Researcher computes speed of expansion of universe
28 July 2011
A new and accurate method to measure the speed of expansion of the universe had been made by measuring the Hubble constant, according to a report.
The report in the `Science Daily' said a PhD student, Florian Beutler, from The International Centre for Radio Astronomy Research (ICRAR) in Perth had produced one of the most accurate measurements ever made of how fast the universe was expanding.
"The Hubble constant is a key number in astronomy because it's used to calculate the size and age of the Universe," Beutler said.
Analysing light originating from a distant galaxy, the speed and direction of that galaxy could be easily measured. However, determining the galaxy's distance from earth was much more difficult proposition, according to an ICRAR statement.
Butler took a radically new approach, drawing on data from a survey of over 125,000 galaxies carried out with the UK Schmidt Telescope in eastern Australia.
Called the 6dF Galaxy Survey, this was the biggest survey till date of relatively nearby galaxies, that covered around half the sky.
Galaxies are not evenly spread through space but are clustered. Beutler used a measurement of the clustering of the galaxies surveyed, plus other information derived from observations of the early universe, and calculated the Hubble constant with an uncertainty of less than five per cent.