At the end of October, a half-century-old dissertation on astrophysics, containing mostly outdated information, became a hit by downloads, "putting down" the site of the University of Cambridge.
What happened?
On October 23, 2017, the University of Cambridge decided to make publicly available the dissertation of the famous scientist and popularizer of science Stephen Hawking, written by him back in 1966. Think about it: 51 years ago! And suddenly the website of the university "went down". By the way, even on October 24, he periodically still "went to bed", although it was still sometimes possible to break through and download the viral dissertation - in the gaps between new failures.
Most of the media interpreted this as a sign of excitement in the scientist's work, but this is not entirely true. There are only about 70 thousand downloads, just the basic version of the pdf file weighs 72 megabytes - that's why a small university server could not stand it. If a file of a couple of megabytes or a server were more powerful, nothing would have happened.
True, no one in Cambridge even thought about such "traffic", because usually "popular" works from there are downloaded a hundred times, and unpopular ones can be counted on one hand. And it's not just that. Most of those who downloaded Hawking's dissertation are unlikely to be able to read it in full. The point is not only that it has 130 pages - more importantly, like any dissertation, it requires decent preparation on the part of the reader. And, nevertheless, its meaning can be summarized rather briefly, which we will do below.
What is this dissertation about?
Promotional video:
Hawking examines the consequences of discovering the expansion of the universe. This became known already in the 1930s and was assumed (by the way, for the first time - by a resident of the USSR) back in the 1920s. Based on the fact of expansion, the Briton analyzed the then popular Hoyle-Narlikar theory of gravity. According to her, matter appeared outside of connection with the expansion of the Universe (today it is known that just the opposite - in close connection).
This theory, as Hawking first showed then, is erroneous, since it is not compatible with the expanding Universe. It's funny that although the very hypothesis that he criticizes is wrong, his criticism … was also wrong! Today we know that the accelerated expansion of the universe makes Hawking's analysis obsolete. He did not take into account the possibility of such acceleration, which is why the calculations of the Hoyle-Narilikar incorrectness themselves turned out to be incorrect.
However, the British dissertation was written 30 years before the discovery of the accelerating expansion of the Universe after the Big Bang, and it is difficult to criticize the scientist for not knowing this fact. In the end, everyone is wrong - Einstein also did not want to believe that the Universe was expanding, this thought seemed so strange to him at first. It is not surprising that the no less exotic concept of ever-accelerating expansion did not occur to Hawking half a century ago.
By the way, shortly before the publication of his dissertation, Hawking suggested that Hoyle and Narlikar could be right - if there is something in the Universe with negative mass. Now this “something” has been replaced by dark energy - the idea of a certain substance that “pushes” space in all directions, a bit like how Hawking’s substance with negative mass does it.
In chapter two, Hawking examines the effect of the expansion of the universe on the distribution of mass in it. They touch upon the mystery of galaxies - "islands of matter" in the desert of the Universe, on one of which we also live. The author comes to the conclusion that galaxies could not arise from initially small inhomogeneities of the early Universe and there must be another explanation. Which one? Alas, this was not fully understood, either in 1966 or today. But the very idea that the mysterious heterogeneities should have been noticeable from the very beginning, is still finding new confirmation.
In the third chapter, the physicist touches on gravitational radiation - the very gravitational waves that were discovered only last year through real observations. The fourth is the problem of singularities. Its essence is that, according to existing concepts, before the Big Bang, matter should have had infinite density and temperature, being compressed into one point with zero width, height and length. In those years, many tried to somehow "get rid" of the singularity in the calculations - after all, any physical formulas with the introduction of infinite density cease to meaningfully describe events. They are simply not intended for such variables.
Stephen Hawking in 1974. Photo: EAST NEWS
Hawking, however, shows that such solutions do not actually work without a singularity. It cannot be said that since then we have advanced in understanding the issue significantly further than the candidate's half a century ago. It is still clear that the singularity may have existed, and it is still unclear whether it can be scientifically described properly.
It may seem that the main value of Hawking's dissertation is in discussing issues that have lost their relevance today (like the Hoyle-Narlikar hypothesis), or in analyzing the situation with galaxies, where he points out problems with their origin, but cannot find a solution (in fact, his are still looking for). As we can see, nothing sensational from the point of view of a person from the street. Where does this excitement come from, why was the site “put down”?
Hype Hawking
To understand this, it is worth remembering who Hawking is, and why the public knows and loves him. He made his greatest contribution to the study of black holes - bodies whose density is so high that light cannot escape from their gravitational field. Outside, they, according to logic, should be completely black - after all, even photons of light cannot fly away from them. The Briton managed to apply thermodynamics to the study of black holes and prove that they actually … radiate! Throw out photons (although very rarely). That is, strictly speaking, they are not that black.
