Scientific discoveries over the centuries have helped shape the way we live today. Without pioneering scientists working towards cures for diseases, new inventions, and better ways to do things, life today would be different. Here are some of the most influential visionaries throughout history, organized in chronological order, who have made a significant contribution to the scientific community and to our everyday lives.

Scientists of Antiquity

Hippocrates (c.460 BC – c.370 BC) Nationality: Greek Known for: Father of Medicine Credited with writing the Hippocratic Oath that today’s medical professionals still follow in their practice. He had the theory of the vapors, which stated that many diseases were the result of a bad diet.	Aristotle (384 BC – 322 BC) Nationality: Greek Known for: Theory of Three Psyches, Scientific Method Wrote about many scientific topics, including biology, physics and zoology. His ideas helped shape Western scientific thought into the Renaissance until they were replaced with with Newtonian physics.	Archimedes (c.287 BC – c.212 BC) Nationality: Greek Known for: Archimedes Principle, Archimedes Screw Astronomer, scientist, and physicist with several inventions to his name. He created a formula to calculate the area of the underside of a parabola. He also designed many machines of antiquity.
Galen (c. 129 AD –  200/216 AD) Nationality: Roman Known for: Father of Medicine Galen was best known as Galen of Pergamon. He was a famous philosopher and surgeon amongst the Romans. His works contributed greatly to the knowledge of anatomy, pathology, physiology, neurology, pharmacology, logic, and philosophy.

Scientists of the Middle Ages

Leonardo da Vinci (1452-1519) Nationality: Italian Known for: Vitruvian man, aerial screw Renaissance thinker who made several inventions and discoveries in the fields of engineering, anatomy, and hydrodynamics. Also one of the most well-known artists throughout history.	Nicolaus Copernicus (1473-1543) Nationality: Italian Known for: Heliocentric Model of the Universe Astronomer and mathematician from the Renaissance era. He theorized that the sun was the center of the universe rather than the Earth, which was a controversial claim at the time.

Scientists of the Scientific Revolution

Galileo Galilei (1564-1642) Nationality: Italian Known for:Father of Modern Science; Heliocentrism Astronomer, physicist, mathematician and philospher who said the earth and planets revolve around the sun. He confirmed the different phases of Venus with a telescope and observed sunspots and the moons of Jupiter.	Johannes Kepler (1571-1630) Nationality: German Known for: Laws of Planetary Motion Defined a new type of astronomy called “celestial physics,” which said that God created the world in a way that can only be studied through reasoning. Also developed the Keplerian Telescope, which was an improvement on previous telescopes.	Evangelista Torricelli (1608-1647) Nationality: Italian Known for: Invented the barometer Mathematician and physicist who built several telescopes and microscopes. He is also known for creating the barometer and Torricelli’s Law. He also studied and produced scientific evidence for the causes of wind.
Blaise Pascal (1623-1662) Nationality: French Known for: Modern theories of probabilities Mathematician and phycisist who is credited with making the first usable calculator, called the Pascaline. He published a treatise on projective geometry and is known for his work in mathematical probability theories.	Robert Boyle (1627-1691) Nationality: English Known for: Boyle’s Law Physicist and chemist who is partially credited with creating the field of modern chemistry. Boyle’s Law refers to the relationship between a gas and pressure in a closed system when the temperature remains the same.	Isaac Newton (1642-1727) Nationality: British Known for: Laws of Gravity and Motion Newton is one of the most influential scientists in history. He published several books, formulated several scientific laws and made significant discoveries. His main credits include formulating the laws of gravitation and motion.
Edmond Halley (1656-1742) Nationality: English Known for: Calculated the orbit of Halley’s Comet Mathematician and astronomer who published important papers on topics like sun spots, the solar system and more. He is also known for trying to measure the distance from the earth to the sun based on the travels of Venus.

Scientists of the Age of Enlightenment

Anders Celsius (1701-1744) Nationality: Swedish Known for: Proposed the Celsius scale for temperatures Astronomer and professor who studied temperature and the connection between the aurora borealis and the planet’s magnetic field. Published findings that noted that part of Scandinavia was rising above sea level.	James Watt (1736-1819) Nationality: Scottish Known for: Electrical unit Watt named after him Mechanical engineer and inventor who improved the efficiency of the steam engine through the use of a separate condenser. Watt also developed the idea of horsepower.	Edward Jenner (1749-1823) Nationality: English Known for: Pioneered the smallpox vaccine Often called the “Father of Immunology,” his research in vaccinations have saved countless lives over the last couple centuries. He was appointed to be official physician to King George IV in 1821.

