I collected over 20 lists of the greatest/most important scientists of all time and compiled them into one meta-list. The results are below: every scientist on two or more of the original source lists, organized chronologically (by birthdate).
NOTE: These are not my personal opinions.
To see another version of the list organized by rank (that is, with the scientists on the most lists at the top), go here.
600 BCE – 1 BCE
Pythagoras of Samos (Ancient Greece, c. 570-c. 495 BCE) (on 4 lists)
Philosopher and mathematician. The Pythagorean theorem (attrib.). Theory of Proportions (attrib.).
A marble bust of Pythagoras.
Hippocrates of Kos (Ancient Greece, c. 460-c. 370 BCE) (on 4 lists)
Physician and philosopher of medicine. Clinical medicine (attrib.). Hippocratic oath (attrib.). Hippcratic Corpus (attrib.).
A replica of a Greek bust of Hippocrates from about 150 CE.
Aristotle (Ancient Greece, 384-322 BCE) (on 11 lists)
Philosopher and scientist. Early theory and observation in all fields of science and medicine. Scala naturae. Physics. History of Animals. Generation of Animals. Movement of Animals. Parts of Animals. On the Soul (De Anima).
This marble bust of Aristotle is a Roman copy of a Greek bronze original by Lysippos, c. 330 BCE. The alabaster mantle is more recent.
Euclid (Ancient Greece: Egypt, fl. 300 BCE) (on 5 lists)
Mathematician. Geometry. The Elements (c. 300 BCE).
This statue of Euclid at Oxford University Museum of Natural History, UK was created by Joseph Durham between 1835 and 1877.
Archimedes (Ancient Greece, c. 287-c. 212 BCE) (on 10 lists)
Physicist, mathematician, engineer and astronomer. The lever (attrib.). The Archimedes screw (attrib.). The mathematical precursors to calculus. The war catapult.
A 1620 painting of Archimedes by Domenico Fetti.
Hipparchus of Nicaea (Ancient Greece, c. 190-c. 120 BCE) (on 3 lists)
Astronomer, geographer and mathematician. Trigonometry. The equinoxes. Latitude and longitude. The classification of stars.
Hipparchus.
1 CE – 1200 CE
Claudius Ptolemy (Ancient Rome: Egypt, c. 90-168 CE) (on 5 lists)
Mathematician, astronomer and geographer. The geocentric model of the solar system. Astronomical observations.
Ptolemy.
Galen (Ancient Greece/Rome, 129-c. 200/c. 216 CE) (on 3 lists)
Physician, surgeon, anatomist and philosopher. Anatomy. Medicine.
Galen.
Muḥammad ibn Mūsā al-Khwārizmi (Persia, 780-850 CE) (on 3 lists)
Mathematician, astronomer and geographer. The Hindu-Arabic number system. Algebra. Geography. The Compendious Book on Calculation by Completion and Balancing (820 CE).
Muhammad ibn Musa al-Khwarizmi.
Ibn al-Haytham (Alhazen) (Iraq/Egypt, c. 965 CE – c. 1040) (on 2 lists)
Physicist, astronomer and mathematician. Scientific method. Visual perception. Alhazen’s problem, Catoptrics. Book of Optics. Doubts Concerning Ptolemy.
An artist’s rendering of Ibn al-Haytham.
Avicenna (Ibn Sina) (Persia, c. 980-1037 CE) (on 6 lists)
Philosopher, physician, astronomer, geographer, geologist, psychologist, physicist and mathematician. Medicine. The scientific method. The Book of Healing. The Canon of Medicine.
Ibn Sina, also known as Avicenna.
1400-1599
Leonardo da Vinci (Italy, 1452-1519) (on 9 lists)
Artist, engineer, mathematician, anatomist, botanist, geologist and cartographer. Human anatomy. Fossils. The parachute. The helicopter. Notebooks.
Self-portrait of Leonardo da Vinci from about 1512.
Nicolaus Copernicus (Royal Prussia, now Poland, 1473-1543) (on 8 lists)
Astronomer and mathematician. The heliocentric model of the solar system. On the Revolutions of Heavenly Spheres (1543).
A 1580 portrait of Nicolaus Copernicus. It is located in the Town Hall of Toruń, Poland.
Andreas Vesalius (Hapsburg Netherlands, now Belgium, 1514-1564) (on 5 lists)
Physician and anatomist. Human anatomy. De Humani Corporis Fabrica (1543).
An engraved portrait of Andreas Vesalius taken from his 1543 treatise.
William Gilbert (England, 1544-1603) (on 3 lists)
Physicist, physician and astronomer. Electricity. Magnetism. The Earth’s magnetic field. De Magnete (1600).
William Gilbert.
Tycho Brahe (Denmark, 1546-1601) (on 3 lists)
Astronomer. Astronomical observations and measurements. Supernovae.
Tycho Brahe.
Galileo Galilei (Italy, 1564-1642) (on 17 lists)
Physicist, astronomer, mathematician, inventor, engineer and philosopher. The law of falling bodies. The moons of Jupiter. Sunspots. The phases of Venus. Confirmed heliocentrism. Dialogue Concerning the Two Chief World Systems (1632).
