Search results
Results From The WOW.Com Content Network
In the case of accelerated expansion, ¨ is positive; therefore, ˙ was smaller in the past than today. Thus, an accelerating universe took a longer time to expand from 2/3 to 1 times its present size, compared to a non-accelerating universe with constant ˙ and the same present-day value of the Hubble constant. This results in a larger light ...
The expansion of the universe is the increase in distance between gravitationally unbound parts of the observable universe with time. [1] It is an intrinsic expansion, so it does not mean that the universe expands "into" anything or that space exists "outside" it.
Something is changing the expansion rate of the universe, scientists have said. For decades, researchers have been attempting to measure the “Hubble constant”, or the speed at which the cosmos ...
The Big Crunch is a hypothetical scenario for the ultimate fate of the universe, in which the expansion of the universe eventually reverses and the universe recollapses, ultimately causing the cosmic scale factor to reach absolute zero, an event potentially followed by a reformation of the universe starting with another Big Bang.
"Yes, it appears there is something missing in our understanding of the universe," added Riess, a 2011 Nobel laureate in physics for the co-discovery of the universe's accelerating expansion.
A problem with the cyclic universe is that it does not reconcile with the second law of thermodynamics, as entropy would build up from oscillation to oscillation and cause the eventual heat death of the universe. [citation needed] Current evidence also indicates the universe is not closed.
Infinite expansion does not constrain the overall spatial curvature of the universe.It can be open (with negative spatial curvature), flat, or closed (positive spatial curvature), although if it is closed, sufficient dark energy must be present to counteract the gravitational forces or else the universe will end in a Big Crunch.
The darkness of the night sky is one piece of evidence for a dynamic universe, such as the Big Bang model. That model explains the observed non-uniformity of brightness by invoking expansion of the universe, which increases the wavelength of visible light originating from the Big Bang to microwave scale via a process known as redshift.