Georges-Louis Le Sage facts for kids
Quick facts for kids
Georges-Louis Le Sage
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Georges-Louis Le Sage
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| Born | 13 June 1724 |
| Died | 9 November 1803 (aged 79) Geneva, France
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Georges-Louis Le Sage (13 June 1724 – 9 November 1803) was a Genevan physicist. He is best known for his theory of gravity. He also invented an early electric telegraph and had ideas similar to the kinetic theory of gases. He even helped write a famous French encyclopedia called Encyclopédie.
Contents
Life and Education
Georges-Louis Le Sage was born in Geneva. His father, Georges-Louis Le Sage, was a writer who taught his son many things from a young age. By age 13, Le Sage was already reading the works of the Roman poet Lucretius. His parents were very strict, which made Le Sage spend a lot of time alone, thinking deeply about different topics. Unlike his father, Le Sage loved to find general rules and big ideas.
Le Sage went to college in Geneva. He studied mathematics with Gabriel Cramer and physics with Jean-Louis Calandrini. Later, he studied medicine in Basel, where he met Daniel Bernoulli. Bernoulli's ideas about how gases work really inspired Le Sage. He then continued his medical studies in Paris. When he returned to Geneva, he tried to become a doctor, but he wasn't allowed because his father was from France.
Even though his father didn't want him to, Le Sage decided to focus his life on mathematics. He was especially interested in understanding how gravity works. He tried to become a math professor in Geneva but didn't get the job.
Le Sage didn't publish many papers himself. However, he wrote many letters to other famous scientists like Leonhard Euler and Daniel Bernoulli. He also taught private math lessons. His students, like Pierre Prévost, were very impressed by him. Le Sage was a member of the Paris Academy of Science and a Fellow of the Royal Society. He passed away in Geneva at 79 years old.
Character and Health
Le Sage often had trouble sleeping, which meant he couldn't work for days at a time. In 1762, he had an accident that left him almost blind.
Because his memory wasn't very good, he wrote down his ideas on playing cards. There are over 35,000 of these cards still kept in the library of Geneva today! Many of his writings were never finished or published because of his health. However, his student Pierre Prévost published some of them after Le Sage died.
Early Telegraph
In 1774, Le Sage created an early version of an electric telegraph. This telegraph had a separate wire for each of the 26 letters of the alphabet. It could only send messages between two rooms in his house.
Kinetic Theory of Gases
Le Sage also tried to explain what gases are made of and how they behave. His ideas were praised by important scientists like Rudolf Clausius and James Clerk Maxwell. Maxwell said that Le Sage's explanation for how gases push outwards (their pressure) was very similar to how we understand it today.
Le Sage was clear that he wasn't the first to think about this. He mentioned earlier thinkers like Lucretius and Daniel Bernoulli.
Gravitation Theory
How Le Sage Developed His Theory
When he was young, Le Sage was very inspired by the Roman poet Lucretius. Lucretius had ideas about how tiny particles could cause things to move. Le Sage used some of these ideas to create his own mechanical explanation of gravity. He worked on this theory and defended it throughout his life. Le Sage wrote that he came up with the main ideas for his theory, now called Le Sage's theory of gravitation, as early as 1743.
His first detailed paper on the theory was written in 1748 but was never published. In 1756, one of his explanations was published. In 1758, he sent an even more detailed paper to a science competition. In this paper, he tried to explain both gravity and how chemicals combine. He won a prize, but only the part about gravity interested other scientists like Leonhard Euler. His most famous explanation of the theory was called "Lucrèce Newtonien" (meaning "The Newtonian Lucretius"). In this work, he showed how his ideas connected to Lucretius's ancient concepts.
Scientists Before Le Sage
Le Sage was not the first person to suggest what is now known as "Le Sage's theory of gravity." Other scientists like Fatio, Cramer, and Redeker had described similar ideas before him. It's debated how much Le Sage knew about these earlier theories.
Nicolas Fatio de Duillier
A very similar theory was first proposed in the 1690s by Nicolas Fatio de Duillier. Fatio was a well-known Swiss scientist and a friend of Isaac Newton. Le Sage said he first heard about Fatio from his father. However, Le Sage later claimed he didn't know Fatio had a gravity theory like his own until his teacher, Gabriel Cramer, told him in 1749. Le Sage admitted he had a very bad memory, so it's hard to know for sure.
After Fatio died in 1753, Le Sage tried to get Fatio's papers. He wanted to save them from being forgotten and use them for a book he planned to write about the history of gravity theories. He got some of Fatio's papers over the years. Le Sage even started writing about Fatio's life but didn't finish it. He also tried to publish some of Fatio's papers without success.
Le Sage wrote to another scientist in 1768, saying that Fatio's theory from 1689 was "so similar to mine." However, Le Sage incorrectly claimed that Fatio thought the tiny particles causing gravity bounced perfectly (elastic collisions). Fatio actually said they lost speed, which was an important part of his theory.
Le Sage was worried people might think he copied Fatio's idea. He even had friends sign a "certificate" saying he hadn't seen Fatio's papers until much later, and that his own ideas were more detailed. Later studies show that Fatio's theory was actually more developed than Le Sage's.
Gabriel Cramer and Franz Albert Redeker
Le Sage said that after he wrote his first paper on gravity, he learned about a very similar theory by Gabriel Cramer, who was his teacher. Le Sage argued that his own paper was written before he knew about Cramer's ideas. He also said that Cramer's theory was too vague and not scientifically strong. Le Sage even accused Cramer of copying Fatio's theory.
In 1751, Le Sage also found out about Franz Albert Redeker's theory. Le Sage started to write a history of gravity theories, including Fatio and Redeker, but he never finished it.
Le Sage's View on Predecessors
Even though Le Sage knew about these earlier theories, he always said he was the first to fully explore all the ideas that came from the theory. In his book "Lucrece Newtonien" (1782), he didn't name any of his predecessors. He just said it was "likely" that others had similar simple ideas before him. But he claimed they had presented them in a "vague" way and hadn't fully developed them. He suggested they might have lacked the courage or love of truth to work on such difficult and unpopular research.
His friend Prévost praised Le Sage for always giving credit to those who came before him. However, Le Sage often spoke negatively about them, as seen in his comments about Cramer.
