Thursday, November 21, 2024

Scientific productivity is declining

String Theory

A team of Chinese and American researchers published on arXiv an article in September 2024 summarizing their study of the development of science and technology over more than two centuries. The study analyzes 213 million scientific articles published between 1800 and 2020, along with 7.6 million patents granted between 1976 and 2020.

The result of this study is the following: while the number of scientific publications has grown exponentially, the knowledge obtained by humanity grows linearly; in other words, the speed of knowledge acquisition is constant and does not grow in the same proportion as the number of publications.

Thursday, November 14, 2024

Was Teilhard de Chardin persecuted for defending evolution?

Pierre Teilhard de Chardin

In a previous post I have mentioned some myths related to the persecution of scientists as a result of their scientific ideas, for religious reasons. I mentioned, for example, Giordano Bruno and Miguel Servet, wrongly presented as martyrs of science, when in reality they were persecuted for their religious ideas, not for their scientific activities, which in the case of Bruno were practically non-existent.

The presentation of a recently published video publicizes one of these myths, also widespread: the claim that Teilhard de Chardin was repressed by his Jesuit order for advocating evolution. That this is false can easily be deduced from the fact that Teilhard was able to publish dozens of articles on the evolution of the ancestors of man in scientific and philosophical journals of impact, without being prevented from doing so by his order. One of these journals was Études, edited by the Jesuits. A curious way of repressing him for advocating evolution.

Thursday, November 7, 2024

Successes and failures in biological and environmental conservation

Usually, when the media talk about environmental conservation and endangered species, the news they give is almost always negative: Everything is going very badly; there are ever more species at risk of extinction; human activities are corrupting the environment; our planet is in danger of becoming a wasteland incompatible with life… Actually, when we say the highlighted phrase, we are using the trope called synecdoche in the form called macrocosm, that is naming the whole by the part, because it is not the planet that is in danger, but us, human beings, along with many other living beings.

I have just read a book published in 2012, written by Andrew Balmford and entitled Wild hope: on the front lines of conservation success, which tries to emphasize the opposite: not all the news is negative; lately there have been a few successes in the conservation of animal species in danger of extinction, or of environments endangered by human voracity. His analysis of these cases points to shortcomings in environmental conservation processes led by politicians, which sometimes achieve exactly the opposite of what they intended, as I indicated in this blog in a post published almost six years ago, entitled The ecological ignorance of ecologists.

Thursday, October 31, 2024

Boethius, time and eternity

Medieval manuscript of
Consolation of Philosophy

1,500 years have passed since the death of Boethius, but the event has gone unnoticed. A century ago, this would not have happened, as history was still being studied. In our times, however, history is despised. And we know what happens to those who despise it, in a phrase attributed to George Santayana: those who do not remember the past are condemned to repeat it.

Anicius Manlius Severinus Boethius was a politician and philosopher of the 5th and 6th centuries, who held important positions in the Ostrogothic kingdom that emerged in Italy shortly after the fall of the Western Roman Empire. In his political activity, Boethius was successively senator, consul and advisor to the Ostrogothic king Theodoric.

Thursday, October 24, 2024

Truth versus usefulness

Alvin Plantinga

As I said in a previous post, natural selection is the statistical observation that, in general, individuals better adapted to their environment tend to leave more descendants than those less adapted. It is, therefore, a question of usefulness. A trait that will increase the reproduction of an individual is, in principle, statistically favored by natural selection.

In my popular science book published in Spanish (Biological evolution and cultural evolution in the history of life and man) I mentioned that 

Evolution acts in the same way, both on life and on culture, although its way of acting is adapted to the specific environment on which it is applied (genes, nervous systems or cultural elements)

Thursday, October 17, 2024

Is research on LLM AI slowing down?

John McCarthy

It looks like the fate of the field of computer technology, wrongly called artificial intelligence, is to alternate between excessive optimism and unbridled pessimism. Here is a sketch of the history of this technology:

  1. At the Dartmouth College summer school in 1956, the name artificial intelligence was proposed for computer programs that could perform tasks that had traditionally been considered exclusively human, such as playing chess and translating from one human language to another. The attendees, led by John McCarthy, predicted that within ten years these two problems would be solved. They hoped that by 1966 there would be programs capable of beating the world chess champion, and others that could translate perfectly between any two human languages. When these objectives were not achieved so early, research into artificial intelligence stopped. At universities, research topics in this field were frowned upon, because they were thought to have no future.

