Somewhere in the afterlife, Stephen Hawking has his legs back and is undoubtedly jumping for joy after he’s been proven right again by scientists back on Earth. In a new paper published in Physical Journal Letters, researchers explain how they used data from gravitational waves to confirm one of Hawking’s best-known theories about black holes – that they can only grow, not shrink. If only clothing were made of black holes!
“It’s the first time that we can put a number on this.”
In a corollary to the Internet trope. “It’s not real if you don’t have a photo,” scientists know that it’s just a theory until you have some numbers to support it. That’s why MIT astrophysicist Maximiliano Isi, co-author of the paper, told Science News he and other astrophysicists decided to search for data to back up Stephen Hawking’s 1970s black hole area theorem that their surface area can only increase over time. That’s true with entropy or disorder and there’s nothing in the universe more disorderly than black holes gulping down everything in their path. While one would naturally assume that its diet would cause it to expand, a black hole eating a spinning object should cause it to spin and lose surface area. Hawking said no – the additional mass would offset it. He just didn’t have the numbers to back up the theory.
To find the numbers, Isi and his team looked at GW150914, the first gravitational waves directly observed in 2015. Those waves were caused by the merger of two black holes that spiraled inward and merged into one bigger black hole. Looking at the before-and-after data generated, they determined that the surface area of the newly formed black hole was greater than that of the two initial black holes combined. That’s one for Stephen Hawking – and another one for Albert Einstein and his general theory of relativity.
“We’re like, ‘aw, it was right again.’”
Astrophysicist and study co-author Will Farr of Stony Brook University in New York and the Flatiron Institute in New York City told Science News that physicists can’t believe how often the general theory of relativity holds up against new challenges. One such challenge is quantum mechanics – what works on the large scale of black holes doesn’t always hold at the tiny quantum end of the spectrum. We’re still here, so no apocalyptic laws have been broken – so far.
Would the merger of the two great minds of Hawking and Einstein follow Hawking’s theorem and merge into a brain greater than the two added together? They’re probably working on it right now.