April 2, 2014
Tracing The Violent History Of The Universe Using A Cosmic Barometer
John P. Millis, Ph.D. for redOrbit.com - Your Universe Online
By studying the composition and other unique properties of sedimentary rock layers, geologists are able to trace the history of our Planet. They can identify periods of ice age, global climate shift, and even magnetic polarity shifts. In short, it is a clever way that researchers can use to reveal the major events in the history of our world.Now, astronomers from Imperial College London have taken this concept to a cosmic scale. By looking at a specific type of aromatic hydrocarbon, called dimethylnaphthalene, researchers are now able to probe the violent events in the history of our Universe.
According to Wren Montgomery, who co-authored the work, "The ability to detect high pressure environments in space has tremendous implications for our ability to learn more about the formation of our solar system and the universe. Dimethylnaphthalenes are like microscopic barometers and thermometers recording changes in pressure and heat as they travel through space. Understanding these changes lets us probe their history, and with that, the history of the galaxy."
The team investigated how the dimethylnaphthalene adapted to varying temperatures and pressures. By placing a sample – no more than the width of a human hair – into a vice-like apparatus the team was able to vary the pressure across the hydrocarbon. As the pressure was applied, they used an infrared light from a synchrotron source to map how the molecular structure changed.
With this data – combined with information about the mineralogy and chemistry of the samples – the team can correlate the structure of the dimethylnaphthalenes with the pressures and temperatures that would have been experienced in space; all that is needed are samples from the cosmos that astronomers could then examine to trace the pressure and temperature history of the Universe. It's lucky that such samples exist in the form of meteorites that have found their way to Earth.
"We now have another instrument to add to our celestial toolbox, which will help us to learn more about high pressure environments in space. Massive heat and pressure waves arcing out through space from cataclysmic events leave an indelible record in these cosmic barometers. It is really exciting to know that we now have a technique at our disposal that will help to reveal pivotal moments in the universe's history,” notes Mark Sephton, who co-authored the study.
Results of their research are published in The Astrophysical Journal.