Scientists of the 19th Century

Michael Faraday (1791-1867) Nationality: British Known for: Discovered electromagnetic induction Physicist and chemist who worked to make electricity a viable technology that could be used. He also did a lot of work with batteries, electrolysis, and magnets.	Charles Babbage (1791-1871) Nationality: British Known for: Discovered electromagnetic induction Physicist and chemist who worked to make electricity a viable technology that could be used. He also did a lot of work with batteries, electrolysis, and magnets.	Thomas Graham (1805-1869) Nationality: Scottish Known for: Invented the dialysis process for kidneys Chemist who studied the diffusion of gasses. He coined Graham’s Law and also developed the process of dialysis, which is still used in medical facilities today. Graham is also credited with being the founder of colloid chemistry.
Charles Darwin (1809-1882) Nationality: British Known for: Theory of Evolution and Natural Selection Darwin formulated a theory that said humans descended from animals through a process called Natural Selection. His ideas have created a great deal of controversy in his day and through today.	Louis Pasteur (1822-1895) Nationality: French Known for: Process of Pasteurization, vaccine for anthrax and rabies Influential in the field of medical microbiology. Pasteur worked toward cures for diseases and processing methods for reducing harmful bacteria in milk, wine, and other products.His work also helped reduce mortality rates from puerperal fever.	Gregor Mendel (1822-1884) Nationality: Austrian Known for: Father of Modern Genetics Scientist who experimented with plant hybridizations. He discovered that many of his findings could be transferred to animals and humans. Coined the terms “recessive” and “dominant” when referring to genes.
William Thomson Kelvin (1824-1907) Nationality: British Known for: Kelvin Scale of Temperature Physicist and engineer who determined the value for absolute zero in regards to temperature. He also estimated that the age of the earth was between 20 and 400 million years old and helped develop the second law of thermodynamics.	Alfred Nobel (1824-1896) Nationality: Swedish Known for: Invented dynamite Best known for the Nobel Prizes, which are named after him and generally awarded to those who excel in the sciences. These prizes are often reserved for those who make a significant discovery or invention in their respective fields.	Ernst Haeckel (1834-1919) Nationality: German Known for: Gave names to thousands of unknown species Zoologist who supported Darwin’s theories regarding evolution and developed the recapitulation theory, also known as the biogenetic law. He also created several terms in the field of biology, including stem cell, ecology, and several others.
Dmitri Mendeleev (1834-1907) Nationality: Russian Known for: Periodic Table Published Principles of Chemistry in 1869 which detailed his work in arranging the various elements accordig to their atomic mass. He is also credited with introducing the metric system to the Russian Empire.	Wilhelm Conrad Rontgen (1845-1923) Nationality: German Known for: Discovered the modern day x-rays Physicist who worked with electromagnetic radiation. He won the Nobel Prize in Physics in 1901 for his discovery of x-rays. he also worked extensively with magnetic fields, although his findings in this field are lesser known.	Thomas Edison (1847-1931) Nationality: American Known for: Phonograph; electric light bulb; motion pictures; etc. Edison created some of the most prominent inventions that are in most households today. He often gets credit for being the person who created the first research laboratory and he held more than 1,000 patents for his inventions.
Nikola Tesla (1856-1943) Nationality: Croatian Known for: A/C Electrical System Created precursors to modern-day inventions, including a global communication system and induction motors, among others. Tesla experimented with radio communications and x-rays, too. He was considered a “mad scientist” because of his unique inventions.	Max Planck (1858-1947) Nationality: German Known for: Quantum Theory Theoretical physicist who won the Nobel Prize in Physics in 1918 for his theory on quantum physics. He revolutionized the way people thought about the atomic process.	George Washington Carver (1864-1943) Nationality: American Known for: Used peanuts in a variety of inventions and products Scientist and botanist who strived to create alternative crops for sweet potatoes, peanuts, cotton and soybeans. He also helped establish a foundation in his name at the Tuskegee Institute and he became a member of England’s Royal Society of Arts.
Marie Curie (1867-1934) Nationality: Polish Known for: Discoveries and work with radioactivity and radium Physicist who was also the first woman to win the Nobel Prize. She won two of the awards – one in Physics and one in Chemistry. She was one of the pioneers in the discovery and use of x-rays.	Ernest Rutherford (1871-1937) Nationality: New Zealand Known for: The Father of Nuclear Physics Physicist and chemist who won the Nobel Prize in 1908 for his work with exploring radioactive substances. He also had a chemical element named after him – rutherfordium – which is synthetic and radioactive.	Albert Einstein (1879-1955) Nationality: German Known for: Theory of Relativity Einstein was one of the most prominent scientists and physicists in history. He won a Nobel Prize in Physics in 1921 for his law concerning the photoelectric effect. He’s also credited with creating the “world’s most famous equation.”

