Dr. Brian P. Schmidt believes our universe is expanding. The expansion is being pushed by an unknown force called Dark Energy, and eventually, the unyielding expansion will simply disappear in a phenomenon called the Big Rip.
So that’s the bad news.
The good news? The Big Rip won’t happen for another 100 billion years.
Schmidt spoke about the ever-expanding universe before a packed Main Auditorium in March at the 17th annual Kaczmarczik Lecture. The lecture series was established in 1995 to honor Paul Kaczmarczik, a key player in building the Physics and Atmospheric Science Departments. The series welcomes leading scientists to lecture on topics at the cutting edge of physics research.
Schmidt, a 2011 Nobel Laureate in Physics, served as leader of the High-Redshift Supernova Search Team in the late 1990s. He and his team used observations to trace back the expansion of the universe over 13 billion years and discovered that it was accelerating, a startling discovery that suggests that more than 70 percent of the cosmos is contained in dark energy. The team not only looked billions of years into the past, but also pondered the ultimate fate of the cosmos.
Schmidt explained that he and his team measured the expansion of the universe by observing exploding stars, or type 1a supernovas, which are excellent indicators of distance over time.
“Measuring distances in space can be difficult; you can’t just lay down a ruler,” Schmidt said. “But we know that a light source becomes fainter as it moves away. The faster the galaxy was moving away, the fainter the stars were.”
These observations were used to determine if the expansion of the universe was slowing down, staying the same or speeding up over time. Slowing down meant the universe could end in another Big Bang phenomenon; no change in the expansion meant the universe could likely go on forever; and acceleration meant the universe could face the Big Rip.
Scientists’ best guess is that dark matter is responsible for the expansion. But what dark matter actually is remains a mystery. “There is a lot of material out there that we can’t account for,” Schmidt says.
The bottom line?
In about 100 billion years, the Big Rip will likely be the undoing of the universe. But, humans of the future need not worry—Schmidt believes it will happen rather quickly.