Observable universe is

Accelerating universe


The observable universe is a spherical universe includes all matter can be observed from Earth or its current space telescopes and probes, because they managed to reach the objects of electromagnetic radiation the solar system and the Earth since the beginning of the cosmological expansion . There are at least 2 trillion galaxies in the observable universe.

Suppose the universe is isotropic , the distance to the edge of the observable universe being approximatelyin the same direction in each direction. That is, in the observable universe, a spherical volume (a ball ) is directed at the observer. Every location in the universe has its own observable world, which may or may not be covered by what is located on Earth.

The word does not refer to the ability of modern technology to detect observable in this sense whether there is light or other information or detectable objects from the object. This means the physical limit created by the speed of light itself. Since no signal can move faster than light, anything that is farther away from us can walk farther away from us around the age of the universe (predicted by 2015)13.799 ± 0.021  billion years ^[5] ) simply cannot be determined because the signals may not have reached us yet. Sometimes the cosmos recombines (when hydrogen atoms are formed from protons and electrons and photons are emitted) - and the observable universe contains signals since the beginning of this cosmological expansion, which astrophysicists sometimes see only as emitted signals since then . (The big bang is traditionally physical cosmology , the end of the inflation period in modern cosmology).

Accelerating universe

According to calculations, the closest distance to a stream - the correct distance to account for the expansion of the universe since light scattering - is 14.0 billion parsecs (about 45 ), which represents the radius of the universe in which these particles emit cosmic microwave background radiation (CMBR). , 7 billion light-years), while the marginal distance of the observable universe is about 14.3 billion parsecs (46.6 billion light-years), ^[10] about 2% larger. The radius is therefore estimated to be 46.5 billion light-years across the observable universe ^[11] [12] and has a diameter of about 28.5 gigaparsecs (93 billion) light-years .or 8.8 × 10 ²⁶ feet or 2.89 × 10 ²⁷ feet), which is 880 Yotameters . ^[13] The total mass of ordinary matter in the universe is ⁵³ kg with a critical density and a diameter of the observable universe of approximately 1.5 × 10 . ^[14] In November 2018, astronomers estimated that extragalactic background light (EBL) was 4 × 10 at ⁸⁴ photons. ^[15] [16]

As the expansion of the universe accelerates, all the objects currently observed solidify over time and at the same time emit increasingly intense and dim rays. For example, existing red-shift objects z 5 to 10 have been tracked for more than 4-6 billion years. In addition, light emitted by objects currently at a certain close distance (currently 19 billion parsecs) will never reach the Earth. Some parts of the universe are too far away for the light to appear since the Big Bang to have enough time to reach the Earth or its scientific spacecraft and therefore lie outside the observable universe. In the future, distant galactic rays will have more time to travel, so additional areas will be observed. 

Accelerating universe

However, due to Hubble's law , regions far enough away from Earth are farther away from it than the speed of light ( special relativity prevents nearby objects in the same local region from moving faster than the speed of light relative to each other, but the gap between them There is no such restriction for distant objects as the scale expands. q; seeto discuss the use of the correct distance ) and also black energy due to which the rate of expansion seems to be accelerating .

Dark energy remains constant (unchanging) cosmological constant ), so there is a "future boundary of vision" for the rate of expansion of the universe to accelerate, beyond which there will never be objects in the infinite future enter our observable universe at any time, for the light emitted by things beyond this limit will never reach the Earth. (The subtlety is that because the Hubble parameter decreases over time, there may be cases where a galaxy retreating from Earth emits a signal that reaches Earth slightly faster than light. ^[12] [18] ) This future co. 'Assuming that the universe will continue to expand indefinitely from 19 billion parsecs (62 billion light-years), this implies the number of galaxies that we can theoretically observe in an infinite future (some of which may be practically impossible to observe). 'ying) As mentioned in the following paragraph, due to the red shift) is greater than the number currently observed by a factor of 2.36.



Accelerating universe

The artist’s logarithmic dimensional concept of the observable universe The solar system is centered, with planets on the inside and outside , the Kuiper belt , the Oort cloud , Alpha Centauri , Perseus Arm , the Milky Way galaxy , the Andromeda Galaxy , nearby galaxies , the Space Network , the Cosmic Microwave radiation and invisible plasma at the edge of the Big Bang. Celestial bodies seem to be magnified to appreciate their shape.

Although more galaxies can be observed in the future, in practice the number of galaxies is increasing due to the ongoing expansion of redshifted ; so much so that they seem to disappear and become invisible. ^{[20] [21] [22]}An additional subtlety is that if we can receive a galaxy at any age in its past history (e.g., 500 million signals sent from a galaxy), a given approaching galaxy must be located within an “observable universe”. A few years after the Big Bang), but because the universe has expanded, the signal sent from that galaxy may be some of the next centuries that will never reach Earth at any point in the infinite future (e.g., we will never see the Big Bang). See what the galaxy will look like 10 billion years from now), ^[23]although it remains at the same close distance (the approaching distance is defined as constant with time - unlike the correct distance used to determine the rate of stagnation due to space expansion), it is less than the approaching radius of the observable universe.  This fact can be used to determine the type of space that the horizon of events changes over time with its distance from the Earth. For example, the distance to this horizon is about 16 billion light-years, which means that a signal from an event that is currently happening could reach the Earth in the future if the event is less than 16 billion light-years, but if the event is 16 billion light-years away.

Accelerating universe

This can be justified by the fact that we can never know anything by conducting a direct experiment on any part of the universe from a disconnected Earth, although many reliable theories requires a much larger total universe than the observable universe. ^{[ quote needed ]}There is no evidence that the boundary of the observable universe constitutes the boundary of the universe as a whole, nor do any of the basic cosmological models assume that the universe has a physical boundary in the first place, but some models may do so numerically but without boundaries, e.g. , but a high-dimensional analogue of the 2D surface of a sphere without an edge.

These galaxies represent only the minuscular part of the galaxies in our observable universe. According to his theory, cosmic inflation was originally introduced by its founders, Alan Gut and D. Kazanas, ^[24] if inflation is assumed to have started at about 10 ⁻³⁷ A few seconds after the Big Bang, the size of the universe before inflation occurs assuming that it is equal to the speed of light relative to its age, the magnitude of the entire universe at present is at least 3 × 10 ²³ (1.5 × 10 ³⁴ light years) greater than the radius of the observed universe. ^[25]

If the universe is finite but infinite, the universe may also be smaller than the observable universe. In this case, what we call very distant galaxies may actually be repetitive images of nearby galaxies formed as a result of light orbiting the universe. This hypothesis is difficult to test experimentally, as different images of the galaxy could show different periods in its history and, as a result, differ from each other. Bielewicz et al. ^[26]claiming to set a lower limit of 27.9 gigaparsecs (91 billion light-years) on the diameter of the final distribution surface (since this is only the lower limit, the paper is larger than the entire universe, even infinite reveals the possibility). 

This value is based on the analysis of the corresponding circle WMAP 7-year data. This approach is controversial.