There are no limits to travel other than those imposed by physics. On a sheet of paper – be careful, only on a sheet of paper – mathematics allows you to enter a black hole and exit somewhere else in the universe or even in a parallel universe. At the cinema “Interstellar” showed us something like this, with the authoritative advice of Kip Thorne, Nobel Prize in physics in 2017, as a guarantee of a scientifically correct screenplay.
In case you were able to go from the formulas on the paper to the real travels, Janna Levin, astrophysicist at Barnard College of Columbia University, wrote a funny “Black hole survival manual” (the Assayer, 148 pages, 16 euros) . Reading it will amaze you. Inside a black hole we enter in free fall, therefore in weightlessness. The passage through the “event horizon” that separates the “hole” from everything else is troubled, but as soon as you cross the fatal border a sensational surprise will welcome you. “The black hole – writes Janna Levin – is not an object. It is nothingness, an absence. In itself, it is pure empty space-time: without atoms, light or particles of any kind (…) to use the lexicon of physics, it is emptiness ”.
One way window
The event horizon hermetically seals the interior of the black hole, nothing can get out of it, not even light. But since everything can enter it, from the inside it is possible to look out as from an unusual one-way window. Three years ago on April 10th, an extraordinary image of the heart of the galaxy M 87 obtained with a battery of eight radio telescopes scattered around the world called the “Event Horizon Telescope” gave us an idea of this fantastic porthole. Yet, despite everything, the “domestic” flights around the corner of the house, like those of astronauts in orbit or on the moon, seem even more extraordinary to me, because there we are not dealing with photons concentrated on the pixels of a CCD. These are men of flesh and blood who risk their lives in order to broaden their knowledge.
He risked six times
Who has risked most of all, even than Neil Armstrong, is John Young: twice in orbit on the “Gemini” spacecraft, once in orbit around the Moon with Apollo 10, once for a walk and in a rover on the lunar plateau Descartes (photo above) with Apollo 16 (exactly half a century has passed: it was April 12, 1972), then back into Earth orbit with the first Shuttle flight forty-one years ago, and finally back on the Shuttle with the task of to bring Spacelab into orbit for the first time, the “seed” from which the International Space Station will sprout – thirty-nine years ago, November 1983. To get to know the greatest veteran in the history of space, there is nothing better than reading his autobiography “Forever Young”, Italian edition Cartabianca, 470 pages, € 19.90, translation by Diego Meozzi, preface by Apollo 11 astronaut Michael Collins, revision by Paolo Attivissimo; also available in e-book (www.cartabianca.com).
Seen from the press box
Young was obsessed with safety precisely because danger was his business. He became so demanding that his insistence – more than justified – was annoying for the leaders of NASA, who did everything to silence him. I was lucky enough to witness the two Shuttle launches with him as the protagonist. At about 2:00 am on April 12, 1981, John Young boarded the shuttle on ramp 39 to take off four hours later. It was the Columbia shuttle: for the first time a crew was leaving aboard an incredibly complex spacecraft never tested before: that was jumping into a black hole, not astrophysical but technological. With him was the driver Robert Crippen. No one else, crew cut to the bone. Obviously NASA wanted to limit the damage in the event of a failure. They triumphantly returned two days later. They had ushered in a new era of space travel. It was the dawn of tourism in orbit today proposed by Richard Branson, Elon Musk and Jeff Bezos.
Sun and downpour
Clouds were gathering on the horizon but a great sun was shining in Cape Canaveral on the morning of November 28, 1983 when the launch window of the STS9, the Shuttle flight that had on board the Spacelab built by Alenia in Turin, opened. Brief clearing, followed by a downpour of a tropical downpour. The powerful vibrations that shook Young and his fellow adventurers when the engines were turned on reached the press stand twenty seconds later, resonating with the spectators’ bodies. The first Spacelab’s shuttle was Columbia again. It will eventually disintegrate on its 28th voyage on February 1, 2003, due to the detachment of the heat shield tiles. We all have in our eyes the plasma cloud in which the lives of six astronauts burned. Young, on the other hand, had a long quiet retirement. He left this world on January 5, 2018. He was 87 years old, 35 days of which he spent in space in six flights spread over 18 years.
Computers and democracy
The Shuttles had five state-of-the-art IBM computers from the late 1970s on board (they were then updated following technological developments). Great redundancy. In the event of a conflict, the fifth would decide democratically. That’s the beauty of odd numbers. It makes me smile to re-read in an article of the time in “Tuttoscienze”: “Compared to the performance of the Saturn 5 computer, computers have a processing speed 40 times higher, a memory capacity five times larger, a number of instructions eight times higher, a weight reduced by one third and a volume reduced by two thirds ”.
They were boxes weighing about 20 kilograms. Today a cell phone is perhaps equivalent to a hundred of those computers.