History of science

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Flammarion's wood engraving (1888): Man sees the new worldview beyond the celestial spheres

The history of natural sciences is understood to mean the development of natural sciences in the past.

Human recognition of nature often led to a use of nature ( mastery of nature ). The potential for this has increased sharply in the course of history - thus the assessment of progress in the knowledge of nature also increased. History is made out of such a sense of success; Historical reflection is thus in itself an indication of the awareness that a great deal has been achieved in the field in question. The corresponding presentation focused on right / wrong / first - d. H. which point of view was right or wrong (based on today's assessment), who recognized something or not yet, and above all: who was first ( priority ). Such a straightforward representation is criticized today as being too simplistic.

As part of the history of science means Discover a mediation : The discoverer acquires the novelty of the Observed by him or theoretically been deduced, and he published the Recognized by him, thus making it the world around accessible. So z. For Europeans, for example, it is not the first person who set foot in America thousands of years ago as the discoverer of America , but the person through whom the existence of America became known to Europeans.

Research field and delimitation

The history of the natural sciences is often used to describe research into this history - according to the double meaning of the word "history". For research and presentation of the history of the natural sciences as well as the other sciences → see the main article History of Science . This article here covers what happened itself.

For more detailed information on the history of astronomy , history of physics , etc. see the relevant articles - as well as the articles on the individual naturalists. This overview article here is not about many details - which should be read in any case at the places mentioned - but about cross-connections and general insights.

The history of the natural sciences has numerous links with the history of mathematics , medicine and technology. However, these disciplines are kept separate. Mathematics can be used in all scientific disciplines, but it is a “pure” science. The history of medicine and the history of engineering include not only scientific research, but also its practical application. For this reason alone, separate treatment is obvious.

Ancient sciences

Sunrise over Stonehenge at the summer solstice in 2005. The arrangement of the stones shows that the builders knew exactly what important astronomical positions were.

An important prerequisite for nature research was that people were sedentary . They discovered simple laws in natural processes such as the change of the seasons or the periodic movements of the heavenly bodies . Many of the so-called calendar structures , such as circular moats , sun temples and numerous megalithic structures, prove that the positions of the sun and stars as well as the phases of the moon were very precisely determined . For example, the gates of circular moat systems were aligned at the exact position that the sunrise of the winter solstice marks from the center of the system. Important dates such as new moons, equinoxes and the winter and summer solstices were recorded and had cultic significance in many early cultures. The development of various calendar systems through astronomical observation can be classified as one of the first and most important scientific achievements of early civilization.

Mesopotamia and Egypt

Sustainable and effective agriculture was made possible especially in the river regions of the Orient , which is why settler communities formed larger cities. With a professional differentiation, an administrative apparatus was created, led by priests and officials, who developed writing systems for the organization of tasks . However, these were quite complex and consisted of thousands of characters so that only the elite could learn to read and write.

Babylonian cuneiform tablet YBC 7289 with a sexagesimal approximation for the length of the diagonals of a square.

The designs of various number systems and units for describing weights, distances, angles, times, amounts of money and other quantities were of great importance . The Sumerians and Babylonians used the so-called sexagesimal system with the base number 60 because it has many whole divisors. Even then, an hour was broken down into 60 minutes. They used multiplication tables to calculate area (such as fields) and volume. Furthermore they mastered simple fractions and solved quadratic and cubic equations with the help of root tables. For the temporal orientation they used the lunar calendar . Since around 700 BC The Babylonians systematically carried out precise observations of the known planets and recorded their positions relative to the fixed stars algebraically. However, they did not develop a geometric conception of a world system from their data, but imagined the earth as a disk surrounded by water, which is vaulted by a celestial hemisphere.

The Egyptians were not as advanced as the Babylonians in astronomy and mathematics, but they were superior to them in medicine . By counting the days between the annual Nile floods and averaging them over the years, the solar year in your calendar resulted in 365 days. They imagined the world to be cuboid, with a flat or slightly domed sky held up by four mountain peaks at the corners of the mainland. In the medical field, the disease was thought to be a demonic spirit that was supposed to be driven away by the administration of medicines. Despite these mythical ideas, around 1600 BC there were Already the description of about 47 diseases with their symptoms, diagnosis and therapy options .

In Babylon and Egypt, the priests, who were also civil servants, performed scientific tasks and recorded their findings in writing, especially in the areas of astronomy, mathematics and medicine. However, in the course of the centuries there has been a tendency in the learned tradition to limit oneself to the appropriation and interpretation of these ancient writings and to forego possible progress. There was a deep gulf to the tradition of the craft (e.g. in the field of metal production), so that the chance of mutual fertilization was wasted. The craftsmen passed on their skills through demonstrations and verbal explanations.

In the 2nd millennium BC In addition to the two advanced cultures of the Egyptians and Babylonians, two very important innovations were introduced: the alphabet and iron processing. It was probably the Phoenicians who were the first to develop a script with around 30 characters, based on pronunciation sounds . This enabled people outside of the elite classes to learn to read and write. At the same time, the process developed in Asia Minor for smelting iron ore spread to the Middle East and the Mediterranean. The end of the Bronze Age had come. Peoples who practiced maritime trade benefited from iron production and in this way went straight from the Stone Age to the Iron Age .

