**Birthdate:**March 14, 1879

**Sun Sign:**Pisces

**Birthplace:**Ulm, Germany

**Died:**April 18, 1955

The 20th century was a very vibrant period for the scientific fraternity. With improved technologies available for scientific enquiries, several significant inventions and discoveries happened in the 20th century. Enrico Fermi, credited with discovering how to create a nuclear chain reaction, which led directly the creation of the atomic bomb, was born at the dawn of the century as was Nikolaas 'Niko' Tinbergen, Dutch biologist and ornithologist. Clinton Richard Dawkins, an English ethologist, evolutionary biologist and author, is among the scientists who were born in the mid-20th century. Information technology is one field that emerged in this century and revolutionized the world of communication and technology. Alan Turing, a pioneering English computer scientist, mathematician, logician, cryptanalyst and theoretical biologist played a pivotal role in the development of theoretical computer science. The inventor of the World Wide Web, Sir Timothy John Berners-Lee, is another one of the major scientists of the 20th century. Lawrence Krauss and Carl Sagan are among the other influential scientists born in this era. Read on to learn more about the life and works of famous scientists of the 20th century.

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1

Albert Einstein

(One of the Greatest Physicists of All Time, Best Known for Developing the Theory of Relativity)

Deemed as the most influential physicist of the 20th century, the German-born physicist Albert Einstein was one of the greatest minds to have ever lived. Even his name is now synonymous with the term genius. The father of Modern Physics is credited with developing the theory of relativity and explaining the photoelectric effect. The latter won him the Nobel Prize.

2

Stephen Hawking

(Theoretical Physicist - First to Set Out a Theory of Cosmology)

Stephen Hawking was an English theoretical physicist and cosmologist, who despite being afflicted motor neurone disease that severely limited his physical abilities, was able to build a phenomenally successful career. He was the first to set out a theory of cosmology explained by a union of the general theory of relativity and quantum mechanics. Hawking was ranked 25 in the BBC's poll of the **100 Greatest Britons,** in 2002.

3

Alan Turing

(English Mathematician Who is Considered as the Father of Theoretical Computer Science and Artificial Intelligence)

Regarded as the father of computer science and artificial intelligence, Alan Turing was a distinguished mathematician and logician. During WWII, he successfully broke the challenging German Enigma machine codes thereby reducing the duration of war by a couple of years. The scientist, who was convicted for being gay, has been an inspiration for numerous films, plays and novels.

4

Marie Curie

(The First Woman to Win a Nobel Prize)

Amongst the most notable scientists of her time, the first woman to win a Nobel Prize, the sole person to win two Nobel Prize in two different category, and the first woman professor at the University of Paris—Marie Curie’s list of achievements is incredible. She did extensive research in the field of *radioactivity* and discovered polonium and radium.

5

Srinivasa Ramanujan

(Mathematician)

A self-taught genius Indian mathematician, Srinivasa Ramanujan is known for his contributions to mathematical analysis, number theory and continued fractions. Born into a humble family, the celebrated mathematician struggled with poverty but still managed to publish first of his papers in the Journal of the Indian Mathematical Society. Later, his collaboration with English mathematician G. H. Hardy proved very productive.

6

Neil deGrasse Tyson

(American Astrophysicist, Planetary Scientist and Science Communicator)

**Public Welfare Medal**-winning astrophysicist and academic Neil deGrasse Tyson hosted shows such as **NOVA ScienceNow**, **Cosmos: A Spacetime Odyssey**, and **Star Talk**. He is the director of **Hayden Planetarium** and contributed to the dismissal of Pluto’s status as the ninth planet. He has also written a monthly column as "Merlin.”

7

Carl Sagan

(Astronomer and Planetary Scientist Best Known for His Scientific Contribution in Research on Extraterrestrial Life)

8

J. Robert Oppenheimer

(American Theoretical Physicist and Former Wartime Head of the ‘Los Alamos Laboratory’)

Hailed as a brilliant scientific mind, American physicist J Robert Oppenheimer, led the Manhattan Project which resulted in the development of atomic bomb during the World War II. The bombs were dropped on the Japanese cities of Hiroshima and Nagasaki in 1945. However, Oppenheimer was in a constant conflict over the moral issue of the weapons of mass destruction and rallied against nuclear proliferation.

9

Richard Feynman

(One of the Joint Winners of Nobel Prize in Physics in 1965)

Theoretical physicist Richard Feynman won the **Nobel Prize in Physics** in 1965, along with Julian Schwinger and Shin'ichirō Tomonaga, for his research on quantum electrodynamics. He also contributed to the development of the atomic bomb. Feyman made it to **Physics World**’s list of the 10 greatest physicists of all time.

