We already knew that the universe had a distinct starting point, and now researchers at MIT have actually seen the very first stars born from that beginning.
Scientists generally accept that, just minutes before the Big Bang, protons and neutrons collided into each other in the nuclear fusion reactions that produced hydrogen and helium. But as the universe cooled down, so did the reactions, and helium was left to make up the majority of the universe. The heavier elements (carbon and oxygen, for instance) didn’t show up until the first stars started forming.
Using the most distant known quasar, which is over 13 billion light-years from Earth, researchers are actually able to peer into the universe when it was still just a baby, a mere 750 million years young. What’s more, the quasar’s light spectrum doesn’t contain any of those heavy elements that could only have come after the universe cooled.
“The first stars will form in different spots in the universe… it’s not like they flashed on at the same time,” said Rober Simcoe, an associate professor of physics at MIT. “But this is the time that it starts getting interesting.”
The only objects we’ve been able to see up to this point have been less than 11 billion years old, and those were all at least old enough to contain heavy elements. From this pont on, Simcoe and his team are hoping to analyse other quasars from the same time period, further confirming their findings and offering a deeper glance into the very beginning of the universe.
“If we can find things in this epoch, we can start to characterise them,” Simcoe says. “There’s always something interesting at the edge.” [The Daily Galaxy]