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How the Universe Stopped Making Sense...

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#1 BillP

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Posted 11 October 2019 - 12:51 PM

Interesting new article.

 

https://www.livescie...make-sense.html

 

Here's a snippet:

 

We're getting something wrong about the universe.  It might be something small: a measurement issue that makes certain stars looks closer or farther away than they are, something astrophysicists could fix with a few tweaks to how they measure distances across space. It might be something big: an error — or series of errors — in  cosmology, or our understanding of the universe's origin and evolution. If that's the case, our entire history of space and time may be messed up. But whatever the issue is, it's making key observations of the universe disagree...

 

You can see that the edges of WMAP and CV SN overlap [see chart in article], mostly outside the red bar. That was the picture of the discrepancy a few years ago, Mack said: Significant enough to worry that the two measurements were turning up different answers, but not so significant as to render them incompatible with a little tweaking.  But in recent years there's been a new measurement of the CMB from a group called the Planck Collaboration. The Planck Collaboration, which released its latest dataset in 2018, put very strict constraints on the mass fraction and expansion rate of the universe, denoted by the black sliver on the plot labeled Planck.  Now, the authors wrote, two wildly different pictures of the universe emerge. Planck and WMAP — along with a range of other approaches to constraining H0 and Ωm — are all more or less compatible.



#2 sg6

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Posted 11 October 2019 - 01:30 PM

Considering that less then 100 years ago we (many) were under the idea that the milky way was the total universe, it seems a bit presumptious that we now think that we know almost all there is to know. And that we know it with accuracy.

 

So

"It's either something new in the universe or it's something we don't understand about our measurements," she said.

Could be more that we do not entirely understand our universe.

 

Seems we try for the more complex and grandiose ideas rather then simple ones. Suppose it makes better headlines but a little unsure of the real state. And I wonder how much off the real path we go.


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#3 BillP

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Posted 11 October 2019 - 05:11 PM

Considering that less then 100 years ago we (many) were under the idea that the milky way was the total universe, it seems a bit presumptuous that we now think that we know almost all there is to know. And that we know it with accuracy.

 

Well put! I quite agree, but as we know many adhere to the ideology of Scientism.



#4 EJN

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Posted 11 October 2019 - 07:56 PM

Didn't you already start a thread about this? Why yes, right here:

https://www.cloudyni...f-the-universe/

 

So rather than re-typing everything I said there all over again, I will just copy & paste it here.

 

And add an additional comment: Hubble's constant cannot be measured directly from the

CMB, instead it is derived by comparing computer models with varying parameters to

the observed power spectrum of the Planck measurements. I personally put more stock

in measurements made directly from Cepheids and Type Ia supernovae in galaxies.

 

And the universe makes more sense now than it did 30 years ago, when it appeared to be

younger than the oldest stars. The discovery of accelerating expansion resolved that paradox.

 

An 8% discrepancy is a lot better than the 2:1 discrepancy in in the late 70s and early 80s.

The difference is then there wasn't the interwebz and pop-sci writers to blow it

all out of proportion.

 

-------------------------------------------------------------------------------------------
From the other thread:
 

It's interesting to look at this compilation of measured values of Hubble's constant
posted by the late John Huchra of Harvard-Smithsonian Center for Astrophysics.
 
If you take the list of values published 1996 and later, and average them, you
get 68 (km/sec)/mpc, which just shows that if enough people measure something you
will eventually converge on a reasonably correct value. The list stops in 2010 because
of his death.
 
Look at some of the earlier measurements, the values are much higher than modern values.
 
In the 70's & 80's, Allan Sandage was consistently getting values around 50, while
Gerard deVaucouleurs was consistently getting values around 100. The
disagreements over these values became known as "The Hubble Wars."
 
Raw data here: https://www.cfa.harv...hubble.plot.dat
 
h1920.jpg
 
 
ho.2004.jpg
 
 
hubble.key.summary.jpg
 

 

 
If Huchra were still alive he would call the current discrepancy a tempest in a teacup.
It is being totally overblown by pop-science writers.


Edited by EJN, 11 October 2019 - 08:10 PM.

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#5 DaveC2042

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Posted 11 October 2019 - 08:04 PM

Ah, the old "if scientists don't understand something then they don't understand anything" gambit.
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#6 EJN

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Posted 11 October 2019 - 08:10 PM

Ah, the old "if scientists don't understand something then they don't understand anything" gambit.

 

Yeah, I sense a recurring theme/agenda in the OP's postings.


Edited by EJN, 11 October 2019 - 08:47 PM.

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#7 russell23

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Posted 12 October 2019 - 08:48 AM

Well I would ask this - with the precision of our current measurements -  shouldn't there be concern that the error bars no longer overlap with the improved accuracy of the measurements?   I do feel that there has been such a hard commit to the current cosmological paradigm that the exploration of certain aspects of our universe are simply not allowed because the telescope time would be seen as "waste".  



#8 llanitedave

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Posted 12 October 2019 - 02:20 PM

Well I would ask this - with the precision of our current measurements -  shouldn't there be concern that the error bars no longer overlap with the improved accuracy of the measurements?   I do feel that there has been such a hard commit to the current cosmological paradigm that the exploration of certain aspects of our universe are simply not allowed because the telescope time would be seen as "waste".  

That's an unstable situation.  Inevitably, those inconsistencies will become impossible to wave away, and that telescope time won't seem so wasted after all.


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#9 theropod

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Posted 12 October 2019 - 06:25 PM

Define “scientism”.

 

If you mean accepting empirical evidence gleaned via repeated testing which consistently returns results of a positive nature as some sort of “ism” then the only alternative is some sort of voodoo. The “ism” implies this is all a matter of faith, which suddenly validates all the other “isms”. Baptism, Buddhism, Hinduism and a never ending list of “isms” that are defined by belief. If anyone thinks it takes faith, or belief, to accept empirical evidence they do not truly understand what empirical evidence is. That, or their agenda is driven by jealousy that their favorite “ism” doesn’t generate the same respect that has accumulated for the scientific method.

 

I feel, after dealing with the type specimens for years, that those using such terms are either creationist, or are of intelligent designer crowd. I would sure love to be wrong, but I’m betting I’m not.


Edited by theropod, 12 October 2019 - 06:25 PM.

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#10 llanitedave

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Posted 12 October 2019 - 10:09 PM


I feel, after dealing with the type specimens for years, that those using such terms are either creationist, or are of intelligent designer crowd. I would sure love to be wrong, but I’m betting I’m not.

Sometimes signature lines are also informative.


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#11 theropod

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Posted 13 October 2019 - 10:23 AM

Sometimes signature lines are also informative.

Yes, had I bothered to do as you suggest I wouldn’t have even posted a comment.

 

Sigh.


Edited by theropod, 13 October 2019 - 10:23 AM.



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