Main article: Universe
Big bounce: What happened before the Big Bang
A traditional cosmological view of the universe suggests that it began with a singularity, followed by a short period of extremely rapid expansion called inflation. However, the authors of the new study, published in 2024, analyzed a more exotic theory known as the nonsingular cosmology of matter bounce, which claims that the universe first went through a compression phase. This phase ended with a rebound due to an increase in the density of matter, leading to the Big Bang and the accelerated expansion we are seeing today.
Then the universe shrank to dimensions about 50 orders of magnitude smaller than today. After the rebound, photons and other particles appeared, marking the Big Bang. Near the rebound, the density of matter was so high that small black holes formed from quantum fluctuations in the density of matter, making them possible candidates for dark matter.
Observations of the movement of stars in galaxies and the cosmic microwave background - the afterglow of the Big Bang - show that about 80% of all matter in the universe is dark matter, a substance that does not reflect, absorb or emit light. Scientists have not yet determined what dark matter consists of.
Small primary black holes can form in the earliest stages of the universe, and if they are not too small, their decay due to Hawking radiation (this hypothetical phenomenon of black holes emitting particles due to quantum effects) will not be effective enough to get rid of them. Therefore, primary black holes will exist now. Their mass is approximately equal to the mass of the asteroid. These black holes may have contributed to the formation of dark matter.
Scientists' calculations show that the curvature of space and microwave background within their assumption correspond to current observations, which confirms this hypothesis.
To further test the hypothesis, the researchers plan to use next-generation gravitational wave observatories. Scientists calculated the properties of gravitational waves formed by the formation of black holes in their model, and it turned out that they could be detected by such gravitational observatories of the future as Laser Interferometer Space Antenna (LISA) and Einstein Telescope. The results of such studies will already be able to confirm whether primary black holes are indeed dark matter. However, it will take a long time, perhaps even a dozen years, before these observatories workNew research hints that the universe had a secret life before the Big Bang.
Big bang: 12.6 or 13.8 billion years?
For 2020, it is generally accepted that the age of the Universe is about 13.8 billion years, but it is not so easy to determine these figures more precisely. You must perform several key calculations and compare them to each other. Due to different approaches to these calculations, the result may also differ, which raises doubts about its accuracy.
The date of the Big Bang that gave rise to the Universe was previously calculated using a mathematical method using computer modeling using estimates of the distance to the oldest stars, the behavior of galaxies and the rate of expansion of the Universe.
Since the universe is expanding at a high rate, the further the object is, the faster it moves away from us. The distance to the object with the speed of its removal is related by the Hubble constant - this coefficient was used as a key factor in a new study to determine the exact age of the universe. Hubble's constant is so named after Edwin Hubble, who first calculated the rate of expansion of the universe in 1929.
The idea behind the 2020 study, led by researchers at the University of Oregon, was to calculate how long it would take all objects to return to the beginning. To do this, you need to determine how quickly objects move away from us - then you can calculate the moment of the logical beginning of this process, the Big Bang.
A new study claims that the universe is almost a billion years younger, and previous calculations were inaccurate.
Researchers at the University of Oregon mapped distances to dozens of other galaxies. They took a novel approach by recalibrating a distance measuring tool known as the Tully-Fisher baryon ratio, which is independent of the Hubble constant. They took distances of up to 50 galaxies, partially determined using the Spitzer Space Telescope, and used them to estimate distances of up to 95 other galaxies.
According to the authors of the study, this approach takes into account the curves of the mass and rotation of galaxies better than the data that was previously used for the equations that determine the beginning of the Big Bang. Thus, scientists, according to them, were able to more accurately calculate the Hubble constant and, accordingly, the age of the Universe.
As a result, astronomers set the Hubble constant to 75.1 (km/s )/Mpc. This means that a galaxy one megaparsec away from Earth (approximately 3.3 million light years) is moving away from us at a speed of 75.1 km every[1] the[2].