Portrait of Galileo Galilei by Giusto Sustermans in 1636.
Francis Bacon (England, 1561-1626) (on 2 lists)
Empiricist and philosopher of science. Empiricism. The scientific method. Novum Organum (1620).
A 1617 portrait of Francis Bacon by Frans Pourbus.
Johannes Kepler (Germany, 1571-1630) (on 7 lists)
Mathematician and astronomer. The laws of planetary motion. Rudolphine Tables. New Astronomy (1609). The Harmony of the World (1619). Epitome Astronomiae Copernicanae (1617-1621).
A 1610 portrait of Johannes Kepler.
William Harvey (England, 1578-1657) (on 4 lists)
Physician and anatomist. The circulatory system. De Motu Cordis (On the Circulation of the Blood).
A portrait of William Harvey.
René Descartes (France, 1596-1650) (on 5 lists)
Philosopher, mathematician and philosopher of science. The scientific method. Analytic geometry. Calculus. The law of refraction. La Géométrie (1637). Discourse on Method (1637).
A late 17th Century copy of Franz Hals’ 1649 portrait of René Descartes, now in the Louvre in Paris.
1600-1699
Blaise Pascal (France, 1623-1662) (on 5 lists)
Mathematician, physicist and inventor. The mechanical calculator. Probability theory. Atmospheric pressure. Projective geometry.
Blaise Pascal.
Robert Boyle (Ireland/England, 1627-1691) (on 5 lists)
Natural philosopher, chemist and physicist. The nature of air. The nature of a vacuum. Boyle’s Law.
Johann Kerseboom’s 1689 portrait of Robert Boyle.
Christiaan Huygens (The Netherlands, 1629-1695) (on 4 lists)
Mathematician, astronomer, physicist, horologist and probabilist. Telescopes. The law of refraction. The wave theory of light. The rings and moon of Saturn. The pendulum clock.
A 1671 portrait of Christiaan Huygens by Caspar Netscher.
Antonie van Leeuwenhoek (The Netherlands, 1632-1723) (on 4 lists)
Microbiologist. Bacteria and other microorganisms.
A portrait of Antonie van Leeuwenhoek by Jan Verkolje from between 1670 and 1693. It is located in the Museum Boerhaave in Leiden.
Robert Hooke (England, 1635-1703) (on 5 lists)
Biologist, physicist and chemist. Cells. Gravity. The air pump. Micrographia (1665).
An artist’s impression of Robert Hooke.
Sir Isaac Newton (England, 1643-1727) (on 17 lists)
Physicist, mathematician and inventor. Classical mechanics and the universal laws of motion. The law of universal gravitation. Calculus. The light spectrum and particle theory of light. The reflecting telescope. Philosophiae Naturalis Principia Mathematica (1687).
Portrait of Sir Isaac Newton painted in 1689 by Sir Godfrey Kneller.
Gottfried Wilhelm Leibniz (Germany, 1646-1716) (on 3 lists)
Philosopher and mathematician. Differential and integral calculus. Law of Continuity. Transcendental Law of Homogeneity. Mechanical calculators.
A portrait of Gottfried Leibniz by Christoph Bernhard Francke.
Edmond Halley (England, 1656-1742) (on 3 lists)
Astronomer, geophysicist, mathematician, meteorologist and physicist. The nature of comets. Astronomical measurements.
A portrait of Edmond Halley by Godfrey Kneller, c. 1721.
Thomas Newcomen (England, 1663-1729) (on 2 lists)
Inventor. The steam engine.
Thomas Newcomen.
Daniel Gabriel Fahrenheit (Germany/Netherlands, 1686-1736) (on 2 lists)
Physicist, inventor and scientific instrument maker. Thermometry. Mercury-in-glass thermometer. Fahrenheit scale.
Daniel Gabriel Fahrenheit.
1700-1799
Anders Celsius (Sweden, 1701-1744) (on 2 lists)
Astronomer, physicist and mathematician. Aurora borealis. Brightness of stars. The shape of the earth. Celsius temperature scale.
A painting of Anders Celsius by Olof Arenius.
Benjamin Franklin (US, 1706-1790) (on 4 lists)
Physicist, chemist, geographer, oceanographer, meteorologist and statistician. Electricity and lightning. The Gulf Stream. Bifocal lenses.
A 1785 portrait of Benjamin Franklin wearing his bifocal lenses by Charles Wilson Peale.
Carl Linnaeus (Sweden, 1707-1778) (on 5 lists)
Zoologist, botanist, physician and taxonomist. A biological classification system. Binomial nomenclature.
A 1775 portrait of Carl Linnaeus by Alexander Roslin.
Charles Messier (France, 1730-1817) (on 2 lists)
Astronomer. Messier catalog. Comets.
A portrait of Charles Messier by Nicolas Ansiaume from c. 1770.
