How does redshift support the big bang
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How Redshift Supports the Big Bang Theory
Introduction to Redshift and the Big Bang Theory
Redshift is a critical observational phenomenon that supports the Big Bang theory. It refers to the way light from distant galaxies shifts towards the red end of the spectrum as they move away from us. This shift is a cornerstone of the expanding universe model, which is central to the Big Bang theory.
Redshift as Evidence of an Expanding Universe
Doppler Effect and Recession of Galaxies
The redshift observed in the light from distant galaxies is primarily interpreted as a Doppler shift, indicating that these galaxies are moving away from us. This recession of galaxies suggests that the universe is expanding, a key prediction of the Big Bang theory1 2. Edwin Hubble's observations in the early 20th century showed that the redshift of galaxies is roughly proportional to their distance from Earth, leading to the formulation of Hubble's Law. This relationship implies that the universe was once concentrated in a much smaller, denser state, supporting the Big Bang model2.
Cosmic Microwave Background Radiation
Another strong piece of evidence for the Big Bang theory is the cosmic microwave background (CMB) radiation. This is the afterglow of the Big Bang, a faint microwave radiation that fills the universe and is a remnant from an earlier, hotter, and denser period. The existence of the CMB was predicted by the Big Bang theory and later confirmed by observations, providing compelling evidence for the theory1.
Challenges and Alternative Theories
Tired Light Hypothesis
The tired light hypothesis was proposed as an alternative explanation for redshift, suggesting that light loses energy and shifts to red as it travels through space. However, this theory has significant shortcomings, such as the blurring of images of distant objects, which is not observed. Consequently, the tired light hypothesis has largely been discredited in favor of the expanding universe model1.
Dispersive Extinction Theory
Another alternative is the dispersive extinction theory, which attributes redshift to the scattering and absorption of starlight by the space medium. This theory also attempts to explain the CMB as a result of this scattering. However, it faces fundamental challenges, such as the need for an unobservable dark mass and the non-linearity of Hubble's Law at high redshifts, which complicates its acceptance2.
Observational Evidence from High-Redshift Galaxies
Early Star Formation
Observations of high-redshift galaxies provide further support for the Big Bang theory. For instance, the detection of a galaxy at a redshift of 9.1096 indicates that star formation began around 250 million years after the Big Bang. This aligns with the timeline predicted by the Big Bang model, showing that galaxies formed relatively quickly after the universe's inception3.
James Webb Space Telescope Discoveries
Recent discoveries by the James Webb Space Telescope (JWST) have identified galaxy candidates at even higher redshifts (z ≈ 17), suggesting that galaxies formed even earlier than previously thought. These findings, if confirmed, would further support the Big Bang theory by demonstrating a rapid sequence of star formation and galaxy assembly consistent with the expanding universe model4.
Conclusion
Redshift is a fundamental observational phenomenon that supports the Big Bang theory. The recession of galaxies, as evidenced by redshift, and the existence of the cosmic microwave background radiation are key pieces of evidence for an expanding universe. While alternative theories like the tired light hypothesis and dispersive extinction theory have been proposed, they face significant challenges and have not gained widespread acceptance. Observations of high-redshift galaxies continue to provide strong support for the Big Bang theory, reinforcing our understanding of the universe's origins and evolution.
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Most relevant research papers on this topic
Conventional Big Bang Theories and Tired Light Theories
The big bang or hot expanding model of cosmology is supported by the recession of galaxies and the cosmic microwave background, while the tired light theory is supported by the redshift-distance relationship.
Dispersive Extinction Theory of Redshift
The dispersive extinction theory proposes that cosmic redshift and 2.7 K background radiation are due to the scattering and absorption of starlight by the space medium, offering an alternative to the Doppler shift and big bang theories.
The onset of star formation 250 million years after the Big Bang
Star formation began at a redshift of about 15, around 250 million years after the Big Bang, and may be detectable in similar galaxies with future telescopes.
Rigorous Journal
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The JWST discovery of high-redshift galaxies supports the Rh = ct universe model, which better accounts for cosmological data and eliminates inconsistencies.
Testing the mapping between redshift and cosmic scale factor
The standard redshift-scale factor relation is strongly degenerated with dark energy, and current SN and BAO data do not constrain dark energy unless they include Ly forest measurements.
The kinematic origin of the cosmological redshift
The cosmological redshift can be most naturally viewed as a Doppler shift, rather than stretching of space, as it corresponds to a family of comoving observers.
A luminous quasar at a redshift of z = 7.085
A quasar at a redshift of 7.085, 0.77 billion years after the Big Bang, has been observed, suggesting the intergalactic medium was not completely reionized until 0.77 billion years after the Big Bang.
Highly CitedRedshift structure of the big bang in inhomogeneous cosmological models. I. Spherical dust solutions
The bang time must be simultaneous in inhomogeneous cosmological models to avoid divergent energy fluxes and ensure that no infinite blueshifts occur.
The evolution of the galaxy UV luminosity function at redshifts z ≃ 8 – 15 from deep JWST and ground-based near-infrared imaging
The galaxy UV luminosity function evolves over the redshift range z = 8-15, with a double power law function up to z 10, and continues to decline gradually up to z 15.
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