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February 17, 2021 by No Comments

Much of the mysterious universe is hidden in the shadows. The so-called “ordinary” atomic matter university of sussex uk that comprises the world we know best is the remnant of the space nest of three. The unidentified exotic form of matter, which scientists call dark matter, is thought to make up 25% of the cosmos. But what is this strange form of non-ottoman matter, which is believed to be the substance responsible for the creation of the first dancing galaxies in the Old Universe? Several theories have been put forward over the years, but the identity of this little-known exotic material has never been established. In October 2019, a group of astronomers offered a new explanation: this dark matter is really “cloud.”

Shortly after the Great Bang Universe was born, about 13.8 billion years ago, dark matter particles would have merged to form clusters in gravitational halos. Clusters attracted surrounding gas clouds to their cores, which gradually cooled and condensed, forming the first galaxies. Although dark matter is considered the “core” of the large-scale structure of the universe, scientists know very little about its true essence. This dark substance has well kept its secrets.

However, a team of scientists from the Massachusetts Institute of Technology, Princeton and the University of Cambridge has now come to their new discoveries that the early universe and the very first galaxies varied greatly depending on the true nature of the mysterious ghost material and the invisible. . Dark matter is invisible or transparent because it does not interact with “normal” atomic matter except under the influence of gravity. For the first time, the team modeled what the formation of ancient galaxies might look like if dark matter were “foggy” rather than “cold” or “hot.”

According to the most common model, ghost matter is “cold”, that is, consists of slow-moving particles that, except for gravitational effects, do not dance with atomic matter. On the contrary, it is considered that “hot” dark matter is a little lighter than if it were “cold” and therefore rotates faster.

Light dark matter is a relatively new concept. This is a completely different matter, and if a fuzzy substance exists, it is thought to consist of ultralight particles, each of which is only about 1 octillion electron mass. On the contrary, the mass of the “cold” particle of dark matter will be much heavier, about 10-fifths of the mass of the electron.

In their supercomputer simulation, the scientists found that if dark matter particles were “cold,” the original galaxies born at the beginning of the universe would form almost spherical halos. On the other hand, if the nature of exotic material were really “foggy” or “hot”, the ancient universe would be very different. In this case, galaxies will first emerge in the form of elongated tail-shaped strands. In space, from “fuzzy” dark matter, these fibers would look like stripes – like harp strings burning with starlight.

With the advent of new telescopes on the Internet, capable of looking into the past into the old cosmos, astronomers can determine – based on the model of formation of galaxies – the nature of dark matter, which is about 85%. % of earth’s substance in Space is “vague” rather than “hot” or “cold.”

“Early galaxies at the beginning of the universe could shed light on the kind of dark matter that we have today. Either we see this fiber structure, and weak dark matter is plausible, or we don’t, and we can rule out this model. Now we have a plan how to do it,” Dr. Mark Vogelsberger said in a press release from mit. He is an assistant professor of physics at the Kavli Institute of Astrophysics and Space Studies at the Massachusetts Institute of Technology.

Dr. Vogelsberger is also a co-author of the October 3, 2019 issue of Physical Review Letters, along with lead author Dr. Philip Moch of Princeton University and Dr. Anastasia Fialkova of the University of Cambridge (formerly the University of Sussex). .

In Search of Our Origin

Although very little is known about its origin, astronomers have been able to show that dark matter played an important role in the formation of galaxies and clusters of galaxies in the ancient universe. Although not directly observed, scientists were able to detect dark matter because of its gravitational effect on how “normal” visible matter is distributed and how it moves in space.

Nearly 14 billion years ago, the universe was born as an unusually small soup made of hot, very densely packed particles, commonly referred to as the original “fireball.” Since then, Cosmos has become bigger and colder. Astronomers often say that much of our universe has disappeared, largely because it consists of a bizarre substance called dark energy that confuses even more than dark matter. Dark energy is usually thought to be the property of space itself, causing the universe to accelerate in its expansion.