Henry Cavendish (England, 1731-1810) (on 4 lists)
Experimental and theoretical chemist and physicist. The composition of air. The properties of gases. The synthesis of water. Electrical attraction and repulsion. The density of the Earth.
Henry Cavendish.
Joseph Priestley (England, 1733-1804) (on 3 lists)
Physicist and chemist. Soda water. Oxygen. Electrical force and conductivity.
Joseph Priestley.
Charles-Augustin de Coulomb (France, 1736-1806) (on 3 lists)
Physicist. Coulomb’s law. The attraction and repulsion of magnetic poles.
A portrait of Charles-Augustin de Coulomb by Hippolyte Lecomte.
James Watt (GB: Scotland, 1736-1819) (on 3 lists)
Inventor, engineer and chemist. Steam engine. Horsepower.
A 1792 portrait of James Watt by Carl Frederik von Breda, now in the National Portrait Gallery, London.
Joseph-Louis Lagrange (Giuseppe Lodovico Lagrangia) (Italy, 1736-1813) (on 2 lists)
Mathematician and astronomer. Calculus of variations. Lagrange multipliers. Variation of parameters. Group theory. Lagrangian points. Lagrangian mechanics. Mécanique analytique,
A portrait of Joseph-Louis Lagrange.
William Herschel (Germany/GB, 1738-1822) (on 3 lists)
Astronomer, physicist and biologist. The planet Uranus and two moons. Two moons of Saturn. Infrared radiation. Coral.
A 1785 portrait of William Herschel by Lemuel Francis Abbott.
Antoine-Laurent Lavoisier (France, 1743-1794) (on 8 lists)
Chemist. The nature of combustion. The law of conservation of mass. Oxygen.
Antoine-Laurent Lavoisier.
Jean-Baptiste Lamarck (Jean-Baptiste de Monet, Chevalier de Lamarck) (France, 1744-1829) (on 2 lists)
Biologist and naturalist. Invertebrates. Lamarckian evolution. Philosophie Zoologique.
An 1802 portrait of Jean-Baptiste Lamarck by Charles Thévenin.
Alessandro Volta (Italy, 1745-1827) (on 7 lists)
Physicist and chemist. The electric battery.
A portrait of Alessandro Volta.
Pierre-Simon Laplace (France, 1749-1827) (on 4 lists)
Mathematician, astronomer and statistician. Laplace’s equation. Probability and statistics. Black holes. Determinants. The Young-Laplace equation. The speed of sound.
Pierre-Simon Laplace.
Edward Jenner (England, 1749-1823) (on 3 lists)
Physician, immunologist and biologist. Vaccination.
A portrait of Edward Jenner by James Northcote, from between 1803 and 1823, which is now in the National Portrait Gallery in London.
Caroline Herschel (Germany/GB, 1750-1848) (on 2 lists)
Astronomer. Comets. New General Catalogue.
A print of an 1829 portrait of Caroline Herschel by M.F. Tielemann.
John Dalton (England, 1766-1844) (on 9 lists)
Chemist, meteorologist and physicist. The atomic theory.
An 1834 portrait of John Dalton by Charles Turner.
Joseph Fourier (France, 1768-1830) (on 2 lists)
Mathematician and physicist. Fourier series. Fourier transform. Fourier’s law of conduction. Fourier-Motzkin elimination. The greenhouse effect. The Analytical Theory of Heat.
A drawing of Joseph Fourier, c. 1820.
Alexander von Humboldt (Germany, 1769-1859) (on 2 lists)
Geographer, geologist, biologist, meteorologist and biogeographer. The Jurassic Period. The Humboldt Current.
An 1843 portrait of Alexander von Humboldt by Joseph Karl Stieler.
André-Marie Ampère (France, 1775-1836) (on 4 lists)
Physicist and mathematician. Electromagnetism. Ampère’s law.
André-Marie Ampère.
Amedeo Avogadro (Italy, 1776-1856) (on 4 lists)
Physicist and chemist. Molecules. Avogadro’s Law.
Amedeo Avogadro.
Carl Friedrich Gauss (Germany, 1777-1855) (on 4 lists)
Mathematician, astronomer and geophysicist. Number theory. Algebra. Ceres. The heliotrope. Disquisitiones Arithmeticae (1801).
An 1840 portrait of Carl Friedrich Gauss by Christian Albrecht Jensen.
Joseph Louis Gay-Lussac (France, 1778-1850) (on 3 lists)
Chemist and physicist. Gay-Lussac’s Law. The composition of the atmosphere. Boron. Iodine.
Joseph Louis Gay-Lussac.
Sir Humphrey Davy (GB, 1778-1829) (on 2 lists)
Chemist and inventor. Electrolysis. Davy lamp. Electrochemistry. Potassium, sodium, calcium, strontium, barium, magnesium, boron, chlorine, iodine. Nitrous oxide. On Some Chemical Agencies of Electricity.
A portrait of Sir Humphrey Davy by Thomas Phillips.
Georg Ohm (Germany, 1789-1854) (on 4 lists)
Physicist and mathematician. Ohm’s Law.