Greek culture

The Greek culture benefited from a lively exchange of knowledge between the surrounding civilizations through maritime trade. The knowledge taken over from other peoples and their own observations of nature were initially interpreted primarily mythologically, but over the centuries an orientation towards mathematics emerged in natural philosophy . At first one tried mainly to make statements about the "essence" of nature and the dynamic principle of all activity and to find its origin ( arché ) or primary material . Anaximenes , for example, suspected air as the original substance and argued that all other substances were different manifestations of the same. Compression of the air creates wind, clouds, and from them water and, with even greater compression, earth and stone. So every single substance observed is to be explained as a kind of aggregate state of the one primordial substance (material monism ). Another example is the four-element theory of Empedocles , which describes dynamic processes between the four "elements" fire, air, water and earth, from which the whole perceptible world is composed. The decisive factor is not only the objective description, but the cause behind the development and transformation of nature ( metaphysics ).

Lunar eclipse 2007. Aristotle justified the spherical shape of the earth, among other things, from the observation that the earth's shadow is always round during a lunar eclipse.

Although the arguments of the natural philosophers of the time differed largely from today's scientific methodology, the most important schools of thought were already followed. The philosophers Leukippus , Democritus and later Epicurus developed the view of atomism , which is based on the indivisibility of the elementary components ( atoms ) of the universe. In this way, diversity and complexity should be explained by reducing them to a few. In contrast, Aristotle's concept of so-called oversummativity assigns a greater content to the whole than to the sum of its parts. This paradigm is based on the observation that a system cannot be fully explained from the properties of its individual parts ( emergence ) and is now known as holism . Dealing with this and numerous other issues of that time is of great importance for the philosophy of science to this day .

The spherical shape of the earth was already in the 6th century BC. Assumed by the Pythagoreans and based on sound arguments from Aristotle in his work Over the Sky . A geometric world system was developed from the known processes of the celestial bodies, which describes the movements of the sun, the moon, the planets and the fixed star sky on separate spheres around the earth. This enabled solar and lunar eclipses to be illustrated and other astronomical phenomena to be explained. Aristarchus of Samos - who, in contrast to the Aristotelian school, represented a heliocentric system - estimated the relative distances between the sun and moon by measuring angles. Eratosthenes was able to use precise angle measurements and geometrical considerations as early as the 3rd century BC. BC determine the circumference of the earth to 250,000 stages (order of magnitude about 40,000 km). The geocentric view of the world was expanded by Claudius Ptolemy through the epicyclic theory and thus enabled a complicated but rather precise description of the mechanics of known celestial bodies. The Ptolemaic worldview dominated for almost 1500 years, right up to the beginnings of modern science in Europe.

China and India

In China, philosophy and technology were largely separate from each other. The scholars viewed practical work - and thus experiments - as demeaning. This was generally the case in societies in which agriculture was dominant - in contrast to societies that were intensively trading. This was important in China, but those products that gained great importance were nationalized.

From around 400 BC There were reliable astronomical observations that led to the determination of the position of 800 stars. Observational astronomy, however, was only practiced algebraically, it remained separate from speculative cosmology and geometrical concepts. Empirical observations and comprehensive theoretical ideas could therefore not enrich one another.

The Chinese conception of the two forces yin and yang (female passive and male active, respectively) became influential in alchemy. This had a heyday during the Han dynasty (around 200 BC - 200 AD); alchemy was looking for the elixir of immortality. An important textbook that emerged at that time was the canon of medicine , which viewed man as a microcosm, analogous to the universe; In addition, the arithmetic was revised in 9 sections .

The Chinese knew magnets and gunpowder, as well as paper and printing. Block printing was used for printing. H. Wooden board printing (one full page each). In the 11th century AD, movable letters made of clay were introduced, but they did not catch on because of the large number of Chinese characters that was hardly any relief.

After the rule of the Mongols, relations with China were made easier - cf. the explorations of Marco Polo (around 1300) from Venice.

In India a decimal number system emerged, and also - before the beginning of our era - an alphabetical script that was used for the sacred script of the Vedas .

Natural Sciences in the Middle Ages

Islamic world

The House of Wisdom (Baghdad) was founded in Baghdad in 825 AD , an academy in which numerous translations of ancient texts were made, but also in which their own research was carried out. Among other things, the earth's circumference was redefined and an astronomical observatory was built. Influential for alchemy was Jabir ibn Hayyan . He emphasized the experience (including mystical) and he used the scales.

The papermaking was adopted from China. In 1005 a "House of Science" was founded in Cairo . There taught Al-Haitham , the u. a. researched optics and developed magnifying glasses.

In the Caliphate of Córdoba in today's Spain a fruitful intercultural science developed. A library and academy was founded in Córdoba in 970 AD, and the Toledaner Tables (astronomical tables with information on future planetary positions) were published around 1080 AD . Averroes also worked in Cordoba .

Europe's craft tradition

The Teutons operated a three-field economy . This effective management led to a food surplus and therefore to prosperity , which was used for several enterprises: to build cathedrals or to found universities . The development of the Hanseatic League (Lübeck was founded in 1243) is also evidence of prosperity.

In the 13th century has been compass known and the production of paper came on the Arabs to Italy and in 1400 in Germany. It was there that Johann Gutenberg invented a letter casting instrument before 1450 . And the gunpowder was known. (Around 1500 AD, letterpress printing and firearms brought about a change comparable to that of the spread of the alphabet and iron around 1000 BC).

