Star Talk: The quest for 1% – the past, present and future for measuring the Hubble Constant and the expansion of the Universe

star_talk_oct “The quest for 1%: the past, present and future for measuring the Hubble Constant and the expansion of the Universe”, presented by Professor Hilding Neilson

Abstract: Almost a century ago, Edwin Hubble discovered that galaxies appear to be moving away from us and that farther galaxies moved at faster rates. This discovery revolutionized our view of the Universe and started the field of modern cosmology. Ever since, astronomers have been trying to better measure the expansion of the Universe, the Hubble constant, using numerous standard candles. In this talk, Professor Neilson will talk about the rich history of measuring the Hubble constant from some of the great arguments to the paradigm shift initiated by the results of the Hubble Space Telescope Key Project. He will conclude by discussing the future for measuring the Hubble constant to 1% precision to shed new insights into the dark matter and dark energy content of the Universe.


October 2016: Picture of the Month


This is the new and highest resolution map of the universe’s most abundant gas, hydrogen. The all-sky map of hydrogen’s 21-cm emission shows the abundance of the gas with brightness and the speed with color. The color in this map has been artificially set as blue to describe the radial motion toward us and green to describe the radial motion away. The band across the center of map is the plane of our own Milky Way, while the bright spots on the lower right is our neighboring Magellanic Clouds. The map collects data from over one million observations from both the northern Effelsberg 100-Meter Radio Telescope in Germany and the southern Parkes 64-Meter Radio Telescope in Australia. It should be noted that still many details are not yet well understood in this map.

For more information, check out APOD!