After the collapse of science in our country, I was forced to spend a year abroad - in Cambridge, where I was born. There I was attached to Darwin College; This is part of Trinity College, of which my father was once a member. The college is mainly engaged in overseas scientists. I was given a small scholarship that supported me, and we lived in the house that my father built. It was there, thanks to a completely inexplicable coincidence of circumstances, I came across the problem of population growth.
I have previously dealt with the global problems of peace and equilibrium - the fact that made us change the point of view on the war with the advent of absolute weaponswhich can destroy all problems at once, although it is not able to solve them. But of all the global problems, in fact, the main one is the number of people who live on Earth. How many of them, where they are driven. This is a central problem in relation to everything else, while at the same time it is least solved.
It cannot be said that nobody had thought about this before. People always worried about how many of them. Plato calculated how many families should live in an ideal city, and it turned out about five thousand. Such was the visible world for Plato - the population of the policies of ancient Greece was tens of thousands of people. The rest of the world was empty - just did not exist as a real arena of action.
Strangely enough, such a limitation of interests existed even fifteen years ago, when I began to deal with the problem of population. It was not customary to discuss the problems of the demography of all mankind: just as in a decent society they do not talk about sex, so in a good scientific society they were not supposed to talk about demography. It seemed to me that it was necessary to begin with humanity as a whole, but such a subject could not even be discussed. Demographics developed from the least to the most: from the city, the country to the world as a whole. There was a demography of Moscow, a demography of England, a demography of China. How to deal with the world when scientists barely cope with areas of one country? To get to the central problem, we had to overcome a lot of what the British call conventional wisdom, that is, generally accepted dogma.
But, of course, I was not the first in this area. The great Leonard Euler, who worked in various fields of physics and mathematics, in the 18th century wrote the main equations of demography, which he still uses. And among the general public, the most famous name of another demographic founder is Thomas Malthus.
Malthus was a curious figure. He graduated from the Faculty of Theology, but he was very well mathematically prepared: he finished ninth in the Cambridge math competition. If Soviet Marxists and modern social scientists knew mathematics at the ninth grade level of a university, I would have calmed down and thought that they were sufficiently mathematically equipped. I was in the office of Malthus in Cambridge and saw Euler’s books with his pencil marks there - it is clear that he was completely proficient in the mathematical apparatus of his time.
Malthus' theory is rather slender, but it is built on the wrong premises. He assumed that the number of people grows exponentially (that is, the growth rate is the higher, the more people already live on earth, give birth and bring up children), but growth is limited by the availability of resources, such as food. Exponential growth to the complete exhaustion of resources is the dynamics that we see in most living beings. Even microbes grow in nutrient broth. But the fact is that we are not microbes.
People are not beasts
Aristotle said that the main difference between man and animal is that he wants to know. But in order to notice how much we differ from animals, there is no need to get into our heads: it is enough just to calculate how many of us are. All creatures on Earth from mouse to elephant obey dependencies: the more body weight, the fewer individuals. Little elephants, many mice. With a weight of about one hundred kilograms of us should be about hundreds of thousands. Now in Russia there are one hundred thousand wolves, one hundred thousand boars. Such species exist in balance with nature. And a man is a hundred thousand times more numerous! While biologically, we are very similar to the large monkeys, wolves or bears.
In the social sciences there are few exact numbers. Perhaps, the population of the country is the only thing that is unconditionally known. When I was a boy, I was taught in school that two billion people live on Earth. Now - seven billion. We have experienced such growth throughout the life of one generation. We can roughly say how many people lived during the birth of Christ — about a hundred million. Paleoanthropologists estimate the population of the Paleolithic people at about one hundred thousand, just as much as we expect in accordance with body weight. But since then, growth has begun: at first barely noticeable, then ever faster, explosive nowadays. Never before has humanity grown so rapidly.
Even before the war, the Scottish demographer Paul Mackendrick proposed a formula for the growth of humanity. And this growth was not exponential, but hyperbolic — very slow at the beginning and quickly accelerated at the end. According to his formula, in 2030, the number of mankind should tend to infinity, but this is an obvious absurdity: people are biologically incapable of giving birth to an infinite number of children in a finite time. More importantly, such a formula perfectly describes the growth of humanity in the past. This means that the growth rate has always been proportional not to the number of people living on earth, but to the square of that number.
Physicists and chemists know what this dependence means: it is a “second order reaction”, where the speed of the process depends not on the number of participants, but on the number of interactions between them. When something is proportional to "n-square", it is a collective phenomenon. Such, for example, is the nuclear chain reaction in an atomic bomb. If every member of the Snob community writes a comment to everyone else, then the total number of comments will just be proportional to the square of the number of participants. The square of the number of people is the number of connections between them, the measure of the complexity of the “humanity” system. The greater the complexity, the faster the growth.