From around 1400, craftsmen and builders began to write down their methods (while previously they only passed them on orally). Around 1500 there were important artist-engineers (such as Leonardo da Vinci ), but they were still not very specialized and therefore, despite their creativity, did not have a strong impact on scientific research .

Europe's scientific tradition

After completing the "first phase" of the reconquest of Spain (1085 AD), Toledo became the capital of Spain and the seat of the archbishop. There were many translations from Arabic into Latin (e.g. from Ptolemy's Almagest). Sicily was also recaptured, and Emperor Frederick II promoted translations, such as Aristotle's biological texts and Arabic alchemy. The astronomical Alfonsine Tables were created by Jewish scholars around 1260 AD.

Leonardo Fibonacci wrote the book of arithmetic ( Liber abbaci ) after 1200 and explained in it the “novem figurae indorum” (nine digits of the Indians).

The first “full universities” emerged in the 12th century in Bologna, Paris and Oxford. The term universitas originally referred to a craft guild; From the 13th century onwards, it was only used to refer to a learned association, namely a universitas magistrorum et scholarium . At the preparatory “artistic faculty”, the “artes liberales” were taught (divided into Trivium and Quadrivium ). A doctorate could be obtained at the three higher faculties (theological, legal and medical).

The Dominicans Albertus Magnus and Thomas von Aquin in Cologne integrated Aristotle into Catholic theology ( scholastic Aristotelianism ); thereby the Neoplatonism of the church fathers was ousted.

In the context of alchemy, experiments were carried out; the ideas developed in the process were speculative: the union of male sulfur with female mercury was supposed to produce metals. The dissection of corpses was important for anatomy, but this was done by the barber (surgeon), while the doctor himself was not active, but only explained - for students. In the late Middle Ages, however, there was gradually an interaction between artisans and scholars.

The Scientific Revolution in Early Modern Europe

In the late Middle Ages and in the early modern period, natural research moved in the field of tension between tradition and empiricism . The researchers were faced with the question of the extent to which they should adopt the traditional knowledge and to what extent their own empirical studies and theories based on them were promising. The tradition was often tied to the ancient authorities Aristotle or Ptolemy, but also to statements in the Bible. With the increasing appreciation of new, verifiable empirical results, the polemic was sometimes associated with assuming that researchers who think differently had excessive adherence to tradition (as the reason for their opinions differing from their own position). From the second half of the 15th century, the machine printing technology developed by Johannes Gutenberg played a key role in the dissemination of new knowledge and the critical examination of them .

Cosmology and physics

Representations of the history of the natural sciences describe the period from around 1500 AD much more intensely than the centuries before that - this is an indication of the general assessment of a clear increase in knowledge around this time. An important prerequisite for this was the convergence of learned and craft tradition.

From around 1540, groundbreaking basic works appeared in several disciplines. From around 1600 the word "new" appears in the titles of some natural science books (Kepler, Bacon, Galilei) - an indication of a changed consciousness: the old is assessed as unsatisfactory, so something new had to be designed.

With Nicolaus Copernicus ' work On the Revolutions of the Heavenly Circles of 1543, the view slowly became public that the earth moves daily around itself and an annual movement around the sun. Copernicus wanted to adhere to two ancient physical principles, namely the circularity and uniformity of all movements in the sky. So he strove for an improvement through a consistent recourse to the ancient tradition. In 1551 the Prussian tables of the planetary positions were published by Copernicus follower Erasmus Reinhold - the spread of these tables also made the heliocentric system better known.

Tycho Brahe's observations questioned the ancient separation between different spheres: in 1572 he noticed a supernova, in 1577 a comet. With the help of many precise observations by Brahe (such as the orbit of Mars) Johannes Kepler discovered the elliptical shape of the planetary orbits, published in his book Astronomia Nova (1609).

William Gilbert studied magnetism (1600). Francis Bacon explained the empirical procedure in detail in his book Novum Organum scientiarum (1620). His saying “knowledge is power” refers to his pragmatic goals. He described various prejudices that cloud our understanding. He saw human knowledge as cumulative - thereby turning away from the earlier attitude that everything essential was already contained in the Bible or in ancient authors like Aristotle.

Another supporter of the heliocentric world system was Galileo Galilei . Because of his offensive propaganda ( dialogue ) he became involved in an ecclesiastical process (1633). His foundation of two new sciences ( due nuove scienze ) was important for physics (1638), namely mechanics (strength theory) and the theory of local movements (i.e. free fall and throw).

From around 1600 the scientific method, the interrelation between empiricism and tradition, became a matter of course. The connection between scholarly and craft tradition did not have to be won over and over again, for example through favorable social conditions.

Just as Bacon strengthened the empirical direction in England, René Descartes influenced France through his rationalist orientation. In his book Discourse de la methode (1637) he described the mathematical method as a means of correct use of reason and the scientific establishment of truth. The title of his other book, Principia philosophiae (1644), was later taken up by Newton. Descartes worked and published in the more liberal Netherlands.

