University of Michigan astrophysicist to describe 'dark energy' research

Astrophysicist Gregory Tarle

It sounds like something that animates an evil empire — and in fact, so-called dark energy does permeate the entire universe, scientists believe.

But this phenomenon is beyond considerations of right and wrong. Instead, it’s a force whose mysteries embody fundamental questions about the workings of the universe. Scientists are closer than ever to answering those questions — and University of Michigan astrophysicist Gregory Tarlé visits Bates College to summarize progress in this effort at 7 p.m. Friday, Sept. 17, in Room 204 of Carnegie Science Building, 44 Campus Ave.

Tarlé’s presentation, titled “Illuminating Dark Energy — A Staged Approach,” is sponsored by the Bates physics and astronomy department and the Southern Maine Chapter of Sigma Xi. For more information, please contact 207-786-6490.

Scientists have concluded that dark energy is causing the expansion of the universe to accelerate.

Dark energy (not to be confused with “dark matter,” a different astrophysical phenomenon) is believed to constitute some three-quarters of the total mass-energy of the universe. Scientists have also concluded that dark energy is causing the expansion of the universe to accelerate.

Cosmologists are engaged in a four-stage program to determine the nature of dark energy, a phenomenon whose existence was hypothesized decades ago, but which lay beyond the capacity of science to measure until recent years.

Tarlé, who also researches cosmic radiation, is a member of a NASA working group that has helped design dark energy experiments. His presentation at Bates will describe the Dark Energy Survey, a ground-based telescope survey that will see first light in 2011; and the Wide Field InfraRed Survey Telescope (WFIRST).

Named the highest-priority new space mission for this decade, and with an expected launch date of 2020, WFIRST will be an orbiting telescope that combines a comprehensive dark energy mission with an exoplanet discovery mission. Both DES and WFIRST will employ multiple techniques to determine the nature of dark energy and illuminate the most profound cosmic mystery of our time.