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Chiefly
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I have heard of and read about the big bang theory for the start of our universe. Are there other competing theories that I should look at.
Thanks
Chiefly
Thanks
Chiefly
If by "competing" you mean "not already ruled out by evidence", then no, there aren't. The main alternative theory historically, steady state theory, had evidence mounting against it during the 1950s, and then was conclusively ruled out by the discovery of the cosmic microwave background radiation in the 1960s.Chiefly said:I have heard of and read about the big bang theory for the start of our universe. Are there other competing theories that I should look at.
Neither of these are competing with the standard hot big bang model of our universe. If they are competing with any theory, it is with inflation theory, which is a theory about what happened before the hot big bang (which is the hot, dense, rapidly expanding state that is the earliest state of our universe for which we have good evidence).sbrothy said:Smolin's fecund universe (discretited if I remember correctly but still fun). Also Penrose's Cyclic Conformal thingy.
ohwilleke said:Cosmologies To Ignore
Many other cosmologies are no longer accepted by the scientific community, even though they were once considered credible scientific theories until new information ruled them out, such as the steady state theory and tired light theories. Both have only historical interest from an astrophysicist's perspective.
Hi Chiefly:Chiefly said:Are there other competing theories that I should look at.
See here:JimJCW said:What is the main information that ruled out tired light theories?
I'm not sure which hypotheses are being referred to here, since every specific tired light hypothesis has been ruled out. Perhaps the author is speculating that someone might invent a different tired light-type hypothesis that would not be ruled out by our current data.JimJCW said:Tired-light hypotheses for the origin of the galactic redshifts are still considered as possible alternatives to the Expanding Universe
PeterDonis said:Perhaps the author is speculating that someone might invent a different tired light-type hypothesis that would not be ruled out by our current data.
Also note that "the origin of the galactic redshifts" is not the only piece of data that needs to be explained. So a tired light hypothesis that explained that data, but was inconsistent with other data, would still be ruled out.
Only if what you're keeping an open mind about, actually is open.JimJCW said:To keep an open mind is a sound attitude.
You are entitled to your opinion, but we cannot base discussion in a PF thread on your opinion. Unless you can give a reference to a peer-reviewed paper that describes such a model which has not been ruled out by data, we cannot discuss this here.JimJCW said:I think a tired light model that can explain the whole range of the observed distance modulus vs. redshift data and provide an alternative origin of the CMB including its blackbody nature is not out of the question.
You already asked for information about this, and I gave it in post #9.JimJCW said:Please let us know your own thoughts on the question, “What is the main information that ruled out tired light theories?”
I'll take a look.JimJCW said:Marmet’s 2018 article, On the Interpretation of Spectral Red-Shift in Astrophysics: A Survey of Red-Shift Mechanisms – II, compiles dozens of proposed physical mechanisms.
ohwilleke said:Definitional Issues
A theory about the beginning of the Universe and similar matters is generally called a "cosmology" and a fairly complete, but not comprehensive, list can be found here.
PeterDonis said:You already asked for information about this, and I gave it in post #9.
Again, unless you can give a reference to a peer-reviewed paper that describes a "tired light" model that is not ruled out by data, discussion of such models is off limits.
It also gives references to things that are peer-reviewed papers or books (as does the rest of Wright's cosmology FAQ and tutorial). The article is simply a convenient summary reference.JimJCW said:The reference you gave in Post #9 is not a peer-reviewed paper; it is just a tutorial page used by Wright to express his opinions.
My "thoughts" are irrelevant. The question is, what does the data say?JimJCW said:I asked for your thoughts
Chiefly said:I have heard of and read about the big bang theory for the start of our universe. Are there other competing theories that I should look at.
Thanks
Chiefly
I think you meant to say that Steinhard was a prominent and cofounder of cosmological inflation. He seemed to have changed his mind on this and is now working wih Neil Turok on a cyclic universe model.Chiefly said:elcaro - your post regarding 'taking the bang out of the big bang' was super interesting not just because P Steinhard was a great proponent of the big bang and has now changed to a cyclic concept but importantly the theory as he explains it does not have any of the problems associated with inflation. This certainly goes a long way in answering my OP.
But it still leaves one question unanswered - how did the supermasive black holes form so early on in time.
Chiefly said:Looking through the various most popular theories (or conjectures, thanks Buzz) I struggle to find one that seems to allow for the super massive black holes that were reported to be formed by Smethurst at around 670 million years from the start of the universe. Super massive BH being around 1 billion solar masses.
What is the most likely source of these BH's, accretion is discredited and a voracious BH eating its fill of stars is also discredited as time was not on the side of that possibility. So are there solutions that formed clumping of mass in the early stages of the formation of the universe that could explain this?
The map of Black Holes.Chiefly said:@elcaro - Do you have the link to that video.
The Big Bang Theory is the most widely accepted scientific explanation for the origin of our universe. It states that approximately 13.8 billion years ago, all matter and energy in the universe was compressed into a single point of infinite density and temperature. This point then expanded rapidly, creating the universe as we know it.
Yes, there are several alternative theories to the Big Bang, such as the Steady State Theory and the Oscillating Universe Theory. However, these theories have not been widely accepted by the scientific community due to a lack of evidence and inconsistencies with observed data.
There are several lines of evidence that support the Big Bang Theory, including the cosmic microwave background radiation, the abundance of light elements in the universe, and the observed expansion of the universe. Additionally, the theory is supported by mathematical models and simulations.
Some theories, such as the Multiverse Theory, suggest the existence of multiple universes. However, this is still a highly debated topic in the scientific community and there is currently no concrete evidence to support the existence of multiple universes.
Scientists use a variety of methods to study the origin of the universe, including observations from telescopes and satellites, experiments in particle accelerators, and mathematical models and simulations. They also continue to develop new technologies and theories to further our understanding of the universe's beginnings.