In 1685, the Huguenots (Protestants) were expelled from France , and they were gladly accepted as businessmen in other countries. Religious ideas were sometimes incorporated into nature research. The “minimal principles” were based on the idea of ​​a prudent creator who does not act awkwardly. We find this already with Bishop John Wilkins , who advocated the heliocentric system and showed how it compatible with biblical texts: A Discourse concerning a New world and another Planet (1640). According to Pierre de Fermat , light always chooses the path with the shortest possible time, and later (1744) Pierre Maupertuis set up the “principle of the smallest effect”. Wilkins also tried to develop a comprehensive scientific language: Essay towards a Real Character and a Philosophical Language (1668).

In 1660 the Royal Society was founded in London. It had around 100 members and was the first to publish a scientific journal: Philosophical Transactions . This journal appeared regularly and was able to include articles on various topics in the context of nature research. It was no longer necessary to publish an entire book if you wanted to make a discovery known - a smaller essay was often enough. Similar scientific societies followed, namely the Académie in Paris in 1666 and the Academy in Berlin in 1700 .

Such academies also chose foreign members - that was a special honor for them. It is noticeable that both the Paris Academy and the London Royal Society had relatively significantly more Protestant than Catholic foreign members, namely compared to the population sizes of the respective countries in question. Possibly the less authoritarian attitude in Protestant societies favored creative natural research, perhaps it was also due to an “empirical individualism” (each individual should recognize the truth for himself: the religious by reading the Bible, the scientific by experiment ...). In particular, by examining which churches the members of the Royal Society belonged to in the 17th century, the American sociologist Robert King Merton came to the conclusion in 1938 that the scientific and technological revolution of the 17th and 18th centuries was essentially by Protestants, mainly English Puritans and German Pietists , was worn ( Merton thesis ).

The Royal Society included a striking number of Christian “nonconformists” - such as B. Isaac Newton , a Unitarian. His main work Philosophiae naturalis principia mathematica (1687) is reminiscent of a work by Descartes. The term “philosophy” was understood very comprehensively at that time, “natural philosophy” referred to what we now call “natural science”. Newton combined the knowledge of Galileo about acceleration and that of Kepler about the planetary orbits, he designed a mechanics comprising earth and sky (this word he referred to the movement of bodies).

One important finding was that the light that spreads at lightning speed - for the human eye - has a finite speed. The Dane Ole Rømer recognized this in 1676 due to the delay in the eclipse of Jupiter's moons, which occurred when the earth is further away from Jupiter. The light needs 22 minutes for the diameter of the earth's orbit. From this, the Dutchman Christiaan Huygens calculated a speed of light of 212,000 km per second; according to modern measurements it is around 300,000 km per second.

Medicine and chemistry

In the field of anatomy, the physician Andreas Vesalius , who comes from Brussels and teaches in Padua, wrote a basic work - printed in Basel, like many other works. His work was called De humani corporis fabrica (1543). Vesal himself, as a trained doctor, had dissected corpses for this purpose. Another important doctor was William Harvey , who described great circulation in 1628.

Another doctor was noteworthy: Theophrast von Hohenheim , called Paracelsus. He received his doctorate in medicine in Ferrara - around 1500 the northern Italian universities were still considered scientific strongholds; but their importance decreased in the following centuries. Paracelsus was often out and about, because of his provocative nature he couldn't stay long anywhere, not even in the tolerant Basel. There he became a city doctor in 1527 and was therefore able to give a lecture at the university - he gave it in German, while at that time (and later) the language of instruction was Latin. His concern was a reorientation of alchemy: instead of aiming for gold production or the production of an elixir of immortality, it should help the doctor in the production of effective medicines. Paracelsus had published very little, but through his work - probably also through impressive healing successes - he became a downright myth, and half a century after his death the first comprehensive edition of his writings was published, from 1589 in Basel (included in the latest printed edition his medical writings 14 volumes, his theological and religious-philosophical writings 8 volumes - an enormous total volume!).

Chemistry grew out of alchemy, and it broke away from its original goals. Robert Boyle wanted to find out the elementary substances - the "elements": Skeptical Chymist (1661).

It was a long way to practical application of chemistry or physics - this required lengthy basic research.

Applied science

There have been important developments in the applied areas of navigation and cartography. While trying to reach (rear) India by sea, Christopher Columbus sailed to America (1492) on behalf of Spain and believed that he had found the inhabitants of India (therefore called "Indians") there. An essential prerequisite for this discovery was a mistake, namely the value that Ptolemy set too low for the circumference of the earth. With the more correct value of Eratosthenes, no one would have dared to sail from Europe to East Asia. The result of the voyages of discovery initiated by Columbus was an upswing in trade and handicraft, but not so much in Spain and Portugal, but above all in the Netherlands and England. These regions then also became important for nature research - just as generally strong trade had a positive effect on nature research. Navigating large seas made corresponding world maps necessary. The problem arose of projecting the curved earth onto a flat map. A good solution for this came from Gerhard Mercator (1569), whose angular design made navigation considerably easier.

Systematization of numerous individual findings in the 18th century

The number of important naturalists increased continuously from around 1500, but temporarily decreased around 1700.

Around 1700, exploration of nature slowed down. Some historians see this as a result of the devastation of the Thirty Years War (1618–1648). Other historians do not observe stagnation until around 1700 or later, particularly clearly in the first half of the 18th century. These impressions were statistically confirmed and made more precise by evaluating time tables of important scientific discoveries. In contrast to the increase in the number of discoveries from around 1500 onwards, a “valley” about half a century wide with a low point around 1705 is evident. The causes of this stagnation are not clear; one consideration sees this as a brief effect of the preceding scientific revolution brought about by Isaac Newton.

