History and People:
Who made the first star map? When did people know that the Earth was round? When were sunspots discovered? The links to the right will lead you to biographies of scientists who lived at different times through history. Discover the people who made science history!
Who made the first star map? When did people know that the Earth was round? When were sunspots discovered? The links to the right will lead you to biographies of scientists who lived at different times through history. Discover the people who made science history!
Ancient People
![]() Archimedes
Archimedes was a Greek mathematician and engineer who lived between 287-212 B.C. His greatest contributions are in the field of geometry and in the development of war machines. Legend has it that Archimedes discovered his famous theory of buoyancy while taking a bath. He was so excited that he ran naked through the streets of Syracuse shouting "Eureka, eureka (I have found it)!". Another legend claims that Archimedes saved the city of Syracuse from a Roman siege by constructing a lens which focused the sun's light and burned Rome's fleet of ships. ![]() Aristotle
Aristotle was a Greek philosopher who lived between 384-322 B.C. He was one of the greatest thinkers of the world and his written works encompassed all major areas of thought. Aristotle mistakenly believed that the Earth was at the center of theuniverse and made up of only four elements: earth, water, air, and fire. He also thought that celestial bodies such as the sun, moon, and stars, were perfect and divine, and made of a fifth element called ether. ![]() Democritus
Democritus was a Greek philosopher who lived between 470-380 B.C. He developed the concept of the 'atom', Greek for 'indivisible'. Democritus believed that everything in the universe was made up of atoms, which were microscopic and indestructible. Democritus had many remarkable insights for his time. He understood that the Milky Way was a large collection of stars and also thought that space was limitless. ![]() Ptolemy
Ptolemy was a Greek astronomer who lived between 85-165 A.D. He put together his own ideas with those of Aristotle and Hipparchus and formed the geocentric theory. This theory states that the Earth was at the center of the universe and all other heavenly bodies circled it, a model which held for 1400 years until the time of Copernicus. Ptolemy is also famous for his work in geography. He was the first person to use longitude and latitude lines to identify places on the face of the Earth. ![]() Pythagoras
Pythagoras was a Greek philosopher who lived between 580-520 B.C. He founded a school in Croton, which made outstanding contributions to the field of mathematics. Pythagoras and his cult members believed that everything was related to mathematics and agreed that, ultimately, "all is number". Pythagoras is also famous for his study of sound and his theorem relating the lengths of the sides of a right triangle. ![]() Socrates
Socrates was a Greek philosopher who lived between 470-399 B.C. He turned Greek attention toward questions of ethics and virtue. Although Socrates was not a scientist, his way of questioning to find out answers laid a foundation for the way that science works today. Socrates spent much time in the Athens marketplace (the Agora) where he held conversations with townspeople. He was known for exposing ignorance and conceit. Despite having many followers, Socrates was disliked by people in Athens, Greece. At the age of 70, he was convicted of atheism, treason and corruption of the young. He was sentenced to death by a jury. He had the opportunity to escape from prison, but he chose not to. He valued the law so much, that he chose to fulfill his sentence of death by drinking hemlock instead of escaping and living in banishment for the rest of his life. An account of his death was recorded by Plato, one of Socrates' students. ![]() Thales
Thales was a Greek philosopher who lived between 624-546 BC. Although none of his writings survive, we have learned of his work through the writings of others. Thales is considered the father of Greek science, mathematics, and philosophy. He is the first person to have asked questions about the nature of the universe and considered the answers without thinking of gods or demons. This was a crucial step in scientific reasoning and led to an intellectual explosion which lasted hundreds of years. Thales also used Egyptian and Babylonian astronomical records to predict an eclipse in 585 BC. |
Middle Ages
Abu Ja'far al-Khwarizmi
Abu Ja'far al-Khwarizmi was an Arab mathematician who lived between 780-850. At a time when the diffusion of ideas was very slow due to the lack of cross-cultural communication, al-Khwarizmi wrote a book which contained many important mathematical concepts of the Middle East. This book revolutionized western (European) mathematics: It introduced the decimal system, as well as rules for solving equations and doing geometry. 'Abd al-Rahman al-Sufi
