SCIENCE’S TIMELINE HISTORY OF MATHEMATICS
Ca. 70,000 BC- south african ochre rocks adorned with scratches of geometric patterns. C. 20,000 BC-1st reference to prime numbers.
2500 bc-multiplication tables
C. 2,000 BC-1st known approximation of the value of pi.
C. 1,800 BC-berlin papyrus 6619 contains the quadratic equation and its solution. 1,650 BC- attempt to square a circle and solutions to linear equations, 1st use of
cotangent, solving linear equations
ANCIENT BABYLON-practical arithmetic, and geometry, use both duodecimal and decimal systems, composite and prime numbers, arithmetic, geometric, and harmonic means, sieve of eratosthenes, perfect number theory (number 6), linear equations, arithmetic and geometric series, solving 2nd order equations
ANCIENT EGYPT- arithmetic and cadastral surveys, use of decimal system C. 2000-1800 bc-pythagorean triples and pythagorean theorem
1,046 BC-256 BC-arithmetic and geometric algorithms and proofs.
C. 8th century BC-earliest concept of infinity.
800 BC-use of quadratic equation
C. 600 BC-calculation of pythagorean triples, quadratic equations
key people: thales, pythagoras, euclid
main accomplishments: geometry, logical reasoning thales-pure geometry, Pythagoras-deductive geometry, special numbers and ratios, eudoxus-method of exhaustion, Mathematical rigor, conics, spherical geometry summation of infinite series
C. 530 BC- discovery of irrational numbers
C. 400 BC-recognition of 5 kinds of infinity
300 BC-earliest information on combinations, fundamental theorem of arithmetic
Key people: archimedes, apollonius, diophantus
Key accomplishments: algebra
euclid- systematization of deductive geometry, archimedes-applied
math, apollonius-conics, hero-algebraic method, archimedes-rational approximation of irrational numbers, Diophantus-algebraic notation
300 BC-proof of infinitely many prime numbers; proof of the fundamental theorem of arithmetic, 1st use of fibonacci numbers and pascal’s triangle
C. 300 BC-1st use of fibonacci numbers and pascal’s triangle
150 BC-knowledge of the theory of numbers, arithmetic operations, geometry,
operations with fractions, simple equations, cubic equations, quartic equations,
permutations, and combinations
150 BC-gaussian elimination, horner’s method, negative numbers, negative numbers 190-120 BC- development of trigonometry
1st century-earliest reference to the square root of a negative number 70-140-menelaus of alexandria on spherical trigonometry
250-350- diophantus- diophantine analysis, diophantine approximations, solutions of
179- china- mathematical formula for gaussian elimination
300-earliest use of zero
300-500-chinese remainder theorem
3rd century- cavalier’s principle to find volume of sphere
C. 400-understanding of logarithms to base 2 and computes square roots of numbers
as large as a million correct to 11 decimal places C. 340-hexagon theorem and centroid theorem
key people: khwarizmi
Key accomplishments: algebra
Khwarizmi- development and name of algebra
4th century-hexagon theorem and centroid theorem
500-aryabhata introduces the trigonometry of functions and how to calculate them 628-brahagupta sums series, Brahmagupta identity, brahamguptl theorem
8th century-virasena gives explicit rules for the fibonacci sequence, derivation of the
volume of a frustum using an infinite procedure, knows the laws for base 2
logarithm; shridhara-volume of sphere and formula for solving quadratic equations 9th century-govindsvamin-newton-gauss interpolation formula
C. 850—mahavira rules for expressing a fraction as sum of unit fractions; alkindi-
895-thabit Ibn qurra-solution and properties of cubic equations, and theorem of how
amicable numbers can be found
953-al-karaji-algebra replaces geometric operations with arithmetic operations, and
discovered the binomial theorem 975-al-batani-inverse of trigonometric functions 895-solutions and properties of cubic equations
10th to 15 centuries-
Key people: fibonacci
Key accomplishment: trigonometry
rediscovery of ancient knowledge, arabic-hindu numerals to west, fibonacci-rediscovery of arabic (greek) mathematics
9th century- algebra of irrational numbers with square roots of 4th roots as solutions and coefficients to quadratic equations, solving 3 nonlinear equations with 3 unknowns C. 1000-abu-mahmud al-khujandi-special case of fermat’s last theorem, law of sines,al-
karaji-1st known proof by induction and proof of binomial theorem, pascal’s triangle, and sum of integral cubes, and was 1st to introduce integral calculus
C. 1000-solving equations higher than degree 2
1000-1st proof by mathematical induction and used to prove binomial theorem, pascal’s
triangle, and the sum of integral cubes
1020-adul waft-formula for sin(a+b) and quadrature of parabola and volume of
1100-omar khayyam-general geometric solutions to cubic equations using intersecting
conic sections and laid foundations for development of analytic geometry and non- euclidean geometry
12th century- bhaskara recognizes that a positive number has 2 square roots, conceives differential calculus, develops rolle’s theorem, pell’s equation, a proof of the pythagorean theorem, proves division by zero is infinity, and calculated time which the earth orbits sun to 9 decimal places
1135-sharafeddin tush-uses algebra to study curves by means of equations-beginning of analytic geometry
C. 1250-nasir al-din-tusi-attempt to develop non-euclidean geometry 1280-1303-china-solution to simultaneous higher order algebraic equations using
method similar to horner’s method
1303-zhu shijie-method of arranging binomial coefficients in a triangle
14th century-madhava-father of mathematical analysis, worked on power series for pi, sine, and cosine, and founded important concepts of calculus, parameshvara- series form of sine function equivalent to Taylor series expansion, and states mean value theorem of differential calculus, bhaskara-2-mathematical objects equivalent or approximately equivalent to infinitesimals, derivatives, mean value theorem, and derivative of sine
1400-madhava-series expansion of inverse-tangent function, infinite series for arctan and sin
15th century-symbolic algebra and for mathematics in general; nilakantha somayaji- infinite series expansion
1424-ghiyath al-kashi-computes pi to 16 decimal places using inscribed and circumscribed polygons
Key people: tartaglia, cardano, napier, kepler
Key accomplishment: logarithms, infinitesimal, solving cubic and quartic equations
Tartaglia, cardano, bombelli-solution of cubic equations, vieta-
algebraic problems solved trigonometrically, Napier- logarithms, briggs-log tables 1639-cardono solves cubic equations
1540-ferrari solves quartic equations
1545-cardano conceives complex numbers
1572-bombelli uses imaginary numbers to solve cubic equations
Key people: newton, Leibniz, Jakob and john Bernoulli, Descartes, fermat
Key accomplishments: calculus, analytic geometry, probability, number
theory, codification algebra development of calculus, kepler-conics as modified circles, Wallis-mathematics of infinitesimal, limits, Newton and Leibniz-calculus, Bernoulli’s Jacques and jean-application of calculus, Descartes-coordinate geometry, desargues- projective geometry, pascal and format-statistical probability
1618- napier uses e in logarithmic work
1619-descartes and fermat- analytic geometry
1629-fermat- rudimentary differential calculus
1637-fermat claims to have proven fermat’s last theorem, 1st use of imaginary numbers 1654-pascal and fermat create theory of probability
1665-newton-fundamental theorem of calculus and infinitesimal calculus 1668-mercator and brouncker discover infinite series for the logarithm while attempting
to calculate area under hyperbolic segment
1671-gregory develops series expansion for inverse-tangent function 1673-leibniz-infintesimal calculus
1675-newton-computation of functional roots
1683-seki-resultant, determinant, elimination theory
1691-leibniz-separation of variables for ordinary differential equations 1696-l’hospital-rule for computing certain limits
1696-jakob and Johann bernoulli solve brachistochrone problem, the first result in
calculus of variations
Key people: euler, Laplace, Lagrange, de moivre, Daniel bernoulli
Key accomplishment: analysis, topology, mathematical physics, complex numbers,
cotes,de moivre, maupertius-complex numbers and trigonometry, Euler- development of analysis, and foundation of topography, Lagrange-calculus of variations, laplace-mathematical physics
1706-john machin develops a quickly converging inverse-tangent series for pi and computes pi to 100 decimal places
1722-de moire formula stated connecting trigonometric functions and complex numbers 1733-de moire introduces normal distribution to approximate binomial distribution in probability
1734-euler’s integrating factor technique to solve 1st-order ordinary differential
1735-euler solves Basel problem relating an infinite series to pi.
