The biggest news in physics in quite awhile—the discovery of gravitational waves rippling through spacetime—has scientists overjoyed around the world.
Researchers with the Laser Interferometer Gravitational-Wave Observatory (LIGO) announced on Thursday that they had detected waves created when two black holes smashed into each other some 1.3 billion light-years away. The finding is the first direct confirmation of gravitational waves as well as the strongest evidence to date that black holes exist. It is also the start of an age where scientists can use gravitational waves to study cosmic objects that otherwise cannot be seen.
“This is the first time the universe has spoken to us through gravitational waves,” LIGO executive director, physicist David Reitze, told a packed house at a press conference held at The National Press Club in Washington, D.C. “Before now, we were deaf.” The crowd erupted into applause when he confirmed the rumors that LIGO had found gravitational waves. “My reaction was, ‘Wow!’” he said of first seeing the data. “I couldn’t believe it.”
“This discovery has taken a long time,” LIGO spokesperson Gabriela González said. “There have been hundreds of people developing the technology, doing the analysis. We are very proud of this work taking a village, a worldwide village,” González added, referring to the more than 1,000 researchers who work on the project.
LIGO collaborators with the European Gravitational Laboratory’s VIRGO gravitational wave project held simultaneous announcements in Italy and Paris while physics departments around the world hosted gatherings to watch the press conference Webcasts. “It’s amazing to be here to finally see what we’ve been talking about for so long,” astrophysicist J. Richard Gott III said at the Princeton University gathering. His colleague, physicist Paul Steinhardt, echoed the sentiment: “I’m very excited about this. It’s the opening of a new era in astronomy in which we’re now going to begin to view the universe with a new set of waves—not light waves, but gravitational waves.”
At Columbia University, a number of students and faculty could stake a claim to some of the fame. “I helped hand-assemble 60 to 70 percent of the timing system,” graduate student Stefan Countryman said. “I’ve been working on it since I was an undergrad. [The discovery] is vindicating, and it’s just exciting scientifically.” Another LIGO collaborator at Columbia, physicist Szabolcs Márka, added, “This will really let us listen to the music of the cosmos.”
“This has never been done before,” said Janna Levin, a theorist at Barnard College. “It's like the first time a telescope was pointed at the sky.”
Scientists have essentially been waiting for this day for a century, since Albert Einstein predicted gravitational waves in 1916 on the basis of his general theory of relativity. “100 years feels like a lifetime but over the course of scientific exploration it’s not that long,” Neil deGrasse Tyson, director of the Hayden Planetarium at the American Museum of Natural History, said at the Columbia gathering. “I lay awake at night wondering what brilliant thoughts people have today that will take 100 years to reveal themselves.” At the D.C. press conference, California Institute of Technology physicist Kip Thorne imagined the visionary’s response to the news. “Einstein would be beaming. This is a very, very special moment.”
Scientists were nearly unanimous in agreeing that gravitational waves would revolutionize astronomy and allow for a whole new realm of study. Yet they did establish some limits to what they can do. “I don’t think it’s going to bring us any closer to being able to time travel,” Thorne said in response to a question at the announcement. “I wish it would.”
—Jennifer Hackett contributed reporting from Columbia University’s press conference Webcast event. Michael Lemonick contributed reporting from Princeton University’s event.