No man is an island: we live and die not alone. We multiply, feed, differing little from animals, but the qualitative difference is that we exchange knowledge. We pass them by inheritance, we pass them horizontally - in universities and schools. Therefore, the dynamics of our development is different. We do not just be fruitful and multiply: we are making progress. This progress is quite difficult to measure numerically, but, for example, the production and consumption of energy can be a good criterion. And the data shows that energy consumption is also proportional to the square of the number of people, that is, the energy consumption of each person is higher, the larger the population of the Earth (as if every contemporary, from Papuan to Aleutia, shares energy with you. –Prim.).
Our development consists in knowledge - this is the main resource of humanity. Therefore, to say that our growth is limited by the depletion of resources is a very rough statement of the question. In the absence of disciplined thinking, there are a lot of all kinds of horror stories. For example, a couple of decades ago, they were seriously talking about the depletion of silver reserves, which is used to make film: allegedly in India, in Bollywood, so many films are being made that soon all the silver on earth will go into the emulsion of these films. So, perhaps, it was, but they invented a magnetic recording, which does not require silver at all. Such assessments — the fruit of speculations and voiced phrases that are intended to impress the imagination — bear only a propaganda and alarmist function.
There is enough food in the world for everyone - we discussed this issue in detail in the "Rome Club", comparing the food resources of India and Argentina. Argentina is a third smaller than India by area, but India has forty times the population. On the other hand, Argentina produces so much food that it can feed the whole world, and not only India, if it tense properly. It's not about the lack of resources, but about their distribution. Someone seemed to be joking that under socialism there would be a shortage of sand in the Sahara; This is not a question of the quantity of sand, but of its distribution. Inequality of individuals and nations has always existed, but as the processes of growth accelerate, inequality increases: balancing processes simply do not have time to work. This is a serious problem for the modern economy, but история teaches that in the past, mankind solved such problems - unevenness was leveled in such a way that the general law of development remained unchanged throughout humanity.
The hyperbolic law of human growth throughout history has demonstrated surprising stability. In medieval Europe, plague epidemics carried away up to three-quarters of the population in some countries. On the growth curve in these places, there are indeed failures, but after a century the number goes to the previous dynamics, as if nothing had happened.
The greatest shock experienced by mankind - the First and Second World Wars. If we compare the real demographic data with what the model predicts, it turns out that the total losses of humanity from two wars are about two hundred and fifty million - three times more than any estimates of historians. The population of the Earth deviated from the equilibrium value by eight percent. But then the curve for several decades steadily goes to the same path. The “global parent” proved to be stable, despite the terrible catastrophe that affected most countries of the world.
The link of times has broken
In history lessons, many schoolchildren are perplexed: why do historical periods become shorter and shorter over time? The Upper Paleolithic lasted for about a million years, and only half a million remained for the rest of human history. The Middle Ages - a thousand years, there are only five hundred. From the Upper Paleolithic to the Middle Ages, history seems to have accelerated a thousand times.
This phenomenon is well known to historians and philosophers. Historical periodization follows not astronomical time, which is uniform and independent of human history, but its own system time. Proper time follows the same dependence as energy consumption or population growth: it flows the faster, the higher the complexity of our system, that is, the more people live on Earth.
When I started this work, I didn’t assume that the periodization of history from the Paleolithic to our days follows logically from my model. If we assume that history is measured not by the revolutions of the Earth around the Sun, but by past human lives, the shortened historical periods are instantly explained. The Paleolithic lasted a million years, but the number of our ancestors was then only about one hundred thousand - it turns out that the total number of people living in the Paleolithic is about ten billion. Exactly the same number of people passed through the earth and over a thousand years of the Middle Ages (the number of humankind is several hundred million), and over one hundred and twenty-five years of modern history.
Thus, our demographic model cuts the entire history of mankind into identical (not by duration, but by content) pieces, during each of which about ten billion people lived. The most amazing thing is that such a periodization existed in history and paleontology long before the appearance of global demographic models. Nevertheless, the humanities, for all their problems with mathematics, can not be denied intuition.
Now ten billion people pass through the earth in just half a century. This means that the “historical era” has shrunk to a single generation. Not to notice this is no longer possible. Today's teenagers do not understand what it was singing thirty years ago, Alla Pugacheva: "... and you can't wait out three people at the machine gun" - what kind of machine gun? Why wait? Stalin, Lenin, Bonaparte, Nebuchadnezzar - for them this is what the grammar calls “pluperfect” - a long time past. Now it is fashionable to complain about the rupture of the connection between generations, the dying of traditions - but perhaps this is a natural consequence of the acceleration of history. If each generation lives in its own era, the legacy of previous eras may simply not be useful.