Based on the new data, the researchers calculated that the age of the universe is only 12.6 billion years, which is much less than the generally accepted figure of 13.8 billion years. And the new result significantly goes beyond the error acceptable for previous calculations. The work is published in the Astrophysical Journal.
Interestingly, studies based on the measurement of relic radiation as a result determine that the Universe is still about 13.8 billion years old, and the Hubble constant is about 67 km/s/Mpc. But the Oregon team's study says all Hubble constant values below 70 can be ruled out with a 95 percent chance.
0 - 380,000 years: From singularity to hydrogen and helium
| Time | Epoch | Event | Time from today, years |
|---|---|---|---|
| 0 | Singularity | The Big Bang. | 13.7 billion |
| 10 − 43 s | Plankov era | The universe expands and cools. | 13.7 billion |
| 10 − 43 - 10 − 35 s | The Era of Great Unification | Separation of gravity from the combined electroweak and strong interaction. Possible birth of monopoles. Destruction of the Great Unification. | 13.7 billion |
| 10 − 35 - 10 − 31 s | Inflationary era | Из вакуума быстро рождаются частицы (кварки и глюоны, лептоны, фотоны), Вселенная экспоненциально увеличивает свой радиус на много порядков. Структура первичной квантовой флуктуации раздуваясь даёт начало крупномасштабной структуре Вселенной [3] Secondary heating. Baryogenesis. | 13.7 billion |
| 10 − 31 - 10 − 12 s | Electroweak epoch | The universe is filled with quark-gluon plasma, leptons, photons, W- and Z-bosons, Higgs bosons. Supersymmetry disorder. | 13.7 billion |
| 10 − 12 - 10 − 6 s | Quark Age | Electroweak symmetry is broken, all four fundamental interactions exist separately. Quarks have not yet been combined into hadrons. The universe is filled with quark-gluon plasma, leptons and photons. | 13.7 billion |
| 10 − 6 - 1 s | The Hadron Era | Adronisation. Annihilation of barion-antibarion pairs. Due to CP disruption, there remains a small excess of baryons over anti-baryons (about 1:109). | 13.7 billion |
| 1 second - 3 minutes | The Lepton Age | Annihilation of lepton-antileptone pairs. Decay of a part of neutrons. Matter becomes transparent to neutrinos. | 13.7 billion |
| 3 minutes - 380,000 years | Proton Age | Nucleosynthesis of helium, deuterium, traces of lithium-7 (20 minutes). Matter begins to dominate radiation (70,000 years), which leads to a change in the expansion mode of the universe. At the end of the era (380,000 years), hydrogen recombination occurs and the universe becomes transparent to photons of thermal radiation. | 13.7 billion |
150 million years of the Dark Ages
| Time | Epoch | Event | Time from today, years |
|---|---|---|---|
| 380,000 - 150 Ma | Dark Ages | The universe is filled with hydrogen and helium, relic radiation, radiation of atomic hydrogen at a wave of 21 cm. Stars, quasars and other bright sources are absent. | 13.55 billion |
12.7 billion hp: Formation of the first stars
| Time | Epoch | Event | Time from today, years |
|---|---|---|---|
| 150 million - 1 billion years | Reionization | The first stars (stars of population III), quasars, galaxies, clusters and superclusters of galaxies are formed. Reionization of hydrogen by the light of stars and quasars. | 12.7 billion |
12.6-4.6 billion hp: Formation of the solar system and planet Earth
| Time | Epoch | Event | Time from today, years |
|---|---|---|---|
| 1 billion years - 8.9 billion years | The Age of Matter | The formation of of the interstellar cloud that gave rise to the solar system. | 4.8 billion |
| 7 billion years | The Age of Matter | 6 млрд лет назад расширение Вселенной ускорилось (см. Sloan Digital Celestial Review) | 6 billion |
| 8.9 billion years - 9.1 billion years | The Age of Matter | Formation of the Earth and other planets of our solar system, hardening of rocks. | 4.6 billion |
See also
Links
Timeline of the Big Bang on Wikipedia
Notes
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