Arguments on Big Bang Theory
Physical Arguments
There are four main arguments supporting the idea that the universe originated from a Big Bang:
1. Expanding Universe
Spectroscopic light observations of galaxies indicate the universe is expanding. This can only be explained if galaxies originated from a single point. The primary evidence is the redshift, showing that: the further galaxies are from us, the faster they are moving away.
2. Cosmic Background Radiation
Discovered in 1965 by Arno Penzias and Robert Wilson, this radiation appears to come from all directions. The Big Bang theory provides an explanation for this radiation.
3. Light Elements
The Big Bang theory accurately describes the ratio of light elements like hydrogen and helium found in the oldest stars. This relates to the original composition before helium was formed through nuclear fusion in stars.
4. Einstein's Theory of Relativity
If matter in the universe were homogeneously distributed, a Big Bang could be deduced from Einstein's general theory of relativity.
Caveat
In the distant future, over 100 billion years, the current observations supporting the Big Bang theory are expected to have almost completely disappeared. Cosmic background radiation will be attenuated to the point of being unobservable.
The expansion of the universe will no longer be observable as all galaxies disappear behind the event horizon, leaving practically empty intergalactic space. By that time, the matter in the universe will also no longer be homogeneously distributed. As a result, the Big Bang will no longer be deducible from a working hypothesis based on the theory of relativity, in the distant future.
The ratio of different elements will have changed significantly, no longer resembling the Big Bang ratio. The chemical ratio will also not resemble the current situation of our universe.
We are currently living in an era where humanity can still make these observations. Now, it is crucial to draw the right conclusions from all cosmological observations.
Fundamental Problems
The Big Bang theory, since the discovery of cosmic background radiation, was widely accepted by cosmologists as the best explanation for the universe's origin and evolution. However, there were still some unanswered questions.
In the 1980s, Alan Guth and Andrei Linde developed the Inflationary Theory, which addressed these problems. This theory is an addition to the Big Bang theory, not a completely independent alternative.
Another problem is that the concept of infinite density is inconsistent with quantum mechanics.
Summary
This page covers the key points supporting the Big Bang theory, its limitations, and the fundamental problems that arise. The text provides an overview of the arguments and challenges associated with the Big Bang theory.