Universe Expansion - Terminal Velocity?

[Efar]

If one looks at the expansion(increasing in speed) of the universe as a "falling away" from The Beginning(not religious,I just hate the Big Bang term)in all directions,and Time as an expansion rather than a linear progression,What is the terminal velocity of the universe?

 

[bcrowell]

Velocity is relative, so you'd have to specify the velocity of some object relative to some other object.

General relativity does not have a uniquely defined notion of the velocity of one object relative to another distant object.

Suppose that you pick as your measure of relative velocity the apparent velocity of galaxy B as determined by its redshift measured by an observer A, who crunches the numbers as if it were a special-relativistic redshift. Then because of the cosmological constant, this velocity will eventually surpass c for any given pair of galaxies A and B, after which B will no longer be observable to A.

On the other hand, there are other measures of relative velocity according to which B could have *always* had a velocity greater than c relative to A, and yet be observable to A: Davis and Lineweaver, Publications of the Astronomical Society of Australia, 21 (2004) 97, msowww.anu.edu.au/~charley/papers/DavisLineweaver04.pdf

 

[Chronos]

The Hubble sphere determines expansion rates. A photon that originated in a superluminal patch of spacetime can eventually reach a subluminal patch of spacetime. This is discussed in the Lineweaver paper bcrowell linked.

 

[Radrook]

Space expansion doesn't have a terminal velocity that we know of since the speed of light limit doesn't apply to it but only to matter moving within space itself.

 

[sardar]

I appreciate your perspective on the expansion of the universe and the concept of time. However, it is important to note that the expansion of the universe is not a result of a "falling away" from a single point, but rather a continuous expansion of space itself. This expansion is driven by the force of dark energy, which is still not fully understood.

In terms of terminal velocity, it is not applicable in the context of the expansion of the universe. Terminal velocity refers to the maximum speed an object can reach while falling through a medium, such as air. However, the expansion of the universe is not limited by any medium and does not have a maximum speed. It is a continuous process that is not bound by traditional physical laws.

Furthermore, the concept of time as an expansion is not a widely accepted theory in the scientific community. Time is currently understood as a linear progression, and while there are some theories that suggest a different understanding of time, they are still being studied and debated.

Overall, the expansion of the universe and the concept of time are complex and constantly evolving areas of study in cosmology. While your perspective is interesting, it is important to approach these topics with an open mind and continue to gather evidence and conduct research to further our understanding.