I buchi neri, così come gli atomi, ballano. Quando due galassie collidono, invece di scontrarsi frontalmente, iniziano una danza.
Mentre siamo impegnati a confonderci nelle nostre illusioni, mentre dimentichiamo di essere esseri umani, mentre discutiamo del nulla e degli inutili perché, l’universo danza.
Un valzer lento dal pensiero leggero. Un valzer che sa di serenità. Un valzer che sa di armonia. Lo dice la scienza*, non solo la poesia. E poi sì, questi buchi neri si scontreranno e annulleranno vicendevolmente per dar vita a un nuovo spettacolo.
L’intera essenza che ci circonda si muove a suon di musica, danzando. Dall’infinitamente piccolo, all’incantevole immenso, siamo fatti e siamo avvolti da leggera, musicale, armonia.
E allora perdono senso i nostri scontri, le nostre barriere, i nostri confini ideologici. Perdono senso le barricate al Brennero così come le urla che – tirando in ballo, a sproposito, l’antropologia – definiscono contro natura gli esseri umani che solo vogliono amarsi e aver uguali diritti. Perdono senso le occhiate di odio e disprezzo verso chi cerca solo di vivere sotto il nostro stesso tetto… quello dell’atmosfera terreste. Perdono senso i giudizi di disprezzo verso uno stile di vita differente dal nostro.
E allora si ridimensionano e perdono peso i ridicoli dibattiti dai banchi dei Consigli comunali a quelli del Parlamento.
E allora tutto torna all’essenza, essenza che cerca verità e pace.
L’universo, ci insegna. L’universo è dentro di noi. Siamo fatti della stessa sostanza degli atomi e delle galassie. Siamo esseri danzanti. Esseri danzanti che devono tornare, realmente, a danzare. A stringersi e intrecciarsi nell’unica vera forza possibile, la fratellanza.
Chiudiamo gli occhi per un instante infinito e respiriamo, assaporiamo e viviamo l’eterno danzare del nostro universo.
But when astronomer Julie Comerford investigates the glowing gas surrounding these giant black holes, she finds something totally unexpected. There’s a cosmic dance going on, on a scale that’s almost unimaginable. «You saw two peaks in the light instead of just one. You’d expect one from one black hole that’s just sitting at rest in its galaxy, but we saw two peaks with different velocities. And that immediately hit us, as this as got to be something interesting».
Julie began thinking about what would happen when two galaxies collide. And if both had black holes at their centers, what would happen to those massive objects?
« So, when two galaxies collide, the black holes at their center, instead of crashing in head-on, they begin this swirl, or dance. And the way that we can detect these waltzing black holes, is by lookink at the light that’s emitted from them. So, for the black hole that’s moving towards us, we detect light that is at smaller wavelengths, scrunched up together, so we see bluer light. And for the black hole that’s moving away from us, we see stretched-out longer-wavelenght light that appears redder. So it’s this redder and bluer light that is a telltale signature of a black-hole waltz. Every time we see it, we high-five in the observation room, and you just can’t get over it».
As Julie scans the universe, she finds the same remarkable dance happening time and time again. In galaxy after galaxy, black holes are paired up and dancing the cosmic night away.
«So, we identified 90 galaxies from when the universe was half its present age, and we found that fully 32 of them, or about a third, had black holes that exhibited this blue-and-red signature. So that was really surprising. That such a high fraction of the black holes were not stationary at the center of the galaxy at all, that they were undergoing this waltz with another black hole».
Scientists like Janna Levin belive the discovery of waltzing black holes opens up a whole new way to learn what’s inside them, because their dance might not only be visible. It could also be audible.
The scientific visionary Albert Einstein saw space and time as a flexible material that could be distorted by gravity. A black hole is merely a very deep well in this material. When to black holes come close to one another, these two orbiting wells stir up space-time and send out ripples that can travel clear across the universe.
«And these waves will move out through the universe, travelling at the speed of light. So we can hope to not see black holes with light but maybe, in some sense, hear them if we can pick up the wobbling of the fabric of space-time itself ».
For the past several years, Janna and her colleagues have been trying to predict the sound black holes make as they spin around one another. The calculations are not for the faint of heart. Modeling what happens when two giant objetcts create a storm in the sea of space-time takes some serious math and months of supercomputing.
«This is the orbit of a small black hole around a bigger black hole, and it’s literally making a knocking sound on the drum, where the drum is space-time itself. Weel, it really sound like a knocking. It starts to get a higher frequency and happen faster, until it falls into the big black hole and goes down the throat. And then the two will ring out together and form one black hole at the end of the day. And then it just sort of you know, brr, chirps up».
Because black holes stir up the space and time around them so much the orbit of one black hole around another looks nothing like the orbit of Earth around the sun.
«An orbit can come in around a black hole and do an entire circle as it loops around before it moves out again. So instead of getting an oval, you get a three-leaf clover that processes around».
This cloverleaf pattern keeps coming out of the simulations. Janna was shocked because this picture of how two of the heaviest objects in the universe move around one another bears an uncanny resemblance to the way two of the lightest objects move around one another the tiny protons and electrons inside an atom.
«We can build a kind of classical atom out of a big black hole, like a nucleus, and a light black hole which acts like an electron. And together, they form a real atom, in a sense».
How could an object that weighs so much behave like a subatomic particle that weighs so little?
«When we talk about ordinary objects, or people even, they are never exactly the same. I mean, you cloud try to clone me, and still the different copies of me would not be exactly the same. In that sense, people and ordinary objects, are not like fundamental particles. They’re distinguishable. But the black hole is quite different from that. Black holes are like fundamental particles, and that’s very surprising because they’re huge, macroscopic objects».