In Great Britain a noticeable number of Christian “nonconformists” worked as naturalists. Individual or institutional deviations probably offered some opportunities for further development of natural research. Modern university foundations were more likely to have the opportunity to make fundamental changes. The university in Halle, founded in 1694, switched to lectures in German. Comprehensive encyclopedias, in which scientific knowledge were also taken into account, made for easier access to the results of science. B. the Encyclopaedia Britannica , which first appeared in 1771 in Edinburgh.

The development of the steam engine ( James Watt ) was preceded by research into air pressure. Blaise Pascal treated the hydrostatics (1653), the theory of the immobile, especially the flow-free liquids and gases. Robert Boyle found that with gases, pressure and volume are inversely proportional. Otto von Guericke founded vacuum technology; he put u. a. states that light penetrates vacuum, but not sound.

The astronomer Nevil Maskelyne noticed that an assistant's observation results systematically deviated - this made it clear that there are individual differences in human perception.

The musician Wilhelm Herschel immersed himself more and more in his hobby astronomy; he sharpened mirror telescopes and surveyed the fixed star sky. In doing so, he discovered a new planet: Uranus (1781). After the other five planets visible to the naked eye had been known for thousands of years, their number has now been expanded for the first time.

The statistical method developed by Carl Friedrich Gauß became important for various disciplines , namely the appropriate placement of a best-fit straight line for scattering data: He developed an averaging using his method of least squares (1809).

Chemistry tried to clarify the combustion process. Georg Ernst Stahl spoke of " phlogiston " (1703) and meant by it greasy earth that escapes when heated. This phlogiston theory was fruitful, but ultimately a dead end from which only the discovery of oxygen by Carl Scheele and Joseph Priestley led out. On this basis, Antoine Laurent de Lavoisier designed his book Traité élémentaire de Chimie (1789). He also included the gases in his quantitative checks and found that the total weight was retained during combustion.

In botany and zoology, Carl Linné succeeded in drafting an accepted system: Systema Naturae (10th edition of 1758).

In embryology, William Harvey achieved important insights. He recognized that life always sprang from an egg ("omne vivum ex ovo"). Karl Ernst von Baer discovered the mammal egg in 1827. In the animal world he distinguished four different modes of development: a vertebrate develops bilaterally, an articulated animal centrally, a mollusc spirally, and a radiant animal radially.

The studies of Georges Cuvier became important for paleontology . By finding the correlations, i.e. H. the interrelationships between organs, with careful consideration, he was also able to reconstruct fragmentarily preserved fossils (a total of around 150 mammal species). In his book Recherches sur les ossements fossiles de quadrupèdes (1812), he reckoned with at least four catastrophes in the past, the last of which (about six thousand years ago) he saw the Flood.

Around 1800 the idea of ​​progress covered many topics, from the universe and living beings (Jean Baptiste Lamarck) to civilization and humans (Joseph Priestley).

Development of natural science subjects in the 19th century

In Germany there were some momentous measures: In 1810 the new university in Berlin began operations. There the habilitation was introduced as a verification of the teaching qualification of lecturers, from around 1820, gradually adopted by other universities. Above all, the university teacher was expected to be able to conduct independent scientific research. Among the successful naturalists in the 19th century, the job of a university teacher was the norm, unlike in the past. To promote encounters and communication among researchers, the Society of German Natural Scientists and Doctors was founded in 1822 on the initiative of Lorenz Oken .

German naturalists in the 19th century had a penchant for particle theories. They recognized the importance of the cell as the basic building block of all living things. Matthias Schleiden established that every plant develops from a cell and is composed of cells (1838). Theodor Schwann transferred this insight to all animals, and Rudolph Virchow recognized that every disease arises from a cell.

There were two strong currents in geology: first, the "volcanists" (or plutonists ), who saw forces at work in the earth's past more gradually; secondly, the " Neptunists ", who saw several major catastrophes as the cause of the present earth shape. An important representative of the Neptunists was Abraham Gottlob Werner , who taught at the Bergakademie in Freiberg in Saxony and had a great influence through his teaching. When he died in 1817, a student published Werner's System of Mineralogy as a book. An important representative of the volcanists was Charles Lyell with his main work Principles of Geology, being an Attempt to explain the Former Changes of the Earth's Surface by Reference to Causes now in Operation (from 1830). This book title is reminiscent of Newton's main work Principia mathematica .

The title of Jean Baptiste Lamarck's main work is also revealing: Philosophy Zoologique (1809), because he (still) called his theory of zoology a “philosophy”. In the following decades the term “philosophy” narrowed and the individual scientific subjects gained a sharper, independent profile. Lamarck's theory of evolution gained attention. He attributed the changes necessary for evolution firstly to an inner developmental force, secondly to an “inheritance of acquired properties” (this view was later called “Lamarckism”). The use or disuse of organs should cause hereditary changes, as well as injuries.

