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Einstein's Cat
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Is there an equation which explains how the recessional velcoity of a galaxy changes with time? Furthermore, does an equation exist that describes the universe's accelerating expansion; is it the Friedman equation?
Chronos said:The concept of 'absolute' time has plagued cosmologists and philosophers since the 'beginning' of time. Einstein helped clear up the mystery with GR, but, the notion of absolute time continues to befuddle both mathematicians and philosophers.
How does proper distance change with time? Is there an equation to describe that? I looked on Wikipedia and found no such thingSimon Bridge said:
I see, so proper distance changes with the expansion of the universe and thus with time because theoretical observers along it would appear to have relative velocity to a relative stationary observers? Therefore, meaning that the relatively moving observers would have a different interpretations of cosmological time and thus the proper distance would appear to be longer? Is this correct please?Chronos said:From the perspective of physicists, the concepts of distance and time have no absolute meaning. Neither can exist independendent of the other. Hermann Minkowski is credited as the first to understand this odd state of affairs between space and time and coined the term spacetime to describe the interchangeability of these four fundamental dimensions of the universe back in 1908. Needless to say this greatly influenced the thinking of Einstein. See http://www.physicsoftheuniverse.com/topics_relativity_spacetime.html for a brief discussion.
Einstein's Cat said:How does proper distance change with time?
The Hubble equation function of time is a mathematical formula that describes the relationship between the rate of expansion of the universe (known as the Hubble constant) and the age of the universe. It is represented as H(t), where t represents time in billions of years and H represents the Hubble constant.
The Hubble equation function of time is a key piece of evidence for the Big Bang theory. It shows that the universe is expanding, which supports the idea that the universe began as a single point and has been expanding ever since.
The Hubble equation function of time is calculated by measuring the redshift of distant galaxies and using the observed value of the Hubble constant to determine the age of the universe. This calculation is based on the assumption that the universe is expanding uniformly.
The Hubble equation function of time is significant because it provides a way to estimate the age of the universe and the rate of its expansion. It also serves as evidence for the Big Bang theory and helps scientists better understand the evolution of the universe.
Yes, the Hubble equation function of time can change over time as new data and observations are collected. The value of the Hubble constant has been refined over the years, and there is still ongoing research to better understand the nature and behavior of the expanding universe.