What evidence supports the validity of the Big Bang theory?

[Chalnoth]

I'll make my introductory post to this forum with a simple and controversial reply. No the Big Bang Theory is NOT valid. It relies on ad hoc addendums to the theory that clearly contradicts known laws of physics, has no validation in real world observation and relies purely on mathematical constructs to support it. This isn't even getting into the unverifiable, untestable issues of "dark matter" and "dark energy".
A very simple way to conclude that BBT is wrong is to read the works of the "father of BBT", Edwin Hubble. Halton Arp does a very credible job of falsifying Hubble. Hubble also went to his grave trying to undo his red shift theory. There simply is NO evidence, whatsoever, that the universe is expanding. In any direction observed, the same structures are observed. Besides, how do you get something from nothing? Talk about violating natural laws. That violates the most basic.
BBT is a purely mathematical construct with no observational evidence to support it. Does no one question why it is that a Catholic priest is the one who coined the phrase? Do you seriously not question an ulterior motive? BBT would go a long way in support of a "creation theory" that religion insists upon. I say BBT is nothing more than a religion, but one that WILL be falsified in the future.

This rant is against the forum rules. Crackpottery is not allowed (and for good reason).

Just in case anybody was confused and thought there might potentially be something valid to this post of DocBar's, however, I urge you to read this:
http://www.talkorigins.org/faqs/astronomy/bigbang.html

It goes into a good amount of detail as to precisely what the big bang theory is, and provides a nice introductory survey into the main lines of evidence in support of it.

 

[Tanelorn]

This essay is a good overview of the evidence for the big bang theory:
http://www.talkorigins.org/faqs/astronomy/bigbang.html

So yes, there is more evidence. A lot more.

Thanks Chalnoth, that is a great link.In section 2 a) Large-scale homogeneity they mention something I was just thinking about:

When we look at galaxy clusters and voids at large redshifts i.e. a long time ago, before they had gone through the same amount of spatial expansion as galaxy clusters and voids at much lower redshifts, do they look different in terms of size and distribution of these structures and the space between them, and does this provide further evidence for the amount of spatial expansion taking place according to the standard model?

Perhaps another way of saying it is that for a given size of cube of space we would expect the ratio of matter to space in that cube to have changed significantly for different red shifts.

 

[Chalnoth]

Thanks Chalnoth, that is a great link.


In section 2 a) Large-scale homogeneity they mention something I was just thinking about:

When we look at galaxy clusters and voids at large redshifts i.e. a long time ago, before they had gone through the same amount of spatial expansion as galaxy clusters and voids at much lower redshifts, do they look different in terms of size and distribution of these structures and the space between them, and does this provide further evidence for the amount of spatial expansion taking place according to the standard model?

Perhaps another way of saying it is that for a given size of cube of space we would expect the ratio of matter to space in that cube to have changed significantly for different red shifts.

This measurement is more or less equivalent to the Baryon Acoustic Oscillation observation, which compares the statistical distribution of distances between galaxies at different redshifts. The answer is basically yes: the distance evolves as you'd expect it to for a flat universe.

 

[Tanelorn]

Thanks Chalnoth, I found this link:

http://en.wikipedia.org/wiki/Acoustic_oscillationsPresumably a telescope like Hubble could also see evidence of the expansion of space by observing variations in the shape and size of voids and clusters at different redshifts? Would'nt the mean distance between the centers of galaxies vary depending on redshift?

 

[nix00]

The Big Bang by itself is not valid, it's a singularity showing where the theory of General Relativity cease to be valid. It corresponds to an epoch where quantum effects play also a large role and need to be considered in the theory. But yeah, this quantum era is really "short" comparing to the rest of the history of the universe, and the λ-CDM standard model of cosmology works pretty well.

 

[Chalnoth]

Thanks Chalnoth, I found this link:

http://en.wikipedia.org/wiki/Acoustic_oscillations


Presumably a telescope like Hubble could also see evidence of the expansion of space by observing variations in the shape and size of voids and clusters at different redshifts? Would'nt the mean distance between the centers of galaxies vary depending on redshift?