Thursday, October 10, 2024

The kingdom of lies

Abraham Lincoln

 Abraham Lincoln is credited with having said this:

You can deceive some people all the time. You can deceive everybody part of the time. But you can't deceive everybody all the time.

When I was young, if a politician was caught lying, he must resign, because he had deceived the people. This was true back then. Famous politicians who resigned during that time because they had lied included John Profumo, the British minister, in 1963, and Richard Nixon, the US president, in 1974.

This is quite rare now. Today, politicians who resign when they are caught lying are not the rule, but the exception. Many politicians lie whenever they speak, they know that everyone knows that they are lying, but don't care about it. This is an example of the discredit into which the concept of truth has fallen, which was one of the most important criteria in history, not just for politics, but for science and all forms of human thought.

Thursday, October 3, 2024

Religious persecution of scientists?

William Harvey

This summer, Jesús Lizcano published an article in El Imparcial entitled. A memory for the scientists persecuted in history (my translation). He classifies the persecuted scientists into three groups: a) persecuted for political reasons; b) persecuted for religious reasons; and c) persecuted for reasons of sexual orientation. Here I am going to refer to those in the second group, which I find debatable.

Of course, among the eleven scientists persecuted for religious reasons, according to Lizcano, Hypatia and Galileo could not be missing. They are mentioned once and again, often with obvious exaggerations, as shown by the fact that many people believe that Galileo was burned alive by the Inquisition, when in fact he was sentenced to house arrest, softened over time. But here I am going to talk about the other nine mentioned in the article.

Thursday, September 26, 2024

Information paradoxes

Woody Allen

As I have mentioned before, time travel, if it were possible, would cause many paradoxes. In a previous post I mentioned the paradox of unsourced information, which can be summarized thus:

A time traveler who lives in time 3 knows that a person A said or did something at time 2, prior to time 3. 

The traveler goes back from time 3 to time 1, prior to time 2, where he meets A. 

While they are together, the traveler suggests person A the idea of ​​doing or saying what he knows that person will do or say in the future, which has not yet taken place. 

Whose idea was it originally? Not the traveler’s, because he learned it from the history of person A at time 3. Not from person A, because the traveler suggested the idea to person A at time 1. 

The information in question has come out of nowhere, without anyone having thought it out.

The following diagram explains it.

Thursday, September 19, 2024

Mistakes regarding natural selection

Charles Darwin

Since Charles Darwin coined this term, and included it in the title of his famous book, published in 1859, the term natural selection has been poorly understood, especially by non-specialists. Let’s review a few of the most frequent mistakes:

  • Natural selection is a force that acts on living beings to cause evolution. This is not true. Natural selection is not a force, nor an object, nor an interaction, nor a phenomenon. It is simply a statistical observation. What is observed is the fact that, in general, individuals better adapted to their environment tend to leave more descendants than those less adapted. Nothing else. It is, therefore, a matter of common sense, not the result of the external action of a mysterious force.

Thursday, September 12, 2024

Longevity and aging

Almost eight years ago I wrote a post on this topic in this blog, which contained a figure that I built starting from data provided by the Spanish Institute of Statistics, which showed mortality data for Spain in three different years: 1900, 1991 and 2013. The three curves in the figure represent the percentage of people who have reached a certain age and will die during the next year. I’m showing here an equivalent figure, with updated data that correspond to the years 1900, 1991 and 2022, as we now have more recent data.

As I said then, the figure shows that medical advances have reduced mortality, especially at the beginning and the end of life, but their effects are little noticeable for people between 20 and 40 years old. The mortality curve, which in 1900 was U-shaped, is approaching an inverted L, with a very low rate for almost all of life and a fairly abrupt rise after age 80.

Thursday, September 5, 2024

Singularities

Hal 9000, from the film
2001, a space odyssey

A singularity is a mathematical concept applied to a function of a variable that reaches an infinite value for one or several finite values of its independent variable.

For example, the function y=1/x presents a singularity for x=0, since it is often said that 1 divided by zero is equal to infinity.

Wednesday, August 28, 2024

What happens with cholesterol?