A photograph of Georg Ohm.
Michael Faraday (UK: England, 1791-1867) (on 14 lists)
Experimental physicist, chemist and inventor. Electromagnetic induction. Diamagnetism. Electrolysis. Benzene. The electric generator.
Photograph of Michael Faraday from about 1861, probably taken by John Watkins.
Charles Babbage (UK: England, 1791-1871) (on 3 lists)
Mathematician, mechanical engineer and inventor. Calculating machines: the difference engine and the programmable analytical calculator.
An 1860 photograph of Charles Babbage.
Charles Lyell (UK: Scotland, 1797-1875) (on 2 lists)
Geologist. Uniformitarianism. Vulcanism and earthquakes. Glaciers.
A photograph of Charles Lyell.
1800-1849
Christian Doppler (Austria, 1803-1853) (on 2 lists)
Mathematician, physicist and astronomer. The Doppler effect. Binary stars. 
A photograph (or daguerreotype?) of Christian Doppler.
Justus von Liebig (Germany, 1803-1873) (on 2 lists)
Chemist. Organic chemistry. Fertilizer. Law of the Minimum. Liebig condenser. Nutrition theory. Annalen der Chemie und Pharmacie (now Justus Liebigs Annalen der Chemie).
Justus von Liebig.
Sir William Rowan Hamilton (Ireland, 1805-1865) (on 2 lists)
Mathematician, astronomer and physicist. Hamiltonian mechanics. Quaternions. Geometrical optics. Cayley-Hamilton theorem. Icosian calculus. Hamilton’s principal function. The hodograph. Elements of Quaternions.
Photographic portrait of Sir William Rowan Hamilton.
Charles Darwin (UK: England, 1809-1882) (on 14 lists)
Biologist, naturalist and geologist. Evolution by means of natural selection. The Voyage of the Beagle (1845). The Origin of Species (1859).
Photograph of Charles Darwin in 1857.
Robert Bunsen (Germany, 1811-1899) (on 3 lists)
Chemist. Spectrochemical analysis. Discovered caesium and rubidium (with Gustav Kirchhoff). Bunsen burner (with Peter Desaga). Organoarsenic chemistry. Carbon-zinc electrochemical cell.
An undated photo of Robert Bunsen.
Julius Robert Mayer (Germany, 1814-1878) (on 2 lists)
Physician, chemist and physicist. Thermodynamics. Law of conservation of energy. Oxidation.
A photograph (or daguerreotype) of Julius Robert Mayer by Friedrich Berrer.
Karl Weierstrass (Germany, 1815-1897) (on 2 lists)
Mathematician. Intermediate Value Theorem. Weierstrass function. (ε, δ)-definition of limit. Weierstrass–Erdmann condition. Weierstrass theorems. Bolzano–Weierstrass theorem.
Karl Weierstrass.
James Prescott Joule (UK: England, 1818-1889) (on 4 lists)
Physicist. The relation of heat to mechanical energy. The law of conservation of energy. Joule’s law.
James Joule.
Hermann von Helmholtz (Germany, 1821-1894) (on 2 lists)
Physician and physicist. Conservation of energy. Vortex dynamics. Ophthalmoscope. Helmholtz resonator.
Hermann von Helmholtz.
Elizabeth Blackwell (UK/US, 1821-1910) (on 2 lists)
Physician and educator. Medical education. Women’s health. The Laws of Life with Special Reference to the Physical Education of Girls.
Elizabeth Blackwell.
Louis Pasteur (France, 1822-1895) (on 14 lists)
Microbiologist and chemist. The germ theory of disease. Vaccination using weakened bacteria. Pasteurization. The cause of fermentation.
An 1878 photograph of Louis Pasteur by Nadar.
Gregor Mendel (Austria-Hungary, now Czech Republic, 1822-1884) (on 8 lists)
Botanist and geneticist. The laws of heredity. Experiments on Plant Hybridization (1865).
A photograph of Gregor Mendel.
Francis Galton (UK: England, 1822-1911) (on 2 lists)
Psychologist, anthropologist, geographer, meteorologist, and statistician. Eugenics. Correlation and regression. Fingerprinting. Psychometrics. The Galton Whistle.
A photograph of Francis Galton from the 1850s.
William Thomson, Lord Kelvin (UK: Northern Ireland, 1824-1907) (on 7 lists)
Physicist, mathematician and engineer. Electricity and magnetism. The second law of thermodynamics. Absolute zero.
A photograph of Lord Kelvin.
Gustav R. Kirchhoff (Germany, 1824-1887) (on 2 lists)
Physicist. Spectroscopy. Kirchhoff’s circuit laws. Black-body radiation. Kirchhoff’s law of thermochemistry.
A photograph of Gustav Kirchhoff.
Bernhard Riemann (Georg Friedrich Bernhard Riemann) (Germany, 1826-1866) (on 2 lists)
Mathematician. Riemannian geometry. Riemann integral. Riemann surfaces. Riemann hypothesis. On the hypotheses which underlie geometry.
