Everything about Julius Robert Von Mayer totally explained
Julius Robert von Mayer (
November 25,
1814 –
March 20,
1878) was a
German physician and
physicist and one of the founders of
thermodynamics. He is best known for enunciating in 1841 one of the original statements of the
conservation of energy or what is now known as one of the first versions of the
first law of thermodynamics, namely:
In 1842, Mayer described the vital
chemical process now referred to as
oxidation as the primary source of
energy for any
living creature. His achievements were overlooked and priority for the discovery of the
mechanical equivalent of heat was attributed to
James Joule in the following year. He also proposed that plants convert light into chemical energy.
Life
Mayer grew up in
Heilbronn, as son of a
pharmacist. After completing his
Abitur, he studied
medicine at the
University of Tübingen, where he was a member of the
Corps Guestphalia, a
German Student Corps. In
1838 he attained his
doctorate as well as passing the
Staatsexamen. After a stay in
Paris (
1839/
40) he left as a ship's
physician on a
Dutch three-mast
sailing ship for a journey to
Jakarta.
Although he'd hardly been interested up to the start of this journey in
physical phenomena, his observation that
storm-whipped
waves are warmer than the calm
sea sparked deep thinking about the
laws of nature, in particular about the physical phenomenon of warmth and the question:
whether the directly developed heat alone or whether the sum of the amounts of heat developed in direct and indirect ways contributes to the temperature. After his return in February 1841 Mayer dedicated all its effors to the solution of this problem.
In 1841 he settled in Heilbronn and married.
Development of ideas
Julius Robert von Mayer was born on
November 25,
1814 in
Heilbronn,
Wurttemberg (modern day Germany). Even as a young child, Mayer showed an intense interest with various mechanical mechanisms. He was a young man who performed various experiments of the physical and chemical variety. In fact, one of his favorite hobbies was creating various types of electrical devices and air pumps. It was very obvious that he was indeed very gifted. Hence, Mayer attended Eberhard-Karls University in May of 1832. He studied medicine during his time there.
In 1837, he and some of his friends were arrested for wearing the colors of a forbidden organization. The consequences for this arrest included a one year expulsion from the college and a brief period of incarceration. This diversion sent Mayer traveling to
Switzerland,
France, and the
Dutch East Indies. Mayer drew some additional interest in mathematics and engineering from his friend Carl Baur through private tutoring. In 1841, Mayer returned to Heilbronn to practice medicine, but physics became his new passion.
In June 1841, he completed his first scientific paper entitled "On the Quantitative and Qualitative Determination of Forces". It was largely ignored by other professionals in the area. Then, Mayer became interested in the area of heat and its motion. He presented a value in numerical terms for the mechanical equivalent of heat. He also was the first person to describe the vital chemical process now referred to as oxidation as the primary source of energy for any living creature.
In 1848 he calculated than in the absence of a source of energy the Sun would cool down in only 5000 years, and he suggested that the impact of meteorites kept it hot.
Since he wasn't taken seriously at the time, his achievements were overlooked and his well-deserved credit was given to
James Joule. Mayer almost committed suicide after he discovered this fact. He spent some time in mental institutions to recover from this and the loss of some of his children. Several of his papers were published due to the advanced nature of the physics and chemistry. He was awarded an honorary doctorate in 1859 by the philosophical faculty at the
University of Tubingen. His overlooked work was revived in 1862 by fellow physicist
John Tyndall in a lecture at the London Royal Institution. In July of 1867, Mayer published "Die Mechanik der Warme." This publication dealt with the mechanics of heat and its motion. In November 1867, Mayer was awarded personal nobility (von Mayer) which is the German equivalent of a British knighthood. Julius Robert von Mayer died from tuberculosis on March 20, 1878 in Germany.
Mayer's place in the history of physics
Mayer was the first person to state the law of the conservation of energy, one of the most fundamental tenets of modern day physics. The law of the conservation of energy states that the total mechanical energy of a system remains constant in any isolated system of objects that interact with each other only by way of forces that are
conservative.
Mayer's first attempt at stating the conservation of energy was a paper he sent to
Johann Christian Poggendorff's
Annalen der Physik, in which he postulated a
Erhaltungssatz der Kraft. However, owing to Mayer's lack of advanced training in
physics, it contained some fundamental mistakes and wasn't published. Mayer continued to pursue the idea steadfastly and argued with the
Tübingen physics professor
Johann Gottlieb Nörremberg, who rejected his
hypothesis. Nörremberg did, however, give Mayer a number of valuable suggestions on how the idea could be examined experimentally; for example, if
kinetic energy transforms into
heat energy,
water should be warmed by
vibration.
Mayer not only performed this demonstration, but determined also the quantitative factor of the transformation, calculating the mechanical equivalent of heat. The result of his investigations was published
1842 in the May edition of
Justus von Liebig's
Annalen der Chemie und Pharmacie (Annalen der Chemie und Pharmacie, 43, 233 (1842)) . In his booklet
Die organische Bewegung im Zusammenhang mit dem Stoffwechsel (
The Organic Movement in Connection with the Metabolism (
1845) he could specified the numerical value of the mechanical equivalent of heat: at first as 365
kgf·m/kcal, later as 425 kgf·m/kcal; the modern values are 4.184
kJ/kcal (426.6 kgf·m/kcal) for the thermochemical calorie and 4.1868 kJ/kcal (426.9 kgf·m/kcal) for the international steam table calorie.
This relation implies that, although work and heat are different forms of energy, they can be transformed into one another. This law is called the first law of the
caloric theory and led to the formulation of the general principle of
conservation of energy, definitively stated by
Hermann von Helmholtz in
1847.
Mayer's Relation
Mayer also derived what is now known as
Mayer's Relation:
» Cp - Cv = R
where
Cp is the
specific heat of a
gas at constant
pressure,
Cv is specific heat of a gas at constant
volume and
R is the
gas constant.
Later life
» For dispute over priority with Joule, see main article Mechanical equivalent of heat: Priority.
Mayer was aware of the importance of his discovery, but his inability to express himself scientifically led to degrading speculation and resistance from the scientific establishment. Contemporary physicists rejected his principle of conservation of energy. Even acclaimed physicists von Helmholtz and Joule viewed his ideas with hostility. The former doubted Mayer's qualifications in physical questions, and a bitter dispute over priority developed with the latter.
In
1848 two of his children died rapidly in succession, and Mayer's
mental health deteriorated. He attempted
suicide on
May 18,
1850 and was committed to a mental institution. After he was released, he was a broken man and only timidly re-entered public life in
1860. However, in the meantime, his scientific fame had grown and he received a late appreciation of his achievement, although perhaps at a stage where he was no longer able to enjoy it.
He continuted to work vigorously as a physician until his death.
Honours
The
Robert-Mayer-Gymnasium and the
Robert-Mayer-Volks- und Schulsternwarte in
Heilbronn bear his name.
Further Information
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