Astrophysicists Find Solid Evidence for Big Bang Inflation

[Biodizzle]

Very Cool. Check out this article on Fox News.

 

[Daecon]

But... I read all about that in a book (The Fabric of the Cosmos) only recently.

 

Why it is only now supposed to be ground-breaking news?

[[Tycho?]]

But... I read all about that in a book (The Fabric of the Cosmos) only recently.

 

Why it is only now supposed to be ground-breaking news?

 

Inflation is an idea, this is evidence to support the idea, which was previously pretty lacking.

[Daecon]

Oh. I must have missed that part of the news story that said what the evidence was.

[Biodizzle]

At the end of the article, it says that the findings will soon be reported in the Astrophysical Journal. We will have to wait to see untill then.

[ydoaPs]

bleh, fox news. got a link to a better news source?

[Biodizzle]

ha...

[GrandMasterK]

Well the universe broke lightspeed for a moment, now it's our turn! vroooooooooooom!!!

[Cap'n Refsmmat]

Not really. It didn't break lightspeed, as the universe isn't a tangible thing. It can expand faster than the speed of light without breaking any laws.

[Martin]

bleh, fox news. got a link to a better news source?

 

We have been discussing the WMAP results in another thread, Yourda.

We have links to the technical articles which will be published in Astrophysical Journal but are already online as preprints.

 

We also have some fairly decent press releases, more reliable than fox.

http://www.scienceforums.net/forums/showthread.php?p=258675#post258675

 

Here is the thread:

http://www.scienceforums.net/forums/showthread.php?t=19248

[ydoaPs]

This article claims that there is no evidence for inflation.

In 1948' date=' George Gamow, using the big bang model, predicted the existence of the cosmic microwave background (CMB), sometimes referred to as the cosmic background radiation (CBR or CMBR). In 1965, Arno Penzias and Robert Wilson discovered what had been predicted, and for their CMB findings, they received the Nobel Prize in physics (1978).

 

The cosmic microwave background (CMB) supposedly arises from an era that took place about 400,000 years after the big bang, when matter had cooled to a temperature of approximately 3,000 K, which allowed electrons and protons to combine to form stable hydrogen atoms for the first time. Prior to this hypothetical “age of recombination,” photons of light could not travel far before they were absorbed by the electrons. This made the universe opaque. After this time, the universe would have been transparent, allowing photons to decouple from matter and pass mostly unhindered through space. Today, we see the radiation from the “age of recombination” coming from all directions after it had traveled billions of light years, but since the universe has expanded about a thousandfold since, this distant radiation has cooled by a factor of a thousand to about 2.73 K.

 

Because the steady-state model, the big bang’s primary competitor in secular astronomy, could not accommodate the CMB, the big bang has thus been the standard cosmogony for the past four decades.

 

As difficulties have arisen for the big bang model, cosmologists have liberally modified the theory to meet each challenge. For instance, in 1981 Alan Guth proposed the idea of “inflation” to solve the horizon and flatness problems. Inflation posits that very shortly after the big bang, the universe underwent a very rapid expansion to a much larger size. Descriptions of the process vary, but typically, inflation supposedly happened about 10–35 seconds after the big bang, during which the now-visible universe expanded from perhaps the size of a proton to the size of an orange. Note that inflation is far faster than the speed of light, and that the normal rate of universal expansion that we see today prevailed after inflation.

 

Cosmologists generally agree that inflation has occurred because it handled the flatness and horizon problems so well. But is there any evidence for inflation? No, but on March 16, 2006 (and as AiG mentioned in a preliminary comment about this finding at The big bang and evidence for the “inflation theory”), NASA posted a story that answered, “Yes.” A quote from the story states, “Scientists peering back to the oldest light in the universe have evidence to support the concept of inflation.”

 

What did the scientists find? In 2001, NASA launched the Wilkinson Microwave Anisotropy Probe (WMAP). WMAP contained two basic types of instruments to measure slight spatial variations in temperature and polarization in the CMB. In the big bang scenario, the early universe must have contained slight variations in density that eventually gave rise to structure, such as galaxies. If the universe were initially too smooth, there would be no structure, and if it were too clumpy, nearly all matter would have been gobbled up into black holes. Either way, we wouldn’t be here to observe the universe. The slight variations in densities in the early universe would manifest themselves as slightly cooler and warmer regions in the CMB. In 1991, the Cosmic Background Explorer (COBE) was barely able to detect the temperature variations, but the temperature probes aboard WMAP were able to map the temperature variations in much greater detail.

 

The WMAP polarization experiments were designed to measure something more subtle. Being a wave phenomenon, light can be polarized. That is, light can vibrate in preferred directions. Most light is unpolarized, but various mechanisms can introduce some polarization. The matter clumping in the early universe ought to manifest itself to a degree in what physicists call “E-mode polarization.” WMAP has found evidence of this. However, B-mode polarization ought to arise from gravity waves resulting from inflation. Has WMAP found B-mode polarization? Quoting from the NASA website: “WMAP detected E-mode polarization but not B-mode yet.” So despite the claim made by the press release and the website, there is no evidence of inflation. What is going on then?

