I still remember well. I had just turned 14. My parents explained to me that I was no longer a child to receive presents on my birthday. I agreed, in silence. It was the end of the 80s, and I understood life was hard.
By D., from Russia.
I think they felt bad for me because they asked what was it that I wanted so badly. I said I wanted Stephen Hawking’s new book, A brief history of time. I was the youngest member of the astronomy club in the local Planetarium, and I had heard about Hawking.
My like for astronomy was born in my early years. I had several books on the subject, and I read them over and over again. I loved to spend the night looking at the sky. I did not want a video game or new shoes like my schoolmates; I had asked for a physics book. That must have caused an impression on my parents because they bought me the book.
I was a privileged child, I won many presents from my parents. But this is the one that I truly remember. I think it was the best present I ever got. So, I left all my super-heroes comics aside and “ate” my new book. The prologue was by Carl Sagan, already known for the documentary Cosmos.
A year and a half later, I was admitted to the Physics School. Stephen Hawking and Carl Sagan were my first real super-heroes. I would later discover a few more.
Stephen Hawking and the Black Holes
Stephen Hawking’s biggest scientific discovery, the one that made him famous, is on black holes. Black holes are the most extreme state of matter, a product of the gravitational collapse of an enormous amount of mass, like big dying stars. Gravity is extremely high around it, and it attracts to it everything that’s close. Not even light escapes – that’s why it is called “black hole.”
Hawking discovered that black holes are not completely black, as they have thermic radiation – so they can evaporate completely. The discovery of this Hawking Radiation could have won a Nobel Prize if experimentally proven, but it is too dim to be measured with our current technology.
So, why is an undetectable radiation of an exotic, distant and invisible object that we only know indirectly so important – up to the point that many consider Stephen Hawking the greatest physician since Einstein? I do not know if he was the greatest physician of our times, there is a high dispute on this title. But, definitely, Hawking Radiation has a major importance for physics as much as for our general understanding of the world, even for those not familiarized with the Theory of Relativity neither with Quantum Mechanics.
Even Hawking believed that black holes represented the end of matter’s existence. A black hole was the alleged physical proof that all movement would one day come to an end. In fact, if gravity is so powerful in a black hole to defeat the repulsion of particles that make a body, nothing else could stop it and so this body would be reduced to volume zero, with infinite density. Technically speaking, a singularity. So yes, the end of matter, and even of space and time.
But Hawking showed that this reasoning was incomplete – gravity is just part of reality, and we cannot leave aside the effects of Quantum Mechanics. If we consider these, we get the Hawking Radiation, and so the black hole is no longer completely black. The movement of matter defeats gravity and emerges from the inside of a black hole.
So, it was clear that a black hole was just another form of matter in motion, and that this movement was still indestructible. Like this, Hawking brought light to our understanding. The most mysterious object in the universe was a little less mysterious, and not so dark anymore.
Hawking’s discovery might have been the first victory in the hard task of combining the Theory of Relativity with Quantum Mechanics. Hawking was also the first one to approach black holes as thermo-dynamic objects, what made it possible to achieve several advances in the understanding of these two sciences and its relationship. In fact, we can say that the serious study of black holes began with Hawking, who had the courage to study a subject that was ridiculed by many, back then.
The Big Bang and the Nature of Time
These discoveries shocked me at 14, but there were many other ideas in his work. One thing in particular, the study of the nature of time, would shock me even more.
Until Hawking, the Big Bang was understood as the beginning of the universe, space and time – so the per se Creation of everything that exists. Just like a black hole was the end of everything, the Big Band was the beginning of everything.
In a conference on physics organized by the Vatican, Pope John Paul II said to the physicists present that there was no problem with them studying the Big Bang, but they should avoid studying the pre-Big Bang, as this was the Church’s field. Hawking, present at this Conference, left the room decidided to ignore the “advice”. He worked on a model that considers time as something not linear but bi-dimensional, a complex magnitude as it is called in Mathematics.
If time seems linear to us today, in the past closer to the Big Bang there was another dimension of time, and the one that we know today – creating the idea of “the beginning of times” – was irrelevant. In other words, time and the universe did not emerge at the Big Bang; this was some kind of transition from a previous form of existence of the universe to the current one. The current astronomic/cosmologic form of the universe might have emerged with the Big Bang but it was preceded by another form of existence of matter in its eternal movement. This was just a hypothesis – still not confirmed until the present – but it was the first time that someone questioned that the pre-Big Bang was not something to study.
To measure the importance of this idea, Hawking himself affirmed that, until then, he believed that science had a place saved for God. A privileged place that our physics could never reach – the beginning of everything. After this hypothesis, he realized that the universe did not need God to explain it – that our physics, even incomplete, could do that. Until the present, so many years later, this idea is highly inspirational to me.
I have absolutely no doubt that Hawking’s tireless search for the truth, many times against everything and everyone, inspired me deeply when I was 14. One year later I would become a Marxist, moved by the same search for truth.
Opposite to the many myths, Hawking called himself an atheist. He was an activist against the Vietnam War. Republican, he rejected the title of Sir offered by the Queen of England. He supported Human Rights and the rights of the minorities; he was a declared enemy of any dictatorship; he criticized British colonialism; he was opposed to the Margaret Thatcher government; he fought against the privatization of the British health system. In solidarity to the Palestinian cause, he boycotted a scientific conference in Israel, affirming that Israel was the South Africa of apartheid. He said capitalism was the biggest threat to the future of humanity. He was known for his deep optimism and sense of humor. All of this in a wheelchair. So we could say he was, at least, a fine man.
Translation: Sofia Ballack.