What do you call a black hole? Anything you want the old joke goes as long as you don’t call it late for dinner. After all, black holes are nothing but hungry.
But what do you call a collection of black holes? The question has become more urgent among astronomers, inspired by recent news of dozens of black holes buzzing in the center of a nearby star cluster.
In recent years, instruments such as the LIGO and Virgo gravitational wave detectors have recorded space-time oscillations through collisions of black holes, making it unequivocally clear that these monstrous concentrations of nothingness not only exist, but are omnipresent. Astronomers expect to see large numbers of these Einsteinian creatures when the next generation of gravitational wave antennas are deployed. What will you call her?
There are geese, pods of whales and murders of crows. Which term would do justice to the peculiarity of black holes? A mass? A sieve? A scream?
Jocelyn Kelly Holley-Bockelmann, astrophysicist at Vanderbilt University, and colleagues are developing an international project called Laser Interferometer Space Antenna (LISA), which can detect collisions between black holes of all sizes across the universe. She recently attempted a group Zoom meeting. “When one of the members said his daughter was wondering what you are calling a collective of black holes – and then the meeting fell apart and everyone was trying to strengthen each other,” she said in an email. “Every time I saw a suggestion, I had to stop and giggle like an idiot, which made us all more excited.”
The question was recently conducted on Twitter as part of what NASA called Black Hole Week (April 12-16) crowdsourced. Among the many candidates so far: A crush. A mosh pit. A silence. A spot. A beehive. A mystery. Or a favorite of mine because of its connection to my youth: an Albert Hall with black holes.
The number of known black holes is only growing. LISA will be able to discover what are known as primordial black holes, if any, that are left over from the early Big Bang moments as well as newer ones, and the researchers “basically a black hole smorgasbord,” Dr. Holly, present -Bockelmann said. The antenna won’t fly until 2034, she added, “so it’s time to find out the term if and when we need it!” The International Astronomical Union, which governs cosmic nomenclature, has no rules for “collectives,” she added, so it is up to people to decide.
Dr. Holly-Bockelmann added that one of her personal preferences was “a void of black holes”. My own candidate is a “catastrophe” of the black holes, since the word “catastrophe” is rooted in the Latin “astro” – star – and later in the Italian term for “bad stars”.
The last week of the black hole was in the fall of 2019 when NASA replayed some of the scary sounding cosmic news about black holes exploding, eating stars, or preparing to consume their neighborhoods. Now, against the backdrop of a global pandemic, black holes offer respite and are a reminder of how small and fleeting our own problems are in the greatest plan. Black holes have become astronomical cat videos.
Last week NASA posted another smorgasbord of black hole news and public service announcements, like this animated video from NASA’s Goddard Space Flight Center.
Of course you can’t visit a black hole, but two years ago astronomers came up with the next best thing: the first picture of you. The supermassive black hole – 6.5 billion suns of vanished mass – is in the center of the galaxy Messier 87.
The image was captured in April 2017 by a worldwide network of radio telescopes known as the Event Horizon Telescope. Last month, the Event Horizon team refined this image to show the surrounding vortex of magnetic fields, causing gas and energy to flow across space at nearly the speed of light.
But there is more. During this first image from 2017, 19 other observatories in space and on the ground jointly examined this energy beam from M87. Their data has now been released along with a video of the jet, which can be seen in various types of light and at various scales from the most intimate dimensions of the black hole to intergalactic space.
The results, astronomers said, would help clarify how black holes work their violent magic, further test the predictions of Einstein’s general theory of relativity, and possibly shed light on the origin of cosmic rays.
The Event Horizon team has just completed a new series of black hole observations – in M87, in the center of our own galaxy, and elsewhere – said Shep Doeleman of the Harvard-Smithsonian Center for Astrophysics and founding director of the telescope collective.
“Every day we meet at 2 p.m. EDT to check the weather and readiness at the sites and then make the call,” said Dr. Doeleman in an email. “Sometimes it’s child’s play: good weather, everyone is ready. Or, just as clearly, the weather at key locations is terrible or there is a major technical problem that needs to be shut down. Sometimes it’s pure agony. “
If you don’t have a rocket or telescope, there’s a lot new to read about black holes. “Hawking Hawking: Selling a Scientific Celebrity” by Charles Soap is an unvarnished look at cosmologist and blackhole expert Stephen Hawking, who died in 2018. The book is rich in reports on Dr. Hawking’s Breakthroughs and His Life (and written in reverse chronological order) seeks to separate man and his science from the Einstein-like aura of insight that he allowed to envelop his public figure.
And “Black Hole Survival Guide” by Janna Levin, astrophysicist at Barnard College, Columbia University, illustrated by artist Lia Halloran, is a pocket-sized poem for these cosmic curiosities.
“Black holes are nothing,” says the opening line. In the end, Dr. Levin raised the possibility that the earth and everything that remains on it will eventually fall into the black hole at the center of the Milky Way.
“This is where our data, our scraps of quantum information, could end up,” she writes. “Everything will wash off the central vortex and flash spectacularly bright, the last desperate explosions of concentrated light in the cosmos, until everything disappears in a darkening silent storm in space-time.”
And we might as well call the whole universe the black hole graveyard. A smorgasbord of screams – just another week of the black hole.