This page provides a nice set of images showing the whole process:
https://www.cfa.harvard.edu/~deisenst/acousticpeak/acoustic_physics.html

And yes, the mean distance does vary based on redshift.

 

[AgentSmith]

I think Big Bang theory is valid because of Inflation theory, it states that universe expanded faster than a light(right?) and that theory can solve the problems that Big Bang had: the Flatness and the Horizon problem. Another reason is Cosmic Microwave Background Radiation, which is first predicted to exist by scientists who support the Big Bang theory, and later was discovered by Hubble.

Are my arguments correct?

Is there any more evidence that support the Big Bang theory??

I think the BB theory is incomplete, or partially true. The analogy of a movie being run backward is just that, analogy and not fact. Everything is quantized, so why not space.? There must be a Plank volume beyond which universe, or a black hole, cannot go.
There is plenty of evidence for the BBT, as others show. I just think it can't be the entire story.
Let the criticisms begin.

 

[bapowell]

I think the BB theory is incomplete, or partially true. The analogy of a movie being run backward is just that, analogy and not fact. Everything is quantized, so why not space.? There must be a Plank volume beyond which universe, or a black hole, cannot go.
There is plenty of evidence for the BBT, as others show. I just think it can't be the entire story.
Let the criticisms begin.

Agree that the theory of quantum gravity is incomplete, and that a complete understanding should yield insight into the earliest moments of the high-density universe. Disagree about the bit about "analogy". There is no analogy to a movie being run backwards -- the dynamical equations quite literally predict what the universe was like in the past given observations of its current state. That's pretty good science to me.

 

[Drakkith]

Everything is quantized, so why not space.?

No, not everything is quantized.

 

[Chronos]

The notion of quantization of spacetime is a work in progress. While there are reasons to suspect this is the case, there is no definitive evidence to date.

 

[Chalnoth]

No, not everything is quantized.

I'm not sure you can build a consistent theory of the universe without quantizing everything.

What is it that you don't think is quantized?

 

[AgentSmith]

Analogy of BB

Agree that the theory of quantum gravity is incomplete, and that a complete understanding should yield insight into the earliest moments of the high-density universe. Disagree about the bit about "analogy". There is no analogy to a movie being run backwards -- the dynamical equations quite literally predict what the universe was like in the past given observations of its current state. That's pretty good science to me.[/QUO


I've read several articles and books about the BB where they liken the expansion to a movie of an explosion. If you run it backwards, everything ends up in a point(actually it doesn't). So they are trying to explain how you arrive at BB using a movie run backward. Its a poor analogy, probably written for the novice. I quite agree with rest of your post.

 

[bapowell]

I've read several articles and books about the BB where they liken the expansion to a movie of an explosion. If you run it backwards, everything ends up in a point(actually it doesn't). So they are trying to explain how you arrive at BB using a movie run backward. Its a poor analogy, probably written for the novice. I quite agree with rest of your post.

Well, yeah. It's a helpful analogy to communicate the physics to the popular audience. That doesn't mean that cosmologists' understanding is also based on the same analogy. As I said, the theory gives you the expansion -- the time reversal of the theory gives you the contraction. Perhaps I misunderstand your criticism -- you seemed to be citing the use of the analogy as a weakness of the big bang model itself; if anything, it's a weakness about the popularization of it.

 

[Chronos]

We can only wait and see, imo. Popular articles, like brian noted, only discuss the history of the universe in reverse. All such models utterly fail at Planck scales. That is why it is such a hot topic.

 

[Viracocha]

Inflation does not "validate" the Big Bang Theory, it is an adjunct to the theory which explains the issues you noted in your post.

This, the big bang is only a basic theory, saying inflation validates it is like saying calculus validates counting.

Some assumptions or principles derived from the big bang concept might be wrong, but the basic concept is sound