Scientists of the 20th Century

Otto Hahn (1879-1968) Nationality: German Known for: Helped discover nuclear fission Known as the “Father of Nuclear Chemistry,” Hahn studied extensively the topics of radioactivity and radiochemistry. He was also a peace activist during WWII.	Alexander Fleming (1881-1955) Nationality: Scottish Known for: Helped create penicillin BIBiologist and pharmacologist who helped discover penicillin which was a medical breakthrough. He shared the Nobel Prize in Physiology for his work with two other people in 1928.This discovery is credited with being the starting point of modern antibiotics.	Niels Bohr (1885-1962) Nationality: Danish Known for: Bohr Model of the Atom Bohr won the Nobel Prize in 1922 in Physics for his work on the atomic structure. He worked towards using atoms for peaceful purposes rather than wartime weapons.He is also credited with creating the principle of complementarity.
Erwin Schrodinger (1887-1961) Nationality: Austrian Known for: One of the founders of quantum physics Shared the Nobel Prize in 1933 for his work in quantum theory. Also did significant work in color theory, cosmology, and other related fields. Published What is Life?, discussing genetics and physics.	Edwin Hubble (1889-1953) Nationality: American Known for: Exploring the Milky Way; Hubble’s Law Astronomer and cosmologist who helped create the field of extragalactic astronomy. He theorized that the universe is ever-expanding due to recessional velocity, which was later termed “Hubble’s Law.”	Frederick Banting (1891-1941) Nationality: Canadian Known for: Discovered insulin Physician and scientist who won the Nobel Prize in Physics/Medicine in 1923 for discovering insulin. He was the youngest recipient of the prize and he was knighted by King George V in 1934 for his discovery.
Alfred Kinsey (1894-1956) Nationality: American Known for: Studies of Human Sexuality Conducted numerous studies about human sexual nature and opened up the Institute of Sex Research at Indiana Universty. He published Sexual Behavior in the Human Male and Sexual Behavior in the Human Female.	Robert Oppenheimer (1904-1967) Nationality: American Known for: Father of the Atomic Bomb Theoretical physicist who explored nuclear fusion, electrons, positrons and black holes. One of the founders of the American school of theoretical physics and a recipient of the Enrico Fermi Award, given by the US Department of Energy.	Edward Teller (1908-2003) Nationality: Hungarian Known for: Father of the Hydrogen Bomb Theoretical physicist who supported and advocated for nuclear energy testing and proliferation. He co-founded the Lawrence Livermore National Laboratory. Some of his awards include the Albert Einstein Award and the Enrico Fermi Award.
Alan Turing (1912-1954) Nationality: British Known for: Pioneer in artificial intelligence and computer science Turin was a mathematician, computer scientist and a codebreaker. He worked for Britain during WWII to create ciphers that helped decode German messages. He has been called the Father of Artificial Intelligence.	Jonas Salk (1914-1995) Nationality: American Known for: Developed the first polio vaccine Medical researcher who spent several years studying the polio virus and finding vaccinations for it. He also studied influenza and searched for ways to cure that. Established the Salk Center for Biological Studies in 1963.	Richard Feynman (1918-1988) Nationality: American Known for: Helped develop the atomic bomb Theoretical physicist who received the Nobel Prize in Physics in 1965 for helping create and develop quantam electrodynamics. He also designed a set of mathematical illustrations concerning subatomic particles, which came to be known as the Feynman Diagrams.
James Watson (1928) Nationality: American Known for: Co-founder of the DNA structure Geneticist and molecular biologist who was awarded the Nobel Prize in Physiology in 1962 for his work and collaboration with others on the molecular structure of DNA.	Carl Sagan (1934-1996) Nationality: American Known for: TV Series Cosmos; exploring extraterrestrial intelligence Astronomer and astrophysicist who wrote several books, co-wrote a TV show about space, and promoted exploration of extraterrestrial intelligence and life. Sagan also had an interest in studying UFOs.	Stephen Hawking (1942) Nationality: British Known for: Hawking Radiation; Authored A Brief History of Time Cosmologist and theoretical physicist who has studied the phenomenon of black holes and gravity. Honorary Fellow of the Royal Society of Arts. His book, A Brief History of Time, was a bestseller for more than four consecutive years.

Written by: Chad A. Hagy