An 1863 photo of Bernhard Riemann.
Joseph Lister (UK: England, 1828-1912) (on 4 lists)
Physician and surgeon. Antiseptic medical procedures.
A 1902 photograph of Joseph Lister.
James Clerk Maxwell (UK: Scotland, 1831-1879) (on 15 lists)
Physicist and mathematician. Electromagnetism (union of electricity, magnetism and light). The wave theory of light. Color photography. The Maxwell-Boltzmann distribution. Matter and Motion (1888). A Treatise on Electricity and Magnetism (1904).
An engraved portrait of James Clerk Maxwell by G. J. Stodart, based on a photograph by Fergus of Greenock.
Alfred Nobel (Sweden, 1833-1896) (on 5 lists)
Chemist and engineer. Dynamite.
A photograph of Alfred Nobel.
Dmitri Mendeleev (Russia, 1834-1907) (on 6 lists)
Chemist. The periodic table.
A photograph of Dmitri Mendeleev.
Ernst Haeckel (Germany, 1834-1919) (on 2 lists)
Biologist, physician, philosopher and naturalist. Human evolution. Recapitulation theory.
An 1860 photograph of Ernst Haeckel.
Robert Koch (Germany, 1843-1910) (on 3 lists)
Physician, microbiologist and bacteriologist. The bacteria causing anthrax, tuberculosis and cholera. (Nobel Prize in Physiology/Medicine 1905)
A photograph of Robert Koch.
Wilhelm Conrad Röntgen (Germany, 1845-1923) (on 4 lists)
Physicist. X-rays. (Nobel Prize in Physics 1901)
Wilhelm Röntgen.
Thomas Alva Edison (US, 1847-1931) (on 8 lists)
Inventor. The incandescent light bulb. The phonograph. The movie camera. The electric power grid.
A 1922 photograph of Thomas Edison by Louis Bachrach.
Alexander Graham Bell (UK: Scotland/US/Canada, 1847-1922) (on 4 lists)
Inventor, engineer and deaf educator. The telephone. The photophone. The metal detector.
A photograph of Alexander Graham Bell taken between 1914 and 1919.
Ivan Pavlov (Russia, 1849-1936) (on 2 lists)
Physiologist. Classical conditioning. The conditioned reflex. Transmarginal inhibition. Behavior modification.
Ivan Pavlov.
1850-1899
Henri Becquerel (France, 1852-1908) (on 2 lists)
Physicist and chemist. Radioactivity. (Nobel Prize in Physics 1903) 
A photograph of Henri Becquerel.
Hermann Emil Fischer (Germany, 1852-1919) (on 2 lists)
Chemist. Fischer esterification. The Fischer projection. Purine. Proteins. Enzymes.
(Nobel Prize in Chemistry 1902)
Hermann Emil Fischer.
William Ramsay (UK: Scotland, 1852-1916) (on 2 lists)
Chemist. The noble gases. (Nobel Prize in Chemistry 1904)
William Ramsay.
Albert Michelson (Germany/Poland/US, 1852-1931) (on 2 lists)
Physicist. Speed of light. Michelson-Morley experiment. (Nobel Prize in Physics 1907)
Albert Michelson.
Santiago Ramón y Cajal (Spain, 1852-1934) (on 2 lists)
Neuroscientist and pathologist. Neuroscience. (Nobel Prize in Physiology/Medicine 1906)
A photograph of Santiago Ramón y Cajal.
Paul Ehrlich (Germany, 1854-1915) (on 3 lists)
Physician and immunologist. The magic bullet theory. Blood cells. Diphtheria. Chemotherapy. The side-chain theory. (Nobel Prize in Physiology/Medicine 1908)
Paul Ehrlich.
Nikola Tesla (Serbia/US 1856-1943) (on 11 lists)
Electrical and mechanical engineer, inventor. Alternating current. The alternating current induction motor. The electric light. The Tesla coil. X-rays. Radio.
An 1890 photograph of Nicolas Tesla by Napoleon Sarony.
Sigmund Freud (Austria, 1856-1939) (on 5 lists)
Neurologist, psychiatrist and psychologist. Psychoanalysis. The Interpretation of Dreams (1899).
A photograph of Sigmund Freud from about 1900.
J.J. Thomson (UK: England, 1856-1940) (on 4 lists)
Physicist. The electron. Isotopes. The mass spectrometer.
J.J. Thomson.
Heinrich Hertz (Germany, 1857-1894) (on 4 lists)
Physicist. Electromagnetic radiation. Photoelectric effect. Hertz’s principle of least curvature.
A photograph of Heinrich Hertz.
Max Planck (Germany, 1858-1947) (on 8 lists)
Theoretical physicist. Quantum theory. (Nobel Prize in Physics 1918)
A 1915 photograph of Max Planck.
Rudolf Diesel (Germany, 1858-1913) (on 2 lists)
Inventor and mechanical engineer. Diesel engine.
Rudolf Diesel.
