1 of 2
1
New proof of cosmic inflation?
Posted: 17 March 2014 10:22 AM   [ Ignore ]
Sr. Member
Avatar
RankRankRankRankRankRankRankRankRankRank
Total Posts:  4545
Joined  2007-08-31

Astronomers discover polarised ripples in the cosmic background radiation that could be caused by gravitational waves of the inflating universe.

Inflation was first proposed in the early 1980s to explain some aspects of Big Bang Theory that appeared to not quite add up, such as why deep space looks broadly the same on all sides of the sky. The contention was that a very rapid expansion early on could have smoothed out any unevenness.

But inflation came with a very specific prediction - that it would be associated with waves of gravitational energy, and that these ripples in the fabric of space would leave an indelible mark on the oldest light in the sky - the famous Cosmic Microwave Background.

The BICEP2 team says it has now identified that signal. Scientists call it B-mode polarisation. It is a characteristic twist in the directional properties of the CMB. Only the gravitational waves moving through the Universe in its inflationary phase could have produced such a marker. It is a true “smoking gun”.

_73634672_73634671.jpg

From here.

Hey, I heard it in the Swiss radio news!

 Signature 

GdB

“The light is on, but there is nobody at home”

Profile
 
 
Posted: 19 March 2014 08:59 PM   [ Ignore ]   [ # 1 ]
Sr. Member
Avatar
RankRankRankRankRankRankRankRankRankRank
Total Posts:  4850
Joined  2007-10-05

Maybe Alan Guth will finally win the Nobel Prize he deserves.

 Signature 

You cannot have a rational conversation with someone who holds irrational beliefs.

Profile
 
 
Posted: 20 March 2014 01:12 AM   [ Ignore ]   [ # 2 ]
Sr. Member
Avatar
RankRankRankRankRankRankRankRankRankRank
Total Posts:  4545
Joined  2007-08-31
DarronS - 19 March 2014 08:59 PM

Maybe Alan Guth will finally win the Nobel Prize he deserves.

Full ack.

From Wikipedia:

As a junior particle physicist, Guth first developed the idea of cosmic inflation in 1979 at Cornell and gave his first seminar on the subject in January 1980. Moving on to Stanford University Guth formally proposed the idea of cosmic inflation in 1981, the idea that the nascent universe passed through a phase of exponential expansion that was driven by a positive vacuum energy density (negative vacuum pressure). The results of the WMAP mission in 2006 made the case for cosmic inflation very compelling. Measurements by the BICEP and Keck Array telescope give support to the idea of cosmic inflation, confirmation of which was given on March 17, 2014, with the findings of the B-mode polarization signature.

Bold by me.

Italics too: it shows the actuality of Wikipedia. People who love their disciplines seem to be pretty fast to update Wikipedia.

 Signature 

GdB

“The light is on, but there is nobody at home”

Profile
 
 
Posted: 22 March 2014 10:55 AM   [ Ignore ]   [ # 3 ]
Sr. Member
Avatar
RankRankRankRankRankRankRankRankRankRank
Total Posts:  4360
Joined  2010-08-15
GdB - 17 March 2014 10:22 AM

Astronomers discover polarised ripples in the cosmic background radiation that could be caused by gravitational waves of the inflating universe.

Inflation was first proposed in the early 1980s to explain some aspects of Big Bang Theory that appeared to not quite add up, such as why deep space looks broadly the same on all sides of the sky. The contention was that a very rapid expansion early on could have smoothed out any unevenness.

But inflation came with a very specific prediction - that it would be associated with waves of gravitational energy, and that these ripples in the fabric of space would leave an indelible mark on the oldest light in the sky - the famous Cosmic Microwave Background.

The BICEP2 team says it has now identified that signal. Scientists call it B-mode polarisation. It is a characteristic twist in the directional properties of the CMB. Only the gravitational waves moving through the Universe in its inflationary phase could have produced such a marker. It is a true “smoking gun”.

_73634672_73634671.jpg

From here.

Hey, I heard it in the Swiss radio news!

Amazing stuff, interesting image, thanks for sharing.

It makes me dizzy trying to comprehend that stuff.

Even the most basic, ‘cosmic waves’, when I think of waves I think of the rock dropping the pond, or noise moving out from something and then settling back to nothing… except for return-waves echoing back from something. 

But in space the big bang and then, on a cosmic scale, there’s nothing for these waves to bounce off of.

Or is it a different wave who’s properties change but it stays localized.

Truly bizarre and beautiful.


In past earlier decades I have had periods where I really got into the history of turn of the century physics and the whole quantum revolution.  And it’s interesting for a non-specialist to read these reports and abstracts that are well over my head, but there were those basics that I did have some idea about, catch here and there. 

Like the modern cell phone conversation where the connection drops out, or distorts horribly, etc.  And when the conversation is done I’m stuck putting the pieces together best I can.  But, it’s fun and interesting, specially considering I’ve been spectator for 50 years, and all the evolution of ideas I’ve witness, even if I can only actually comprehend a small fraction of those scientific insights.