1736-euler-7 bridges of konigsberg, graph theory
1739-euler-solves general homogeneous linear ordinary differential equations with
1761-proof of bake’s theorem, lambert-pi irrational 1762-lagrange-divergence theorem
1796-gauss-regular 17-gon constructed with compass and straightedge 1796-legrendre-prime number theorem conjectured
1797-wessel-associates vectors with complex numbers and studies complex numbers
in geometric terms
1799-gauss-fundamental theorem of algebra; ruffini partial proof (abel-ruffini theorem)
quintic or higher equation cannot be solved by general formula
Key people- legendre, gauss, Riemann, Hamilton, abel, galois, Cauchy, Jacobi,
dirichlet, labochevski, weierstrauss, lie, klein, Hausdorff, Fourier
Key accomplishments- non-euclidean geometry, vector calculus, matrices, set
theory, group theory, boolean algebra, n-dimestions, theory of infinite gauss-number theory and method of least squares, fundamental theorem of algebra, quadratic law of reciprocity, bolyais (fracas and janos), lobachevski, Riemann-noneuclidean geometry, dedikind-dedikind cuts and
number theory, cantor-theory of infinite sets, mobiles-topology, babage- calculatikng engine, hamilton-quanternions, grassmann-vector analysis, Boole-boolean algebra, cayley-matrices, Venn-graphic solutions of set theory
19th century-hermann grassmann-vector spaces, galois-group theory, cantor-set theory 1805-legendre-methods of least squares for fitting a curve to given set of observations 1806-argand diagram
1807-fourier-trigonometric decomposition of functions
1811-gauss-integrals with complex limits
1815-poisson-integration along paths of complex plane 1817-bolzano-intermediate value theorem
1822-cauchy-cauchy integral theorem-integrate around boundary of rectangle in
1823-sophie germain theorem
1824-abel partial proof abel-ruffini theorem
1825-cauchy integral theorem for general integration paths, and theory of residues in
complex analysis; dirichlet and legendre-proof Fermat last theorem n=5, ampere-
1828-proof green’s theorem
1829-bolyai, gauss, labochevsky-hyperbolic non-euclidean geometry
Early 1800s-elliptical geometry
1831-ostrogradsky-proof divergence theorem and founding group and galois theory 1832-dirichlet-proof n=14 format’s last theorem, galois general condition for solving of
algebraic equations, thereby founding group theory and galois theory 1835-proof dirichlet theorem about primes in arithmetic progressions 1837-wantzel-proof impossibility double cube and trisect angle with compass and
straight edge, and constructability of regular polygon; dirchlet-analytic number
1841-1843-weierstrauss and laurent-laurent expansion theorem 1843-hamilton-quanternions
1847-boole-symbolic logic/boolean algebra
1850-stoke’s theorem proved
1854-cayley-quanternions in 4-dimensional space
1870-klein-analytic geometry for labochevskian geometry
1873-hermite- e transcendental; frobenius-series solutions to linear differential
equations with regular singular points
1874-cantor-real numbers uncountably infinite, but all algebraic numbers countably
1882-lindemann-pi transcendental and circle cannot be squared with compass and
straightedge; klein bottle
1895-cantor-set theory containing arithmetic of infinite cardinal numbers and continuum
1896-hadamard and vallée poussin prove prime number theorem 1899-cantor-contadiction in set theory
Key people: poincare, von neuman, godel, Russell, hilbert, lebesgue, manelbrot Key accomplishments: game theory, mathematical logic, chaos theory, statistics
einstein-theories of relativities, von neuman-game theory, Russell-math
logic, model- yodel’s theorem, measure theory, qualitative study of dynamical systems, axiomatization of probability theory, development of functional analysis, distribution theory, fixed point theory, knot theory, ergodic theory, singularity theory, catastrophe theory, lie theory, non-standard analysis, information theory, control theory
1903-runge-fast fourier transform algorithm
1903-landau-much simpler proof prime number theorem 1908-zermelo-axiometization of set theory avoiding cantor’s condradiction; plemelj-
solves reman problem about existence of differential equation with given
monochromic group and uses sokhotsky-plemelj formula
1912-brouwer fixed-point theorem
1915-noether-proves her symmetry theorem which shows symmetry in physics has a corresponding conservation law
1919-brun’s constant b2 for twin primes
1931-godel imcompleteness theorem
1931-de rham-theorems in cohomology and characteristic classes
1933-boruk-ulam antipodal-point; kolmogorov-axiomatization of probability based on
1940-gode-neither continuum hypothesis nor axiom of choice can be disproven from standard axioms of set theory
1942-fast fourier transform algorithm
1945-mac lane and eilenbery-category theory
1950-ulam and von neumann-cellular automata dynamical systems
1961-qr algorithm to calculate eigenvalues and eigenvectors of a matrix; smale-proof
dimensions >=5 for poincare conjecture
1963-cohen-neither continuum hypothesis nor axiom choice can be proven with
standard axioms of set theory; butterfly effect
1967-langlands program of conjectures relating number theory and representation
1968-proof of atiyah-singer-index theorem about index of elliptical operators 1975-mandelbrot-fractal
1976-proof 4-color theorem
1983-falting proves morsel conjecture-only infinite many whole number solutions for
each exponent fermat last theorem 1985-branges proves biererbach conjecture 1986-proof rib’s theorem
1991-connes and lott-non-commutative geometry 1994-shor’s algorithm, a quantum algorithm for
1995-wiles-proof format’s last theorem 1995-baily-borwein-plouffe formula to find nth binary digit of pi 1998-hales-almost certainly proof kepler conjecture
1999- proof taniyama-shimura conjecture
2000-clay mathematics institute millenium prize problems
2002-mihailescu proof Catalan’s conjecture
2003-perelman-proof poincare conjecture
2009-ngo baa-proof fundamental lemma (langlands program)
2005-green and tao prove the green-tao theorem
2009-fundamental lemma (langlands program) proved by ego ban Chau
2014-complete kepler’s conjecture proof, calculation of pi to 13.3 trillion digits 2015-tao-solves erdos discrepancy problem, lassie babai found that a quasi polynomial
complexity algorithm would solve the graph isomorphism problem
PHYSICS ANCIENT GREEKS AND ROMANS
C. 570-490 bc-pythagorean theorem: a^2+b^2=c^2 for a triangle
Early 5th century bc-leucippus opposed the idea of direct intervention in the universe. he and his student democritus were the first to develop a theory of atomism, a theoretical approach that regards something as interpretable through analysis into Distinct and separable, and independent elementary components.
424-347 bc-plato is said to have disliked democritus so much, that he wished his books Burned. Nowadays, many consider democritus to be the father of modern science.
384-322 bc-Aristotle, a student of plato, promoted the concept of natural laws for physical phenomena, which he attempted to explain with the theory of the 4 elements, earth, air, fire, and water. he had a geocentric view of the universe. Aristotelian physics became enormously popular in Europe with the scientific and scholastic developments of the middle ages and remained the mainstream scientific paradigm until the time of Galilei and newton.
310-ca. 230 bc-in contract to Aristotle’s geocentric view, aristarchus of Samos proposed a heliocentric model of the solar system, but received little support from ancient astronomers, although his student seleucus was according to Plutarch, the first to prove the heliocentric system through reasoning. But the argument got lost.
287-212 bc-archimedes- he was responsible for: the foundations of statics and hydrostatics Mathematics of the lever
The archimedes screw/pump
archimede’s principle-law of buoyance
His hypotheses are that the fixed stars and the sun remain
unmoved, that the earth revolves about the sun on the circumference of a circle.
90-168-based on previous work by Hipparchus (190-120 bc), ptolemy one of the leading minds of the roman empire, perfected the geocentric system, so that accurate predictions of the planetary movements became possible.
destruction of the library of alexandria in 48 bc. Most of the direct work of the ancient world got lost (about 40,000), including all 14 books of Hipparchus.
Hindu-arabic numeral system (0,1,2,3…)
awareness of ancient works re-entered the west through translations from arabic to latin.
C. 1270-roger bacon-conducted studies in optics
systematic theory and observation conducted to analyze nature in order to understand how the universe behaves.
1473-1543- Nicolaus copernicus-heliocentism 1546-1601-tycho brace-precise planetary data 1571-1630-johannes kepler-three laws of planetary motion
1564-1642-galilei galileo-birth of modern science. Use of telescope to see 4 of Jupiter’s moons, inertial frames (galileo relativity)
1642-1727-isaac newton-three laws of motion. priincipia mathematic. law of universal gravitation. Calculus.
1690-christian huygen-published a wave theory of light 1738-daniel Bernoulli-hydrodynamics
1798-count rumford-stated that the motion of particles in a substance produces heat. 1799-1825-laplace-celestial mechanics
1650-otto von guerricke-vacuum pump
1662-boyle’s law 1698,1711-savory,newcomen-theory of steam engine 1763-watt-steam engine
1831-robert brown-brownian movement
1840-1850-mayer, joule, thomphson-1st law of thermodynamics (energy conserved) 1851-kelvin, 1854-clausius-2nd law of thermodynamics
ELECTRODYNAMICS 1824-alexandra Volta-battery
1820-orsted, ampere-current-magnetic force, current-current force 1821-michael faraday-electric motor
1850-hippolyte fizeau, león foucault-accurate measurement of speed of light 1864-james clerk maxell-maxwell equations: c=1/ sqrt(u(0)e(0) 1890-electromagnetic waves, ether (false), radio
1887-michaelson-morley, 1905-einstein-c is independent of the motion of its source
BIRTH OF MODERN PHYSICS 1895-wilhelm rontgen-x-rays
1896-henri becquerel-natural radioactivity 1897-j.j. thomson-electron, isotopes Curies-isolate radioactive radium and polonium
1905-einstein-special theory of relativity (electrodynamics of moving bodies) 1906-einstein- e=mc^2
1911-rutherford-rutherford scattering-atomic structure 1916- einstein-general relativity (gravity)
QUANTUM MECHANICS 1900-max planck
1913-bohr- bohr model
(with contributions from einstein, de Broglie, born, jordan, Pauli, dirac, bose)
1928-dirac-relativistic dirac equation-antimatter
1932-sir john Cockcroft and Ernest watson-bulit first particle accelerator
1938-otto Hahn and fritz strassman-achieved fission of uranium atom
1942-enrico fermi-first controlled nuclear chain reaction 1947-bardeen, Shockley, brattain-invented transistor
BIRTH OF QUANTUM FIELD THEORY 1950-quantum electrodynamics
1964-murray gell-mann-proposed quark as a fundamental particle 1973-quantum chromodynamics
STANDARD MODEL OF PARTICLE PHYSICS
1975-(fermi, bethe, Feynman, schwinger, tomonaga, gell-mann,
higgs, brout, Sangler, kibble, guralnik, hagen, kibble, Glashow, salam, Weinberg, gross, wilczek, Politzer)
COSMOLOGY 2011-perlmutter, schmidt, ries
HISTORY OF CHEMISTRY
1 1/2 million years ago- used fire
35,000 bc- bronze (melting copper and tin together)
c. 3000 BC
Egyptians formulate the theory of the Ogdoad, or the “primordial forces”, from which all was formed. These were the elements of chaos, numbered in eight, that existed before the creation of the sun.
