For the first time scientists are measuring the expansion of the universe 3 billion years after what is called the “big bang.” Kyle Dawson, Assistant Professor of Physics and Astronomy at the University of Utah and co-author of the study, says the universe’s rate of expansion is speeding up and can be seen by measured clumps of hydrogen gas.
“By measuring that clumping we can actually make distance measurements to very distant times in the past. And by doing that it’s like measuring the slope of a hill, you have to measure how tall the hill is and how far away that point of the hill is to measure what the slope is. That’s essentially what we are doing, we are trying to figure a way to measure how far away that part of the universe is by direct measurement almost by meters basically,” he says.
According to the Big Bang Theory, the universe formed 13.8 billion years ago. Dawson says a new 3-D map that measures hydrogen gas found that the universe was expanding at a much slower rate 11-billion years ago. He says after 2-years of tracking the hydrogen gas, they’ve found the rate has sped up over the past 5-billion years.
“We are still in the process of trying to make these measurements of the expansion history over the entire life of the universe to really understand what its past is, what its composition is, what its behavior is, what the basic laws of physics are, basic laws of gravity. Its 80 years in the making and we are still sorting through the details,” he says.
Dawson says it will take 5-years to track the entire sky. The study is performed using a 2.5 meter Sloan Telescope at the Apache Point Observatory in New Mexico.