Charles Darwin , too, was to a certain extent a Lamarckist; i.e., he tried the variability and a. to explain. In addition, he relied on the experience of animal breeders who achieved enormous racial differences within a species. Darwin believed that such differences would gradually lead to the formation of new species, so he tried to reduce the meaning of the term species. In addition to variability, there was a selection: particularly cheap variants should have a greater chance of survival. The more detailed title of his work already gives an accurate impression of the content: On the Origin of the Species by Means of Natural Selection, or the Preservation of Favored Races in the Struggle for Life (1859). In contrast, the title of the essay by Gregor Mendel (Augustinian monk in Brno) was not very meaningful: Experiments on plant hybrids (1866). In it he reported on the crossbreeding in peas and the inheritance rules that became recognizable (uniformity, segregation, new combination of hereditary factors). This essay did not remain unknown, but its meaning was not recorded - until these rules were rediscovered in 1900. August Weismann was important for the theoretical development of the theory of evolution : In his book Das Keimplasma (1892) he founded neo-Darwinism; he argued against Lamarckism, so there should be no repercussions on genes.

Atomic theory was introduced to chemistry by John Dalton , most notably through his book New System of Chemical Philosophy (1808); however, it did not gain any great importance in the following decades. The periodic table of the elements (1869, Dmitri Mendelejeff ) then proved the great value of atomic theory. The decades around 1800 were referred to as the “heroic age of geology”, because geologists came across numerous new minerals; as a result, chemists were able to identify around 30 new elements (while Lavoisier's list only contained 23 chemical elements). Henri Antoine Becquerel discovered radioactivity (1896); Theoretical chemistry and theoretical physics came ever closer together through their common theme of atomic structure and chemical bonding.

The wave model of light was founded by Christiaan Huygens . Thomas Young measured the wavelength of light, and Hippolyte Fizeau measured the speed of light with the help of a rotating gear (1849). The Doppler effect (1842), named after Christian Doppler , states that the frequency of the oscillation decreases as the source moves away (this applies to both sound and light).

In several steps it was recognized that electricity and magnetism are in some ways similar (and can stimulate one another); In addition, other phenomena were recognized as comparable (such as light). William Gilbert had recognized that in addition to amber (which was already known in antiquity), other materials (e.g. glass or sulfur) are also electrically charged through friction. Benjamin Franklin recognized in 1749 that lightning was electrically charged. Luigi Galvani recognized the conductivity of animal nerves on the basis of frogs' legs (1789). In 1820, Hans Christian Oersted showed the magnetic effects of electric current. Clerk Maxwell proposed an electromagnetic theory of light.

The 18th century was not only the time of the phlogiston theory, but also the time of " warmth matter ". Previously, heat had already been interpreted as the movement of the smallest parts of matter. Then the idea of ​​warmth took hold - it was understood to be a weightless substance that appears to leave an object that is getting colder. In the 19th century, however, this idea was given up. The doctor Julius Robert Mayer was able to convert heat and mechanical energy into one another in 1842. In 1865, Rudolf Clausius spoke of entropy (energy that can no longer be used for work), which, as a whole, constantly increases over time.

The industrial revolution came around 1800: machine tools were produced that were capable of producing standardized machine parts. Technology developed for a long time without drawing on scientific help. Experience and trial and error led to some improvements. It was not until the late 19th century that technicians began to use scientific methods - which radically transformed human life in the 20th century.

Friedrich Wilhelm Bessel succeeded in observing a fixed star parallax in 1838. This finally proved the annual motion of the earth.

In chemistry, Justus von Liebig came up with a momentous application: the arable soil was to be supplied with missing nutrients by means of chemical fertilizers made from potash and phosphate salts. Microbiology was founded by Louis Pasteur . The process of "pasteurization" (killing germs by brief heating) is still known today. He also made it clear that there is no such thing as "spontaneous generation"; the general rule is: "vivo ex vivo". Microbiology was also able to identify pathogens: Robert Koch discovered the tubercle bacillus and the cholera bacillus.

Due to the numerous scientific discoveries in the 19th century, the scientific methodology of observation and recognition gained a special reputation. It was believed that the humanities should also orient themselves towards scientific methods.

The scientification of the lifeworld in the 20th century

Overview of cells in the growing root tip of onion ( Edmund Beecher Wilson , 1900)

In the decades around 1900 there were developments in the field of biology and physics, which are described with the terms modern biology and modern physics . This should not be confused with the term used in modern science , which stands for developments since the early modern period .

For biology and its practical application, the study of cells became important, especially the germ cells . And how inheritance worked was an important topic in the history of evolution . Electron microscopes were valuable for examining cells : they have been developed since the 1930s and have a resolution of about 0.1 nanometers . A light microscope achieved a resolution of down to 200 nanometers (about half the wavelength of light ). By staining the cell nucleus , processes could be better differentiated.

Thomas Hunt Morgan was the founder of a genetics school in the USA . He used the fruit fly ( Drosophila melanogaster ) for experiments, as it has only four chromosomes and develops in twelve days.

The mechanical explanations of life were often felt to be inadequate and additional forces (such as a life force ) were used for explanation - for example by Hans Driesch , who outlined his position in terms of a vitalism in the book Philosophy of the Organics (1909).

The Lamarckism could not be convincingly confirmed experimentally, but he was represented by some biologists. In the Soviet Union, it went well with the hope of changing the environment to make better people . There was of Stalin and Khrushchev the Lysenkoism supported - against the scientific knowledge in the field of biology.