c. 1200 BC
Tapputi-Belatikallim, a perfume-maker and early chemist, was mentioned in a cuneiform tablet in Mesopotamia.
c. 450 BC
Empedocles asserts that all things are composed of four primal elements: earth, air, fire, and water, whereby two active and opposing forces, love and hate, or affinity and antipathy, act upon these elements, combining and separating them into infinitely varied forms.
c. 440 BC
Leucippus and Democritus propose the idea of the atom, an indivisible particle that all matter is made of. This idea is largely rejected by natural philosophers in favor of the Aristotlean view (see below).
c. 360 BC
Plato coins term ‘elements’ (stoicheia) and in his dialogue Timaeus, which includes a discussion of the composition of inorganic and organic bodies and is a rudimentary treatise on chemistry, assumes that the minute particle of each element had a special geometric shape: tetrahedron (fire), octahedron (air), icosahedron (water), and cube (earth).
c. 350 BC
Aristotle, expanding on Empedocles, proposes idea of a substance as a combination of matter and form. Describes theory of the Five Elements, fire, water, earth, air, and aether. This theory is largely accepted throughout the western world for over 1000 years.
c. 50 BC
Lucretius publishes De Rerum Natura, a poetic description of the ideas of atomism.
Zosimos of Panopolis writes some of the oldest known books on alchemy, which he defines as the study of the composition of waters, movement, growth, embodying and disembodying, drawing the spirits from bodies and bonding the spirits within bodies.
Abu Musa Jabir ibn Hayyan (aka Geber), an Arab/Persian alchemist who is “considered by many to be the father of chemistry”, develops an early experimental method for chemistry, and isolates numerous acids, including hydrochloric acid, nitric acid, citric acid, acetic acid, tartaric acid, and aqua regia.
Abū al-Rayhān al-Bīrūnī and Avicenna, both Persian chemists, refute the practice of alchemy and the theory of the transmutation of metals.
Magister Salernus of the School of Salerno makes the first references to the distillation of wine.
Robert Grosseteste publishes several Aristotelian commentaries where he lays out an early framework for the scientific method.
Tadeo Alderotti develops fractional distillation, which is much more effective than its predecessors.
St Albertus Magnus discovers arsenic and silver nitrate. He also made one of the first references to sulfuric acid.
Roger Bacon publishes Opus Maius, which among other things, proposes an early form of the scientific method, and contains results of his experiments with gunpowder.
Pseudo-Geber, an anonymous Spanish alchemist who wrote under the name of Geber, publishes several books that establish the long-held theory that all metals were composed of various proportions of sulfur and mercury.  He is one of the first to describe nitric acid, aqua regia, and aqua fortis.
Paracelsus develops the study of iatrochemistry, a subdiscipline of alchemy dedicated to extending life, thus being the roots of the modern pharmaceutical industry. It is also claimed that he is the first to use the word “chemistry”.
Andreas Libavius publishes Alchemia, a prototype chemistry textbook.
17th and 18th centuries
Sir Francis Bacon publishes The Proficience and Advancement of Learning, which contains a description of what would later be known as the scientific method.
Michal Sedziwój publishes the alchemical treatise A New Light of Alchemy which proposed the existence of the “food of life” within air, much later recognized as oxygen.
Jean Beguin publishes the Tyrocinium Chymicum, an early chemistry textbook, and in it draws the first-ever chemical equation.
René Descartes publishes Discours de la méthode, which contains an outline of the scientific method.
Posthumous publication of the book Ortus medicinae by Jan Baptist van Helmont, which is cited by some as a major transitional work between alchemy and chemistry, and as an important influence on Robert Boyle. The book contains the results of numerous experiments and establishes an early version of the law of conservation of mass.
The Sceptical Chymist by Robert Boyle (1627–91)
Robert Boyle publishes The Sceptical Chymist, a treatise on the distinction between chemistry and alchemy. It contains some of the earliest modern ideas of atoms, molecules, and chemical reaction, and marks the beginning of the history of modern chemistry.
Robert Boyle proposes Boyle’s law, an experimentally based description of the behavior of gases, specifically the relationship between pressure and volume.
Swedish chemist Georg Brandt analyzes a dark blue pigment found in copper ore. Brandt demonstrated that the pigment contained a new element, later named cobalt.
Joseph Black isolates carbon dioxide, which he called “fixed air”.
Louis Claude Cadet de Gassicourt, while investigating arsenic compounds, creates Cadet’s fuming liquid, later discovered to be cacodyl oxide, considered to be the first synthetic organometallic compound.
Joseph Black formulates the concept of latent heat to explain the thermochemistry of phase changes.
Henry Cavendish discovers hydrogen as a colorless, odourless gas that burns and can form an explosive mixture with air.
Carl Wilhelm Scheele and Joseph Priestley independently isolate oxygen, called by Priestley “dephlogisticated air” and Scheele “fire air”.
Antoine-Laurent de Lavoisier (1743–94) is considered the “Father of Modern Chemistry”.
Antoine Lavoisier, considered “The father of modern chemistry”, recognizes and names oxygen, and recognizes its importance and role in combustion.
Antoine Lavoisier publishes Méthode de nomenclature chimique, the first modern system of chemical nomenclature.
Jacques Charles proposes Charles’s law, a corollary of Boyle’s law, describes relationship between temperature and volume of a gas.
Antoine Lavoisier publishes Traité Élémentaire de Chimie, the first modern chemistry textbook. It is a complete survey of (at that time) modern chemistry, including the first concise definition of the law of conservation of mass, and thus also represents the founding of the discipline of stoichiometry or quantitative chemical analysis.
Joseph Proust proposes the law of definite proportions, which states that elements always combine in small, whole number ratios to form compounds.
Alessandro Volta devises the first chemical battery, thereby founding the discipline of electrochemistry.
John Dalton proposes Dalton’s law, which describes relationship between the components in a mixture of gases and the relative pressure each contributes to that of the overall mixture.
Joseph Louis Gay-Lussac discovers that water is composed of two parts hydrogen and one part oxygen by volume.
Joseph Louis Gay-Lussac collects and discovers several chemical and physical properties of air and of other gases, including experimental proofs of Boyle’s and Charles’s laws, and of relationships between density and composition of gases.
John Dalton publishes New System of Chemical Philosophy, which contains first modern scientific description of the atomic theory, and clear description of the law of multiple proportions.
Jöns Jakob Berzelius publishes Lärbok i Kemien in which he proposes modern chemical symbols and notation, and of the concept of relative atomic weight.
Amedeo Avogadro proposes Avogadro’s law, that equal volumes of gases under constant temperature and pressure contain equal number of molecules.
Friedrich Wöhler and Justus von Liebig perform the first confirmed discovery and explanation of isomers, earlier named by Berzelius. Working with cyanic acid and fulminic acid, they correctly deduce that isomerism was caused by differing arrangements of atoms within a molecular structure.
William Prout classifies biomolecules into their modern groupings: carbohydrates, proteins and lipids.
Friedrich Wöhler synthesizes urea, thereby establishing that organic compounds could be produced from inorganic starting materials, disproving the theory of vitalism.
Friedrich Wöhler and Justus von Liebig discover and explain functional groups and radicals in relation to organic chemistry.
Germain Hess proposes Hess’s law, an early statement of the law of conservation of energy, which establishes that energy changes in a chemical process depend only on the states of the starting and product materials and not on the specific pathway taken between the two states.
Hermann Kolbe obtains acetic acid from completely inorganic sources, further disproving vitalism.
Lord Kelvin establishes concept of absolute zero, the temperature at which all molecular motion ceases.
Louis Pasteur discovers that the racemic form of tartaric acid is a mixture of the levorotatory and dextrotatory forms, thus clarifying the nature of optical rotation and advancing the field of stereochemistry.
August Beer proposes Beer’s law, which explains the relationship between the composition of a mixture and the amount of light it will absorb. Based partly on earlier work by Pierre Bouguer and Johann Heinrich Lambert, it establishes the analytical technique known as spectrophotometry.
Benjamin Silliman, Jr. pioneers methods of petroleum cracking, which makes the entire modern petrochemical industry possible.
