From analyzing ancient light emitted by the Big Bang, physicists have been able to provide a new estimate of the Earth's age. While previous estimates were 13.7 billion years old, give or take 130,000 years, new predictions hone in with more precision- at around 13.77 billion years, plus or minus 40 million years.
From data collected by multiple telescopes in the Chilean Atacama Desert, the findings weigh in on one of the most pertinent disagreements in astrophysics: the speed at which the universe is expanding. While the results support one side of the argument, they are unable to adequately disprove the other.
But why is this figure so controversial? The age of the universe is fundamental for understanding the rate at which the universe is expanding. This, by itself, is then essential for the field of cosmology- understanding the universe's past, present, and future. Although dark energy, an unknown matter, is thought to fuel this expansion, astronomers are in disagreement of when it began largely due to different methods of measurement.
While one method is based on how fast nearby galaxies are moving away from the Milky Way, the other is based on studying the oldest light in space, also known as cosmic microwave background (CMB). Differing results between the two methods have led some to ponder whether physicists have a blindspot in their theories and methods of measurement, the current findings support findings from the CMB theory.
"We find an expansion rate that is right on the estimate by the Planck satellite team (another study of the CMB)," says Steve Choi, an astrophysicist at Cornell University and lead author of one of two new papers. "This gives us more confidence in measurements of the universe's oldest light."
Although in support of the CMB theory, researchers warn that these results are still inconclusive, meaning the age of the universe may still remain a mystery.