David Hilbert (Germany, 1862-1943) (on 2 lists)
Mathematician. Hilbert’s basis theorem. Hilbert’s axioms. Einstein-Hilbert action. Hilbert spaces. Hilbert’s problems. Hilbert’s program. Grundlagen der Mathematik.
Thomas Hunt Morgan (US, 1866-1945) (on 2 lists)
Evolutionary biologist, geneticist and embryologist. The location of genes on chromosomes. (Nobel Prize in Physiology/Medicine 1933)
Thomas Hunt Morgan.
Marie Curie (Poland/France, 1867-1934) (on 17 lists)
Physicist and chemist. Radioactivity. Radium and polonium. Radioactive Substances (1904). (Nobel Prize in Physics 1903; Nobel Prize in Chemistry 1911)
Marie Curie in 1920.
Wilbur Wright (US, 1867-1912) (on 3 lists)
Inventor and engineer. The airplane.
Wilbur Wright.
Karl Landsteiner (Germany, 1868-1943) (on 4 lists)
Physician and biologist. Blood types. (Nobel Prize in Physiology/Medicine 1930)
A photograph of Karl Landsteiner from the 1920s.
Fritz Haber (Germany, 1868-1934) (on 3 lists)
Chemist. Haber process. Born-Haber Cycle (with Max Born). Fertilizer. Haber-Weiss reaction. (Nobel Prize in Chemistry 1918)
A photograph of Fritz Haber.
Ernest Rutherford (NZ/UK, 1871-1937) (on 8 lists)
Theoretical and experimental physicist. The atomic nucleus. The structure of the atom. (Nobel Prize in Chemistry 1908)
A photograph of Ernest Rutherford.
Guglielmo Marconi (Italy, 1874-1937) (on 2 lists)
Inventor and electrical engineer. Radio. Marconi’s law. (Nobel Prize in Physics 1909)
Guglielmo Marconi shown with an early radio in 1896.
Lise Meitner (Austria/Sweden, 1878-1968) (on 2 lists)
Physicist. Nuclear fission.
A photograph of Lise Meitner.
Albert Einstein (Germany/US, 1879-1955) (on 19 lists)
Theoretical physicist. The special and general theories of relativity. The photoelectric effect. Brownian motion. Relativity: The Special and General Theory (1916). Ideas and Opinions (1995). (Nobel Prize in Physics 1921)
Albert Einstein in Vienna in 1921. Photo by F. Schmutzer.
Otto Hahn (Germany, 1879-1968) (on 4 lists)
Chemist and physicist. Nuclear fission. (Nobel Prize in Chemistry 1944)
Otto Hahn.
Alfred Wegener (Germany, 1880-1930) (on 3 lists)
Geophysicist and meteorologist. Continental drift.
A 1910 photograph of Alfred Wegener.
Alexander Fleming (UK: Scotland, 1881-1955) (on 7 lists)
Biologist, pharmacologist, botanist, bacteriologist and immunologist. Penicillin.
(Nobel Prize in Physiology/Medicine 1945)
Alexander Fleming.
Neils Bohr (Denmark, 1885-1962) (on 11 lists)
Theoretical and experimental physicist. Quantum atomic structure. Quantum mechanics. Electron complementarity. Atomic Theory and the Description of Nature (1934). (Nobel Prize in Physics 1922)
Niels Bohr in 1922.
Erwin Schrödinger (Austria, 1887-1961) (on 5 lists)
Physicist. Quantum mechanics. The Schrödinger equation. (Nobel Prize in Physics 1933)
A photograph of Erwin Schrödinger.
Chandrasekhara Venkata Raman (India, 1888-1970) (on 2 lists)
Physicist. Raman scattering. The Raman effect. Quantum photo spin. Acoustics. Raman spectroscopy. (Nobel Prize in Physics 1930)
Chandrasekhara Venkata Raman.
Edwin Hubble (US, 1889-1953) (on 8 lists)
Astronomer and cosmologist. The expansion of the universe. The existence of other galaxies. The Hubble constant. The Realm of the Nebulae (1935).
A photograph of Edwin Hubble.
James Chadwick (UK, 1891-1974) (on 2 lists)
Physicist. The neutron. The atomic bomb.
James Chadwick.
Louis de Broglie (France, 1892-1987) (on 2 lists)
Physicist. Wave-particle duality. Quantum theory. The principle of least action.
(Nobel Prize in Physics 1929)
Louis de Broglie.
Leo Szilard (Hungary/Germany/US, 1898-1964) (on 2 lists)
Physicist and inventor. Nuclear chain reaction. Linear accelerator. Cyclotron. Electron microscope. Szilard-Chalmers effect. Absorption refrigerator. Chemostat.
Leo Szilard.
1900-1949
Linus Pauling (US, 1901-1994) (on 7 lists)
Chemist, biochemist, quantum chemist and molecular biologist. Atomic structure. Chemical bonds. Protein architecture. The Nature of the Chemical Bond (1960).
(Nobel Prize in Chemistry 1954)
A photograph of Linus Pauling.