William Henry Perkin synthesizes Perkin’s mauve, the first synthetic dye. Created as an accidental byproduct of an attempt to create quinine from coal tar. This discovery is the foundation of the dye synthesis industry, one of the earliest successful chemical industries.
Friedrich August Kekulé von Stradonitz proposes that carbon is tetravalent, or forms exactly four chemical bonds.
Gustav Kirchhoff and Robert Bunsen lay the foundations of spectroscopy as a means of chemical analysis, which lead them to the discovery of caesium and rubidium. Other workers soon used the same technique to discover indium, thallium, and helium.
Stanislao Cannizzaro, resurrecting Avogadro’s ideas regarding diatomic molecules, compiles a table of atomic weights and presents it at the 1860 Karlsruhe Congress, ending decades of conflicting atomic weights and molecular formulas, and leading to Mendeleev’s discovery of the periodic law.
Alexander Parkes exhibits Parkesine, one of the earliest synthetic polymers, at the International Exhibition in London. This discovery formed the foundation of the modern plastics industry.
Alexandre-Emile Béguyer de Chancourtois publishes the telluric helix, an early, three-dimensional version of the periodic table of the elements. 1864
John Newlands proposes the law of octaves, a precursor to the periodic law.
Lothar Meyer develops an early version of the periodic table, with 28 elements organized by valence.
Cato Maximilian Guldberg and Peter Waage, building on Claude Louis Berthollet’s ideas, proposed the law of mass action.
Johann Josef Loschmidt determines exact number of molecules in a mole, later named Avogadro’s number.
Friedrich August Kekulé von Stradonitz, based partially on the work of Loschmidt and others, establishes structure of benzene as a six carbon ring with alternating single and double bonds.
Adolf von Baeyer begins work on indigo dye, a milestone in modern industrial organic chemistry which revolutionizes the dye industry.
Mendeleev’s 1869 Periodic table
Dmitri Mendeleev publishes the first modern periodic table, with the 66 known elements organized by atomic weights. The strength of his table was its ability to accurately predict the properties of as-yet unknown elements.
Jacobus Henricus van ‘t Hoff and Joseph Achille Le Bel, working independently, develop a model of chemical bonding that explains the chirality experiments of Pasteur and provides a physical cause for optical activity in chiral compounds.
Josiah Willard Gibbs publishes On the Equilibrium of Heterogeneous Substances, a compilation of his work on thermodynamics and physical chemistry which lays out the concept of free energy to explain the physical basis of chemical equilibria.
Ludwig Boltzmann establishes statistical derivations of many important physical and chemical concepts, including entropy, and distributions of molecular velocities in the gas phase.
Svante Arrhenius develops ion theory to explain conductivity in electrolytes. 
Jacobus Henricus van ‘t Hoff publishes Études de Dynamique chimique, a seminal study on chemical kinetics.
Hermann Emil Fischer proposes structure of purine, a key structure in many biomolecules, which he later synthesized in 1898. Also begins work on the chemistry of glucose and related sugars.
Henry Louis Le Chatelier develops Le Chatelier’s principle, which explains the response of dynamic chemical equilibria to external stresses.
Eugene Goldstein names the cathode ray, later discovered to be composed of electrons, and the canal ray, later discovered to be positive hydrogen ions that had been stripped of their electrons in a cathode ray tube. These would later be named protons.
Alfred Werner discovers the octahedral structure of cobalt complexes, thus establishing the field of coordination chemistry.
William Ramsay discovers the noble gases, which fill a large and unexpected gap in the periodic table and led to models of chemical bonding.
J. J. Thomson discovers the electron using the cathode ray tube.
Wilhelm Wien demonstrates that canal rays (streams of positive ions) can be deflected by magnetic fields, and that the amount of deflection is proportional to the mass-to-charge ratio. This discovery would lead to the analytical technique known as mass spectrometry.
Maria Sklodowska-Curie and Pierre Curie isolate radium and polonium from pitchblende.
Ernest Rutherford discovers the source of radioactivity as decaying atoms; coins terms for various types of radiation.
Mikhail Semyonovich Tsvet invents chromatography, an important analytic technique.
Hantaro Nagaoka proposes an early nuclear model of the atom, where electrons orbit a dense massive nucleus.
Fritz Haber and Carl Bosch develop the Haber process for making ammonia from its elements, a milestone in industrial chemistry with deep consequences in agriculture.
Albert Einstein explains Brownian motion in a way that definitively proves atomic theory.
Leo Hendrik Baekeland invents bakelite, one of the first commercially successful plastics.
Robert A. Millikan performed the oil drop experiment.
Robert Millikan measures the charge of individual electrons with unprecedented accuracy through the oil drop experiment, confirming that all electrons have the same charge and mass.
S. P. L. Sørensen invents the pH concept and develops methods for measuring acidity.
Antonius van den Broek proposes the idea that the elements on the periodic table are more properly organized by positive nuclear charge rather than atomic weight.
The first Solvay Conference is held in Brussels, bringing together most of the most prominent scientists of the day. Conferences in physics and chemistry continue to be held periodically to this day.
Ernest Rutherford, Hans Geiger, and Ernest Marsden perform the gold foil experiment, which proves the nuclear model of the atom, with a small, dense, positive nucleus surrounded by a diffuse electron cloud.
William Henry Bragg and William Lawrence Bragg propose Bragg’s law and establish the field of X-ray crystallography, an important tool for elucidating the crystal structure of substances.
Peter Debye develops the concept of molecular dipole to describe asymmetric charge distribution in some molecules.
The Bohr model of the atom
Niels Bohr introduces concepts of quantum mechanics to atomic structure by proposing what is now known as the Bohr model of the atom, where electrons exist only in strictly defined orbitals.
Henry Moseley, working from Van den Broek’s earlier idea, introduces concept of atomic number to fix inadequacies of Mendeleev’s periodic table, which had been based on atomic weight.
Frederick Soddy proposes the concept of isotopes, that elements with the same chemical properties may have differing atomic weights.
J. J. Thomson expanding on the work of Wien, shows that charged subatomic particles can be separated by their mass-to-charge ratio, a technique known as mass spectrometry.
Gilbert N. Lewis publishes “The Atom and the Molecule”, the foundation of valence bond theory.
Otto Stern and Walther Gerlach establish concept of quantum mechanical spin in subatomic particles.
Gilbert N. Lewis and Merle Randall publish Thermodynamics and the Free Energy of Chemical Substances, first modern treatise on chemical thermodynamics.
Gilbert N. Lewis develops the electron pair theory of acid/base reactions. 1924
Louis de Broglie introduces the wave-model of atomic structure, based on the ideas of wave–particle duality.
Wolfgang Pauli develops the exclusion principle, which states that no two electrons around a single nucleus may have the same quantum state, as described by four quantum numbers.
The Schrödinger equation
Erwin Schrödinger proposes the Schrödinger equation, which provides a mathematical basis for the wave model of atomic structure.
Werner Heisenberg develops the uncertainty principle which, among other things, explains the mechanics of electron motion around the nucleus. 1927
Fritz London and Walter Heitler apply quantum mechanics to explain covalent bonding in the hydrogen molecule, which marked the birth of quantum chemistry.
Linus Pauling publishes Pauling’s rules, which are key principles for the use of X-ray crystallography to deduce molecular structure.
Erich Hückel proposes Hückel’s rule, which explains when a planar ring molecule will have aromatic properties.
Harold Urey discovers deuterium by fractionally distilling liquid hydrogen.
Model of two common forms of nylon
James Chadwick discovers the neutron.
Linus Pauling and Robert Mulliken quantify electronegativity, devising the scales that now bear their names.
Wallace Carothers leads a team of chemists at DuPont who invent nylon, one of the most commercially successful synthetic polymers in history.
Carlo Perrier and Emilio Segrè perform the first confirmed synthesis of technetium-97, the first artificially produced element, filling a gap in the periodic table. Though disputed, the element may have been synthesized as early as 1925 by Walter Noddack and others.
Eugene Houdry develops a method of industrial scale catalytic cracking of petroleum, leading to the development of the first modern oil refinery. 1937
Pyotr Kapitsa, John Allen and Don Misener produce supercooled helium-4, the first zero-viscosity superfluid, a substance that displays quantum mechanical properties on a macroscopic scale.
Otto Hahn discovers the process of nuclear fission in uranium and thorium. 
Linus Pauling publishes The Nature of the Chemical Bond, a compilation of a decades worth of work on chemical bonding. It is one of the most important modern chemical texts. It explains hybridization theory, covalent bonding and ionic bonding as explained through electronegativity, and resonance as a means to explain, among other things, the structure of benzene.
Edwin McMillan and Philip H. Abelson identify neptunium, the lightest and first synthesized transuranium element, found in the products of uranium fission. McMillan would found a lab at Berkeley that would be involved in the discovery of many new elements and isotopes.
Glenn T. Seaborg takes over McMillan’s work creating new atomic nuclei. Pioneers method of neutron capture and later through other nuclear reactions. Would become the principal or co-discoverer of nine new chemical elements, and dozens of new isotopes of existing elements. 1945
Jacob A. Marinsky, Lawrence E. Glendenin, and Charles D. Coryell perform the first confirmed synthesis of Promethium, filling in the last “gap” in the periodic table.