Cholesterol is an essential lipid, used to build the membrane of many of our cells. In addition, various steroids, bile acids and vitamin D are synthesized from cholesterol within the body. High cholesterol increases the chances of suffering from heart attacks and strokes. On the other hand, too low cholesterol is associated with depression that can even lead to suicide.

When someone says: I have had an analysis and it turns out that I have cholesterol, we should answer: If you didn’t have cholesterol, you’d be dead. What you have is high cholesterol.

Wednesday, August 21, 2024

Is science taught correctly?

According to many evaluations, education at the elementary and secondary levels is faulty. Every year, students arrive at the university knowing less, which makes it necessary to lower the level at the university or use desperate remedies, such as the implementation of level zero courses.

On the other hand, textbook publishers sometimes launch a race. Secondary education is supposed to provide students with general, non-specialized training. However, in some subjects, such as chemistry and biology, students may be made to learn questions or solve problems that should be encountered in college, several years later. It seems a contradiction that they are forced to learn more, but actually get out knowing less.

Wednesday, August 14, 2024

Inventing worlds

Isaac Newton

Physicists seem to have lost touch with reality. Instead of figuring out how the universe works, they dedicate themselves to designing possible universes, an activity that possibly they find pleasurable, but which doesn't seem very practical. The worst thing is that they often insist that their imaginary universes are real, putting speculations above experimentation and transgressing one of the fundamental principles of the scientific method: theories must adapt to facts, not the other way around.

One of the weak points of modern physics is the difficulty of explaining the passage of time. Since Newton’s theory, but especially with Einstein’s relativity, our physicists have not been able to deal with time. This happens, despite the fact that other conceptions of physics, such as thermodynamics and quantum mechanics, require unidirectional time: quantum superposition and collapse make no sense except with the hypothesis of irreversible time.

Wednesday, July 3, 2024

A few trivia about the fine structure constant

Clifford Pickover

In a post I published in this blog over three years ago, I talked about the fine structure constant and some of its physical peculiarities. In this post I am going to talk about some of its mathematical peculiarities. I have taken them from a book I have mentioned on other occasions: A Passion for Mathematics, by Clifford A. Pickover.

As we know, the most exact value of this constant is this:

α = 1/137.035999206

Pickover points out that Eric W. Weisstein, in his World of Physics website, offers two mathematical approximations incredibly close to this value:

Thursday, June 27, 2024

Black holes or gravastars?

As I explained in a previous post, our two fundamental physical theories, general relativity and quantum mechanics, predict infinities that physicists don’t like. General relativity does this in gravitational singularities: the Big Bang and black holes. Quantum mechanics, in vacuum energy and the quantities that must be renormalized in quantum field theory.

Until a little time ago, the theory of black holes, formulated by Subrahmanyan Chandrasekhar in 1930, stated the following: when a star 30 to 70 times more massive than the sun undergoes a supernova explosion, it expels most of its mass, but a part of it (at least 3.8 times more massive than the sun) collapses to such a point that it occupies zero volume, and so it will have an infinite density.

Thursday, June 20, 2024

The dream of antigravity

Man has always wished to be able to fly. Seeing how birds do it and not being able to do it has obsessed him, to the point of causing quite a few accidents. It is a craving that even very young children know. Some mishaps caused by the viewing of the movie Superman at the end of the seventies may be proof.

At the end of the 19th century, two fundamental interactions were known: electromagnetic and gravitational. In one respect, both are quite different. Electrically charged bodies can have a positive or a negative charge. A positive and a negative charge attract each other; two positive or two negative charges repel each other. Likewise, magnetic bodies have two ends with magnetism of a different type, north and south. If we bring two magnets together, the north end of one and the south end of the other attract each other; ends of the same type repel each other.

Wednesday, June 12, 2024

Does science explain everything?

William Shakespeare

Scientism is the philosophical theory that affirms that science is the only valid source of human knowledge. Taken literally, this statement sometimes leads to absurd conclusions. Perhaps the following case is an example of scientism. I’ve taken it from a recent article by Joseph Pearce entitled Shakespeare and Science.

Kathryn Harkup, British doctor in chemical sciences and science communicator, has published several books analyzing various literary works from the point of view of science. I don’t know if Harkup is a case of scientism, but her emphasis on science makes me think that perhaps she is. She has recently published a book titled Death by Shakespeare, where she criticizes how Shakespeare presents death in his plays, based on what she believes science modern knows about death. Pearce highlights two examples, which show some of the absurd conclusions caused by basing only on science.