Recent measurements show that Cosmos is 70% dark energy and 25% dark matter. A much smaller percentage of the universe – only about 5% – consists of the so-called “ordinary” atomic matter mentioned in the well-known periodic table. While the rest of the waste is unambiguous, “ordinary” atomic matter is unusual because it is the substance of stars and life on Earth. Only hydrogen, helium and lithium traces were born as a result of the Big Bang.

The stars boiled all the other atomic elements in their hot, whirling, suffocating smelting furnaces. When the stars died, they threw these freshly forged atomic elements into space, where they became the matter of our familiar world. The iron in your blood, the stones under your feet, the iron in your blood, the calcium in your bones, the water you drink, and the air you breathe were created in the warm hearts of the stars of the universe from a small amount of “ordinary” atomic matter.

Apart from the mystery, the universe seems exactly the same wherever we look. It shows the same frothy and sparkling look in all directions, with extremely massive and huge fibers that intertwine with each other like antennae in a web woven by a giant invisible spider. The huge fibers of this cosmic web consist of elusive dark matter, and the structure is brightly illuminated by the star fire of billions and billions of bright stars. The bright flames of starlight and clouds of glowing gas describe what we cannot see with human eyes. This is because these beautiful objects trace the otherwise invisible strands of ghostly dark matter. The threads themselves are interrupted by huge, very black and cavernous cavities. Unlike strands, the voids are sparsely populated by galaxies.

When scientists talk about the “observed” universe, they actually mean only a relatively small space-time that can be observed – which we see. Much of the universe is far beyond what is called the cosmological horizon. The light wandering towards us from these unimaginably remote areas of the universe has not reached us since the Big Bang. This is due to the accelerated expansion of space-time. No known signal can move faster than light in a vacuum, which sets a universal speed limit that prevents us from directly observing much of the universe beyond the horizon of our vision. Although none of the known signals can move faster than light, space itself can.

The temperature of the original fireball, which eventually grew in the universe as we know it, was almost, but not exactly, everywhere the same. This very slight deviation from the ideal homogeneity is responsible for shaping everything we have and know. Before a period called inflation, when the newborn universe grew faster than the speed of light, it was completely homogeneous. At that time, Cosmos was smooth and uncharacteristic. It is believed that the exponential expansion of the inflation period has made the pulsation of the early universe smooth and homogeneous.

Fuzzy harp strings

Dark matter was not found directly. However, he nevertheless discovered his ghostly presence through the way his gravity affects the movements of objects that can be observed. The theory that defines dark matter as “cold,” that is, slow, has so far proved effective in describing the large-scale structure of the observable universe. Because of the success of cold dark matter, the models of galaxy formation are based on the assumption that it is indeed “cold”.

“The problem is that there are discrepancies between observations and predictions of cold dark matter. For example, if you look at very small galaxies, the estimated distribution of dark matter in these galaxies is not quite the same as what theoretical models predict.” Dr. Vogelsberger said in a press release from the Massachusetts Institute of Technology on October 3, 2019.

This contradiction opened the door to other theories that could better explain the nature of the invisible material. These alternative theories include both “hot” and “fuzzy” dark matter.

“The nature of dark matter is still a mystery. Fuzzy dark matter is defined by fundamental physics, such as string theory, and is therefore an interesting candidate for the role of dark matter. Cosmic structures are the key to confirming or eliminating such dark matter models. This was announced by Dr. Fialkov in a press release from MIT.

String theory basically states that elementary particles are not dots. Instead, they are extremely small vibrating strings – and the vibration of a particular string defines its role as a particle.

It is believed that fuzzy dark matter consists of such light particles that they act as quantum waves, not as separate particles. According to Dr. Mocha, this quantum fuzzy nature could be responsible for the formation of the first galaxies. If so, these very old galaxies will be very different from what standard models for cold dark matter predict.

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