 Signature 

We need each other, to keep ourselves honest

Profile
 
 
Posted: 22 March 2014 10:57 AM   [ Ignore ]   [ # 4 ]
Sr. Member
Avatar
RankRankRankRankRankRankRankRankRankRank
Total Posts:  4360
Joined  2010-08-15

yea, and what does ‘localized’ mean on a cosmic scale   LOL

 Signature 

We need each other, to keep ourselves honest

Profile
 
 
Posted: 25 March 2014 09:53 AM   [ Ignore ]   [ # 5 ]
Sr. Member
RankRankRankRankRankRankRankRankRankRank
Total Posts:  791
Joined  2012-04-25

This is a perfect example of what’s “wrong” with science (and obviously I’m being sarcastic). Capitalism, Religion, Politics are spoiled selfish children who want it all, right now, give it to ME ME ME. Science is a patient group of adults who will take a little bit at a time, over the course of even 30+ years, and will work together to get it. And even then, they want to make sure it’s the real thing, versus C,R, and P who will be ok with a good fake as long as they can convince others it’s not a fake.

Profile
 
 
Posted: 26 March 2014 12:27 PM   [ Ignore ]   [ # 6 ]
Sr. Member
Avatar
RankRankRankRankRankRankRankRankRankRank
Total Posts:  4360
Joined  2010-08-15
citizenschallenge.pm - 22 March 2014 10:57 AM

yea, and what does ‘localized’ mean on a cosmic scale   LOL

a point in the “fabric” of space ?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

CuthbertJ - 25 March 2014 09:53 AM

This is a perfect example of what’s “wrong” with science (and obviously I’m being sarcastic). Capitalism, Religion, Politics are spoiled selfish children who want it all, right now, give it to ME ME ME. Science is a patient group of adults who will take a little bit at a time, over the course of even 30+ years, and will work together to get it. And even then, they want to make sure it’s the real thing, versus C,R, and P who will be ok with a good fake as long as they can convince others it’s not a fake.

Good observation.

 Signature 

We need each other, to keep ourselves honest

Profile
 
 
Posted: 30 March 2014 11:06 AM   [ Ignore ]   [ # 7 ]
Member
RankRankRankRankRankRankRankRank
Total Posts:  191
Joined  2010-10-09

So the CMB is polarised in a manner consistent with inflation having happened. Very good.

(Puts Devil’s Advocate hat on).

But ...... Could there be an alternative explanation? Or possibly several alternative explanations?

Has anyone looked for alternative explanations?

Or is this just one more example of confirmation bias?

And - more basic still - how accurate are these measurements?

- Just a few heretical thoughts ........ nothing really (ducks down behind a chair).

TFS

Profile
 
 
Posted: 30 March 2014 11:08 AM   [ Ignore ]   [ # 8 ]
Sr. Member
Avatar
RankRankRankRankRankRankRankRankRankRank
Total Posts:  4850
Joined  2007-10-05

TFS, scientists have been looking for alternative explanations for 30 years and found nothing that matches the new observations.

 Signature 

You cannot have a rational conversation with someone who holds irrational beliefs.

Profile
 
 
Posted: 30 March 2014 11:42 AM   [ Ignore ]   [ # 9 ]
Sr. Member
Avatar
RankRankRankRankRankRankRankRankRankRank
Total Posts:  4360
Joined  2010-08-15
Theflyingsorcerer - 30 March 2014 11:06 AM

Has anyone looked for alternative explanations?

I’m surprised paradigm hasn’t commented.
Seems this would be up his alley smile

 Signature 

We need each other, to keep ourselves honest

Profile
 
 
Posted: 31 March 2014 02:03 PM   [ Ignore ]   [ # 10 ]
Member
RankRankRankRankRankRankRankRank
Total Posts:  191
Joined  2010-10-09
DarronS - 30 March 2014 11:08 AM

TFS, scientists have been looking for alternative explanations for 30 years and found nothing that matches the new observations.

Darron, CMB polarisation has only recently been discovered, so I don’t see that it makes much sense to say that scientists have been looking for alternative explanations for it for thirty years.

What cosmologists have been looking for for thirty years is evidence for inflation - which they now think they’ve found. No-one, to my knowledge, has seriously suggested any alternative to the current Big Bang + Inflation model, despite its glaring inconsistencies - not the least of them being the necessity for the universe to have expanded at greater than the velocity of light, post-inflation.

TFS

Profile
 
 
Posted: 31 March 2014 02:07 PM   [ Ignore ]   [ # 11 ]
Sr. Member
Avatar
RankRankRankRankRankRankRankRankRankRank
Total Posts:  4850
Joined  2007-10-05

What makes you think the universe expanded faster than light post-inflation?

And cosmologists have been working on alternate theories to the Big Bang far longer than 30 years. No one has come up with a viable alternate theory. You know, one which would explain the observations better than the Big Bang Theory.

 Signature 

You cannot have a rational conversation with someone who holds irrational beliefs.

