Scientific revolutions

Andreas Vesalius publishes 'De Humani Corporis Fabrica,' the most accurate atlas of the human body ever made.

He finds over 200 errors in Galen's revered texts — mostly because Galen had been dissecting pigs and monkeys, not people.

De Humani Corporis Fabrica Libri Septem is a set of books on human anatomy written by Andreas Vesalius (1514–1564) and published in 1543. It was a major advance in the history of anatomy over the long-dominant work of Galen, and presented itself as such.

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Galileo Galilei points his telescope at Jupiter and spots four small lights circling it night after night.

He initially names them the 'Medicean Stars' to flatter the Medici family and secure a court appointment in Florence.

The Galilean moons, or Galilean satellites, are the four largest moons of Jupiter. They are, in descending-size order, Ganymede, Callisto, Io, and Europa. They are the most readily visible Solar System objects after Saturn, the dimmest of the classical planets; though their closeness to bright Jupiter makes naked-eye observation very difficult, they are readily seen with common binoculars, even under night sky conditions of high light pollution. The invention of the telescope allowed astronomers to discover the moons in 1610. Through this, they became the first Solar System objects discovered since humans have started tracking the classical planets, and the first objects to be found to orbit any planet beyond Earth.

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William Harvey publishes his discovery that blood circulates continuously around the body, pumped by the heart.

He calculates that the heart pumps roughly 245 litres of blood per hour — far too much for the liver to be constantly creating.

William Harvey was an English physician who made influential contributions to anatomy and physiology. He was the first known physician to describe completely, and in detail, pulmonary and systemic circulation as well as the specific process of blood being pumped to the brain and the rest of the body by the heart.

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Edmond Halley publishes his calculation that the comets of 1531, 1607, and 1682 are all the same object on a 76-year orbit.

He boldly predicts it will return around 1758 — but dies in 1742, never seeing himself proved right.

Halley's Comet is the only known short-period comet that is consistently visible to the naked eye from Earth, appearing roughly every 75–76 years, though with the majority of recorded apparitions occurring after 75–77 years. It last appeared in the inner parts of the Solar System in 1986 and will next appear in mid-2061. Officially designated 1P/Halley, it is also commonly called Comet Halley, or sometimes simply Halley.

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Michael Faraday discovers that moving a magnet through a coil of wire produces an electric current.

When asked by a politician what use electricity could possibly be, Faraday reportedly replies: 'What use is a newborn baby?' — but more verifiably, his lab notebook records the crucial experiment on 17 October in a single dry line.

Electromagnetic induction or magnetic induction is the production of an electromotive force (emf) across an electrical conductor in a changing magnetic field.

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Hungarian physician Ignaz Semmelweis orders doctors at Vienna General Hospital to wash their hands in chlorinated lime solution before delivering babies.

Mortality on his ward plunges from roughly 10% to under 2% — yet his colleagues largely dismiss and mock him for implying that doctors themselves are killing patients.

Ignaz Philipp Semmelweis was a Hungarian medical doctor and scientist of German descent who was an early pioneer of antiseptic procedures and was described as the "saviour of mothers". Postpartum infection, also known as puerperal fever or childbed fever, consists of any bacterial infection of the reproductive tract following birth and in the 19th century was common and often fatal. Semmelweis demonstrated that the incidence of infection could be drastically reduced by requiring healthcare workers in obstetrical clinics to disinfect their hands. In 1847, he proposed hand washing with chlorinated lime solutions at Vienna General Hospital's First Obstetrical Clinic, where doctors' wards had thrice the mortality of midwives' wards. The maternal mortality rate dropped from 18% to less than 2%, and he published a book of his findings, Etiology, Concept and Prophylaxis of Childbed Fever, in 1861.

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Gregor Mendel publishes the results of eight years breeding pea plants in a monastery garden.

His paper is read aloud to a small local society and then ignored for 34 years until three separate scientists rediscover the same laws.

Gregor Johann Mendel was an Austrian biologist, meteorologist, mathematician, Augustinian friar and abbot of St. Thomas' Abbey in Brno (Brünn), Margraviate of Moravia. Mendel was born in a German-speaking family in the Silesian part of the Austrian Empire and gained posthumous recognition as the founder of the modern science of genetics. Though farmers had known for millennia that crossbreeding of animals and plants could favor certain desirable traits, Mendel's pea plant experiments conducted between 1856 and 1863 established many of the rules of heredity, now referred to as the laws of Mendelian inheritance.

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Wilhelm Röntgen notices that a fluorescent screen across his lab glows even when blocked by cardboard, revealing a new kind of ray.

The first X-ray image he makes is of his wife Bertha's hand; on seeing her own skeleton, she says, 'I have seen my death.'

Wilhelm Röntgen's accidental discovery of a new kind of radiation allows the interior of the body to be seen without a scalpel for the first time.

Marie Curie coins the word 'radioactivity' and identifies two new elements — polonium and radium — in a single year.

She works in a leaky shed, and her lab notebooks are still so radioactive today that researchers must sign a waiver to read them.

Maria Salomea Skłodowska Curie, better known as Marie Curie, was a Polish and naturalised-French physicist and chemist. She shared the 1903 Nobel Prize in Physics with her husband, Pierre Curie, "for their joint researches on the radioactivity phenomena discovered by Professor Henri Becquerel". She won the 1911 Nobel Prize in Chemistry "[for] the discovery of the elements radium and polonium, by the isolation of radium and the study of the nature and compounds of this remarkable element".

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James Watson and Francis Crick announce the double-helix structure of DNA at Cambridge.

Their model is built largely from X-ray diffraction data taken by Rosalind Franklin, whose crystallography work they accessed without her explicit knowledge.

Identifying the double-helix structure of DNA explains how genetic information is stored and copied, founding molecular biology.