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Expansion of universe measurement may be in crisis

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#1 CounterWeight

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Posted 02 August 2019 - 11:29 AM

Good article here for those interested, does not seem sensationalist.  had a friend years ago working on the gravitational lensing part for his masters or PhD, can't remember and have not seen or heard after they moved to another country.  To me interesting stuff.  LINK


 

#2 EJN

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Posted 02 August 2019 - 11:39 AM

Did you not see the other 2 threads here about this?

 

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

 

https://www.cloudyni...ho-controversy/


Edited by EJN, 02 August 2019 - 11:45 AM.

 

#3 sg6

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Posted 02 August 2019 - 11:49 AM

My only comment is that the Hubble Constant appears to be anything other then constant.

Everytime someone measures it it comes out different. And I have said other times no one is going to measure it and say "After 5 years of research and measurement to previous guy got it right. We have added nothing." In effect they have to get a different answer.


 

#4 EJN

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Posted 02 August 2019 - 11:51 AM

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

 

 


 

#5 TOMDEY

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Posted 02 August 2019 - 12:16 PM

Well, Hubble most certainly discovered/quantified the ~locally/nearly homogeneous and isotropic expansion~, which captures the lion's share of the evidence attesting to Universal Expansion. Now that we are able to reach farther out into space, farther back into history, and with more finesse... should come as no great surprise that we seem to be finding evidence that there may be higher-order terms that best-fit the curve.    Tom


 

#6 GShaffer

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Posted 02 August 2019 - 01:19 PM

Closing this as there is already a 2 page discussion in progress that can be found here


 


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