April 23, 2013
Radiation Around Black Holes Can Help Measure The Universe
Alan McStravick for redOrbit.com - Your Universe Online
In 2011, the Nobel Prize for Physics was awarded to a trio of researchers. Adam Riess, Saul Perlmutter and Brian Schmidt were able to determine that the speed and scope of the expansion of the universe is not so uniform as once believed. This simple discovery threw the whole prospect of dating and measuring time in galaxies far from our own.However, this week saw a multi-national collaboration come together to detail just how we might place certain occurrences in divisions of space and time. The method developed by researchers from Tel Aviv University´s School of Physics and Astronomy, the Institute of High Energy Physics of the Chinese Academy of Sciences, and the Observatoire de Paris, has the potential to measure distances of billions of light years with an almost certain accuracy. And, as the team points out, having the ability to record these measurements over vast distances will translate into our being able to see further into the past of the universe — and possibly even allow us to estimate its rate of expansion at a very young age.
The team, which has published their findings in the journal Physical Review Letters, contends that the system of measurement they developed works by taking into account the radiation emitted from material that surrounds a black hole before its ultimate absorption into it. The closer this material travels to a black hole, the higher its temperature and radiation output. To put a point on it, the radiation is so great it exceeds 1,000 times the energy expended by a large galaxy containing 100 billion stars. This fantastically elevated radiation output allows the radiation signature to be seen from very far distances.
It is important to note that the use of radiation has long been a reliable tool for astronomers. Where this new study diverges is by singling out the use of radiation in and around a black hole. As the team notes, measuring the energy around a black hole and comparing that to radiation that is able to reach Earth will give astronomers the ability to infer the distance to the black hole itself as well as pinpointing the time in the history of the universe when the energy was initially emitted.
As Professor Hagel Netzer of Tel Aviv University states, the work done by this team of scientists and researchers will add a valuable tool for all astronomers to help determine the time and distance of black holes beyond those regarded as being in our own astronomical vicinity, which the team focused on for their research. Though it would seem these black holes are regarded as being near the vicinity of Earth, it is important to realize the black holes observed for this study are several hundred million light years away.
The universe in which we live is approximately 14 billion years old. By recognizing and utilizing this new method, Netzer believes we are on the precipice of being able to unravel some of the greatest mysteries known to man and the cosmos. “When we are looking into a distance of billions of light years, we are looking that far into the past,” he commented. “The light that I see today was first produced when the universe was much younger.”
One of the mysteries alluded to by Netzer is that of the mysterious ℠dark energy´. It was the proving of its existence that led to the aforementioned 2011 Nobel Prize going to Reiss, Perlmutter and Schmidt. If we can gain a better understanding of this force, often referred to as ℠anti-gravity´, we might understand the physics behind the accelerated expansion of our universe. By broadening our limited understanding, we are moving ever closer to understanding dark energy on physical grounds. When that occurs, we will have answered questions about the consistency of this force through time and whether or not we might expect a change in its properties and characteristics in the future.