'Abd al-Rahman al-Sufi was a Persian astronomer who lived during the 10th century. In 964, he documented the existance of the Andromeda galaxy, our closest neighbor, and called it "little cloud". This was the first record of a star system outside our own galaxy. Al-Sufi's book on stars was translated into many languages and had a great influence on European astronomy. Leonardo Fibonacci
Leonardo Fibonacci was an Italian mathematician who lived between 1170-1240. He travelled a lot on business with his father and was exposed to many different mathematical techniques used throughout the world. Fibonacci collected these ideas in books, for people to learn without having to travel as he had. His writings introduced Arabic numerals into European mathematics. Fibonacci also made significant contributions to mathematics himself, in number theory and on recursive sequences. He is most famous for the Fibonacci sequence, in which each number is the sum of the previous two. Jabir Ibn Haiyan
Jabir Ibn Haiyan was an Arab chemist who lived in the late 700's. Although he died in 803, the date of his birth is uncertain. His experimental investigation increased our understanding of common chemical processes, and he is considered the father of modern chemistry. Ibn Haiyan was a pioneer in the field of applied science. He developed techniques for the making of steel, dyeing of cloth, and prevention of rust, which improved the quality of everyday life. Ibn Haiyan also discovered many acids and practiced medicine. Renaissance Epoch
The period during the years of 1450-1600 ![]() Nicholas Copernicus
Nicholas Copernicus was a Polish astronomer who lived between 1473-1543. Before his time, people believed in the Ptolemaic model of the solar system, which maintained that the Earth was the center of the universe. Copernicus changed this belief when he introduced the heliocentric model, centered around the sun. He claimed that all the planets, including Earth, moved in orbits around the sun, and showed how this new system could accurately calculate the positions of the planets. ![]() Leonardo da Vinci
Leonardo da Vinci was an Italian artist and scientist who lived between 1452-1519. Leonardo was the original Renaissance man, whose roles included inventor, engineer, architect, mathematician, geologist, and astronomer. While he is best known as a painter, Leonardo primarily worked for the military, producing designs of tanks, airplanes, and submarines, hundreds of years before such war machines were created. He is also famous for his sketches of the muscles and bones in the human body. ![]() Galileo Galilei
Galileo Galilei was an Italian astronomer and physicist who lived between 1564-1642. He challenged Aristotle's proposition that heavenly bodies were divine and therefore perfect and blemish-free. Galileo was the first person to use a telescope to look at the heavens. He discovered sunspots, and craters and peaks in the moon. Galileo's work offended the Roman Catholic Church and he was sentenced to house arrest for the later years of his life. Today, he is remembered as a martyr for scientific truth. ![]() Johan Kepler
Johan Kepler was a German astronomer who lived between 1571-1630. He introduced three important laws of planetary motion and helped theCopernican model of the solar system gain general acceptance. Kepler inherited Tycho Brahe's observational data on Mars followingBrahe's death and showed, mathematically, that Mars followed an elliptical orbit. This new revelation contradicted the age old belief that heavenly bodies all moved in perfect circles. During his life, Kepler also cast horoscopes and wrote science fiction novels. Simon Marius
Simon Marius was a German astronomer who lived between 1573-1624. He made observations of the heavens using a telescope and published yearly astronomical tables. Throughout most of his life, Marius was troubled with charges of copying data from other scientists. Although he named the four moons of Jupiter, their discovery is generally credited to Galileo. Due to his strong religious beliefs, Marius never accepted the Copernican model of the universe. |
Age of Enlightenment
![]() Giovanni Cassini
Giovanni Cassini was Italian-French astronomer who lived between 1625-1712. He discovered that Saturn's Rings are split into two parts, and today the gap between them is called the "Cassini Division". He also discovered four of Saturn's moons, in addition to those found by Huygens twenty years earlier. Cassini studied hydrology and how to avoid the damaging floods that plagued Europe. His greatest mistakes were rejecting theCopernican model of the solar system and Newton's theory of universal gravitation. ![]() Charles Darwin
Charles Darwin was an English Naturalist who lived between 1809-1882. He laid the foundations for the modern science of biology, and changed how other scientists understood the appearance of life onEarth. In 1859, following 30 years of study and travels, Darwin published a book called The Origin of Species by Means of Natural Selection, which started a scientific revolution. It showed that life on Earth is constantly changing and only the fittest organisms survive ![]() Ben Franklin