Felix Bloch and Edward Mills Purcell develop the process of nuclear magnetic resonance, an analytical technique important in elucidating structures of molecules, especially in organic chemistry.
Linus Pauling uses X-ray crystallography to deduce the secondary structure of proteins.
Alan Walsh pioneers the field of atomic absorption spectroscopy, an important quantitative spectroscopy method that allows one to measure specific concentrations of a material in a mixture.
Robert Burns Woodward, Geoffrey Wilkinson, and Ernst Otto Fischer discover the structure of ferrocene, one of the founding discoveries of the field of organometallic chemistry.
James D. Watson and Francis Crick propose the structure of DNA, opening the door to the field of molecular biology.
Jens Skou discovers Na+/K+-ATPase, the first ion-transporting enzyme. 1958
Max Perutz and John Kendrew use X-ray crystallography to elucidate a protein structure, specifically sperm whale myoglobin.
Neil Bartlett synthesizes xenon hexafluoroplatinate, showing for the first time that the noble gases can form chemical compounds.
George Olah observes carbocations via superacid reactions.
Richard R. Ernst performs experiments that will lead to the development of the technique of Fourier transform NMR. This would greatly increase the sensitivity of the technique, and open the door for magnetic resonance imaging or MRI.
Robert Burns Woodward and Roald Hoffmann propose the Woodward– Hoffmann rules, which use the symmetry of molecular orbitals to explain the stereochemistry of chemical reactions.
Hitoshi Nozaki and Ryōji Noyori discovered the first example of asymmetric catalysis (hydrogenation) using a structurally well-defined chiral transition metal complex.
John Pople develops the Gaussian program greatly easing computational chemistry calculations.
Yves Chauvin offered an explanation of the reaction mechanism of olefin metathesis reactions.
Karl Barry Sharpless and group discover a stereoselective oxidation reactions including Sharpless epoxidation, Sharpless asymmetric dihydroxylation, and Sharpless oxyamination.
Harold Kroto, Robert Curl and Richard Smalley discover fullerenes, a class of large carbon molecules superficially resembling the geodesic dome designed by architect R. Buckminster Fuller.
Sumio Iijima uses electron microscopy to discover a type of cylindrical
fullerene known as a carbon nanotube, though earlier work had been done
in the field as early as 1951. This material is an important component in the
field of nanotechnology.
First total synthesis of Taxol by Robert A. Holton and his group.
Eric Cornell and Carl Wieman produce the first Bose–Einstein condensate,
a substance that displays quantum mechanical properties on the
Alchemists learned ways to make acids
HISTORY OF ASTRONOMY
Babylonian astronomers discover an 18.6-year cycle in the rising and setting of the Moon. From this they created the first almanacs – tables of the movements of the Sun, Moon and planets for the use in astrology. In 6th century BC Greece, this knowledge is used to predict eclipses.
Thales predicts a solar eclipse. 467 BC
Anaxagoras produced a correct explanation for eclipses and then described the sun as a fiery mass larger than the Peloponnese , as well as attempting to explain rainbows and meteors . He was the first to explain that
the moon shines due to reflected light from the sun.
Plato, a Greek philosopher, founds a school (the Platonic Academy) that will influence the next 2000 years. It promotes the idea that everything in the universe moves in harmony and that the Sun, Moon, and planets move around Earth in perfect circles.
Aristarchus of Samos proposes heliocentrism as an alternative to the Earth-centered universe. His heliocentric model places the Sun at its center, with Earth as just one planet orbiting it. However, there were only a few people who took the theory seriously.
The earliest recorded sighting of Halley’s Comet is made by Babylonian astronomers. Their records of the comet’s
movement allow astronomers today to predict accurately how the comet’s orbit changes over the centuries.
The astronomer Shi Shen is believed to have cataloged 809 stars in 122 constellations, and he also made the earliest known observation of sunspots.
Ptolemy publishes his star catalogue, listing 48 constellations and endorses the geocentric (Earth- centered) view of the universe. His views go unquestioned for
nearly 1500 years in Europe, and are passed down to Arabic and medieval European astronomers in his book the Almagest.
The Hindu cosmological time cycles explained in the Surya Siddhanta, give the average length of the sidereal year (the length of the Earth’s revolution around the Sun) as 365.2563627 days, which is only 1.4 seconds longer than the modern value of 365.256363004 days. This remains the most accurate estimate for the length of the sidereal year anywhere in the world for over a thousand years.
Indian mathematician-astronomer Aryabhata, in his Aryabhatiya first identifies the force gravity to explain why objects do not fall when the earth rotates.  propounds a geocentric solar system of gravitation, and an eccentric elliptical model of the planets, where the planets spin on their axes and follow elliptical orbits,the Sun and the moon revolve around the earth in epicycles. He also writes that the planets and the Moon do not have their own light but reflect the light of the Sun, and that the Earth rotates on its axis causing day and night and also sun around the earth causing years.
Indian mathematician-astronomer Brahmagupta, in his Brahma-Sphuta-
Siddhanta, first recognizes gravity as a force of attraction, and briefly describes the second law of Newton’s law of universal gravitation. He gives methods for calculations of the motions and places of various planets, their rising and setting, conjunctions, and calculations of the solar and lunar eclipses.
The Sanskrit works of Aryabhata and Brahmagupta, along with the Sanskrit text Surya Siddhanta, are translated into Arabic, introducing Arabic astronomers to Indian astronomy.
Muhammad al-Fazari and Yaqub ibn Tariq translate the Surya Siddhanta and Brahmasphutasiddhanta, and
compile them as the Zij al-Sindhind, the first Zij treatise. 
The first major Arabic work of astronomy is the Zij al- Sindh by al- Khwarizimi. The work contains tables for the movements of the sun, the moon and the five planets known at the time. The work is significant as it introduced Ptolemaic concepts into Islamic sciences. This work also marks the turning point in Arabic astronomy. Hitherto, Arabic astronomers had adopted a primarily research approach to the field, translating works of others and learning already discovered knowledge. Al-Khwarizmi’s work marked the beginning of nontraditional methods of study and calculations.
al-Farghani wrote Kitab fi Jawani (“A compendium of the science of stars“). The book primarily gave a summary of Ptolemic cosmography. However, it also corrected Ptolemy based on findings of earlier Arab astronomers. Al- Farghani gave revised values for the obliquity of the ecliptic, the precessional movement of the apogees of the sun and the moon, and the circumference of the earth. The books were widely circulated through the Muslim world, and even translated into Latin.
The earliest surviving astrolabe is constructed by Islamic mathematician- astronomer Mohammad al-Fazari. Astrolabes are the most advanced instruments of their time. The precise
measurement of the positions of stars and planets allows Islamic astronomers to compile the most detailed almanacs and star atlases yet.
Abū Rayḥān al-Bīrūnī discussed the Indian heliocentric theories of Aryabhata, Brahmagupta and Varahamihira in his Ta’rikh al-Hind (Indica in Latin). Biruni stated that the followers of Aryabhata consider the Earth to be at the center. In fact, Biruni casually stated that this does not create any mathematical problems.
Abu Said Sinjari, a contemporary of Abu Rayhan Biruni, suggested the possible
heliocentric movement of the Earth around the Sun.
Chinese astronomers record the sudden appearance of a bright star. Native- American rock carvings also show the brilliant star close to the Moon. This star is the Crab supernova exploding.
Abu Ubayd al-Juzjani published the Tarik al-Aflak. In his work, he indicated the so- called “equant” problem of the Ptolemic model. Al-Juzjani even proposed a solution for the problem. In al-Andalus, the anonymous work al- Istidrak ala Batlamyus (meaning “Recapitulation regarding Ptolemy”), included a list of objections to the Ptolemic astronomy.
One of the most important works in the period was Al- Shuku ala Batlamyus (“Doubts on Ptolemy“). In this, the author summed up the inconsistencies of the Ptolemic models. Many astronomers took up the challenge posed in this work, namely to develop alternate models that evaded such errors.
Islamic and Indian astronomical works (including Aryabhatiya and Brahma- Sphuta-Siddhanta) are translated into Latin in Córdoba, Spain in 1126, introducing European astronomers to Islamic and Indian astronomy.
Indian mathematician-astronomer Bhāskara II, in his Siddhanta Shiromani,
calculates the longitudes and latitudes of the planets, lunar and solar eclipses, risings
and settings, the Moon’s lunar crescent, syzygies, and conjunctions of the planets with each other and with the fixed stars, and explains the three problems of diurnal rotation. He also calculates the planetary mean motion, ellipses, first visibilities of the planets, the lunar crescent, the seasons, and the length of the Earth’s revolution around the Sun to 9 decimal places.
Mo’ayyeduddin Urdi develops the Urdi lemma, which is later used in the Copernican heliocentric model.
Nasir al-Din al-Tusi resolved significant problems in the Ptolemaic system by
developing the Tusi-couple as an alternative to the physically problematic equant introduced by Ptolemy. His Tusi- couple is later used in the Copernican model.
Tusi’s student Qutb al-Din al-Shirazi, in his The Limit of Accomplishment concerning Knowledge of the Heavens, discusses the possibility of heliocentrism. Najm al-Din al-Qazwini al-Katibi, who also worked at the Maraghah observatory, in his Hikmat al-‘Ain, wrote an argument for a heliocentric model, though he later abandoned the idea.
