Timeline of scientific discoveries


The timeline below shows the date of publication of possible major scientific breakthroughs, theories and discoveries, along with the discoverer. This article discounts mere speculation as discovery, although imperfect reasoned arguments, arguments based on elegance/simplicity, and numerically/experimentally verified conjectures qualify. The timeline begins at the Bronze Age, as it is difficult to give even estimates for the timing of events prior to this, such as of the discovery of counting, natural numbers and arithmetic.
To avoid overlap with timeline of historic inventions, the timeline does not list examples of documentation for manufactured substances and devices unless they reveal a more fundamental leap in the theoretical ideas in a field.

Bronze Age

Many early innovations of the Bronze Age were prompted by the increase in trade, and this also applies to the scientific advances of this period. For context, the major civilizations of this period are Egypt, Mesopotamia, and the Indus Valley, with Greece rising in importance towards the end of the third millennium BC. The Indus Valley script remains undeciphered and there are very little surviving fragments of its writing, thus any inference about scientific discoveries in that region must be made based only on archaeological digs. The following dates are approximations.
File:Nippur cubit.JPG|thumb|upright=1.5|The Nippur cubit-rod, c. 2650 BCE, in the Archeological Museum of Istanbul, Turkey
  • 3000 BC: Units of measurement are developed in the Americas as well as the major Bronze Age civilizations: Egypt, Mesopotamia, Elam and the Indus Valley.
  • 3000 BC: The first deciphered numeral system is that of the Egyptian numerals, a sign-value system.
  • 2650 BC: The oldest extant record of a unit of length, the cubit-rod ruler, is from Nippur.
  • 2600 BC: The oldest attested evidence for the existence of units of weight, and weighing scales date to the Fourth Dynasty of Egypt, with Deben balance weights, excavated from the reign of Sneferu, though earlier usage has been proposed.
  • 2100 BC: The concept of area is first recognized in Babylonian clay tablets, and 3-dimensional volume is discussed in an Egyptian papyrus. This begins the study of geometry.
  • 2100 BC: Quadratic equations, in the form of problems relating the areas and sides of rectangles, are solved by Babylonians.
  • 2000 BC: Pythagorean triples are first discussed in Babylon and Egypt, and appear on later manuscripts such as the Berlin Papyrus 6619.
  • 2000 BC: Multiplication tables in a base-60, rather than base-10, system from Babylon.
  • 2000 BC: Primitive positional notation for numerals is seen in the Babylonian cuneiform numerals. However, the lack of clarity around the notion of zero made their system highly ambiguous.
  • Early 2nd millennium BC: Similar triangles and side-ratios are studied in Egypt for the construction of pyramids, paving the way for the field of trigonometry.
  • Early 2nd millennium BC: Ancient Egyptians study anatomy, as recorded in the Edwin Smith Papyrus. They identified the heart and its vessels, liver, spleen, kidneys, hypothalamus, uterus, and bladder, and correctly identified that blood vessels emanated from the heart.
  • 1800 BC: The Middle Kingdom of Egypt develops Egyptian fraction notation.
  • 1800 BC – 1600 BC: A numerical approximation for the square root of two, accurate to 6 decimal places, is recorded on YBC 7289, a Babylonian clay tablet believed to belong to a student.
  • 1800 BC – 1600 BC: A Babylonian tablet uses = 3.125 as an approximation for, which has an error of 0.5%.
  • 1550 BC: The Rhind Mathematical Papyrus contains the first documented instance of inscribing a polygon into a circle to estimate the value of.

    Iron Age

The following dates are approximations.
  • 700 BC: Pythagoras's theorem is discovered by Baudhayana in the Hindu Shulba Sutras in Upanishadic India. However, Indian mathematics, especially North Indian mathematics, generally did not have a tradition of communicating proofs, and it is not fully certain that Baudhayana or Apastamba knew of a proof.
  • 700 BC: Pell's equations are first studied by Baudhayana in India, the first diophantine equations known to be studied.
  • 700 BC: Grammar is first studied in India.
  • 600 BC: Thales of Miletus is credited with proving Thales's theorem.
  • 600 BC: Maharshi Kanada gives the ideal of the smallest units of matter. According to him, matter consisted of indestructible minutes particles called paramanus, which are now called as atoms.
  • 600 BC – 200 BC: The Sushruta Samhita shows an understanding of musculoskeletal structure . It refers to the cardiovascular system as a closed circuit. In it identifies the existence of nerves.

