Physicists 19th century
Bernard Bolzano, full name Bernard Placidus Johann Nepomuk Bolzano, was an Italian-born Czech scientist, mathematician, logician, philosopher and theologian.
Bolzano graduated from the University of Prague and was immediately appointed professor of philosophy and religion at the university. Within a few years, however, Bolzano had already shown himself to be a free thinker with his teachings on the social costs of militarism and the needlessness of war. He called for a complete reform of the educational, social, and economic systems that would direct the nation's interests toward peace rather than armed conflict between states. In 1819, Bolzano was expelled from the university for his beliefs and thereafter turned his full attention to works on social, religious, philosophical, and mathematical issues.
Bolzano held advanced views on logic, mathematical quantities, limits, and continuity. He is the author of the first rigorous theory of real numbers and one of the founders of set theory. In his studies of the physical aspects of force, space, and time, he proposed theories opposed to those advanced by the German philosopher Immanuel Kant. His contributions to logic, in particular, established his reputation as the greatest logician of his time. Much of his work remained unpublished during his lifetime and was not widely disseminated until the late nineteenth and early twentieth centuries, when a number of his conclusions were reached independently.
Bolzano was multi-talented in various fields of science to which he made significant contributions. His published works include The Binomial Theorem (1816), A Purely Analytic Proof (1817), The Functional Model and the Scientific Model (1834), An Attempt at a New Statement of Logic (1837), and The Paradoxes of Infinity (1851).
Among other things, Bolzano was also a great philanthropist. Together with his friends and students, he supported the activities of almshouses, homes for the blind, loan banks for the working class, libraries, and elementary schools in rural areas.
Mathurin Jacques Brisson was a French zoologist, ornithologist, naturalist and physicist, a member of the Academy of Sciences.
He is known for his published works in natural history: Le Règne animal ("The Kingdom of Animals", 1756) and Ornithologie ("Ornithology", 1760), in which he described 1,500 species of birds grouped into 115 genera, twenty-six orders, and two classes. Brisson was one of the first to come close to the concept of "type" in zoology, although he does not use the term, but his classification was used for about 100 years. He translated a number of important books on zoology for his time into French.
Brisson's works in physics are related to the measurement of specific gravity of various bodies, the study of gases and refraction of light, mirrors, magnetism, atmospheric electricity, and barometers.
Augustin Louis Cauchy was a French mathematician and mechanic, military engineer, and founder of mathematical analysis.
Cauchy studied at the École Polytechnique and at the Paris School of Bridges and Roads. After becoming a military engineer, he went to Cherbourg in 1810 to work on harbors and fortifications for Napoleon's English invasion. Here he began independent mathematical research. Cauchy returned to Paris in 1813, and Lagrange and Laplace convinced him to devote himself entirely to mathematics. The following year he published a memoir on definite integrals, which formed the basis of the theory of complex functions. From 1816, Cauchy held professorships at the Faculty of Natural Sciences, the Collège de France, and the École Polytechnique in Paris.
Cauchy developed the foundation of mathematical analysis, and made enormous contributions to analysis, algebra, mathematical physics, and many other areas of mathematics. He almost single-handedly founded the theory of functions of a complex variable, which has extensive applications in physics. Cauchy's greatest contributions to mathematics are published primarily in three of his treatises, "Courses in Analysis at the Royal Polytechnic School" (1821), "Summary of Lessons on Infinitesimal Calculus" (1823), and "Lessons on the Application of Infinitesimal Values in Geometry" (1826-28). In all, Augustin Louis Cauchy wrote about 800 scientific articles.
Cauchy was a member of the Paris Academy of Sciences, the Royal Society of London, the St. Petersburg Academy of Sciences, and other academies.
John Dalton was a British scientist, chemist and physicist, naturalist, and pioneer in the development of modern atomic theory.
In the 1800s, he was the first scientist to explain the behavior of atoms in terms of weight measurements. Some of the tenets of Dalton's atomic theory proved to be false, but most of the conclusions remain valid to this day.
Problems with his own eyesight led Dalton to research and describe the visual defect he himself suffered from in 1794 - color blindness, later named color blindness in his honor.
Albert Einstein was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theory of relativity, but he also made important contributions to the development of the theory of quantum mechanics. Relativity and quantum mechanics are together the two pillars of modern physics. His mass–energy equivalence formula E = mc2, which arises from relativity theory, has been dubbed "the world's most famous equation". His work is also known for its influence on the philosophy of science. He received the 1921 Nobel Prize in Physics "for his services to theoretical physics, and especially for his discovery of the law of the photoelectric effect", a pivotal step in the development of quantum theory. His intellectual achievements and originality resulted in "Einstein" becoming synonymous with "genius".
Michael Faraday was a British physicist and chemist, explorer and experimenter.
Faraday, because of his family's poverty, was unable to receive a formal education, but at the bookbinding shop in London where he worked, he read many books, including encyclopedias and textbooks on chemistry and physics. He persevered in self-education, attending hearings at the City Philosophical Society and later lectures by Sir Humphry Davy at the Royal Institution, who as a result took the able student on as an apprentice. In 1825 he replaced the seriously ill Davy in the management of the laboratory of the Royal Institution.