Ibn al-Shatir (1304–1375), in his A Final Inquiry Concerning the Rectification of Planetary Theory, eliminated the need for an equant by introducing an extra epicycle, departing from the Ptolemaic system in a way very similar to what Copernicus later also did. Ibn al-Shatir proposed a system that was only approximately geocentric, rather than exactly so, having demonstrated trigonometrically that the Earth was not the exact center of the universe. His rectification is later used in the Copernican model.
Nicolaus Copernicus publishes De revolutionibus orbium coelestium containing his theory that Earth travels around the Sun. However, he complicates his theory by retaining Plato’s perfect circular orbits of the planets.
A brilliant supernova (SN 1572 – thought, at the time, to be a comet) is observed by Tycho Brahe, who proves that it is traveling beyond Earth’s atmosphere and therefore provides the first evidence that the heavens can change.
Dutch eyeglass maker Hans Lippershey invents the refracting telescope. The invention spreads rapidly across Europe, as scientists make their own
instruments. Their discoveries begin a revolution in astronomy.
Johannes Kepler publishes his New Astronomy. In this and later works, he
announces his three laws of planetary motion, replacing the circular orbits
of Plato with elliptical ones. Almanacs based on his laws prove to be highly accurate.
Galileo Galilei publishes Sidereus Nuncius describing the findings of his observations with the telescope he built. These include spots on the Sun, craters on the Moon, and four satellites of Jupiter. Proving that not everything orbits Earth, he promotes the Copernican view of a Sun- centered universe.
As the power and the quality of the telescopes increase, Christiaan Huygens studies Saturn and discovers its largest
satellite, Titan. He also explains Saturn’s appearance, suggesting the planet is surrounded by a thin ring.
Scottish astronomer James Gregory describes his “gregorian” reflecting telescope, using parabolic mirrors instead of lenses to reduce chromatic aberration and spherical aberration, but is unable to build one.
Isaac Newton builds the first reflecting telescope, his Newtonian telescope.
Isaac Newton publishes his first copy of the book Philosophiae Naturalis Principia Mathematica, establishing the theory of gravitation and laws of motion. The Principia explains Kepler’s laws of planetary motion and allows astronomers to understand the forces acting between the Sun, the planets, and their moons.
Edmond Halley calculates that the comets recorded at 76-year intervals from 1456 to 1682 are one and the same. He predicts that the comet will return again in 1758. When it reappears as expected, the comet is named in his honor.
French astronomer Nicolas de Lacaille sails to southern oceans and begins work compiling a catalog of more than 10000 stars in the southern sky. Although Halley
and others have observed from the Southern Hemisphere
before, Lacaille’s star catalog is the first comprehensive one of the southern sky.
Amateur astronomer William Herschel discovers the planet Uranus, although he at first mistakes it for a comet. Uranus is the first planet to be discovered beyond Saturn, which was thought to be the most distant planet in ancient times.
Charles Messier publishes his catalog of star clusters and nebulas. Messier draws up the list to prevent these objects from being identified as comets. However, it soon becomes a standard reference for the study of star clusters and nebulars and is still in use today.
William Herschel splits sunlight through a prism and with a thermometer, measures the energy given out by different colours. He notices a sudden increase in energy beyond the red end of the spectrum, discovering invisible infrared and laying the foundations of spectroscopy.
Italian astronomer Giuseppe Piazzi discovers what appears to be a new planet orbiting between Mars and Jupiter, and names it Ceres. William Herschel proves it is a very small object, calculating it to be only 320 km in diameter, and not a planet. He proposes
the name asteroid, and soon other similar bodies are being found. We now know that Ceres is 932 km in diameter, and is now considered to be a dwarf planet.
Joseph von Fraunhofer builds the first accurate spectrometer and uses it to study the spectrum of the Sun’s light. He discovers and maps hundreds of fine dark lines crossing the solar spectrum. In 1859 these lines are linked to chemical elements in the Sun’s atmosphere. Spectroscopy becomes a method for studying what stars are made of.
Friedrich Bessel successfully uses the method of stellar parallax, the effect of Earth’s annual movement around the
Sun, to calculate the distance to 61 Cygni, the first star other than the Sun to have its distance from Earth measured. Bessel’s is a truly accurate measurement of stellar positions, and the parallax technique establishes a framework for measuring the scale of the universe.
German Amateur astronomer Heinrich Schwabe, who has been studying the Sun for the past 17 years, announces his discovery of a regular cycle in sunspot numbers – the first clue to the Sun’s internal structure.
Irish astronomer William Parsons, 3rd Earl of Rosse completes the first of the
world’s great telescopes, with a 180-cm mirror. He uses it to study and draw the structure of nebulas, and within a few months discovers the spiral structure of the Whirlpool Galaxy.
French physicists Jean Foucault and Armand Fizeau take the first detailed photographs of the Sun’s surface through a telescope – the birth of scientific astrophotography. Within five years, astronomers produce the first detailed photographs of the Moon. Early film is not sensitive enough to image stars.
A new planet, Neptune, is identified by German astronomer Johann Gottfried Galle while searching in the position suggested by Urbain Le Verrier. Le Verrier has calculated the position and size of the planet from the effects of its gravitational pull on the orbit of Uranus. An English mathematician, John Couch Adams, also made a similar calculation a year earlier.
Astronomers notice a new bright emission line in the spectrum of the Sun’s atmosphere during an eclipse. The emission line is caused by an element’s giving out light, and British astronomer Norman Lockyer concludes that it is an element unknown on Earth. He calls it helium, from the Greek word for the Sun. Nearly 30 years later, helium is found on Earth.
An American astronomer Henry Draper takes the first photograph of the spectrum of a star (Vega), showing absorption lines that reveal its chemical makeup. Astronomers begin to see that spectroscopy is the key to understanding how stars evolve. William Huggins uses absorption lines to measure the redshifts of stars, which give the first indication of how fast stars are moving.
Konstantin Tsiolkovsky publishes his first article on the possibility of space flight. His greatest discovery is that a rocket, unlike other forms of propulsion, will work in a
vacuum. He also outlines the principle of a multistage launch vehicle.
A comprehensive survey of stars, the Henry Draper Catalog, is published. In the catalog, Annie Jump Cannon proposes a sequence of classifying stars by the absorption waves in their spectra, which is still in use today.
Ejnar Hertzsprung establishes the standard for measuring the true brightness of a star. He shows that there is a relationship between color and absolute magnitude for 90% of the stars in the Milky Way Galaxy. In 1913, Henry Norris Russell publishes a diagram that shows this relationship. Although astronomers agree that the diagram shows the sequence in which stars evolve, they argue about which way the sequence progresses. Arthur Eddington finally settles the controversy in 1924.
German physicist Karl Schwarzschild uses Albert Einstein’s theory of general relativity to lay the groundwork for black hole theory. He suggests that if any star collapse to a certain size or smaller, its gravity will be so strong that no form of radiation will escape from it.
Edwin Hubble discovers a Cepheid variable star in the “Andromeda Nebula” and proves that Andromeda and other nebulas are galaxies far beyond our own. By 1925, he produces a classification system for galaxies.
Robert Goddard launches the first rocket powered by liquid fuel. He also demonstrates that a rocket can work in a vacuum. His later rockets break the sound barrier for the first time.
Edwin Hubble discovered that the universe is expanding and that the farther away a galaxy is, the faster it is moving away from us. Two years
later, Georges Lemaître suggests that the expansion can be traced to an initial “Big Bang”.
By applying new ideas from subatomic physics, Subrahmanyan Chandrasekhar
predicts that the atoms in a white dwarf star of more than 1.44 solar masses will
disintegrate, causing the star to collapse violently. In 1933, Walter Baade and Fritz Zwicky describe the neutron star that results from this collapse, causing a supernova explosion.
Clyde Tombaugh discovers the dwarf planet Pluto at the Lowell Observatory in Flagstaff, Arizona. The object is so faint and moving so slowly that he has to compare photos taken several nights apart.
Karl Jansky detects the first radio waves coming from space. In 1942, radio waves from the Sun are detected. Seven years later radio astronomers identify the first
distant source – the Crab Nebula, and the galaxies Centaurus A and M87.
German physicist Hans Bethe explains how stars generate energy. He outlines a series of nuclear fusion reactions that turn hydrogen into helium and release enormous amounts of energy in a star’s core. These reactions use the star’s hydrogen very slowly, allowing it to burn for billions of years.
A team of German scientists led by Wernher von Braun develops the V-2, the first rocket-powered ballistic
missile. Scientists and engineers from Braun’s team were captured at the end of
World War II and drafted into the American and Russian rocket programs.
The largest telescope in the world, with a 5.08m (200 in) mirror, is completed at Palomar Mountain in California. At the time, the telescope pushes single-mirror telescope technology to its limits – large mirrors tend to bend under their own weight.
Russia launches the first artificial satellite, Sputnik 1, into orbit, beginning the space age. The US launches its first satellite, Explorer 1, four months later.
(July 29) Beginning of the NASA (National Aeronautics and Space Administration), agency newly created by the United States to catch up with Soviet space technologies. It absorbs all research centers and staffs of the NACA (National Advisory Committee for Aeronautics), an organization founded in 1915.
