A study published by Dartmouth researchers last week ruled out a previous mathematical hypothesis that placed Earth near the center of the universe. The research, conducted by physics and astronomy professor Robert Caldwell and Nina Maksimova ’15, is the first to directly oppose this particular model.
The universe has been expanding since the Big Bang, which scientists say occurred almost 14 billion years ago. In 1998, researchers discovered that the universe has been expanding at an accelerating rate for about the past five billion years.
Scientists believe that a force called “dark energy,” which may make up about 70 percent of the matter in the universe, may be responsible for the expansion. Dark energy may be anti-gravitational and could be pushing the approximately 3.5 percent of tangible matter in the universe, such as Earth and stars, apart instead of pulling it closer together. Accounting for the role of dark matter would require the revision of the laws of nature and physics.
The only mathematical model to date that has been able to fully explain the accelerating expansion of the universe is one that does not account for dark energy and, as a result, places Earth near the center of the universe.
Caldwell and Maksimova’s paper debunks this hypothesis. Using data from the NASA-owned Cosmic Background Explorer satellite, Caldwell and Maksimova proved that the actual spectrum of thermal radiation left over from the Big Bang, known as cosmic microwave background, is inconsistent with the model that requires that Earth be in the middle of the universe.
COBE examines light from the observable portion of space, which Caldwell and Maksimova analyzed to determine whether Earth was in a central position in the universe. Their findings ultimately concluded that it is not.
The only other way to rule out the center-of-the-universe theory, Caldwell said, would be to collect reference data from the vantage point of a faraway planet, which is currently not feasible.
Their findings rule out both the added that the universe exists according to currently accepted laws of physics and the idea that dark energy does not exist.
Astronomy professor Robert Fesen said he found the study convincing, but said the findings only reaffirm previous assumptions made in the field.
“It’s like saying, ‘Yes, the world is not flat,’” he said.
Caldwell and Maksimova worked on the project consistently for about a year.
Maksimova said she was not familiar with the vast majority of the physics, math and computer science necessary to participate in the study, and had to learn quickly to keep up.
She has already shared the results with the Theoretical Cosmology Group at Dartmouth and will present at the Texas Symposium on Relativistic Astrophysics in December and the Conference for Undergraduate Women in Physics at the University of Chicago in January.
“I’ve been given a fantastic opportunity unique to Dartmouth to participate in research, something that many physics students do not do until graduate school,” she said in an email.
Caldwell hopes that the paper will challenge researchers who insist on supporting the center of the universe model and will open up future avenues for studying dark energy.
He said he hopes that non-scientists with an interest in cosmology and astronomy will be able to enjoy and learn from the findings.
“I think people in general have a natural curiosity for how the universe works,” he said. “I think there’s an interested audience out there.”