Enrico Fermi (Italy/US, 1901-1954) (on 5 lists)
Physicist. Nuclear fission. The nuclear reactor. (Nobel Prize in Physics 1938)
Enrico Fermi in the 1940s.
Werner Heisenberg (Germany, 1901-1976) (on 5 lists)
Theoretical physicist. Quantum mechanics. The uncertainty principle. Physics and Philosophy (1958). (Nobel Prize in Physics 1932)
Werner Heisenberg in 1933.
Barbara McClintock (US, 1902-1992) (on 4 lists)
Biologist. Cytogenetics. Gene transposition. Role of telomere and centromere. (Nobel Prize, Physiology/Medicine 1983)
A 1947 photograph of Barbara McClintock.
Paul Dirac (UK: England, 1902-1984) (on 3 lists)
Theoretical physicist. Quantum mechanics and quantum electrodynamics. The Dirac equation. Quantum field theories. Magnetic monopoles. (Nobel Prize in Physics 1933)
Paul Dirac.
John von Neumann (Hungary/US, 1903-1957) (on 2 lists)
Mathematician, physicist, economist, computer scientist and statistician. Continuous geometry. Measure theory. Lattice theory. Quantum mechanics. Game theory. Operator theory. The Ergodic theorem. Thermonuclear weapons. Computers. Zur Theorie der Gesellschaftsspiele (1928). Theory of Games and Economic Behavior (1944).
A photograph of John von Neumann from the 1940s.
Konrad Lorenz (Austria, 1903-1957) (on 2 lists)
Zoologist, ethologist and ornithologist. Animal behavior (ethology). Imprinting. On Aggression. (Nobel Prize in Physiology/Medicine 1973)
Konrad Lorenz with greylag geese.
Robert Oppenheimer (US, 1904-1967) (on 6 lists)
Theoretical and experimental physicist. Uranium and plutonium atomic fission bombs.
Robert Oppenheimer in 1946.
Maria Goeppert-Mayer (Germany/Poland/US, 1906-1972) (on 3 lists)
Physicist. Two-proton absorption. Nuclear shell structure. (Nobel Prize in Physics 1963)
A 1963 photograph of Maria Goeppert-Mayer.
Hans Bethe (Germany/US, 1906-2005) (on 2 lists)
Nuclear physicist and astrophysicist. Quantum mechanics. Atomic nuclei. Stellar nucleosynthesis. Cosmic rays. Hydrogen energy levels. (Nobel Prize in Physics 1967)
Hans Bethe.
Rachel Carson (US, 1907-1964) (on 5 lists)
Marine biologist and conservationist. Effect of pesticides. The Sea Around Us (1951). Silent Spring (1962). The Sense of Wonder (1965).
A 1940 photograph of Rachel Carson.
Edward Teller (Hungary/US, 1908-2003) (on 4 lists)
Theoretical physicist. The hydrogen bomb.
A 1958 photograph of Edward Teller.
John Bardeen (US, 1908-1991) (on 3 lists)
Physicist and electrical engineer. The transistor. Superconductivity.
(Nobel Prize in Physics 1956 & 1972)
John Bardeen with a transistor.
Rita Levi-Montalcini (Italy, 1909-2012) (on 2 lists)
Neurobiologist. Nerve growth factor. Mast cells. (Nobel Prize in Physiology/Medicine 1986)
Rita Levi-Montalcini.
Alan M. Turing (UK: England, 1912-1954) (on 3 lists)
Computer scientist, mathematician and logician. The Turing Machine. The Universal Computer.
A photograph of Alan Turing.
Wernher von Braun (Germany/US, 1912-1977) (on 2 lists)
Aerospace engineer and space architect. Rocket science. V-2 rocket. Intermediate-range ballistic missile. Saturn V. Marshall Space Flight Center.
Wernher von Braun with a model of a V-2 rocket.
Jonas Salk (US, 1914-1995) (on 4 lists)
Medical researcher and virologist. A polio vaccine.
A 1956 photograph of Jonas Salk by Yousuf Karsh.
Norman Ernest Borlaug (US, 1914-2009) (on 2 lists)
Botanist, agricultural scientist, plant pathologist and geneticist. The Green Revolution. Agriculture. Food production. (Nobel Peace Prize 1970)
Norman Borlaug.
Charles Hard Townes (US, 1915- ) (on 2 lists)
Physicist. The maser and the laser. (Nobel Prize in Physics 1964)
Charles Townes.
Francis Crick (UK: England, 1916-2004) (on 5 lists)
Molecular biologist, biophysicist and neuroscientist. The structure of DNA.
(Nobel Prize in Physiology/Medicine 1962)
Francis Crick.
Richard Feynman (US, 1918-1988) (on 3 lists)
Theoretical physicist. Quantum electrodynamics. The path integral formulation. Feynman diagrams. Supercooled liquid helium. Weak decay. The Feynman Lectures on Physics (1963). (Nobel Prize in Physics 1965)
Richard Feynman.
