7. Biographical Notes on Major Scientists

The following short biographical notes provide the nationality, era, and one key fact about each major scientist covered in this chapter — useful for objective-type questions that ask to match a scientist with their nationality or a distinguishing fact.

Sir Isaac Newton — English, 1643–1727. Formulated the three laws of motion and the law of universal gravitation in his 1687 work Principia Mathematica; also made major contributions to optics and invented calculus independently of Leibniz.

Galileo Galilei — Italian, 1564–1642. Often called the 'father of modern physics/observational astronomy'; pioneered the use of the telescope for astronomical observation and laid groundwork for the concept of inertia later formalised by Newton.

Albert Einstein — German-born (later Swiss and American citizen), 1879–1955. Developed the Special and General Theories of Relativity and explained the photoelectric effect (for which he won the 1921 Nobel Prize in Physics), not for relativity as commonly misunderstood.

Michael Faraday — British (English), 1791–1867. A self-taught scientist with little formal mathematical training, he discovered electromagnetic induction and laid the foundations of electric motor and generator technology.

James Clerk Maxwell — Scottish, 1831–1879. Formulated the classical theory of electromagnetic radiation, unifying electricity, magnetism, and light through Maxwell's equations, published around 1865.

Johannes Kepler — German, 1571–1630. Formulated the three laws of planetary motion using the precise observational data of Tycho Brahe; also worked extensively in optics.

Archimedes — Greek (of Syracuse, Sicily), c. 287–212 BCE. Ancient Greek mathematician, physicist, and engineer, famed for the principle of buoyancy discovered while bathing (the 'Eureka' legend), and for his contributions to geometry and mechanics.

Blaise Pascal — French, 1623–1662. A mathematician, physicist, and philosopher who formulated the law of pressure transmission in fluids; the SI unit of pressure, the pascal (Pa), is named in his honour.

Robert Boyle — Anglo-Irish, 1627–1691. Often regarded as one of the founders of modern chemistry; formulated Boyle's law relating gas pressure and volume in 1662.

Jacques Charles — French, 1746–1823. A physicist and inventor known for Charles's law of gas volume and temperature; also a pioneer of hydrogen balloon flight.

Georg Simon Ohm — German, 1789–1854. Formulated Ohm's law relating voltage, current, and resistance in 1827; the SI unit of electrical resistance, the ohm (Ω), is named after him.

Charles-Augustin de Coulomb — French, 1736–1806. A physicist known for Coulomb's law of electrostatic force; the SI unit of electric charge, the coulomb (C), is named in his honour.

André-Marie Ampère — French, 1775–1836. Often called the 'father of electrodynamics'; the SI unit of electric current, the ampere (A), is named after him.

Gustav Robert Kirchhoff — German, 1824–1887. Formulated Kirchhoff's circuit laws in 1845 and made major contributions to spectroscopy and black-body radiation theory.

Max Planck — German, 1858–1947. Originated quantum theory in 1900 with his hypothesis of energy quanta, considered the founder of quantum mechanics; won the Nobel Prize in Physics in 1918.

Niels Bohr — Danish, 1885–1962. Proposed the Bohr model of the atom in 1913, incorporating quantum theory into atomic structure; won the Nobel Prize in Physics in 1922.

Ernest Rutherford — New Zealand-born British physicist, 1871–1937. Known as the 'father of nuclear physics'; discovered the atomic nucleus through the gold foil experiment (1909–1911) and won the 1908 Nobel Prize in Chemistry (for earlier work on radioactivity).

Werner Heisenberg — German, 1901–1976. Formulated the uncertainty principle in 1927, a cornerstone of quantum mechanics; won the Nobel Prize in Physics in 1932.

Robert Hooke — English, 1635–1703. A polymath scientist and architect who formulated Hooke's law of elasticity in 1660 and made significant contributions to microscopy, publishing the influential work Micrographia.

Daniel Bernoulli — Swiss (Dutch-born), 1700–1782. A member of the famous Bernoulli family of mathematicians; formulated Bernoulli's principle of fluid dynamics in his 1738 work Hydrodynamica.

Sir George Gabriel Stokes — Irish (British), 1819–1903. A mathematician and physicist known for Stokes' law of viscous drag and significant contributions to fluid dynamics and optics.

Christian Doppler — Austrian, 1803–1853. Proposed the Doppler effect in 1842, initially applied to the colour of binary stars, later shown to apply broadly to sound and light waves.

Willebrord Snellius (Snell) — Dutch, 1580–1626. A mathematician and astronomer after whom Snell's law of refraction is named, though the relationship was also independently derived by René Descartes.

James Prescott Joule — English, 1818–1889. A brewer by profession and physicist by passion, he established the mechanical equivalent of heat and Joule's law of electrical heating; the SI unit of energy, the joule (J), is named after him.

Heinrich Lenz — Baltic German (Russian Empire), 1804–1865. Formulated Lenz's law in 1834, describing the direction of induced current, a direct consequence of energy conservation.

John Ambrose Fleming — British (English), 1849–1945. An electrical engineer and physicist who devised the left-hand and right-hand rules as mnemonic aids for electromagnetism; also invented the thermionic valve (vacuum tube diode).

Wolfgang Pauli — Austrian, 1900–1958. Formulated the exclusion principle in 1925, fundamental to atomic structure and the periodic table; won the Nobel Prize in Physics in 1945.

Henry Moseley — English, 1887–1915. Established Moseley's law relating X-ray frequency to atomic number, correcting the periodic table's arrangement; died young in World War I at the Battle of Gallipoli.

Walther Nernst — German, 1864–1941. Formulated the third law of thermodynamics (Nernst heat theorem); won the Nobel Prize in Chemistry in 1920.

Rudolf Clausius — German, 1822–1888. A physicist and mathematician who formalised the concept of entropy and gave one of the classic statements of the second law of thermodynamics.