BANG: The universe is expanding rapidly
By Emily Giegerich
Situations of astronomical measure occur on the earth’s surface every day, but the science of astronomy is concerned with situations far detached from the earth’s surface.
Robert Kirshner, a Harvard University astronomer, discussed the basics of astronomy and the evidence that suggests the universe is expanding at an accelerated rate in LaRose Digital Theatre Wednesday night. Nearly every seat was occupied for Kirshner’s visually interactive presentation.
To begin, Kirshner asked the audience to look at the big picture.
“Our galaxy is one of a hundred billion galaxies that make up the universe,” Kirshner said.
Kirshner discussed the traditional theories of astronomy, all the way back to Einstein’s era – theories such as general relativity and cosmological concepts – as well as the initial research that proved that the universe is expanding, which is accredited to Henrietta Leavitt. Leavitt was a female astronomer who noticed that the brightness of stars denoted distance, Kirshner explained.
Kirshner said that another renowned astronomer, Edward Hubble, expanded on Leavitt’s findings. It was an accepted truth that the universe was expanding, but Hubble wanted to know at what rate the expansion was occurring. His telescope, the Hubble telescope, provided the initial evidence of whether the universe was speeding up or slowing down.
“Hubble determined that by measuring the apparent brightness of objects at a given regimen, we ought to be able to figure out whether the universe is speeding up or speeding down,” Kirshner said.
Kirshner presented photographs, charts and graphs that gave evidence to a decelerated universe.
“The universe started with a Big Bang, the expansion had started slowing down through gravity and the expansion went on for a long time,” Kirshner said.
The extensive research conducted by Einstein, Leavitt, Hubble and many other historic astronomers provided Kirshner and his team of researchers with a base of information that led to their own personal developments.
“What we found is something very similar to what Henrietta Leavitt found,” Kirshner said. “The ones [stars] that get bright and dim the fastest turn out to be intrinsically dim, and the ones that get bright and dim the slowest turn out to be intrinsically bright.”
Kirshner said that as a result, distances between space and time could be measured more accurately. His team continued to do more experiments and in 1998 one of Kirshner’s graduate students discovered what Science Magazine called the “science breakthrough of the year.”
Adam Reiss, a graduate of M.I.T., found that the mass of the universe was negative. Kirshner said that after initially doubting his students’ findings, Reiss’ mathematics were indeed accurate.
“This proved that the universe was not just expanding, but the expansion was speeding up,” Kirshner said.
What does such an important scientific breakthrough as this mean for the universe and its inhabitants?
“The universe could have an acceleration without end,” Kirshner said. “Or it could have a collapse in the future, or something much worse.”
In response to the possible outcomes, Kirshner discussed two main steps that will be undertaken: the space telescope will be repaired and a telescope similar to the Hubble, but capable of taking infrared measurements, may be built.
The in-depth conversation that included a wide range of complex astronomical issues may or may not have gone (literally) over the heads of some non-science students in the audience, but Kirshner said his purpose for the science of astronomy is much simpler than those terms denote.
“People want to know where we came from, what is the universe and what is gonna happen in the future,” Kirshner said. “This kind of science is worth doing for the joy of finding out how the world works.”