Wednesday, June 5, 2024

Contradictions of naturalism

Mary Midgley

Several times I have pointed out some of the contradictions stated by naturalist philosophy and its different variants: materialism, reductionism, physicalism, scientism, etc. In the previous post I pointed out that Raymond Tallis has detected two important contradictions that he calls darwinitis and neuromania. In this post I am going to bring together a few more, because when one sees them together their power is multiplied. Here are those I have selected:

  • Science is the only valid source of human knowledge: Which science has reached this conclusion? Physics? Biology? None of the sciences. Therefore, if what this statement says is true, this statement must be false. We arrive at a contradiction. On the other hand, if this statement is false, there is no problem. Ergo, this statement is false. Therefore, scientism (and thus naturalism) is false.

Thursday, May 30, 2024

Neuromania and Darwinitis

Raymond Tallis

Chapter 11 of the book The Naturalist Worldview of Moisés Pérez Marcos, which I discussed in the previous post, is dedicated entirely to the philosopher and neuroscientist Raymond Tallis, who despite his atheistic religious stance opposes some of the modern exaggerations of reductionist naturalism. Tallis published a book in 2011 titled, significantly, Aping Mankind: Neuromania, Darwinitis and the misrepresentation of humanity. This book describes two very widespread philosophical pathologies, which emerge from professional journals and educated colloquiums to discussions in the pub or TV screens. (Pérez Marcos, paraphrasing Tallis). They are the following:

Thursday, May 23, 2024

Naturalism or naturalisms

La cosmovisión naturalista (The Naturalist Worldview) is a monumental book, written in Spanish by Moisés Pérez Marcos, about naturalist philosophies. As with the multiverse, of which there are many different theories, usually incompatible with each other, there are (almost) as many naturalistic philosophies as there are naturalistic philosophers. In other words, they don’t agree among themselves.

The first thing to do when confronted with naturalism is to try to define it and differentiate it from related worldviews:

Thursday, May 16, 2024

Will the multiverse change the scientific method?

Antony Flew

These are my last comments on Man Ho Chan’s article, which reviews and refutes recent attempts to make multiverse theories scientific. Here I’ll deal with those attempts that propose renouncing the scientific method to make the theories of the multiverse scientific. This group of proposals, the most radical, can be summarized as follows:

  • Epistemological anarchy: Proposed by Feyerabend in 1988, it argues that science is an essentially anarchic enterprise: theoretical anarchism is more humanitarian and more likely to foster progress than its law-and-order alternatives. In other words: We had better give up applying the scientific method, lest we miss some pseudoscientific theory that could have been useful. 

Man Ho Chan comments this: It is doubtful that multiverse theories can make any real scientific advancement. In some versions of multiverse theories, they suggest that all that can happen happens. In other words, these versions can explain everything. If a theory can explain everything, it does not lead to any scientific advancement… Therefore, it seems that multiverse theories are passively driven by empirical findings or theoretical constructions rather than actively leading to any new scientific advancement.

Thursday, May 9, 2024

Will the multiverse cause a change in the scientific paradigm?

Thomas Kuhn

I continue my comments on Man Ho Chan’s article, which reviews and refutes recent attempts to make multiverse theories scientific. In this post I’ll refer to those attempts that try to modify the current scientific paradigm to include the theories of the multiverse, so that they can be considered scientific. To do this, epistemological changes or scientific paradigm changes should be made.

According to Thomas Kuhn, there are five criteria that make it possible to evaluate the paradigmatic character of a theory:

  1. Accuracy: Indicates whether the predictions of the theory agree with experimental data discovered after the theory is formulated. This criterion is similar to falsifiability in the Popper-style theory, and corresponds to what I have called in another post validation of the theory. It is clear that multiverse theories do not meet this criterion, since they do not make testable predictions.

Thursday, May 2, 2024

Are the multiverse theories scientific?

Virgo galactic cumulus

In previous posts I have said that the theories of the multiverse (there are several, some of them contradictory to the others) are not scientific, because it’s not possible to prove them false, according to Karl Popper’s criterion: a theory is not scientific unless it can be proved false with an experiment.

