space with ultracold potassium atoms suggests that in a warped, expanding universe, pairs of particles emerge from empty space.
This groundbreaking experiment aims to better understand cosmic phenomena that are difficult to detect because particles can emerge from empty space as the universe expands.
In the course of the work, physicists from the University of Heidelberg in Germany cooled more than 20,000 potassium atoms in a vacuum, using lasers to slow them down and lower the temperature.
As a result of extreme cooling, the atoms formed a small cloud (about the width of a human hair), turning into a quantum, liquid-like substance – a Bose-Einstein condensate.
In essence, the new experiment allows you to change the properties of atoms, forcing them to follow an equation that in the real universe determines its properties, including the speed of light and the influence of gravity near massive objects.
As the authors of the scientific work note, this is the first experiment in which cold atoms were used to simulate a curved and expanding (with acceleration) Universe.
When the researchers shone light on the frozen atoms, they moved as if pairs of particles were born in the real universe.
The new experiment makes it possible to combine quantum effects and gravity, which is surprising, since physicists do not quite understand how two contradictory theories fit together in the universe.
It also means that future experiments with can lead to a better understanding of the quantum universe and possibly closer to creating a theory of everything.
Universe of probabilities
Our expanding universe is, in fact, a perfectly valid solution to the equations of general relativity. However, its expansion rate creates problems for quantum mechanics – there are many possible states in which particles can be.
But the question arises – if space is expanding at an ever-increasing rate, is the number of particles in it growing? And is it possible to get something from nothing?
Imagine that we have an empty space in front of us – the limit of physical non-existence, which, under certain conditions and manipulations, will inevitably lead to the appearance of something.
Thus, the collision of two particles in the abyss of empty space can lead to the appearance of a particle-antiparticle pair.
If we try to separate a quark from an antiquark, then a new set of pairs must emerge from the empty space between them.
Theoretically, a strong enough electromagnetic field can pull particles and antiparticles out of a vacuum, even without any initial particles or antiparticles at all, the physicists explain.
In early 2022, strong electric fields were created in a simple laboratory setup that exploited the unique properties of graphene, allowing particle-antiparticle pairs to be spontaneously created from nothing.
You will be surprised, but the assumption that something can be created from the void appeared about 70 years ago – then this idea came to one of the founders of quantum theory, Julian Schwinger, and subsequently received confirmation.
The universe really creates something out of nothing.
This means that at a fundamental level in our universe, atoms can be broken down into separate particles – quanta, which, however, cannot be further split. The same is true of electrons, neutrinos, and their antimatter counterparts.
The same fate awaits photons, gluons and bosons (including the Higgs boson). However, if you remove all these particles, the remaining “empty space” will not really be empty – in many physical senses.
Just as we cannot take away the laws of physics from the universe, we cannot take away the quantum fields that permeate it. On the other hand, no matter how far we push any sources of matter, there are two long-range forces whose consequences will still remain: electromagnetism and gravity.
Although we can create clever settings to ensure that the electromagnetic field strength in a certain area is zero, we cannot do this for gravity; space cannot be “totally emptied” in any real sense for that matter.
Something from Nothing
Demonstrating that empty space is not actually empty space is a laborious task, but at the same time a real one.
So, even if you create a perfect vacuum, devoid of all particles and antiparticles, and electric and magnetic fields are equal to zero, there will still be something in the vacuum that physicists can call, say, “maximum nothingness”.
So thought Julian Schwinger in 1951, describing how (theoretically) it is possible to create matter from nothing: this would require a strong electric field.
And although his colleagues proposed something similar in the 1930s, it was Schwinger who was able to accurately determine the necessary conditions for this experiment, based on the fact that quantum fluctuations are somehow present in empty space, the physicists say.
According to the Heisenberg Uncertainty Principle, if quantum fields exist everywhere, then in any given time and region of space, there will be an initially indeterminate amount of energy present. And the shorter the period of time we are considering, the greater the uncertainty in the amount of energy.
In fact, the only places where particles emerge from the void are the regions in space surrounding black holes and neutron stars. But at the vast cosmic distances separating us from the closest objects, our assumptions remain purely theoretical.
But since we know that electrons and positrons literally come from nothing (they are simply plucked out of the quantum vacuum by electric fields), the universe demonstrates the impossible.
Luckily, there are many ways to explore our strange world, whether it’s through math, experiments with graphene (we’ve covered this in more detail earlier), or lasers.
And although we are still far from the truth and the creation of a unified theory of everything, today we know not so little about the world in which we live. Is not it?
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