{"id":9947,"date":"2021-03-09T13:45:48","date_gmt":"2021-03-09T13:45:48","guid":{"rendered":"https:\/\/www.innovationnewsnetwork.com\/?p=9947"},"modified":"2021-03-09T13:45:48","modified_gmt":"2021-03-09T13:45:48","slug":"universe-is-expanding","status":"publish","type":"post","link":"https:\/\/www.innovationnewsnetwork.com\/universe-is-expanding\/9947\/","title":{"rendered":"New data on speed in which Universe is expanding"},"content":{"rendered":"
A new estimate of the local expansion rate, measured with the Hubble constant, reinforces that discrepancy. Using a relatively new and potentially more precise technique for measuring cosmic distances, which employs the average stellar brightness within giant elliptical galaxies, astronomers calculate that the Universe is expanding at approximately 73.3 kilometres per second per megaparsec. This estimate lies in the middle of three other good estimates, including estimates from Type Ia supernovae. This means that for every megaparsec \u2013 3.3 million light years \u2013 from Earth, the Universe is expanding an extra 73.3 \u00b12.5 kilometres per second. The average from the three other techniques is 73.5 \u00b11.4 km\/sec\/Mpc.<\/p>\n
Estimates of the local expansion rate based on fluctuations in the cosmic microwave background and in the density of normal matter in the early Universe (baryon acoustic oscillations), give a very different result: 67.4 \u00b10.5 km\/sec\/Mpc.<\/p>\n
Astronomers are concerned about this conflicting data because the expansion rate is a critical parameter in understanding the physics and evolution of the Universe and is key to understanding dark energy<\/a> \u2013 which accelerates the rate of expansion of the Universe and thus causes the Hubble constant to change more rapidly than expected with increasing distance from Earth. Dark energy comprises approximately two-thirds of the mass and energy in the Universe, however, its true nature is still a mystery.<\/p>\n For the new estimate, astronomers measured fluctuations in the surface brightness of 63 giant elliptical galaxies to determine the distance and plotted distance against velocity for each to obtain the Hubble constant. The surface brightness fluctuation (SBF) technique is independent of other techniques and has the potential to provide more precise distance estimates than other methods within about 100 Mpc of Earth, or 330 million light years. The 63 galaxies in the sample are at distances ranging from 15 to 99 Mpc, looking back in time a mere fraction of the age of the Universe.<\/p>\nNew measurements of Universe expansion<\/h3>\n