A recent article by Man Ho Chan reviews and refutes various attempts to claim that multiverse theories are indeed scientific. Here I am going to speak about those that try to prove that the multiverse theories should be considered scientific without asking big changes to the current criteria. Carroll 2018 uses three main arguments to justify this:

Thursday, April 25, 2024

Quantum paradoxes

The Copenhagen interpretation of quantum mechanics causes paradoxes, at least apparent, when one tries to apply it to the macroscopic world. These two are the best known:

  • Schrödinger’s cat paradox. A live cat, a radioactive atom, a vial filled with hydrocyanic acid, and a device that breaks the vial if the radioactive atom decays are placed in an opaque box. If the vial is broken, the cat dies. If it isn’t broken, the cat lives. While the box is closed, the Copenhagen interpretation of quantum mechanics tells us that the radioactive atom is in a superposition of states, decayed and intact, until someone checks it, at which point the superposition of states collapses into one of them. But then, while the box is closed, the cat must be in a superposition of states: alive and dead. Can a cat be alive and dead at the same time? Intuition denies it, but the Copenhagen interpretation of quantum mechanics asserts it. As its name indicates, this paradox was proposed in 1935 by Erwin Schrödinger, one of the fathers of quantum mechanics.

Thursday, April 18, 2024

The aliens are coming!

Before the 20th century, some philosophers considered the possibility of the existence of intelligent aliens, from outside the Earth. We can cite Lucretius (De Rerum Natura, book II, 1st century BC), Nicholas of Cusa (15th century), and Giordano Bruno (16th century). The idea was happily adopted by science fiction writers, such as Lucian of Samosata (Vera Historia, 2nd century) and Cyrano de Bergerac (Comic History of the States and Empires of the Moon, 1656), of whom I spoke in another post.

During the 19th century, public attention focused on possible intelligent inhabitants of other bodies in the solar system, especially the moon and Mars. In 1835, The Sun newspaper published in New York six false reports declaring that flying men had been discovered on the moon. It is said that nine out of ten Americans believed it. In fact, The Sun had published a science fiction novel as though if it were real news, making reference to existing people, such as the astronomer Sir John Herschel. Near the end of the century, The War of the Worlds by H.G. Wells (1898) raised the possible existence of Martians, at the time of the scientific controversy over the canals of Mars, which was not finally solved until 1965.

Thursday, April 11, 2024

Impossible? Perhaps not!

Lord Kelvin

Throughout the history of science there have been proofs that something is impossible. These proofs are usually true in mathematics, such as that it is impossible to generate the number π with a ruler and compass. Despite which, many amateurs continue to assert that they have made it. I myself have had to face one of these “proofs”.

Another similar case is the proof, this time related to physical science, that it is impossible to build machines with perpetual motion, because they oppose the first or the second principle of thermodynamics. Also, in this case many amateurs insist that they have made it. In these cases, one should not waste time looking for the error, which is known to exist.

Thursday, April 4, 2024

Genes arising from nothing?

I have been asked me to clarify a recent piece of news that has hit the popular science press with headlines like the following:

New genes found that can arise from nothing. (Phys.org, 12/8/2023)

The tenacity of the media (and some scientists) to abuse the concept of nothing is unbelievable. They don’t know that nothing does not exist, and that nothing can arise from what does not exist. This is something that pre-Socratic Greek philosophers did know. (The first to assert this was Parmenides). Twenty-five centuries later, modern man, so proud of the advancement of science and technology, makes the same mistake once and again. In these posts I have often criticized the phrase, common today, that the universe arose spontaneously from nothing, which atheists often formulate to deny the creation and, therefore, the existence of God. This phrase does not belong to science (because current theories do not let us go back to the moment of the Big Bang). As philosophy, it’s just a flagrant proof of ignorance.

Thursday, March 28, 2024

The mystery of the cosmological constant

Alexander Friedmann
(Александр Фридман)

This post completes a previous post with a similar title:

The problem of the cosmological constant.