Wave property of matter: the probability density of an electron in passing a double gap

In the 19th century a medium for the propagation of light was imagined , the ether . Attempts to prove it failed completely and led to contradictions within classical physics . This resulted in the necessity of a fundamental change in the physical world view, which led to Albert Einstein's theory of relativity : The special theory of relativity (on the electrodynamics of moving bodies, 1905) and the general theory of relativity ( basic ideas of the general theory of relativity, 1915).

Another fundamental change resulted from the quantum hypothesis . Max Planck recognized that the energy of a quantum is directly proportional to the frequency of the radiation (1900). A connection to atomic theory could be established. In order to imagine the shape and function of such an atom, Nagaoka Hantarō introduced the comparison with astronomy : The electrons move (as if on planetary orbits) around the atomic nucleus. The number of electrons corresponded to the atomic number in the periodic table . Electromagnetic radiation (in quanta) only existed when an electron changes from one orbit to another ( Niels Bohr ). The descriptive planetary model was soon replaced by quantum mechanical models (see orbital model ) (from 1925). Louis de Broglie predicted in 1925 that matter, like radiation, has both particle and wave properties ( wave-particle dualism ).

The reflecting telescope mentioned in the text
in Pasadena, California during construction

In 1919, Ernest Rutherford bombarded nitrogen with alpha particles and achieved the first artificial transmutation . At the end of 1938 Otto Hahn and his assistant Fritz Straßmann carried out experiments in Berlin in search of transuranium elements and discovered nuclear fission using radiochemical methods , which was first interpreted physically and theoretically by Lise Meitner and her nephew Otto Robert Frisch in early 1939 . In the fall of 1939, Niels Bohr and John A. Wheeler published a comprehensive theory of nuclear fission. Enrico Fermi and his team succeeded in the first uranium chain reaction in 1942 .

The Astrophysics penetrated - with better telescopes - deeper into the universe prior to grasp more about its construction. Our Milky Way is a closed system of stars (like the sun ) with a diameter of about 100,000 light years recognized. In 1917, a reflecting telescope with an opening over 2.5 meters (100 inches ) in diameter was built on Mount Wilson (in Pasadena, California ) .

BC177 transistor from the 1970s and VHF electron
tube 955 from 1954

After the glow-electric effect (glow emission, today called Edison-Richardson-Effect ) was already known in the 19th century, the first vacuum diode was constructed in 1904 by John Ambrose Fleming . 1906 invented independently Robert of ones and Lee De Forest with the Lieben- and the audio tube , the first reinforcing electron tubes . These gave a boost to the development of telecommunications and formed the backbone of electronics for around half a century .

Julius Edgar Lilienfeld (1925), Oskar Heil (1934) and Heinrich Welker (1945) described designs that were forerunners of the field effect transistors . In 1947 William B. Shockley , John Bardeen and Walter H. Brattain constructed the first bipolar transistor from germanium . Werner Jacobi (1949) and Jack Kilby (1958) constructed circuits from several transistors on a common substrate, Robert Noyce followed in 1959 with the first monolithic circuit: the integrated circuit was invented, the basis of microelectronics .

In 1948 Claude E. Shannon published his work A Mathematical Theory of Communication and thus provided the theoretical foundation for data transmission and thus one of the foundations of the information age .


The evaluative and selective historiography often hesitates to turn to the last decades, since convincing evaluation and selection are only possible after some time. In so far as a representation tries to lead up to the present, it resembles a chronological table and is often content with listing numerous individual discoveries. The recognition of the great lines and the important breakthroughs is left to posterity.


  • Alistair C. Crombie: From Augustine to Galileo. Cologne-Berlin 1964 (translation of The History of Science. From Augustine to Galileo . New York 1995, 1st edition 1959)
  • Ludwig Darmstaedter , René du Bois-Raymond: 4000 years of pioneering work in the exact sciences (sorted by year), Berlin 1904, online at archive.org
  • Karen Gloy : Understanding Nature. CH Beck, Munich 1995. Vol. 1. The history of scientific thinking. ISBN 3-406-38550-8
  • JL Heilbron (Ed.): The Oxford Companion to the History of Modern Science , Oxford University Press, Oxford-New York 2003.
  • Arne Hessenbruch: Reader's Guide to the History of Science . Fitzroy Dearborn, London-Chicago 2000.
  • Stephen F. Mason: History of Science in the Development of Its Thoughts. GTN, 3rd edition 1997; engl. Orig .: A History of the Sciences , 1962 (still up-to-date overall presentation on the subject)
  • R. C. Olby, G. N. Cantor, J. R. R. Christie, MJ S. Hodge (Eds.): Companion to the History of Modern Science. London-New York 1990.
  • George Sarton : A guide to the history of science. Ronald Press, New York 1952 (German: The Study of the History of Natural Sciences. Klostermann, Frankfurt / M. 1965, 92 pages)
  • Michel Serres (ed.): Elements of a history of the sciences. Frankfurt / M. 1994; French orig. Éléments d'histoire des sciences. Paris 1989 (no overall presentation, but extensive 22 individual studies).
  • Hendrik Floris Cohen: The Scientific Revolution. A Historiographical Inquiry , University of Chicago Press 1994 (on the causes of the emergence of modern science)
  • R. Rashed (Ed.): Encyclopedia of the History of Arabic Science. 3 volumes. London / New York 1996.
  • John Krige, Dominique Pestre (eds.): Companion to Science in the Twentieth Century , Taylor & Francis, New York 2003, ISBN 9789057021725 .
  • Lars Jaeger: The natural sciences: A biography , Springer, Heidelberg 2015, ISBN 9783662433997

