Prophecy: real glimpse of the future or simple placebo effect?

Prophecy, transmitted by a being – whether prophet, diviner or simple human being – is none other than a transcendent message which gives indications of future events. Such messages are the prerogative of Greek mythology, where tragic heroes find themselves confronted with destinies where their free will has no place. Prophecies are still anchored in the best-known fictional stories today, whether it is the quest of a famous sorcerer or the journey of a not-quite-human mutant… In a more down-to-earth way , the American sociologist Robert Merton described in the middle of the 20^e century the idea of ​​self-fulfilling prophecy, a kind of placebo effect pushing beings to conform to the message heard. At a time when meteorologists announce to us every evening the weather the next day, where is the limit with the prophecy? Besides, is this science of the weather really more reliable than a guess?

Prophecy: an ominous bird

In fictional stories, the use of a prophecy very often leads to a red thread at the origin of multiple adventures. Thus, the message transmitted to the main characters is alarming. This is how Harry Potter sees himself declaimed a very short-term prophecy by his divination teacher Sibylle Trelawney, at the end of an exam: “It will happen tonight! The Dark Lord is there, lonely, abandoned by his friends. For 12 years his servant was chained. Tonight, before midnight, the servant will break his chains and go to join his master. With the help of his servant, the Dark Lord will arise again, more powerful and more terrible than ever. Tonight… before midnight… the servant will go… join… his master…” (Harry Potter and the Prisoner of Azkaban by JK Rowling, 1999). The minion in question being none other than Peter Petigrew who, after betraying his friends for He-Who-Must-Not-Speak-The-Name, lurked in the shadows in the form of a rat – Ron’s, Scabbers.

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On an even larger scale, the predicted assertion can directly announce the end of the world as we know it. This is what the elf prophetess Ithlinne portrays in Andzej Sapkowski’s saga The Witcher (1986-2013): “The Blizzard of the Wolf draws near, the Age of Sword and Axe, the Time of Immaculate Light, the Time of Immaculate Cold, the Time of Madness, the Time of Contempt. Tedd Deiveadh, The Ultimate Age. The world will perish in ice and be reborn under a new Sun. Born again from the Old Blood of hen Ichaen, from a seed, planted… A plant that will not grow: it will catch fire! “. The Elder Blood in question is one of a long line, the latest of which seems to be Ciri, the ward of the witcher Geralt of Rivia – a mutant shaped to defeat the worst monsters imaginable. Note all the same that here the prophecy leaves a certain uncertainty. Is Ciri the cause of the end of the world, or the catalyst for a new beginning? A question that those who hunt her down to use her power do not ask themselves…

The Placebo Effect of Self-Fulfilling Prophecy

In 1948, the American sociologist Robert Morton stated the concept of self-fulfilling prophecy: “it is an initially false definition of a situation, but this erroneous definition gives rise to a new behavior, which makes it true”. In other words, the mere existence of the prophecy greatly increases the chances that it will come true. But the terms “false” and “true” are easily criticized. Indeed, how to quantify such notions? This is why the geographer Jean-François Staszak decides to propose a modified version of the concept in his article “Self-fulfilling prophecies and geography”, published in Geographical Space in 2000. He defines the self-fulfilling prophecy there as an assertion inducing behaviors likely to validate the said assertion. A striking example is that of March 1979 in California. While the newspapers publish on an impending gasoline shortage, a rush of motorists descends on the stations in order to fill the tanks of their vehicles. Nearly 12 million tanks, previously three-quarters empty, suddenly find themselves full. The assault exhausts the substantial reserves of gasoline available, leading to the announced shortage. A situation which could however have been avoided, the delivery of fuel having finally barely decreased…

Examples of self-fulfilling prophecies can be found even in Greek mythology. In the story of Oedipus, his future parents consult the oracle at Delphi, a site at the foot of Mount Parnassus in Greece. In fact oracle, it is an answer to a question, administered by the prophetess (or Pythia) in the name of Apollo. She therefore predicts that if they have a son, he will end up killing his father and marrying his mother. Out of fear, once Oedipus was born, his parents chose to abandon him on Mount Cithaeron. He will be collected there by a shepherd, before being adopted by the king and queen of Corinth. Her destiny can then begin… In a more contemporary register, Sibylle Trelawney enters a trance during a job interview with Albus Dumbledore, director of Hogwarts. She recites to him the prophecy that will lead to the anthology duel between Harry Potter and Voldemort: “He who has the power to defeat the Dark Lord approaches… he will be born of those who have defied him three times, he will be born when he dies. the seventh month…and the Dark Lord will mark him as his equal but he will have a power that the Dark Lord knows not…and one must die by the hand of the other because neither of them can live as long as the ‘other survives… He who holds the power to kill the Dark Lord will be born when the seventh month dies…’ (Harry Potter and the Order of the Phoenix by JK Rowling, 2003). Informed by Severus Snape, who overheard the conversation, Voldemort goes to the Potters, who match the description given by Trelawney. And so begins the Harry Potter saga… Each time, the prophecy seems to force individuals to comply with its plans.

Not infallible weather forecasts

What about modern “prophecies”? Of these forecasts made by scientists, as for the weather for example? Interviewed for the Science and Life Q&A » June 2021, the deputy director of operations for forecasting at Météo-France Véronique Ducrocq presented meteorology as a science based on data from the external environment. To adjust the different values ​​of the parameters to be inserted into the forecasting models – temperature, pressure, wind speed, humidity – scientists can rely on a multitude of measuring instruments. Among them are surface stations, for measurements near the ground; weather balloons for those at altitude; radars to record precipitation (hailstone, rain, snow, etc.); and even satellites to scan the Earth from space. Once all this data has been collected, it is transferred to the Météo-France site in Toulouse. There, they are combined with those from other countries through international coordination work overseen by the World Meteorological Organization (WMO).

>> Read also: How to predict the weather?

The forecast is then calculated on an atmosphere divided into volume grids in which various parameters are estimated at the present time. These are the famous initial conditions. It is from them that the evolution of the weather over time is simulated. At Météo-France, depending on the model used, forecasts are reliable over two to four days. But this reliability is not perfect, despite the hourly refresh of the input information by new data recorded by the measuring devices. Indeed, the slightest variation on the input values ​​can lead to radical modifications of the output results. To improve reliability, meteorologists carry out as many simulations as possible with slight modifications of the initial conditions. The more the simulations tend to converge, the more the results will be considered promising. A science certainly, but not for all that infallible. Finally, which of the self-fulfilling prophecy or the weather forecast is more certain? We just have to wait to find out…