 

Cosmologists now regularly take data from very different experiments and combine them into a single result, though press results rarely discuss the input of the disparate data. An example of this was the February 2003 announcement of the latest 13.7 billion year age estimate of the universe, along with estimates of the percentages of mass distributed amongst lighted and dark matter and “dark energy.” Also left unsaid is how extremely model-dependent the conclusions are. That is, if we change the model slightly, the conclusions change as well. The recent claim of the discovery of evidence for inflation builds upon the earlier WMAP work, among others, and, like the others, is very model-dependent. For instance, how the observed E-mode polarization constrains the amount of inflation energy is model-dependent. The model dependence amounts to a type of circular reasoning—cosmologists interpret the data assuming inflation, and then used the data to support inflation.

 

It appears that the claim that we have found evidence of inflation is overstated. At best, the evidence is very indirect and to the point of being premature.

 

So, why all the fanfare now? In a few years, new experiments currently underway ought to measure B-mode polarization directly. However, even if B-mode polarization is found, the conclusion that it must result from inflation will be model-dependent. Inflation is such a foundation for modern big bang cosmogony that it is almost unthinkable among cosmologists that it might not exist. Thus the claim of first discovery of evidence for inflation carries much reward when compared to the risk of eventually being proved wrong.[/quote']

[[Tycho?]]

You are surely joking, that site is about as far from science as you can get.

[ydoaPs]

<sarcasm>what's unscientific about AiG?</sarcasm>

 

that is one of their best articles. i can't find anything wrong with it, but i don't know much about the subject. what is wrong with this specific article?

[Severian]

Well, I hope I am never tried in front of a Jury of Fox News journalists. Their idea of 'solid evidence' is a little bit suspect...

[sunspot]

Very little theoretical physics has any solid evidence. If we took only one or two data points to explain any phenomena on earth, it would be considered bull. But if one does that in space or subspace, it is considered proof.

 

One finds a tiny particle anomaly and that is proof of other dimensions. One can't find strings but that means they are everywhere. Quarks are only found in the lab and hardly exist, so that means they are also everywhere. The CMB is microwaves. Atoms and molecules coming off stars will give off heat and microwaves in all direction too. Maybe CMB has nothing to do with the beginning of the universe. Excuse me, I forgot, physics only needs a couple of data point to prove anything.

[[Tycho?]]

Very little theoretical physics has any solid evidence. If we took only one or two data points to explain any phenomena on earth' date=' it would be considered bull. But if one does that in space or subspace, it is considered proof.

 

One finds a tiny particle anomaly and that is proof of other dimensions. One can't find strings but that means they are everywhere. Quarks are only found in the lab and hardly exist, so that means they are also everywhere. The CMB is microwaves. Atoms and molecules coming off stars will give off heat and microwaves in all direction too. Maybe CMB has nothing to do with the beginning of the universe. Excuse me, I forgot, physics only needs a couple of data point to prove anything.[/quote']

 

Your ignorance is causing me physical pain. Although you've spent enough time on these forums, I think you're just being a troll.

[[Tycho?]]

<sarcasm>what's unscientific about AiG?</sarcasm>

 

that is one of their best articles. i can't find anything wrong with it' date=' but i don't know much about the subject. what is wrong with this specific article?[/quote']

 

Well you can boil that article down into a very short argument:

 

Astronomers were looking for several things which would confirm inflation. Some were found supporting it, some were not found at all. Therefore there is no evidence.

 

Which is stupid. It isn't perfect evidence, but confirming bits of it is still evidence, and its the first hard evidence. Just because its not complete doesn't totally invalidate it.

[Severian]

Very little theoretical physics has any solid evidence. If we took only one or two data points to explain any phenomena on earth' date=' it would be considered bull. But if one does that in space or subspace, it is considered proof.

[/quote']

 

Rubbish. The vast majority of theoretical physics has incredibly good evidence to back it up. Just look at the anomalous magnetic moment of the electron. String theory of course has no evidence and some cosmology is on shakey ground, but this is a very small part of theoretical physics.

 

One finds a tiny particle anomaly and that is proof of other dimensions. One can't find strings but that means they are everywhere.

 

No serious scientist claims there is evidence for strings or extra dimensions.

 

Quarks are only found in the lab and hardly exist, so that means they are also everywhere.

 

There is now 30 years worth of experimental evidence for quarks. (I have no idea what you mean by 'hardly exist'.) Short of a quark knocking on your front door and introducing himself, I don't know what further evidence you require to be convinced. (Incidentally, the the evidence for the existance of quarks is orders of magnitude better than the evidence for evolution of the species by natural selection, which I would also claim as indisputable.)

 

The CMB is microwaves. Atoms and molecules coming off stars will give off heat and microwaves in all direction too. Maybe CMB has nothing to do with the beginning of the universe. Excuse me, I forgot, physics only needs a couple of data point to prove anything.

 

Go look at the latest WMAP data. Do you see just a 'couple of data points'? No - it is a very comprehensive analysis. The radiation given off by stars has a very different temperature and therefore a very different spectrum. the CMBR is a perfect black body spectrum at 2.7K, exactly as predicted.