First of all, we should define three different concepts that could be closely related:

  1. Vacuum energy: due to the constant appearance of pairs of particles and antiparticles that immediately mutually disintegrate, so they are undetectable through direct experimentation. Their appearance is a consequence of the uncertainty principle: ΔΔt<ħ/2, which implies that a particle with energy ΔE can appear spontaneously during a time Δt<ħ/(2ΔE), which is smaller for larger ΔE. Thus, a virtual electron would last less than 4×10-21 seconds. A proton, whose mass is 1837 times greater, would last 1837 times less. By applying quantum field theory to all the known particles, the energy of the vacuum can be estimated.
  2. The cosmological constant: introduced by Einstein in his cosmological equation, which in the format devised by Alexander Friedman is expressed as follows: The symbol Λ is the cosmological constant. Einstein proposed a negative value, to compensate for a cosmic expansion, in which he initially did not believe. Today it is thought to be positive, which would explain the accelerated expansion of the universe discovered in 1998.
  1. Dark energy: an unknown agent that would cause the accelerated expansion of the universe.

Thursday, March 21, 2024

They bark, therefore we ride

Illustration by Gustavo Doré

In September 2003, reading the book On the Will in Nature (1836) by the German philosopher Arthur Schopenhauer, I found the following words in page 40 of its Spanish translation by Alianza Editorial:

…according to those verses by Goethe: “The dog would like to come with us from the stable: the echo of its barking proves that we are riding.”

I immediately thought that this phrase must be the origin of the Spanish proverb they bark, therefore we ride, which used to be attributed to Don Quixote. Since I didn’t remember having read it there, just in case, I found a digitalized version of Don Quixote and looked up the phrase in question. It was not there. Next I did a Google search of the phrase, which came up with about sixty references, all of which stated that it was a phrase from Don Quixote. I also looked for the German translation of Goethe’s phrase as quoted by Schopenhauer, and got five references to Goethe’s poem Kläffer (Barker, 1808). Therefore, at that time the information used by Google to search for that phrase in Spanish was totally wrong, while the information written in German was correct, although less abundant.

Thursday, March 14, 2024

Pope Francis, Technocracy and Artificial Intelligence

The last Apostolic Exhortation by Pope Francis, entitled Laudate Deum and published on October 4, 2023, dedicates a chapter to the technocratic paradigm that has been imposed throughout the world, to which the following definition applies: a certain way of understanding human life and activity [that] has gone awry, to the serious detriment of the world around us. It refers mainly to the degradation of the environment in relation to climate change of anthropogenic origin, although the phrase used can be interpreted broadly, since there are many more ways to degrade the environment, in addition to releasing gases into the atmosphere.

But it doesn't stop there. The next paragraph says this:

21. In recent years, we have been able to confirm this diagnosis, even as we have witnessed a new advance of the above paradigm. Artificial intelligence and the latest technological innovations start with the notion of a human being with no limits, whose abilities and possibilities can be infinitely expanded thanks to technology. In this way, the technocratic paradigm monstrously feeds upon itself.

Wednesday, March 6, 2024

Chance, design and artificial life

In previous posts in this blog I have mentioned my experiments on artificial life: the simulation in a computer of processes similar to those that take place in living beings. Artificial life should not be confused with synthetic life: construction of artificial living beings in the laboratory.

One of the most used tools in artificial life (and in other related fields) are genetic algorithms, which simulate biological evolution within the computer, and make it act on the entities that are the subjects of the research. In these experiments, a mixture of chance and necessity (the title of Monod’s book mentioned in the previous post) is used. Chance is usually applied with a pseudo-random number generator that modifies the operation of the rest of the algorithm, which represents necessity.

Thursday, February 29, 2024

Different types of chance

Jacques Monod

When we don’t know why something happens, we usually say that it is due to chance. But this statement is ambiguous, because there are two different types of chance:

  • Epistemological chance, where the cause of what’s happening is well-known, but so complex that it remains outside the scope of our knowledge. Almost all games of chance (dice, roulette, lottery jackpot) are examples of this type of chance. Rolling dice conforms to the laws of mechanics, but the conditions are so complex that we cannot predict the result of each roll. This type of chance is what Jacques Monod called operational uncertainty in his book Chance and Necessity (1970):

This term is used... in relation to the game of dice, or roulette, and the calculation of probabilities is used to predict the result of a play. But these purely mechanical and macroscopic games are not "the result of chance" except because of the practical impossibility of controlling the throwing of the dice or the ball with sufficient precision. It is evident that a very high precision launching mechanism is conceivable, and would make it possible to largely eliminate the uncertainty of the result... The same thing happens, as will be easily seen, in... many phenomena where the notion of chance and the calculation of probabilities are applied for purely methodological reasons. (My translation into English).