Three possibilities in the future of the Universe. .

Big Rip - dark energy increasing, an ultimate expansion of the universe to the extent that the particles and space and time of which it consists are torn apart. 

Constant Dark Energy - as space expands, the dark energy density remains constant, rather than decreasing or increasing. As a result, after the Universe has expanded for long enough, dark energy comes to dominate the energy budget of the Universe.

Big Crunch - Dark energy decreasing, gravity takes over - a contraction of the universe to a state of extremely high density and temperature (a hypothetical opposite of the Big Bang).

                                                                 * * * * * * * 

Soviet mathematician Alexander Friedmann's model gave rise to three different types of models for the evolution of the Universe.

First, the Universe would expand for a given amount of time, and if the expansion rate is less than the density of the Universe (leading to gravitational attraction), it would ultimately lead to the collapse of the Universe at a later stage.

Secondly, the Universe would expand, and at some time, if the expansion rate and the density of the Universe became equal, it would expand slowly and stop, leading to a somewhat static Universe.

Thirdly, the Universe would continue to expand forever, if the density of the Universe is less than the critical amount required to balance the expansion rate of the Universe.

#BigRip #ConstantDarkEnergy #BigCrunch #AlexanderFriedmann

The tug of war between gravity and dark energy:

The energy from the Big Bang drove the universe's early expansion. Since then, gravity and dark energy have engaged in a cosmic tug of war.

Gravity pulls galaxies closer together; dark energy pushes them apart. Whether the universe is expanding or contracting depends on which force dominates, gravity or dark energy

 

 

#gravity #darkenergy

Dark energy highly affects the structure of large cluster of galaxy:

“Gravity dominates at distances, while antigravity is stronger than gravity; therefore, a gravitationally bound system with its mass can exist only inside the zero gravity sphere of its radius. Whereas, dark energy is effective in the outer region of the domination of gravitating mass and practically have no effect within the strong domination of gravitating mass. 

The density of dark energy is high enough to affect the structure of a large rich cluster of galaxy-as a gravitationally bound physical system embedded in the perfectly uniform static dark energy background. The antigravity of dark energy affects strongly a cosmic structure at large scale. 

The dark energy background produces antigravity which is stronger than the matter gravity in the present Universe as a whole. This makes the cosmological expansion accelerated. The cosmic antigravity can be stronger than gravity not only globally, but also locally on the scale of ~3.26 - 32.63 mega-lightyear (~1 – 10 Mpc).

The local weakfield dynamical effects of dark energy adequately described in term of Newtonian mechanics, and its effective gravitating density is negative, producing antigravity.”

 

#DarkEnergy #AntiGravity #ClusterOfGalaxy #Expansion

 

Credit: Source

The youngest and most distant known galaxy - it's light travel distance and present proper distance.

HD1 is a purported high red-shift galaxy, and as of April 2022, it is considered to be the earliest, youngest and most distant known galaxy yet identified in the observable universe, located only about (330 million years) after the Big Bang (13.8 billion years ago), a light-travel distance of 13.5 billion light-years from Earth, and, due to the expansion of the universe, a present proper distance of 33.4 billion light-years.


[NOTE: Co-moving distance and proper distance are two closely related distance measures used by cosmologists to define distances between objects. Proper distance roughly corresponds to where a distant object would be at a specific moment of cosmological time, which can change over time due to the expansion of the universe. Co-moving distance factors out the expansion of the universe, giving a distance that does not change in time due to the expansion of space (though this may change due to other, local factors, such as the motion of a galaxy within a cluster]

 

#HD1 #LightTravelDistance #ProperDistance

 

The space, time and the existential universe are seperate considerations: The space-time concept invalid.

The expression, "expansion of space" would mean the expansion of space against time, even if time is not mentioned there.

Another expression, "expansion of the universe" would mean, expansion of the existential universe, against time, occupying three dimensional space.

However, the expansion rate of said existential universe is not likely to be the same rate of expansion as of space, because of the reason that space is dragging out the existential universe along with it by some mysterious force. The rigidity of the existential universe likely to counteract against said dragging of space, as a consequence, respective rates of expansion between space and existential universe likely to be different for same said reason. 

Whatsoever, said expansions of both - space and material universe - conveys their expansions only against time. 

Therefore, time cannot be an embedded part, either of the space or material universe; for the reason time is concept, devised to track or witness such expansions, and events, when space and material universe are tracked or witnessed by time, as if, time acts like an umpire, and space, existential universe act like the players. 

There is another inconsistency in the concept of space-rime is that, in case of expanding space, or the existential universe, the time, in space-time continuum, unlikely to be in uniformed secession, considering irreversible nature of time. This is undesirable. 

And the accelerated expansion of space would make the space-time idea even worse, and defective, no wonder such defects are very likely when time is preferred to be reversible or modifiable against the normal secession of time, and even time being a concept. 

There is no reasonably to consider and accept space and time as a space-time continuum, as in general relativity of Einstein. 

• Einstein preferred time to be reversible or modifiable, against the normal secession of time.
• Space, Universe - their expansions only against time, even if time is not mentioned.
• Space-time continuum results inconsistency, un-uniformed secession of time, undesirable.
• Accelerated expansion of space would make time even worse in space-time continuum.
• Time is a concept, devised to track expansions and events, so cannot be embedded with space.

- Soumendra Nath Thakur 19-Apr-2022

#spacetime #spacetimecontinuum #space #time #expansion #expansionofspace