Ben Franklin was an American scientist and statesman who lived between 1706-1790. At a time when little was known about electricity, he carried out many experiments to learn of its dangers and possible uses. Franklin's famous kite experiment led to his invention of the lightning rod, which protects buildings from lightning damage. His other inventions included bifocals, glasses that let you see both far and near, and a stove which heats houses more safely than a fireplace. Franklin also worked on a Peace treaty between England, France, and the U.S. which ended the American Revolution. ![]() Edmond Halley
Edmond Halley was an English astronomer who lived between 1656-1742. Using historical records, his own observations, and Newton'suniversal law of gravitation, he reasoned that the comets which had appeared in 1456, 1531, 1607, and 1682, were one and the same. He then predicted the comet's return about every 76 years. Although Halley died in 1742, the comet reappeared 16 years later, and today bears his name.In addition to his work on comets, Halley studied the Earth's weatherand magnetic field, and the ocean's tides. Caroline Herschel
Caroline Lucretia Herschel was a German astronomer who lived between 1750-1848. Caroline originally came to England to receive a music education, but she worked in England most of her life alongside her brother, William Herschel, helping him make astronomical observations and then making her own. She discovered three new nebulae in 1783. She also discovered eight comets between 1786-1797. In addition, she published two astronomical catalogues which are still used today. Caroline received the Gold Medel for Science from the King of Prussia in 1846. Caroline Herschel was 98 years old when she died. She is buried in Germany. ![]() Christian Doppler
Christian Doppler was an Austrian mathematician who lived between 1803-1853. He is known for the principle he first proposed inConcerning the coloured light of double stars in 1842. This principle is now known as the Doppler Effect. He hypothesised that the pitch of a sound would change if the source of the sound was moving. Doppler's hypothesis was tested by Buys Ballot in 1845. He used two sets of trumpeters: one set stationary at a train station and one set moving on an open train car. Both sets of musicians had perfect pitch and held the same note. As the train passed the station, it was obvious that the frequency of the two notes didn't match, even though the musicians were playing the same note. This proved Doppler's hypothesis. Later, a scientist named Fizeau generalized Doppler's work by applying his theory not only to sound but also to light. ![]() Christian Huygens
Christian Huygens was a Dutch physicist and astronomer who lived between 1629-1695. He found new methods for grinding and polishing lenses, making telescopes more powerful. Using a telescope he had made, Huygens first identified Saturn's rings and one of Saturn's moons. Huygens also invented the pendulum clock, increasing the accuracy of timekeeping, and proposed the wave theory of light. ![]() James Clerk Maxwell
James Clerk Maxwell was a Scottish physicist who lived between 1831-1879. He studied Saturn's rings and suggested that they were composed of solid particles. This theory was confirmed 100 years later by the Voyager 1 space probe. Maxwell is most famous for his equations linking electricity andmagnetism. His revolutionary work lead to the development of quantum physics in the early 1900's and to Einstein's theory of relativity. ![]() Isaac Newton
Isaac Newton was an English scientist and mathematician who lived between 1642-1727. He had one of the most brilliant minds the world has ever known. Legend has it that seeing an apple fall gave Newton the idea that gravity, the force which keeps us bound to the Earth, also controls the motion of planets and stars. Newton's contributions to science include the universal law of gravitation, the development of a whole new field in mathematics called calculus, and his famous three laws of motion. ![]() Louis Pasteur
Louis Pasteur was a French chemist who lived between 1822-1895. He discovered that fermentation, the process used to make beer and wine, is carried out by tiny animals. Pasteur called these microorganisms "germs", and learned that they are also responsible for spreading contagious diseases. He thus solved the mystery behind rabies, and created vaccines for this and other deadly illnesses, saving many lives. Pasteur also dispelled the myth of spontaneous generation, proving that all life comes from pre-existing life. |
Modern Era
![]() Niels Bohr
Niels Bohr was a Danish physicist who lived between 1885-1962. He investigated atomic structure, modifying Rutherford's old model of an atom. Bohr also claimed that an atom's chemical properties are determined only by the electrons with the largest orbits. After helping build the first nuclear bomb, Bohr spent the later years of his life promoting peaceful uses of atomic energy. ![]() Marie Curie