Web link

Single receipts

  1. On the importance of communication see Franz Stuhlhofer : Lohn und Strafe in der Wissenschaft. Naturalist in the Judgment of History . Böhlau, Vienna 1987, chap. II, 2 and III, 4.
  2. Stephen Mason : History of Science in the Development of Its Thoughts . GTN, 3rd edition 1997, p. 20
  3. Mason: Geschichte , p. 23f
  4. Mason: Geschichte , pp. 27f.
  5. On the gap between scholars and artisans, see Mason: Geschichte , pp. 28–28.
  6. On the transition to the Iron Age, see Mason: Geschichte , pp. 29–31.
  7. Mason: History , p. 33.
  8. ^ Mason: History , p. 40.
  9. Aristoteles : Metaphysik (Aristoteles) Book 8. 6. 1045a: 8-10.
  10. ^ Mason: History , p. 49.
  11. Mason: History , p. 66.
  12. ^ Joseph Needham: Scientific Universalism. About the importance and particularity of Chinese science. Suhrkamp, ​​Frankfurt / M. 1979, p. 152.
  13. On trade as a prerequisite for the emergence of modern science, see Needham: ... Chinese science. Pp. 80, 157, 164.
  14. On the gap between philosophy and technology, see Mason: Geschichte , pp. 88, 91 (on trade, p. 108).
  15. On astronomy in China see Colin A. Ronan: The Shorter Science and Civilization in China. An abridgement of Joseph Needham's original text. Vol. 2, Cambridge University Press, Cambridge et al. a. 1981, pp. 67-221.
  16. The geometry was weak in China, see Needham: ... Chinese science. P. 122.
  17. Mason: Geschichte , pp. 97f.
  18. Jim al-Khalili: In the House of Wisdom . S. Fscher, Frankfurt 2010.
  19. Mason: Geschichte , p. 128f.
  20. ^ As judged by Mason: Geschichte , pp. 132f.
  21. ^ Franz Graf-Stuhlhofer : Tradition (s) and empiricism in early modern natural research . In: Helmuth Grössing, Kurt Mühlberger (ed.): Science and culture at the turn of the ages. Renaissance humanism, natural sciences and everyday university life in the 15th and 16th centuries (= writings from the archives of the University of Vienna ; 15). V&R unipress, Göttingen 2012, pp. 63–80.
  22. ^ Fritz Krafft (ed.): Great natural scientists. Biographical Lexicon. Düsseldorf 1986, pp. 88-91 (via Copernicus ).
  23. ^ I. Bernard Cohen (ed.), Puritanism and the Rise of Modern Science: the Merton Thesis , Rutgers University Press, 1990, ISBN 0-8135-1530-0
  24. ^ Piotr Sztomka, Robert K. Merton , in George Ritzer (ed.), Blackwell Companion to Major Contemporary Social Theorists , Blackwell Publishing, 2003, ISBN 1-4051-0595-X
  25. Franz Stuhlhofer: Our knowledge doubles every 100 years. Foundation of a "knowledge measurement" . In: Reports on the history of science . 6, 1983, pp. 169–193, there 180: an evaluation of the lifetimes of Fritz Krafft, Adolf Meyer-Abich (ed.): Große Naturwissenschaftler. Biographical Lexicon . Frankfurt / Main 1970, selected 298 researchers.
  26. About Rudolf Burckhard: History of Zoology. Leipzig 1907, p. 58: "... devastation of Central and Northern Europe by the Thirty Years' War, which shut down scientific production for decades ...", or Paul Walden : Chronological overview tables on the history of chemistry. Berlin u. a. 1952, p. VI.
  27. Mason: Geschichte der Naturwissenschaft , 1997, p. 360: "... stagnation in natural research, which began to make itself felt towards the end of the 17th century ..."
  28. So Mason: Geschichte der Naturwissenschaft , 1997, p. 334: "The first half of the 18th century presents itself to us as a rather unproductive epoch in the history of scientific thought compared with both the preceding and the following period."
  29. ^ Similar to John Desmond Bernal : Science in History. Vol. 2; he names Chapter 8.1 as follows: "The Early Eighteenth-Century Pause 1690-1760".
  30. Franz Stuhlhofer: Our knowledge doubles every 100 years. Foundation of a knowledge measurement. In: Reports on the history of science . 6, 1983, pp. 169-193, especially p. 183. DOI: 10.1002 / bewi.19830060117
  31. The same low point in J. C. Sheldon: A Cybernetic Theory of Physical Science Professions: The Causes of Periodic Normal and Revolutionary Science between 1000 and 1870 AD. In: Scientometrics 2, 1980, pp. 147-167.
  32. Derek de Solla Price : Ups and Downs in the Pulse of Science and Technology. In: Sociological Inquiry 48, 1978, p. 3f, calls the low around 1700 “a post-scientific revolution slump”.
  33. ^ Gerhard Otto Oexle: Natural science and historical science. Moments in a problem story. In: Gerhard Otto Oexle (Ed.): Natural science, humanities, cultural studies. Unity - opposition - complementarity. Göttingen 1998, pp. 99-151.