The compression of historical time has now reached its limit, it is limited to the effective generation time — about forty-five years. This means that a hyperbolic increase in the number of people cannot continue - the basic law of growth simply has to change. And it is already changing. According to the formula, today we should have about ten billion. And there are only seven of us: three billion is a considerable difference that can be measured and interpreted. A demographic transition is taking place before our very eyes - a turning point from the unrestrained growth of the population to some other way of progress.
For some reason, many people like to see signs of impending catastrophe. But the disaster here is more in the minds of people than in reality. A physicist would call this a phase transition: you put a pot of water on the fire, and for a long time nothing happens, just lonely bubbles rise. And then suddenly everything boils. So is humanity: the accumulation of internal energy is slowly going on, and then everything takes on a new look.
A good image is the rafting of a forest along mountain rivers. Many of our rivers are shallow, so they do this: they build a small dam, accumulate a certain number of logs, and then suddenly open the floodgates. And a wave runs along the river, which carries trunks - it runs faster than the flow of the river itself. The most terrible place here is the transition itself, where the smoke is a yoke, where the smooth current at the top and bottom is divided by a section of chaotic movement. This is what is happening now.
Around 1995, mankind passed through a maximum growth rate when eighty million people were born per year. Since then, growth has noticeably decreased. The demographic transition is a transition from a growth regime to a stabilization of the population at the level of no more than ten billion. Progress will naturally continue, but will proceed at a different pace and at a different level.
I think that many of the troubles that we are experiencing - and the financial crisis, and the moral crisis, and the disorder of life - this is a stressful, disequilibrium state associated with the suddenness of the onset of this transition period. In a sense, we got into the thick of it. We are used to the fact that irrepressible growth is our law of life. Our morality, social institutions, values were adapted to the mode of development that was unchanged throughout history, and is now changing.
And it changes very quickly. Both statistics and a mathematical model indicate that the transition width is less than one hundred years. This is despite the fact that it occurs simultaneously in different countries. When Oswald Spengler wrote about “The Decline of Europe”, he probably had in mind the first signs of the process: the very concept of a “demographic transition” was first formulated by Landry demographer using the example of France. But now the process is affecting already less developed countries: the growth of the population of Russia has almost stopped, the population of China is stabilizing. Perhaps the prototypes of the future world should be sought in the regions that were the first to enter the area of transition, for example, in Scandinavia.
It is curious that in the course of the “demographic transition” lagging countries are quickly catching up with those who embarked on this path earlier. The pioneers - France and Sweden - the process of stabilization of the population took a half century, and the peak came at the turn of the XIX and XX centuries. And for example, in Costa Rica or Sri Lanka, which passed the peak of growth rate in the eighties, the entire transition takes several decades. The later the country enters the stabilization phase, the sharper it goes. Russia in this sense is more likely to the countries of Europe - the peak of the speed of growth has remained behind us in the thirties, and therefore it can count on a softer transition scenario.
Of course, there is reason to fear this unevenness of the process in different countries, which may lead to a sharp redistribution of wealth and influence. One of the most popular horror stories is Islamization. But Islamization comes and goes, as religious systems have come and gone, more than once in history. The law of population growth did not change either the crusades or the conquests of Alexander the Great. The laws will also be immutable during the period of the demographic transition. I can not guarantee that everything will happen peacefully, but I do not think that the process will be very dramatic either. Perhaps this is just my optimism against the pessimism of others. Pessimism has always been a much more fashionable trend, but I’m rather an optimist. My friend Zhores Alferov says that there are only optimists left, because the pessimists have left.
I am often asked about recipes - they are used to asking, but I am not ready to answer. I cannot offer ready-made answers to pretend to be a prophet. I'm not a prophet, I'm just learning. History is like the weather. There is no bad weather. We live in such and such circumstances, and we must accept and understand these circumstances. It seems to me that a step towards understanding has been achieved. I do not know how these ideas will develop in the next generations; These are their problems. I did what I did: it showed how we approached the transition point, and indicated its trajectory. I can not promise you that the worst is over. But “scary” is a subjective concept.
Sergey Petrovich Kapitsa - Soviet and Russian scientist-physicist, broadcaster, editor-in-chief of the journal “In the world of science”, vice-president of the Russian Academy of Natural Sciences. Since 1973, he has consistently led the popular science TV program "The Obvious - The Incredible." The son of the Nobel Prize winner Peter Leonidovich Kapitsa.