A SIGNAL IN SPACE-TIME
Direct evidence of gravitational waves is “the story today. But what’s really exciting is what comes next,” said LIGO’s David Reitze. Researchers of all stripes are buzzing about the new scientific questions the discovery of gravitational waves can answer.
Cool chirp, gravitational waves. But what can you do for us? LIGO’s link to Kip Thorne — the theoretical physicist who consulted on the movie Interstellar — may trigger dreams of tumbling through wormholes. That was the first question LIGO collaborators fielded from the public: some version of “so, can we time travel yet or what?” The short answer to that is no. Sorry. The main way gravitational waves will affect human beings is letting us study new science.
Up until now, astronomers who wanted to probe some feature of the universe relied on one or more types of electromagnetic radiation: visible light, infrared light, x-rays, radio waves. Gravitational waves belong to an entirely different fundamental force. This is why LIGO scientists keep hammering on the idea that we can now hear the universe as well as see it. This is especially true because gravity, unlike light, interacts so weakly with matter, allowing us to peer way deeper into the universe than ever before. “This could be as big a deal as the revolution that started when Galileo first pointed his telescope to the sky. We won’t know till we look,” said Matthew Johnson, a professor of physics and astronomy at York University.
Thursday was also the first observational evidence of two black holes merging into one. LIGO will certainly be used to examine other instances of this phenomenon, and of the physics of black holes generally. In fact, although scientists had all kinds of evidence about how matter behaves around black holes, some noted that Thursday’s detection announcement is also final, definitive proof that black holes really exist too.
The bottom line is that gravitational waves will allow scientists to answer questions about all sorts of strange and extreme physics.