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Old November 2nd 19, 09:50 AM posted to sci.astro.research
Steve Willner
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Default Is the Universe Younger than We Thought?

In article , I wrote:
The upshot is that the discrepancy between the local and the CMB
measurements of H_0 is between 4 and 5.7 sigma, depending on how
conservative one wants to be about assumptions.


We had another colloquium on the subject yesterday. Video at
https://www.youtube.com/watch?v=K1496gv8KCo

The points I took away a 1. both the local ("direct") measurements
and the distant ("indirect") measurements are made by two
_independent_ methods, which agree in each case. That is, the two
direct methods (SNe, lensing) agree with each other, and the two
indirect methods (CMB, something complicated) agree with each other,
but the direct and indirect measurements disagree.

2. contrary to what I wrote earlier, even a non-physical change of
dark energy with time (say an abrupt increase at some fine-tuned
epoch) cannot fix the disagreement.

3. while there have been several suggestion for new physics to fix
the problem, none of them so far seems to work without disagreeing
with other data.

What fun!

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