Russia and the US both launch probes to the Moon, but NASA’s Pioneer probes all failed. The Russian Luna
program was more successful. Luna 2 crash-lands on the Moon’s surface in September, and Luna 3 returns the first pictures of the Moon’s farside in October.
Russia takes the lead in the space race as Yuri Gagarin becomes the first person to orbit Earth in April. NASA astronaut Alan Shepard becomes the first American in space a month later, but does not go into orbit, although he is the first person to land with himself still inside his spacecraft and thus technically achieving the first complete human spaceflight by FAI definitions. John Glenn achieves orbit in early 1962.
Mariner 2 becomes the first probe to reach another planet, flying past Venus in December. NASA follows this with the successful Mariner 4 mission to Mars in 1965, both the US and Russia send many more probes to planets through the rest of the 1960s and 1970s.
Dutch-American astronomer Maarten Schmidt measures the spectra of quasars, the mysterious star-like radio sources discovered in 1960. He establishes that quasars are active galaxies, and among the most distant objects in the universe.
Arno Penzias and Robert Wilson announce the discovery of a weak radio signal coming from all parts of the sky. Scientists figure out that this must be emitted by an object at a temperature of -270 °C. Soon it is recognized as the remnant of the very hot radiation from the Big Bang that created the universe 13 billion years ago, see Cosmic microwave background. This radio signal is emitted by the electron in hydrogen flipping from pointing up or down and is approximated to happen once in a million years for every particle. Hydrogen is present in interstellar space gas throughout the entire universe and most dense in nebulae which is where the signals originate. Even though the electron of hydrogen only flips once every million years the mere quantity of hydrogen in space gas makes the presence of these radio waves prominent.
Russian Luna 9 probe makes the first successful soft landing on the Moon in January, while the US lands the far more complex Surveyor missions, which follows up to NASA’s Ranger series of crash-landers, scout sites for possible manned landings.
Jocelyn Bell Burnell and Antony Hewish detected the first pulsar, an object emitting regular pulses of radio waves. Pulsars are eventually recognized as rapidly spinning neutron stars with intense magnetic fields – the remains of a supernova explosion.
NASA’s Apollo 8 mission becomes the first human spaceflight mission to travel beyond Earth’s gravitational influence and to orbit another celestial body.
The US wins the race for the Moon, as Neil Armstrong steps onto the lunar surface on July 20. Apollo 11 is followed by five further landing missions, three carrying a sophisticated lunar rover vehicle.
The Uhuru satellite, designed to map the sky at X-ray wavelengths, is launched by NASA. The existence of X rays from the Sun and a few other stars has already been found using rocket-launched experiments, but Uhuru charts more than 300 X-ray sources, including several possible black holes.
Russia launches its first space station, Salyut 1, into orbit. It is followed by a series of stations, culminating with Mir in 1986. A permanent platform in orbit allows cosmonauts to carry out serious research and to set a series of new duration records for spaceflight.
Charles Thomas Bolton was the first astronomer to present irrefutable evidence of the existence of a black hole.
The Russian probe Venera 9 lands on the surface of Venus and sends back the first picture of its surface. The first probe to land on another planet, Venera 7 in 1970, had no camera. Both break down within an hour in the hostile atmosphere.
Two NASA probes arrive at Mars. Each Viking mission consists of an orbiter, which photographs the planet from above, and a lander, which touches down on the surface, analyzes the rocks, and searches unsuccessfully for life.
(August 20) The Voyager 2 space probe launched by NASA to study the Jovian system, Saturnian system, Uranian system, Neptunian system, the Kuiper belt, the heliosphere and the interstellar space. (September 5) The Voyager 1 space probe launched by NASA to study the Jovian system, Saturnian system and the interstellar medium.
Columbia, the first of NASA’s reusable space shuttles, makes its maiden flight, ten years in development, the shuttle will make space travel routine and eventually open the path for a new International Space Station.
The first infrared astronomy satellite, IRAS, is launched. It must be cooled to extremely low temperatures with liquid helium, and it operates for only 300 days before the supply of helium is exhausted. During this time it completes an infrared survey of 98% of the sky.
NASA’s spaceflight program comes to a halt when Space Shuttle Challenger explodes shortly after launch. A thorough
inquiry and modifications to the rest of the fleet kept the shuttles on the ground for nearly three years.
The returning Halley’s comet is met by a fleet of five probes from Russia, Japan, and Europe. The most ambitious is the European Space Agency’s Giotto spacecraft, which flies through the comet’s coma and photographs the nucleus.
The Magellan probe, launched by NASA, arrives at Venus and spends three years mapping the planet with radar. Magellan is the first in a new wave of probes that include Galileo, which arrives at Jupiter in 1995, and Cassini which arrives at Saturn in 2004.
The Hubble Space Telescope, the first large optical telescope in orbit, is launched using the Space Shuttle, but astronomers soon discovered that it is crippled by a problem with its mirror. A complex repair mission in 1993 allows the telescope to start producing spectacular images of distant stars, nebulae, and galaxies.
The Cosmic Background Explorer satellite produces a detailed map of the background radiation remaining from the Big Bang. The map shows “ripples”, caused by slight variations in the density of the early universe – the seeds of galaxies and galaxy clusters.
The 10 meter Keck telescope on Mauna Kea, Hawaii, is completed. The first revolutionary new wave of
telescopes, the Keck’s main mirror is made of 36 six- sided segments, with computers to control their alignment. New optical telescopes also make use of interferometry – improving resolution by combining images from separate telescopes.
Construction work on a huge new space station named ISS has begun. A joint venture between many countries, including former space rivals Russia and the US.
Mike Brown and his team discovered a large body in the outer solar system. It was temporarily named as (2003) UB313. Initially, it appeared larger than Pluto, and was called tenth planet.
International Astronomical Union (IAU) adopted a new definition of planet. A new distinct class of objects called dwarf planets was also decided. Pluto was redefined as a dwarf planet along with Ceres and Eris, formerly known
as (2003) UB313. Eris was named after the IAU General Assembly in 2006.
(May 2) First visual proof of existence of black holes is published. Suvi Gezari’s
team in Johns Hopkins University, using the Hawaiian telescope Pan-STARRS 1, record images of a supermassive black hole 2.7 million light-years away that is swallowing a red giant.
In October 2013, the first extrasolar asteroid is detected around white dwarf star GD 61. It is also the first detected extrasolar body which contains water in liquid or solid form.
In July 14, with the successful encounter of Pluto by NASA’s New Horizons spacecraft, the United States became the first nation to explore all of 9 major planets recognized in 1981. Later in September 14, LIGO was the first to directly detect gravitational waves.
TIMELINE OF SPACE EXPLORATION
This is for a timeline of space exploration including notable achievements and first accomplishments in humanity’s exploration of outer space.
Event leading to space exploration
First telescopic observation of the night sky: Discovery of Jupiter’s moons, lunar craters and the phases of Venus.
Republic of Venice Galileo Galilei
1687 Publication of the Philosophiæ Naturalis Principia Mathematica
Sir Isaac Newton
First exposition of the rocket equation based on Newton’s third law of motion: Treatise on the Motion of Rockets
UK William Moore
First clear telescopic photograph of another world: the Moon.
United States John William Draper
From the Earth to the Moon published.
France Jules Verne
The War of the Worlds published. This inspired Robert Goddard to investigate rocketry.
H. G. Wells
Inspired by the writings of Jules Verne, first serious work published that showed physical space exploration was theoretically possible: Исследование мировых пространств реактивными приборами (The Exploration of Cosmic Space by Means of Reaction Devices)
Goddard files for and is subsequently awarded U.S. patents on multistage and liquid-fueled rockets
Robert H. Goddard
Goddard’s widely influential paper “A Method of Reaching Extreme Altitudes” discussed solid- and liquid- fueled rocketry
Robert H. Goddard
15 December 1923
Die Rakete zu den Planetenräumen (“By Rocket into Planetary Space”) self-published after its rejection as a doctoral thesis.
Germany Hermann Oberth
Society for Studies of Interplanetary Travel founded
Members include Konstantin Tsiolkovsky, Friedrich Zander, Yuri Kondratyuk
16 March 1926
Goddard launches the first liquid-fueled rocket
Robert H. Goddard
Verein für Raumschiffahrt (Society for Space Travel) formed; it includes many top European rocket scientists.
The Conquest of Interplanetary Space discusses rocket mechanics and orbital effects including the gravitational slingshot
Das Problem der Befahrung des Weltraums – der Raketen-Motor (The Problem of Space Travel – The Rocket Motor) discusses space travel and its potential uses for scientific experiments.
Oberth, with students including Wernher von Braun, launches his first liquid-fueled rocket
First German military liquid-fueled rocket engines developed
Work begins on the Aggregate series of rockets which leads to the V-2 rocket.
Wernher von Braun
17 August 1933
Group for the Study of Reactive Motion (GIRD) launches the first Soviet liquid-fueled rocket
Sergey Korolev (group leader), Friedrich Zander (designer)
Graduate student Frank Malina under his professor Theodore von Kármán begins work on a sounding rocket
20 June 1944
V-2 Rocket (MW 18014): First man-made object to cross what would later be defined as the Kármán line and hence first spaceflight in history.
