What do you call a bunch of black holes: a crush? A scream?

What do you call a black hole? Whatever you want, the old joke works, as long as you don’t call her late for dinner. Black holes, after all, are nothing but starvation.

But what do you call a collection of black holes? The question took on an urgency among astronomers inspired by recent news of dozens of black holes buzzing around the center of a nearby group of stars.

In recent years, instruments such as the LIGO and Virgo gravitational wave detectors have recorded space-time vibrations from black hole collisions, making it clear without a doubt that these monstrous concentrations of nothingness not only exist, but are ubiquitous. Astronomers anticipate detecting a large number of these Einsteinian creatures when the next generation of gravitational wave antennas is implemented. What will they call them?

There are gangs of geese, whale pods and crows. What term would justify the special nature of black holes? A table? A colander? A scream?

Jocelyn Kelly Holley-Bockelmann, an astrophysicist at Vanderbilt University, and her colleagues are developing an international project called the Laser Interferometer Space Antenna, or LISA, which will be able to detect collisions between all dimensions of black holes in the universe. She recently tried to hold a Zoom meeting of the group “when one of the members said that his daughter was wondering what you call a black hole collective – and then the meeting broke up, everyone trying to get up with each other,” she said. in an email. “Every time I saw a suggestion, I had to stop and giggle like a meadow, which prompted us all to more.”

The question was crowdsourced on Twitter recently, as part of what NASA began calling Black Hole Week (April 12-16). Among the many candidates so far: A crush. A mosh pit. A silence. A stain. A hive. An enigma. Or a favorite of mine for his connection to my youth: an Albert Hall with black holes.

The number of known black holes will only increase. LISA will be able to detect the so-called primordial black holes, if any, left over from the first moments of the Big Bang, as well as the most recent ones, by presenting researchers with “practically a black hole smorgasbord”, Dr. Holly said Bockelmann. The antenna will not fly until 2034, she added, “so it’s time to figure out if we need it!” The International Astronomical Union, which regulates cosmic nomenclature, has no rules on “collectives,” she added, so it is up to people to decide.

Dr. Holly-Bockelmann added that her personal preferences include “a” hole “in black holes.” My own candidate is a “disaster” of black holes, because the word disaster is rooted in the Latin “astro” – star – and, later, in the Italian term for “stupid star”.

The previous week of the black hole was in the fall of 2019, when NASA aired some of the most frightening cosmic news, involving the explosion of black holes, eating stars or preparing to consume its neighborhoods. Now, against the backdrop of a global pandemic, black holes provide a respite and a reminder of how small and transient our problems are in the grandest scheme. Black holes have become the astronomy cat videos.

So last week, NASA offered another soul of black hole news and public service announcements, such as this animated video from NASA’s Goddard Space Flight Center.

Of course, you can’t make a black hole, but two years ago astronomers offered the following: the first image of one. The supermassive black hole – a missing mass of 6.5 billion suns – is at the center of the Messier 87 galaxy.

The image was taken by a global network of radio telescopes known as the Event Horizon Telescope in April 2017. Last month, the Event Horizon team refined that image to show the whirlwind of magnetic fields flowing gas and energy through space at near the speed of light. .

But there are more. While the first image from 2017 was being taken, another 19 space and ground observatories were studying this M87 energy jet together. Their data has now been published along with a video of the jet, as seen in different types of light and at different 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 theory of general relativity, and shed light on the origin of cosmic rays.

For its part, the Event Horizon team has just completed a new series of observations of black holes – in the 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 team. telescope.

“Every day we gather at 14:00 EDT to analyze all the weather conditions and the preparation on the sites, then to make the call,” Dr. Doeleman said in an e-mail. “Sometimes it’s a piece of cake: good weather, everyone is ready. Or, just as clearly, the weather on key sites is awful or there is a major technical issue that needs to be addressed. Sometimes it is pure agony. ”

If you don’t have a rocket or a telescope, there are many new things to read about black holes. “Hawking Hawking: Selling a Science Star,” by Charles Seife, is a non-vernacular look at cosmologist and black hole expert Stephen Hawking, who died in 2018. The book, rich in the account of Dr. Hawking’s discoveries and his life (and written in reverse chronological order), tries to separate man and his science from the aura of Einstein-like sagacity that he allowed to envelop his public figure.

And “The Black Hole Survival Guide,” by Janna Levin, an astrophysicist at Columbia University’s Barnard College and illustrated by artist Lia Halloran, is a pocket-sized poem for these cosmic curiosities.

“Black holes are nothing,” reads the opening line. In the end, Dr. Levin considers the possibility that the Earth and all that remains on it will eventually fall into the black hole in the center of the Milky Way.

“This is where our data, the remnants of quantum information, can go,” she writes. “Everything will wash away the central whirlpool, shining spectacularly bright, the last desperate bursts of concentrated light from the cosmos, until everything disappears in a silent and dark storm in space-time.”

And we might as well call the whole universe a graveyard of black holes. A smorgasbord of screams – just another week of black hole.