A new project headed by the University of Texas (UT) is set to shed light on dark energy, the mysterious force that scientists believe might have caused the expansion of the universe. The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) is the first major project that will attempt to locate the elusive force by measuring the expansion rate of the universe.
Although scientists have been working on HETDEX for the past decade, they only began using the Hobbly-Eberly Telescope to collect data as of November of last year. The optical telescope - one of the largest in the world - can observe over 70 percent of the sky. Furthermore, UT researchers enhanced its range using 150 attached spectrographs with more than 34,000 optic fiber cables. These devices break up light into individual wavelengths, revealing the distance between galaxies as well as the rate at which they are retreating from Earth.
Contrary to other optical telescopes, the Hobbly-Eberly Telescope uses cost-effective spectrographic replications in order to collect data in a timely manner.
"Normally in astronomy, a lot of the cost is in the engineering of an instrument," said Karl Gebhardt, a UT astronomy professor. "What we did is something very different. Ultimately, we do a blind shot of the sky, go through and find galaxies, measure how far away they are, and then make a map of the universe."
Understanding dark energy is essential for scientists to understand how the universe is growing and to solve our fundamental misunderstanding of the universe.
"Dark energy is not an entity - it may not be dark, and it may not be energy, but it is the phrase we use to represent our ignorance about how the universe is expanding," Gebhardt said.
This misunderstanding lies in the fact that the universe is accelerating at a rate that cannot be explained by current models.
"If the universe is a car, right now someone is hitting the gas pedal, and there is no law of gravity that includes a gas pedal," said Greg Zeimann, a UT postdoctoral researcher. "It only includes a brake. Something else is hitting the gas pedal - that's the expansion rate. So, by measuring how much someone is hitting the gas pedal, you know how much dark energy there is."
Scientists believe that dark energy could make up around 70 percent of all matter and energy in the universe, although our lack of understanding of it is causing some to question if it even exists at all. Hopefully, the HETDEX will eventually put this question to rest.