By the way, this also means that they are not eternal, but small black holes are extremely short-lived. All their energy is converted into such radiation, and they literally "evaporate". They call it that - Hawking radiation. After all, it was he who first calculated it, as well as the fact that because of it black holes evaporate and die. Calculated … but did not open.
Yes, the Hawking radiation, as is often the case in science, was not discovered at all by the one after whom this phenomenon was named. Hawking's work on radiation ("evaporation of black holes") was published in 1974. And a year before that, he had visited the USSR. There, Soviet scientists Zeldovich and Starobinsky demonstrated to him from a theoretical point of view that photons with a wavelength longer than the event horizon of a black hole (the zone where the rest of the photons are intercepted by gravity) must overcome the gravity of the black hole due to quantum tunneling.
The essence of this effect is that a photon, according to the laws of quantum mechanics, with a certain probability can overcome a seemingly unavoidable obstacle (a mirror, or the gravity of a black hole) if its energy is above a certain level.
Demonstration of the described effect.
In fact, Zeldovich did not come up with all this himself - the idea was expressed by the Soviet physicist Vladimir Gribov, even before Hawking's arrival in the USSR. That is, the radiation should have been called Gribov's radiation - if, of course, the Soviet scientist formalized his thought in the appropriate work with the necessary calculations. Alas, he did not do this, only voicing it orally, from where Zeldovich learned about her.
Hawking also has many other works - for example, it was he who mathematically proved that "black holes have no hair." More precisely, it is impossible to learn anything about the black hole that these photons left from such photons (Gribov-Hawking radiation). It follows from this that the contents of black holes are unknowable to us - despite the fact that they occasionally emit. Even if the black hole consisted not of our matter, but of antimatter, it would be absolutely impossible to understand this by the radiation photons reaching us.
And yet, let's be honest - many interesting works among modern physicists have been written by not so few people. Smolin, Thorne, Penrose - and a whole host of others. Nevertheless, if you stop a passer-by on the street and ask what he thinks of these people, then most likely he will say that he does not know any of them. Why is Hawking so famous? There are many factors of his success, but the main one is his unusual fate and his extraordinary character as a person.
Hawking's charisma
The physicist suffers from amyotrophic lateral sclerosis. This is a very rare disease with an unclear mechanism of action, due to which motor neurons die off in humans. First comes paralysis, and then death from respiratory arrest. This terrible diagnosis was made to him in 1963. Since the doctors were just beginning to study an exotic disease, in addition, they also said that he had 2-3 years left to live. Hawking was then 21 years old, and the prospect of a somewhat premature death upset him. Then he concentrated and decided to do as much as possible in the scientific field. As the scientist honestly admits, before that he studied and worked willingly, but without fanaticism - but after the diagnosis, everything changed. When you realize that there is no more time, it becomes much easier to appreciate it.
54 years have passed since then, and the scientist is still alive. True, only the muscles in the cheek area retained his mobility. Twitching them, he controls a specially modified computer that synthesizes signals from the physicist's muscle into words. In this laborious way, the researcher communicates at scientific conferences and even lectures to the general public. He is perhaps the most famous person with a disability among living scientists - and the most successful in overcoming such a serious illness. Of course, a theoretical physicist with such peculiarities is more likely than others to get the attention of the media and the “broad masses”.
Well, here the second component of Hawking's popularity "shoots out" - modern science pop. Sadly, it has its own laws, among which the media and hype of the character you are writing about is almost the main factor that determines whether it is worth writing about him at all. Who knows about Gribov, who suggested the radiation of black holes? No one, he died in 1997, virtually unknown outside of academia. Zeldovich, once a very "media" physicist of the Soviet era, is also, let's say, not too much of a rumor today. Yes, Hawking is very well able to create analogies accessible to people of different professions, but the cosmologist Novikov knew how to invent them just as well … What is the only brilliant explanation of the physical nature of time travel to them - the famous Novikov principle!
Of course, this does not mean that a scientist must necessarily be disabled for popularity. There is also the Higgs (the Higgs boson), or the astronomer Mike Brown (the planet Batygin-Brown, it is the ninth planet). But if you have not discovered the particle that determined the parameters of literally everything in the surrounding world or a new planet in the solar system, it will not be easy to count on popularity. A person who does not give up before a serious illness twenty times longer than doctors expected is, perhaps, a worthy candidate for such "atypical celebrities."
ALEXANDER BEREZIN