Marie Curie was a physicist and chemist who lived between 1867-1934. She contributed greatly to our understanding of radioactivity and the effects of x-rays. She was born Maria Skłodowska in Warsaw, Poland, then part of the Russian empire. Women were not permitted to study at the University of Warsaw, and Maria, together with her sister, attended the classes at night in an illegal "floating university". When Maria was 24, she moved to Paris to study mathematics, physics and chemistry at Sorbonne University. There she met and married Pierre Curie. Together they studied radioactive materials and discovered two new elements: polonium, named after Poland, and radium. They did their early work in difficult conditions, in crowded and damp makeshift labs. They also studied the medical uses of radioactivity in radiography and treating cancer tumors. In 1903, they shared the Nobel Prize in physics with Henri Becquerel for their research in radioactivity. Marie Curie was the first woman to be awarded a Nobel Prize. After Pierre's tragic death in 1906, Marie took his place as Professor of General Physics in the Faculty of Sciences, the first time a woman had held this position. In 1911, she also received the Nobel Prize in chemistry and became the first person to win two Nobel Prizes. She did a lot to raise money for research on radioactivity, and helped establish radioactivity laboratories in Paris and Warsaw. During World War I, she promoted use of radium for the treatment of wounded soldiers. Marie Curie died from a blood disease in 1934, due to her constant exposure to radioactive materials. Next year their daughter Irène Joliot-Curie shared the Nobel prize in chemistry with her husband Frédéric Joliot-Curie. What an exceptional family! ![]() Thomas Edison
Thomas Edison was an American inventor who lived between 1847-1931. He patented over a thousand inventions, including the light bulb, which generates light using electricity passed through a filament. Edison also invented the phonograph (which records and plays back sound), and a motion picture machine used to make movies. He credited hard work for his success and used to say that "genius is one percent inspiration and 99 percent perspiration". ![]() Albert Einstein
Albert Einstein was a German physicist who lived between 1879-1955. Probably the most well-known scientist of the twentieth century, Einstein came up with many original theories and invented modern physics. He is most famous for his theory of relativity, which makes bold statements about the nature of light and also shows the relationship between mass and energy. Einstein's accurate predictions on the link between gravity with space and time also made him a celebrity. ![]() Werner Heisenberg
Werner Heisenberg was a German physicist who lived between 1901-1976. He developed new theories in quantum mechanics about the behavior of electrons which agreed with the results of previous experiments. Heisenberg is most famous for his "uncertainty principle", which explains the impossibility of knowing exactly where something is and how fast it is moving. However, this principle is only significant for tiny particles such as electrons. Heisenberg also wrote the plans for the first nuclear reactor in Germany and promoted such peaceful uses of nuclear energy. ![]() Edwin Hubble
Edwin Hubble was an American astronomer who lived between 1889-1953. His observations of galaxies helped him develop the idea of an expanding universe, which forms the basis of modern cosmology, the study of the origin of the universe. He also discovered a relationship between a galaxy's speed and its distance. Hubble's studies were interrupted by service in both World Wars. The Hubble space telescope, currently on an observation project in space, bears his name. ![]() Max Planck
Max Planck was a German physicist who lived between 1858-1947. His theories changed our understanding of atomic processes and started the field of quantum physics, which studies energy inside atoms. Many of Planck's ideas were later used by Einstein when he developed his theory of relativity. Planck believed that the physical universe exists independently of humans and that we have no control over the laws of nature. He claimed that we can observe and try to understand such laws, but we can't change them. ![]() Wilhelm Roentgen
Wilhelm Roentgen was a German physicist who lived between 1845-1923. His accidental discovery of x-rays in 1895 changed the fields of physics and medicine. X-rays are a type of radiation which can penetrate materials that ordinary light cannot. They allow us to "view" the insides of objects (like a human body) without having to open them. Today, we use x-rays to locate bone fractures and breaks, cancerous tumors, and tooth cavities. For his brilliant experimental work, Roentgen received the first Nobel Prize, in 1901. ![]() Ernest Rutherford
Ernest Rutherford was a New Zealand-born physicist who lived between 1871-1937. He is considered the father of nuclear physics because of his discoveries on atomic structure. Rutherford believed that an atom is like a small planetary system, with the protons and neutrons in the center (like the sun), circled by electrons (likeplanets). Rutherford also studied radioactivity. He named and identified alpha and beta particles, and showed how an element changes when it experiences radioactive decay. |