Strange Posted August 11, 2019 Posted August 11, 2019 Several new methods of measuring the Hubble constant have produced inflicting values and more evidence that new physics is needed Quote Cosmologists Debate How Fast the Universe Is Expanding New measurements could upend the standard theory of the cosmos that has reigned since the discovery of dark energy 21 years ago. https://www.quantamagazine.org/cosmologists-debate-how-fast-the-universe-is-expanding-20190808/ 1
QuantumT Posted August 11, 2019 Posted August 11, 2019 Quote Meanwhile, the next data release from the Gaia space telescope, due in two or three years, will enable researchers to calibrate cepheids and TRGBs geometrically based on their parallax, or how far apart they look from different positions in the sky. The James Webb Space Telescope, Hubble’s successor, will also yield a wellspring of new and better data when it launches in 2021. Cosmologists will know the value of H0 — probably within the decade — and if there is still a discrepancy with predictions, by decade’s end they could be well on their way to discovering why. They’ll know it’s a tension or a crisis and not a surd. It seems its gonna take a decade before we can be sure whose method is the most precise, so aren't we getting a little ahead of ourselves with the crisis here?
Strange Posted August 11, 2019 Author Posted August 11, 2019 1 minute ago, QuantumT said: It seems its gonna take a decade before we can be sure whose method is the most precise, so aren't we getting a little ahead of ourselves with the crisis here? As you can see, the H0LiCOW and SH0ES measurements are already fairly precise, as are the very different Planck and DES results. The difference between these is far greater than the error bars. The slightly shocking thing is that the other new result is in the middle of these. So ... who knows ...
Mordred Posted August 13, 2019 Posted August 13, 2019 There is another related paper that our local region may be an underdensity region which would account for some of the discrepancies https://arxiv.org/pdf/1907.12402.pdf 2
Curious layman Posted August 13, 2019 Posted August 13, 2019 (edited) On 8/11/2019 at 7:52 PM, Strange said: more evidence that new physics is needed https://www.quantamagazine.org/cosmologists-debate-how-fast-the-universe-is-expanding-20190808/ When people say "new physics", do they mean a completely new branch of physics, something completely new, like the theory of relativity or evolution, or do they mean new ways of looking at current methods/ideas? Edited August 13, 2019 by Curious layman
Strange Posted August 13, 2019 Author Posted August 13, 2019 2 minutes ago, Curious layman said: When people say "new physics", do they mean a completely new branch of physics, something completely new, like the theory of relativity or evolution, or do they mean new ways of looking at current methods/ideas? Any of the above! It could be either a completely new theory that "replaces" GR, or it could be a realisation that a particular small tweak is needed, or it could be the discovery of completely new particles, forces, or something not yet thought of. 2
Mordred Posted August 13, 2019 Posted August 13, 2019 One of the more common usage for the term new physics involves the TeV range good example the Higgs metastability and potential for MSSM particles (Susy) were reaching the energy scales where it's getting potentially possible.
stephaneww Posted August 20, 2019 Posted August 20, 2019 (edited) Oops, I got the wrong thread, sorry. Edited August 20, 2019 by stephaneww
stephaneww Posted September 15, 2019 Posted September 15, 2019 To add to the current confusion, this new measure: https://science.sciencemag.org/content/365/6458/1134
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