10 May 1946
First space research flight (cosmic radiation experiments)
captured and improved V-2 rocket
22 May 1946
First U.S.-designed rocket to reach edge of space (80 km (49 mi))
24 October 1946
First pictures of Earth from 105 km (65 mi) 
20 February 1947
First animals in space (fruit flies) 
22 July 1951
First dogs in space (Dezik and Tsygan) 
Mission Achievements Country/Organization Mission Name
21 August 1957
First intercontinental ballistic missile (ICBM)
R-7 Semyorka/SS-6 Sapwood 4 October 1957 First artificial satellite
First signals from space
3 November 1957
First animal in orbit, the dog Laika
31 January 1958
Confirmed the existence of the Van Allen belts
USA (ABMA) Explorer 1
2 January 1959
First firing of a rocket in Earth orbit
First reaching Earth escape velocity or Trans Lunar
First detection of solar wind
4 January 1959
First artificial satellite to reach the Moon vicinity and first artificial satellite in heliocentric orbit
7 August 1959
First photograph of Earth from orbit
USA (NASA) Explorer 6
13 September 1959
First impact into another world (the Moon)
First delivery of national (USSR) pennants to a celestial body
4 October 1959
First photos of another world from space: The far side of the Moon
Mission Success Country/Organization Mission Name
First solar probe.
19 August 1960
First plants and animals to return alive from Earth orbit
10 October 1960
First probe launched to Mars (failed to reach target)
31 January 1961
First Hominidae in space, first tasks performed in space; Ham (chimpanzee).
12 February 1961
First launch from Earth orbit of upper stage into a heliocentric orbit
First mid-course corrections
12 April 1961
First human spaceflight–(Yuri Gagarin) First human- crewed orbital flight
5 May 1961
First human-piloted space flight–(Alan Shepard)
First human-crewed suborbital flight
First human space mission that landed with pilot still in spacecraft, thus the first complete human spaceflight by FAI definitions.
19 May 1961
First planetary flyby (within 100,000 km of Venus – no data returned)
7 March 1962
First orbital solar observatory
26 April 1962
First spacecraft to impact the far side of the Moon
First Mars flyby (11,000 km) but contact was lost
14 December 1962
First successful planetary flyby (Venus closest approach 34,773 kilometers)
16 June 1963
First woman in space (Valentina Tereshkova)
19 July 1963
First reusable crewed spacecraft (suborbital)
X-15 Flight 90
18 March 1965
First extra-vehicular activity-(Alexei Leonov)
First crewed spacecraft to change orbit
14 July 1965
First Mars flyby (closest approach 9,846 kilometers; returned pictures)
14 July 1965
First close-up photographs of another planet: Mars
15 December 1965
First orbital rendezvous (parallel flight, no docking)
Gemini 6A/Gemini 7
3 February 1966
First soft landing on another world (the Moon) First photos from another world
1 March 1966
First impact into another planet (Venus)
16 March 1966
First orbital docking between two spacecraft
Gemini 8/Agena target vehicle
3 April 1966
First artificial satellite around another world (the Moon)
First probe to map the Moon
Lunar Orbiter 1
30 October 1967
First automated (crewless) docking
Cosmos 186/Cosmos 188
First animals and plants to orbit moon, and the first to return safely to Earth
7 December 1968
First orbital ultraviolet observatory
21 December 1968
First piloted orbital mission of another celestial body (Moon),
First-ever Trans-Earth injection
First human space mission to escape Earth’s influence(25 December)
First docking between two crewed spacecraft in Earth orbit, also the first crew exchange in space
Soyuz 4 and Soyuz 5
First to parachute in Venus’s atmosphere, lost contact before landing.
20 July 1969
First human on the Moon, and first space launch from a celestial body other than the Earth
First sample return from the Moon
August 4, 1969
First photograph of Phobos from Space
19 November 1969
First rendezvous on the surface of a celestial body
USA (NASA) Apollo 12/Surveyor 3
Mission Success Country/Organization Mission Name
24 September 1970
First automatic sample return from the Moon
17 November 1970 First lunar rover
12 December 1970
First X-ray orbital observatory
15 December 1970
First soft landing on another planet (Venus) First signals from another planet
19 April 1971
First space station
First Manned orbital observatory
14 November 1971
First to maintain orbit around another planet (Mars)
27 November 1971 First impact into Mars USSR
2 December 1971
First soft Mars landing
First signals from Mars surface
3 March 1972
First human made object sent on escape trajectory away from the Sun
15 July 1972
First mission to enter the asteroid belt and leave inner Solar System
15 November 1972
First orbital gamma ray observatory
3 December 1973
First Jupiter flyby (at 130,000 km)
5 February 1974
Venus flyby at 5768 kilometers, first gravitational assist manoeuvre
First photograph of Venus from Space
29 March 1974
First Mercury flyby at 703 kilometers
15 July 1975
First multinational manned mission
USSR USA (NASA)
Apollo-Soyuz Test Project
20 October 1975
First orbit around Venus
22 October 1975
First photos from the surface of another planet (Venus)
17 April 1976
Closest flyby of the Sun (43.432 million kilometers) Maximum speed record among spacecraft (252,792 km/ h)
USA (NASA) West Germany (DFVLR)
Helios 2 20 July 1976
First photos and soil samples from the surface of Mars
26 January 1978
First real time remotely operated ultraviolet orbital observatory
USA (NASA) ESA UK (SERC) International Ultraviolet Explorer
4 December 1978
First extended (multi-year) orbital exploration of Venus from 1978 to 1992
Pioneer Venus Orbiter
5 March 1979
Jupiter flyby (closest approach 349,000 km) encounters with Five Jovian moons, discovery of volcanism on Io
1 September 1979
First Saturn flyby at 21,000 km, first photographs of Titan from Space
12 November 1980
Saturn flyby (closest approach 124,000 kilometers), close encounter of Titan and encounters with a dozen others.
12 April 1981
First Reusable manned spacecraft (orbital)
1 March 1982
First Venus soil samples and sound recording of another world
25 January 1983
First Infrared orbital observatory
USA (NASA) UK (SERC) Netherlands (NIVR) IRAS
13 June 1983
First spacecraft beyond the orbit of Neptune (first spacecraft to pass beyond all Solar System planets)
7 February 1984
First untethered spacewalk, Bruce McCandless II
24 January 1986
First Uranus flyby (closest approach 81,500 kilometers (44,000 nmi)
28 January 1986
Challenger explosion with Christa McAuliffe (teacher at high school in Concord, New Hampshire)
19 February 1986
First consistently inhabited long-term research space station
8 August 1989
First astrometric satellite
25 August 1989
First Neptune flyby (closest approach at 29,240 km)
18 November 1989
First orbital cosmic microwave observatory
14 February 1990
First photograph of the whole Solar System
24 April 1990
Optical orbital observatory
USA (NASA) ESA
Hubble Space Telescope
15 September 1990
Extended (multi-year) orbital exploration of Venus
21 October 1991
First asteroid flyby (951 Gaspra closest approach 1,600 kilometers)
8 February 1992
First polar orbit around the Sun
USA (NASA) ESA
22 March 1995
Record longest duration spaceflight (437.7 days) set by Valeri Polyakov
Russia (FKA) Mir
7 December 1995 First orbit of Jupiter
7 December 1995
First mission into the atmosphere of a gas giant (Jupiter)
Galileo‘s atmospheric entry probe
12 February 1997 First orbital radio observatory
Japan (ISAS) HALCA
4 July 1997
First operational rover on another planet (Mars) USA (NASA)
20 November 1998
First multinational space station,
Largest man-made object built in space to date Russia(FKA) USA (NASA) Europe (ESA) Japan (JAXA) Canada (CSA)
International Space Station
14 February 2000
First orbiting of an asteroid (433 Eros)
USA (NASA) ESA
12 February 2001
First landing on an asteroid (433 Eros)
1 July 2004
First orbit of Saturn
ESA Italy (ASI)
8 September 2004
First sample return beyond lunar orbit (solar wind)
14 January 2005
First soft landing on Titan
ESA USA (NASA) Italy (ASI)
19 November 2005
First asteroid ascent (25143 Itokawa)
First interplanetary escape without undercarriage cutoff
Japan (JAXA) Hayabusa
15 January 2006
First sample return from comet (81P/Wild) USA (NASA)
6 March 2009
Kepler Mission is launched, first space telescope designated to search for Earth-like exoplanets
13 June 2010
First sample return from asteroid (25143 Itokawa)
18 March 2011
First orbit of Mercury
16 July 2011
First orbit of giant asteroid Vesta
25 August 2012
First manmade probe in interstellar space.
12 November 2014
First man-made probe to make a planned and soft landing on a comet (67P/Churyumov–Gerasimenko).
6 March 2015
First orbit of dwarf planet (Ceres).
First spacecraft to orbit two separate celestial bodies.
First flyby of dwarf planet (Pluto).
Last original encounter with one of the nine major planets recognized in 1981.
10 August 2015
Lettuce was the first food eaten that was grown in space.
USA (NASA) Japan (JAXA)
1 March 2016
Astronaut Scott Kelly and Cosmonaut Mikhail Kornienko return to Earth after their 340-day space mission, longest recorded time in space for ISS crew members.
USA (NASA) Russia(FKA)
ISS year long mission