In 1833 Faraday was appointed to a research chair of chemistry created especially for him, where, among other achievements, the scientist liquefied various gases, including chlorine and carbon dioxide. His study of heating and lighting oils led to the discovery of benzene and other hydrocarbons, and he experimented extensively with various steel alloys and optical glasses. Faraday was an excellent experimentalist who presented his ideas in simple language. He is best known for his contributions to the understanding of electricity and electrochemistry. The concepts behind electromagnetic induction, diamagnetism, and electrolysis were some of his most important discoveries. His electromagnetic research formed the basis of the electromagnetic equations that James Clerk Maxwell developed in the 1850s and 1860s.
Between 1831 and 1855, Faraday read a series of 30 papers before the Royal Society, which were published in his three-volume Experimental Investigations in Electricity. His bibliography numbers some 500 printed articles. By 1844 he had been elected a member of some 70 scientific societies, including the St. Petersburg Academy of Sciences.
Joseph Fourier, full name Jean-Baptiste Joseph Fourier, was a French mathematician and physicist and historical Egyptologist.
Fourier famously accompanied Napoleon Bonaparte on his Egyptian expedition in 1798 as a scientific advisor and was appointed secretary of the Institute of Egypt. During the occupation of Egypt, Fourier worked in the French administration, supervised archaeological excavations, and worked to shape the educational system.
But the main thing in Fourier's life was science. Back in France, he studied the mathematical theory of heat conduction, established the partial differential equation governing heat diffusion, and solved it using an infinite series of trigonometric functions. Fourier showed that heat diffusion obeyed simple observable physical constants that could be expressed mathematically. His work The Analytic Theory of Heat (1822) had a great influence on the development of physics and pure mathematics.
Joseph Fourier was a member of the Paris Academy of Sciences, the French Academy, a foreign honorary member of the St. Petersburg Academy of Sciences, and a member of the Royal Society of London.
Sir John Frederick William Herschel, 1st Baronet was a British astronomer and son of the Uranus discoverer Wilhelm Herschel. He is credited with the first double star and nebula catalogues of the southern starry sky, which he observed during a five-year stay near Cape Town.
Heinrich Rudolf Hertz was a German physicist and inventor of radio waves.
Hertz graduated from the University of Berlin, studying under Hermann von Helmholtz and Gustav Kirchhoff, then was a professor of physics at the University of Karlsruhe, and from 1889 became a professor of physics at the University of Bonn.
A tireless experimenter, Hertz conducted various experiments with electric waves. Hertz reported his first discovery at the end of 1887 in a treatise "On the electromagnetic effects caused by electrical perturbations in insulators," which he sent to the Berlin Academy. For a time the waves he discovered were called Hertzian waves, but today they are known as radio waves. Hertz's discovery was a confirmation of James Clerk Maxwell's electromagnetic theory and paved the way for numerous advances in communication technology.
Hertz is also known for the discovery of the photoelectric effect, which occurred during his research on electromagnetic waves. Hertz was only 37 years old at the time of his death and many of his experiments and work remained unfinished, but his discovery of radio waves had a huge impact on the world in the 20th century, paving the way for the development of radio, television and radar.
James Clerk Maxwell was a British physicist, mathematician and mechanic, and a Fellow of the Royal Society of London.
James Clerk Maxwell was one of the most influential scientists of the nineteenth century. His theoretical work on electromagnetism and light largely determined the direction physics would take in the early 20th century. Maxwell conducted research in a number of areas, but was particularly preoccupied with the nature of Saturn's rings. In 1860 he obtained a professorship at King's College, London, and it was his years there that were most fruitful. For his electromagnetic theory,
Maxwell is most often credited with fundamentally changing the course of physics. Maxwell saw electricity not just as another branch of physics, but "as an aid to the interpretation of nature." He showed the importance of electricity to physics as a whole by advancing "the important hypothesis that light and electricity are the same in their ultimate nature." This theory, one of the most important discoveries in nineteenth-century physics, was Maxwell's greatest achievement and laid the foundation for Einstein's theory of relativity.
Giovanni Vincenzo Petrini was an Italian priest and theologian, philosopher, mathematician, and expert in mineralogy.
Along with Scipio Breislacus, Petrini was one of the founders of Italian volcanology. He taught philosophy and mathematics, theology, but specialized in mineralogy and created the Mineralogical Cabinet in Nazareth. This museum was famous in Europe and was visited, among others, by Emperor Joseph II, who gave him rare specimens from the lands of the Empire and especially from Hungary.
Giovanni Petrini was the author of the catalog Gabinetto mineralogico del Collegio Nazareno ("The Mineralogical Cabinet of the Nazarene Collegium, described by external features and distributed by component parts" (Rome, 1791-1792). The specimens in it are classified according to a standard structure: salts, earths, bitumens, combustibles, and metals. There is also a section on gemstones.
Max Planck, full name Max Karl Ernst Ludwig Planck, is a German theoretical physicist and the founder of quantum theory, which won him the Nobel Prize in Physics in 1918.
Planck made many discoveries in theoretical physics, but his quantum theory revolutionized our understanding of atomic and subatomic processes, just as Albert Einstein's theory of relativity revolutionized our understanding of space and time. Together they represent the fundamental theories of 20th-century physics. They forced humanity to reconsider some philosophical beliefs and began to be applied to industry, including the military, affecting all aspects of modern human life.
Planck was one of the first scientists to realize the importance of Einstein's special theory of relativity, and his influence played a crucial role in its acceptance in Germany. As dean of the University of Berlin, he personally visited Einstein in Zurich in 1913 to persuade him to move to Berlin, which became his base for the next 20 years. Einstein's 1905 work on the photoelectric effect (for which he was awarded the Nobel Prize) is based on Planck's constant (h), the fundamental unit of quantum theory.