    500 BC – 1 BC

The following dates are approximations.
  • 500 BC: Hippasus, a Pythagorean, discovers irrational numbers.
  • 500 BC: Anaxagoras identifies moonlight as reflected sunlight.
  • 5th century BC: The Greeks start experimenting with straightedge-and-compass constructions.
  • 5th century BC: The earliest documented mention of a spherical Earth comes from the Greeks in the 5th century BC. It is known that the Indians modeled the Earth as spherical by 300 BC
  • 460 BC: Empedocles describes thermal expansion.
  • Late 5th century BC: Antiphon discovers the method of exhaustion, foreshadowing the concept of a limit.
  • 4th century BC: Greek philosophers study the properties of logical negation.
  • 4th century BC: The first true formal system is constructed by Pāṇini in his Sanskrit grammar.
  • 4th century BC: Eudoxus of Cnidus states the Archimedean property.
  • 4th century BC: Thaetetus shows that square roots are either integer or irrational.
  • 4th century BC: Thaetetus enumerates the Platonic solids, an early work in graph theory.
  • 4th century BC: Menaechmus discovers conic sections.
  • 4th century BC: Menaechmus develops co-ordinate geometry.
  • 4th century BC: Mozi in China gives a description of the camera obscura phenomenon.
  • 4th century BC: Around the time of Aristotle, a more empirically founded system of anatomy is established, based on animal dissection. In particular, Praxagoras makes the distinction between arteries and veins.
  • 4th century BC: Aristotle differentiates between near-sighted and far-sightedness. Graeco-Roman physician Galen would later use the term "myopia" for near-sightedness.File:Birch bark MS from Kashmir of the Rupavatra Wellcome L0032691.jpg|thumb|Pāṇini's Aṣṭādhyāyī, an early Indian grammatical treatise that constructs a formal system for the purpose of describing Sanskrit grammar.
  • 4th century BC: Pāṇini develops a full-fledged formal grammar.
  • Late 4th century BC: Chanakya establishes the field of economics with the Arthashastra, a prescriptive treatise on economics and statecraft for Mauryan India.
  • 4th – 3rd century BC: In Mauryan India, The Jain mathematical text Surya Prajnapati draws a distinction between countable and uncountable infinities.
  • 350 BC – 50 BC: Clay tablets from Babylon describe the mean speed theorem.
  • 300 BC: Finite geometric progressions are studied by Euclid in Ptolemaic Egypt.
  • 300 BC: Euclid proves the infinitude of primes.
  • 300 BC: Euclid proves the Fundamental Theorem of Arithmetic.
  • 300 BC: Euclid discovers the Euclidean algorithm.
  • 300 BC: Euclid publishes the Elements, a compendium on classical Euclidean geometry, including: elementary theorems on circles, definitions of the centers of a triangle, the tangent-secant theorem, the law of sines and the law of cosines.
  • 300 BC: Euclid's Optics introduces the field of geometric optics, making basic considerations on the sizes of images.
  • 3rd century BC: Archimedes relates problems in geometric series to those in arithmetic series, foreshadowing the logarithm.
  • 3rd century BC: Pingala in Mauryan India studies binary numbers, making him the first to study the radix in history.
  • 3rd century BC: Pingala in Mauryan India describes the Fibonacci sequence.
  • 3rd century BC: Pingala in Mauryan India discovers the binomial coefficients in a combinatorial context and the additive formula for generating them, i.e. a prose description of Pascal's triangle, and derived formulae relating to the sums and alternating sums of binomial coefficients. It has been suggested that he may have also discovered the binomial theorem in this context.
  • 3rd century BC: Eratosthenes discovers the Sieve of Eratosthenes.
  • 3rd century BC: Archimedes derives a formula for the volume of a sphere in The Method of Mechanical Theorems.
  • 3rd century BC: Archimedes calculates areas and volumes relating to conic sections, such as the area bounded between a parabola and a chord, and various volumes of revolution.
  • 3rd century BC: Archimedes discovers the sum/difference identity for trigonometric functions in the form of the "Theorem of Broken Chords".
  • 3rd century BC: Archimedes makes use of infinitesimals.
  • 3rd century BC: Archimedes further develops the method of exhaustion into an early description of integration.
  • 3rd century BC: Archimedes calculates tangents to non-trigonometric curves.
  • 3rd century BC: Archimedes uses the method of exhaustion to construct a strict inequality bounding the value of within an interval of 0.002.
  • 3rd century BC: Archimedes develops the field of statics, introducing notions such as the center of gravity, mechanical equilibrium, the study of levers, and hydrostatics.
  • 3rd century BC: Eratosthenes measures the circumference of the Earth.
  • 260 BC: Aristarchus of Samos proposes a basic heliocentric model of the universe.
  • 200 BC: Apollonius of Perga discovers Apollonius's theorem.
  • 200 BC: Apollonius of Perga assigns equations to curves.
  • 200 BC: Apollonius of Perga develops epicycles. While an incorrect model, it was a precursor to the development of Fourier series.
  • 2nd century BC: Hipparchos discovers the apsidal precession of the Moon's orbit.
  • 2nd century BC: Hipparchos discovers Axial precession.
  • 2nd century BC: Hipparchos measures the sizes of and distances to the Moon and Sun.
  • 190 BC: Magic squares appear in China. The theory of magic squares can be considered the first example of a vector space.
  • 165 BC – 142 BC: Zhang Cang in Northern China is credited with the development of Gaussian elimination.