Gertrude B. Elion (US, 1918-1999) (on 3 lists)
Biochemist and pharmacologist. Purines. Immunosuppressive and antiviral drugs. (Nobel Prize in Physiology/Medicine 1988)
Gertrude Elion.
Frederick Sanger (UK: England, 1918-2013) (on 2 lists)
Biochemist. The structure of proteins. Sequencing of insulin. Sequencing RNA and DNA. (Nobel Prize in Chemistry 1958 & 1980)
Frederick Sanger.
Rosalind Franklin (UK: England, 1920-1958) (on 7 lists)
Chemist and X-ray crystallographer. The structure of DNA.
Rosalind Franklin.
James Watson (US, 1928- ) (on 8 lists)
Molecular biologist, geneticist and zoologist. The structure of DNA. The Double Helix (1968). (Nobel Prize in Physiology/Medicine 1962)
James Watson.
Noam Chomsky (US, 1928- ) (on 2 lists)
Cognitive scientist, linguist, logician and philosopher. Transformational grammar. Universal grammar. Generative grammar. Chomsky hierarchy. Syntactic Structures (1957).
Noam Chomsky.
E.O. Wilson (US, 1929- ) (on 4 lists)
Biologist, conservationist, sociobiologist and mymecologist. Ant behavior. Sociobiology. The Insect Societies (1971). Sociobiology (1975). The Ants (with Bert Holldobler) (1990).
E.O. Wilson.
Gordon Moore (US, 1929- ) (on 2 lists)
Physicist, chemist and computer scientist. Moore’s Law. Integrated circuits. Single chip microprocessor.
Gordon Moore.
Peter Higgs (UK, 1929- ) (on 2 lists)
Physicist. Mass of subatomic particles. Higgs mechanism. Higgs boson. Higgs field. Broken symmetry. (Nobel Prize in Physics 2013)
A 2013 photograph of Peter Higgs.
Roger Penrose (UK: England, 1931- ) (on 2 lists)
Physicist, mathematician and philosopher of science. Moore-Penrose inverse. Penrose triangle. Penrose-Hawking singularity theorems. Penrose tilings. Big Bang. Consciousness.
Roger Penrose.
Steven Weinberg (US, 1933- ) (on 3 lists)
Theoretical physicist. The electroweak force. Technicolor interactions. The First Three Minutes (1977). (Nobel Prize in Physics 1979)
Steven Weinberg.
Jane Goodall (UK: England, 1934- ) (on 5 lists)
Primatologist, ethologist and anthropologist. Chimpanzee behavior. Jane Goodall: 50 Years at Gombe (2010).
Jane Goodall and friend.
Carl Sagan (US, 1934-1996) (on 2 lists)
Astronomer, astrophysicist, cosmologist and educator. Surface temperature of Venus. Liquid on Europa. Organic material on Titan. Extraterrestrial life. Creating amino acids. The Cosmic Connection (1973). Cosmos (1985).
Carl Sagan.
Lynn Margulis (US, 1938-2011) (on 2 lists)
Biologist. Endosymbiosis theory. Symbiogenesis. Protists. Gaia hypothesis. Symbiotic Planet (1999).
Lynn Margulis.
Donald Knuth (US, 1938- ) (on 3 lists)
Computer scientist and mathematician. Analysis of algorithms. Literate programming. METAFONT. MMIX.
A 1958 photograph of Donald Knuth.
Stephen Jay Gould (US, 1941-2002) (on 2 lists)
Paleontologist, evolutionary biologist and science historian. Punctuated equilibrium. Land snails. Evolutionary theory. The Mismeasure of Man (1981). Wonderful Life (1989).
Stephen Jay Gould and friend.
Stephen Hawking (UK: England, 1942-2018) (on 11 lists)
Theoretical physicist and cosmologist. Quantum gravity. The nature of black holes. The origin of galaxies. A Brief History of Time (1988).
Stephen Hawking during a visit to NASA in the 1980s.
Christiane Nüsslein-Volhard (Germany, 1942- ) (on 2 lists)
Biologist. Genetic control of embryonic development. Toll genes. (Nobel Prize in Physiology/Medicine 1995)
A 2008 photograph of Christiane Nüsslein-Volhard.
Craig Venter (US, 1946- ) (on 3 lists)
Biochemist and geneticist. The human genome.
Craig Venter.
Alan Guth (US, 1947- ) (on 2 lists)
Theoretical physicist and cosmologist. Cosmic inflation theory.
A photograph of Alan Guth by Deanne Fitzmaurice (National Geographic).
1950-Present
Edward Witten (US, 1951- ) (on 2 lists)
Theoretical physicist and mathematician. String theory. Topological quantum field theory. Quantum gravity.
Edward Witten.
Tim Berners-Lee (UK: England, 1955- ) (on 8 lists)
Computer scientist. The World Wide Web.
Tim Berners-Lee in 2008.
Mae Jemison (US, 1956- ) (on 2 lists)
Engineer, physician and astronaut. Space shuttle mission specialist, STS-47 (1992).
A 1992 photograph of Dr. Mae Jemison.