The cosmos or universe is, by definition, all that has existed, exists, and will exist. It is built by three basic elements: space-time, energy, and the laws of physics. The universe and its history is a very vast subject, and we will try to explain some of its mysteries later in this text.
This theory assumes that the universe began at a single point the size of a pinhead, which, as a result of a huge explosion, began to expand and continues to expand to this day. One of the shreds of evidence supporting the validity of the Big Bang theory and the expansion of the universe is the fact that the farther away from Earth the observed galaxy is, the faster it is moving away from it.
As the temperature dropped, subatomic particles and then atoms separated. The universe was filled with primordial matter – gaseous clouds consisting mainly of hydrogen and a small amount of helium and lithium. Under the influence of gravity, the first atoms began to move closer together and form denser clusters, giving rise to the first stars and galaxies.
The limit of error in the calculation is 21 million years.
The very early universe lasted only a picosecond, during which time the laws of physics that we know today had not yet developed.
During the first stages of this period, it was still too hot for the elements to form spontaneously by combining subatomic particles. Twenty minutes after the Big Bang, the universe was filled with light-impermeable plasma. From then on, 18 thousand years had to pass before the first atoms could begin to form.
About 47 thousand years after the Big Bang, the universe cooled enough for matter to become the dominant element for the first time in history.
After 370 thousand years after the explosion, matter in the universe reached a ground state (the state of a quantum system having the lowest possible energy) emitting photons. Space began to make itself permeable to these photons and light appeared in the universe. Today we can observe it in the form of cosmic background radiation.
This period lasted from 370 thousand to 1 billion years after the Big Bang. During this time, matter in the universe was grouped under the influence of gravity. New stars were formed and merged into larger structures.
For the first three million years, the universe was filled with orange light emitted by photons released from hydrogen atoms. Over time, the wavelength shifted to infrared, and thus the wavelength range was invisible to the human eye, and the universe became a dark place again.
Only between 200 and 500 million years after the Big Bang did the first stars and galaxies form. So far, astronomers have not been able to observe a single star formed during this period. At the final stage of this period, the first clusters and superclusters of galaxies formed and the universe slowly filled with light and began to resemble the one we know today.
It resembles the one 12.8 billion years ago and will continue to look like this for the next billions of years.
There will eventually come a point in the history of the universe when new stars will stop forming. It will have expanded so much that the ability to concentrate enough hydrogen clouds necessary for star formation will become impossible. The expanded universe will be so vast that the only observable part of it will be the native galaxy and its immediate surroundings; beyond that, the observer will be surrounded only by a perfect black cosmic void.
Each has a different composition and size. The largest galaxies can span up to 2 million light years.
Located 1.04 billion light-years from Earth, this giant has a diameter of more than two million light years and is made up of more than 100 trillion stars. The object was discovered in 1790 by British astronomer William Herschel.
It is 114.000 light years away from us and is approaching at a speed of 40 km/s towards us. It is made up of about 1000 stars and has a diameter of 221.79 light years, so it is more than 9000 times smaller than IC 1101.
According to the simples calculation taking into account the number of galaxies and the average number of stars in a galaxy, the number of stars was estimated to be 1 quadrillion, or 1000000000000000000000000.
We can perceive only the visible region of it (one from which light can move faster than the expanding space-time and reach our eyes).
Perhaps the entire universe is infinitely large and we will never be able to reach with our eyes beyond our “visible” region, which is approximately 92 billion light years in diameter.
According to one theory, the balance of this cloud was upset by the explosion of a nearby supernova. Under the influence of this force, the cloud began to move and concentrated matter began to form inside. Under the influence of its gravity, the cloud began to collapse and rotate faster and faster, and the temperature inside it increased. Under the influence of the rotation speed, the cloud began to flatten into a disk and at one point the temperature and pressure in the center of the cloud were so high that a new star–the Sun–was born there.
Our galaxy ranks rather average, its diameter is 100 to 120 thousand light years. Perhaps a unique feature of the Milky Way is the existence of life in it, although we will probably have to wait several decades for definitive conclusions. The Milky Way is a spiral galaxy with a crossbar (sBBc) and is made up of 100 to 400 billion stars.
It orbits around the galactic center of gravity at a speed of 268 km/s. It takes about 230 million years to fully orbit the galaxy, in a similar position relative to the galactic core we were last in the Upper Triassic when the first dinosaurs began to appear on Earth.
It is about 109 times larger than the Earth and its mass is approximately 333.000 Earth masses. The Sun accounts for about 99.86 percent of the mass of the solar system.
This gas giant is made up of 90 percent hydrogen and about 10 helium. The diameter of Jupiter is 139.822 kilometers. This means that it takes as many as 11 earths lined up side by side to reach this size. Jupiter’s mass is 317 Earth masses, Jupiter, however, has a much lower density than Earth.
The crater has a diameter of 15.600 kilometers and was discovered on 7th August 2020. So far it has not been named.
It is located on the Yucatan peninsula under the waters of the Gulf of Mexico. The crater was formed about 66 million years ago as a result of the impact of a comet or asteroid with a diameter of 10 kilometers. It was this object that sealed the fate of the avian dinosaurs. The cater is 150 kilometers in diameter and 20 kilometers deep.
The canyon is located just below the Martian equator.
This extinct volcano rises above the Martian surface to a height of about level. The diameter of the volcano at the base is 624 kilometers. At the top of the mountain is an impact crater measuring 85x60x3 kilometers. The volcano is extinct and currently shows no significant activity and the last eruption took place between 100 and 200 million years ago. The extraordinary size of Olympus Mons is probably because there are no moving tectonic plates on Mars, so the lava underneath it can continuously erupt to the surface, contributing to its growth.
The farther away the celestial body is from the observer, the longer the light emitted or reflected from that object takes to reach the observer. For example, when observing a galaxy 4 billion years away, we are viewing it at a time when life did not yet exist on Earth.