Jacques Alexandre César Charles

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Jacques Charles, portrait by Julien Léopold Boilly

Jacques Alexandre César Charles (born November 12, 1746 in Beaugency , † April 7, 1823 in Paris ) was a French physicist .

Act

Charles got into physics after learning about Benjamin Franklin's theory of electricity .

In 1785 he was elected to the Académie française and later became professor of physics. He gave lectures on experimental physics in Paris , which were well received by the students. Especially in difficult experiments , he was characterized by a special skill.

In 1787, before Gay-Lussac , he discovered the relationship between temperature change and volume change in gases, which is why the resulting law is often referred to as Charles' law.

In 1795 he became a member of the Académie des Sciences . From 1804 he was a member of the Institut français and later also its librarian.

aviation

The experimental balloon that bursts near Gonesse, causing a rebellion among the inhabitants. Under the leadership of the clergy, they throw themselves on the "devil's device" and kill it.

When the Montgolfier brothers made their attempts at aviation, Charles soon entered this new field. Since he was interested in the physics of ballooning as a scientist, he approached the project entrusted to him by the king in a completely different way. Thanks to his knowledge of gases, he was able to use their properties and, together with the brothers Anne-Jean Robert and Marie-Noël Robert, constructed a dense silk balloon. He filled it with hydrogen gas.

The first successful flight was on August 27, 1783. The balloon, later named Charlière after him , had a diameter of around four meters and could carry up to nine kilograms. The flight lasted 45 minutes and led from the Paris Field of Mars to the neighboring village of Gonesse. The audience at the start was the then American ambassador to France, Benjamin Franklin . When someone asked him what the purpose of this new invention was, he replied with the counter-question: "What is the purpose of a newborn child?"

Charles made his first manned voyage with Marie-Noël Robert on December 1, 1783, during which the production of the necessary hydrogen gas from iron filings and sulfuric acid took almost three days. They stayed in the air for two hours and landed in the village of Nesles-la-Vallée, 36 kilometers away. After that, Charles rose again alone. He was the first person to fly alone in a balloon. Despite this success, he had lost the competition with the Montgolfier brothers - by only 10 days. Apart from that, Charles could chalk up the flight as a success, because he had also proven that it is not the smoke that makes the balloon rise. During his balloon ride he had a barometer and a thermometer on board. With the help of the former he was able to determine that its highest reached height was 3467 m.

Web links

Individual evidence

  1. ^ List of members since 1666: Letter C. Académie des sciences, accessed on October 28, 2019 (French).
  2. ^ Richard Aßmann and Arthur Berson (eds.): Wissenschaftliche Luftfahrten , Volume 1, Vieweg, Braunschweig 1899, p. 3