Profile
 
 
Posted: 01 April 2014 05:12 PM   [ Ignore ]   [ # 12 ]
Member
RankRankRankRankRankRankRankRank
Total Posts:  191
Joined  2010-10-09

In every direction we look, we see galaxies that are, supposedly, up to 12 billion light years away from us.

But, of course, when we look at these galaxies we’re looking into the past; we’re seeing them, not as and where they “are” today, but as AND WHERE they were, 12 billion years ago.

Thus, 12 billion years ago, the universe was already AT MINIMUM a sphere of 12 billion light years radius.

But the universe is only 13.8 billion years old, by the most recent estimates; therefore, in less than two billion years, the universe expanded to AT A MINIMUM 12 billion light years radius.

i.e. much faster than the velocity of light.

And to say “space is curved” doesn’t help. Space is curved locally around centres of mass, but by the most reliable measurements, on the cosmic scale the universe is “flat” within 2%.

TFS

Profile
 
 
Posted: 01 April 2014 05:26 PM   [ Ignore ]   [ # 13 ]
Sr. Member
Avatar
RankRankRankRankRankRankRankRankRankRank
Total Posts:  4850
Joined  2007-10-05

That is an epic logic fail. Other galaxies are 12 billion light years from us because the universe has been expanding in the intervening years. We are seeing those galaxies as they were 12 billion years ago, not where they were 12 billion years ago. Even though the expansion rate of the universe is accelerating it is nowhere near the speed of light and has not been since the Inflationary Period.

See How fast is the universe expanding? on NASA’s site.

 Signature 

You cannot have a rational conversation with someone who holds irrational beliefs.

Profile
 
 
Posted: 02 April 2014 07:48 AM   [ Ignore ]   [ # 14 ]
Sr. Member
RankRankRankRankRankRankRankRankRankRank
Total Posts:  1913
Joined  2007-10-28

We must consider how to resolve the horizon problem

This presents a serious problem; if the universe had started with even slightly different temperatures in different areas, then there would simply be no way it could have evened itself out to a common temperature by this point in time.

Inflation as a possible solution:

The theory of cosmic inflation provides one solution to the problem (along with several others such as the flatness problem) by postulating a short 10^32 second period of exponential expansion (dubbed “inflation”) in the first seconds of the history of the universe.

However, from the wiki here

A recurrent criticism of inflation is that the invoked inflation field does not correspond to any known physical field, and that its potential energy curve seems to be an ad hoc contrivance to accommodate almost any data obtainable. Paul J. Steinhardt, one of the founding fathers of inflationary cosmology, has recently become one of its sharpest critics. He calls ‘bad inflation’ a period of accelerated expansion whose outcome conflicts with observations, and ‘good inflation’ one compatible with them: “Not only is bad inflation more likely than good inflation, but no inflation is more likely than either…. Roger Penrose considered all the possible configurations of the inflaton and gravitational fields. Some of these configurations lead to inflation ... Other configurations lead to a uniform, flat universe directly – without inflation. Obtaining a flat universe is unlikely overall. Penrose’s shocking conclusion, though, was that obtaining a flat universe without inflation is much more likely than with inflation – by a factor of 10 to the googol (10 to the 100) power!”

Bold added by me.

Alternative to inflation:

The flatness and horizon problems are naturally solved in the Einstein-Cartan-Sciama-Kibble theory of gravity, without needing an exotic form of matter and introducing free parameters.This theory extends general relativity by removing a constraint of the symmetry of the affine connection and regarding its antisymmetric part, the torsion tensor, as a dynamical variable. The minimal coupling between torsion and Dirac spinors generates a spin-spin interaction that is significant in fermionic matter at extremely high densities. Such an interaction averts the unphysical Big Bang singularity, replacing it with a cusp-like bounce at a finite minimum scale factor, before which the Universe was contracting. The rapid expansion immediately after the Big Bounce explains why the present Universe at largest scales appears spatially flat, homogeneous and isotropic. As the density of the Universe decreases, the effects of torsion weaken and the Universe smoothly enters the radiation-dominated era.

Bold added by me.

The unphysical big bang singularity is highly problematic.

 Signature 

I am, therefore I think.

Profile
 
 
Posted: 02 April 2014 04:03 PM   [ Ignore ]   [ # 15 ]
Member
RankRankRankRankRankRankRankRank
Total Posts:  191
Joined  2010-10-09
DarronS - 01 April 2014 05:26 PM

That is an epic logic fail. Other galaxies are 12 billion light years from us because the universe has been expanding in the intervening years. We are seeing those galaxies as they were 12 billion years ago, not where they were 12 billion years ago.

How do you figure we’re not seeing them where they were 12 billion years ago? What you’re saying sounds like post hoc rationalisation to me - more like theology than science. You’re doing exactly what “pseudoscientists” are often accused of doing - beginning with the conclusion (“The Big Bang happened”) and then cherrypicking the “evidence” to suit.

TFS

Profile
 
 
   
1 of 2
1