SoylentNews is people
SoylentNews
Cosmic magnifying glasses yield independent measure of universe's expansion:
A team of astronomers using NASA's Hubble Space Telescope has measured the universe's expansion rate using a technique that is completely independent of any previous method.
Knowing the precise value for how fast the universe expands is important for determining the age, size, and fate of the cosmos. Unraveling this mystery has been one of the greatest challenges in astrophysics in recent years. The new study adds evidence to the idea that new theories may be needed to explain what scientists are finding.
The researchers' result further strengthens a troubling discrepancy between the expansion rate, called the Hubble constant, calculated from measurements of the local universe and the rate as predicted from background radiation in the early universe, a time before galaxies and stars even existed.
This latest value represents the most precise measurement yet using the gravitational lensing method, where the gravity of a foreground galaxy acts like a giant magnifying lens, amplifying and distorting light from background objects. This latest study did not rely on the traditional "cosmic distance ladder" technique to measure accurate distances to galaxies by using various types of stars as "milepost markers." Instead, the researchers employed the exotic physics of gravitational lensing to calculate the universe's expansion rate.
The astronomy team that made the new Hubble constant measurements is dubbed H0LiCOW (H0 Lenses in COSMOGRAIL's Wellspring). COSMOGRAIL is the acronym for Cosmological Monitoring of Gravitational Lenses, a large international project whose goal is monitoring gravitational lenses. "Wellspring" refers to the abundant supply of quasar lensing systems.
The research team derived the H0LiCOW value for the Hubble constant through observing and analysis techniques that have been greatly refined over the past two decades.
H0LiCOW and other recent measurements suggest a faster expansion rate in the local universe than was expected based on observations by the European Space Agency's Planck satellite of how the cosmos behaved more than 13 billion years ago.
The gulf between the two values has important implications for understanding the universe's underlying physical parameters and may require new physics to account for the mismatch.
"If these results do not agree, it may be a hint that we do not yet fully understand how matter and energy evolved over time, particularly at early times," said H0LiCOW team leader Sherry Suyu of the Max Planck Institute for Astrophysics in Germany, the Technical University of Munich, and the Academia Sinica Institute of Astronomy and Astrophysics in Taipei, Taiwan.
More information: Kenneth C. Wong, et al. H0LiCOW XIII. A 2.4% measurement of H0 from lensed quasars: 5.3σ tension between early and late-Universe probes. arXiv:1907.04869v2 [astro-ph.CO]: arxiv.org/abs/1907.04869
Previously: New Measurement of Hubble Constant Adds to Cosmic Mystery
(Score: 2) by The Mighty Buzzard on Tuesday January 21 2020, @04:42PM (1 child)
I am comparing expansion velocity and acceleration to expansion velocity and acceleration. If you can't see how that's a valid comparison, you need to take up something in the humanities instead of talking physics.
My rights don't end where your fear begins.
(Score: 2) by PiMuNu on Tuesday January 21 2020, @04:53PM
> I am comparing expansion velocity and acceleration to expansion velocity and acceleration
Apologies, this was not apparent from your comment.