Astrophysicist Dr. Becky explains the Hubble tension, the disagreement between expansion-rate measurements from the cosmic microwave background and the distance ladder, and what early JWST Cepheid observations add.
Why Hacker News points people here: Recommended as an accessible layperson introduction to the Hubble tension when new expansion-rate results make the news.
“Dr.Becky goes over this in a video [0] from a year ago about the divergent results obtained by the two main ways we measure the rate of expansion.”
Covers diverging CMB versus supernova measurements of the expansion rate
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Dr.Becky goes over this in a video [0] from a year ago about the divergent results obtained by the two main ways we measure the rate of expansion. Cosmic Microwave Background Vs. Supernovae. As the accuracy of each method has improved, the end results have diverged. [0] 'theJWST just made the "Crisis in Cosmology" WORSE' this video
RecommendsjugMar 2024
“she introduces laymen to the problems well”
Accessible introduction to the Hubble tension and JWST measurements for laymen
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I can recommend Dr. Becky's introduction to the issues surrounding the Hubble Tension and recent JWST measurements in this 16 minute clip, as she introduces laymen to the problems well: this video It's an older clip, but it checks out... ;) (still JWST discoveries and she most importantly introduces the viewer to the still remaining conflicts)
Cites itlovelearningDec 2022
“the distance ladder itself seems to have come under some doubt recently”
Explains the crisis in cosmology and doubts about the distance ladder
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> "we can be absolutely confident of their fantastic distances" My current layperson's understanding is: 1) Redshift-to-distance conversion is a calibration based on the distance ladder. 2) And the distance ladder itself seems to have come under some doubt recently due to the "cosmological crisis" [1]. Can someone here ELI5 how they can be absolutely confident of these distances? [1] "JWST just made the Crisis in Cosmology WORSE" this video
Cites itSkyMarshalJan 2023
“the question seems unsettled at best”
Supports that expansion-rate measurements disagree and the question is unsettled
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Considering the two methods for measuring the rate of the universe’s expansion differ by about 10%, the question seems unsettled at best. You’re not wrong to question it. this video
