Think about everything that exists in the universe. Giant space furnaces like our Sun. Gas giants, next to which our planet will be just a dwarf. Rows of asteroids racing through empty space. Distant stars thousands of light years away. All of this is less than 5% of the mass of the universe. Where is the rest? This is still a mystery. Our gigantic universe could have formed with dark matter particles that we hadn't even had the opportunity to observe. Scientists are trying to prove their existence, and with them the existence of "dark stars".
There is one element that can make up as much as 25% of the universe. We cannot feel or see it. It does not interact with light. It does not even consist of the building blocks we are used to - electrons and protons inside atoms that make up all matter.
This is "dark matter", and scientists have been trying to understand what it is for decades. Theoretical astrophysicist Katherine Freese is one of those who hunt for these mysterious bricks of life. Thirty years ago, her theory of an invisible glue that helped shape the universe led to the construction of underground particle accelerators all over the earth, like the machines at CERN. What are they looking for? These particles are called wimps (WIMPs), and according to Freese, stars made from this ghostly material could have helped the cosmos to form billions of years ago.
Wimps (weakly interacting massive particles) are large particles that do not interact with electromagnetic forces. This makes them "dark" - they cannot be observed using the electromagnetic sensors that humans have used to survey the universe for the past hundred years.
But thanks to the theory of supersymmetry - which implies that every known particle has an "antimatter" equivalent - there is a gap in our current particle atlas, and WIMPS can fill that gap perfectly. They are everywhere, but they don't leave any traces because they are reluctant to interact with the ordinary particles around them.
“Well, if we take all the objects in our daily life - your body, the chair on which it sits, the air that breathes, the walls around us, add the planets, add the stars - all this is made of atoms that we understand, but all this atomic matter makes up only 5% of our universe - five percent! Therefore, there is another 95% that we need to understand. And this is where dark matter and dark energy comes in. When they pass through you - billions of particles every second - you don't notice it, because the weak interaction is really weak, nothing happens."
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“A good analogy for dark matter is wind. We do not see it, it is invisible, and yet we are sure that it exists because the leaves rustle. The same is the case with dark matter. We see that it pulls things together … it is matter, which means that it feels gravity. She huddles together and pulls things together. We know that it exists for this reason, but we do not know what it consists of."
If wimps exist - and Freese is sure they do - they should have appeared shortly after the Big Bang.
Freese explored this theory with fellow astrophysicists Paolo Gondolo at the University of Utah and Doug Spoliar at the University of Stockholm in Sweden. They searched for the first "dark stars" that formed in the early days of the universe.
Despite their name, these ancient stars were dazzling - they lived on the annihilation of dark matter. And some of them could live in the far corners of the Universe, radiantly shining.
"Dark stars started out with the same masses as the Sun, but could grow larger and larger until they became a mass of millions of suns and billions of times brighter."
“The next large telescope, the James Webb Space Telescope, an extension of the famous Hubble Space Telescope, will be able to find dark stars. By doing this, we will not only find a completely new type of stars, which is already surprising in itself, but we will also prove that they live off WIMPs. So the problem will be solved by itself."
And that could spell the end for one of the most difficult challenges in modern science. Scientists have been trying to solve the problem of dark matter since the 1930s, but hints of its existence appeared long before that.
“When people studied the movement of the sun and the planets around them, they realized that the central planets move quite quickly, but the further from the center, the slower the movement,” says Freese.
"So they thought, okay, these are Newton's laws, we know them, these are the laws of nature, let's look at bigger structures - galaxies and galaxy clusters."
“But that's not what they found: they found that as you move from the center of the galaxy, everything moves at the same speed. It was pretty weird."
Freese believes that the stars and planets we see in the night sky are the culmination of a long chain of reactions that began with these weakly interacting particles. And she says that without particles of dark matter, the universe could not have become what it is. "The structures we live in, galaxies and galaxy clusters, could not have formed if dark matter had not formed the cosmic web we live in."
“That is, first dark matter came together, and then ordinary atoms, neutrons and protons and so on, together with dark matter, formed protogalaxies, which led to the appearance of galaxies, planets and stars. But to start forming this structure, dark matter is needed."
ILYA KHEL