10

George Washington Carver

(American Agricultural Scientist and Inventor Who Promoted Alternative Crops to Cotton and Methods to Prevent Soil Depletion)

Agricultural scientist George Washington Carver is best remembered for promoting crops that were alternative to cotton, such as peanuts and sweet potatoes. He invented ways to prevent soil depletion and developed scores of products made from peanuts, including paints and cosmetics. He won numerous honors, such as the **Spingarn Medal**.

11

Steve Wozniak

(Co-Founder of Apple Inc.)

Widely recognized as one of the two important pioneers of the personal computer revolution, Steve Wozniak is credited with co-founding *Apple Inc.* along with Steve Jobs. Not surprisingly, he has been described as one of the men that changed the course of history through technology. Apart from being a programmer and technology entrepreneur, Steve Wozniak is also a well-known philanthropist.

12

John Forbes Nash Jr.

(Mathematician)

The inspiration behind the movie **A Beautiful Mind**, John F. Nash was a legendary mathematician whose work in the area of game theory earned him the **Nobel Memorial Prize in Economic Sciences**. In his later years, he was riddled with mental illness. He later died in a car crash.

13

Niels Bohr

(Danish Physicist Who Made Foundational Contributions to Understanding Atomic Structure and Quantum Theory)

14

John von Neumann

(Great Mathematician Who Were Equally at Home in Pure and Applied Mathematics)

Hungarian-American scientist John von Neumann contributed to the development of game theory and the concept of self-replication. His work covered vast areas including math, economics, physics, and computer science. His research on nuclear physics led him to be part of the advisory committee of the **U.S. Atomic Energy Commission**.

15

Alexander Fleming

(Physician and Microbiologist Who Discovered ‘Penicillin’ World’s First Broadly Effective Antibiotic Substance)

Alexander Fleming was a Scottish microbiologist and physician. He is credited with discovering *penicillin*, the world's first effective antibiotic substance; a discovery that changed the course of history. He also discovered *lysozyme*, an antimicrobial enzyme which forms part of the innate immune system. In 1999, Fleming was named in *Time *magazine's *100 Most Important People of the 20th century* list.

16

Werner Heisenberg

(German Theoretical Physicist and One of the Main Pioneers of the Theory of Quantum Mechanics)

German theoretical physicist Werner Heisenberg is best known for pioneering quantum mechanics. He received the 1932 **Nobel Prize** in Physics. He had also helped Germany plan nuclear weapon strategies during **World War II **and was the director of what is now known as the **Max Planck Institute for Physics**.

17

Erwin Schrödinger

(Austrian Physicist Who Made Important Contributions to the Development of Quantum Mechanics)

Austrian physicist Erwin Schrödinger, is best known for the "Schrödinger's cat" experiment, or the Schrodinger equation. His book **What Is Life?** explored genetics through physics. The **Nobel Prize** winner also wrote on a variety of topics, such as color theory and thermodynamics, and tried to create a unified field theory.

18

Homi Bhabha

(Indian physicist)

**Padma Bhushan**-winning physicist Homi Bhabha revolutionized the Indian nuclear program singlehandedly. Born into an affluent family, he was educated at **Cambridge**. Initially geared toward a career in mechanical engineering, he later drifted to physics, eventually contributing to the formation of **TIFR**. The **Bhabha Atomic Research Centre** is named after him.

19

Ernest Rutherford

(New Zealand Physicist Who is Known as the Father of Nuclear Physics)

New Zealand physicist Ernest Rutherford is remembered as the father of nuclear physics. His discovery of radioactive half-life and of radon, and his differentiation of alpha and beta radiation, won him the **Nobel Prize in Chemistry** in 1908. *Element 104* was named *rutherfordium* in his honor.

20

Rosalind Franklin

(Chemist)

Chemist and X-ray crystallographer Rosalind Franklin is remembered for her pathbreaking X-ray diffraction studies of DNA, which helped in the **Nobel Prize**-winning discovery of the double helix structure of DNA by Francis Crick, James Watson, and Maurice Wilkins later. She also worked on the molecular structures of viruses.

21

Max Planck

(German Theoretical Physicist and Originator of 'Quantum Theory')

German theoretical physicist Max Planck is remembered for originating the *quantum theory of physics*, which earned him the 1918 **Nobel Prize in Physics**. He laid down concepts such as the *Planck constant* and the *Planck postulate*. The **Kaiser Wilhelm Society** was later renamed **Max Planck Society **in his honor.

22

Enrico Fermi

(Italian Physicist, Nobel Laureate and Creator of the World's First Nuclear Reactor)

Italian physicist Enrico Fermi created the* Chicago Pile-1*, the world's first nuclear reactor. Known widely as the "architect of the atomic bomb," he was equally proficient in theoretical and experimental physics, and won the **1938 Nobel Prize in Physics** for his work on radioactivity and for discovering transuranium elements.

23

Subrahmanyan Chandrasekhar

(Astrophysicist Known for his 'Theoritical Studies of the Physical processes of importance to the Structure and Evolution of the Stars')

Remembered for his varied contribution to astrophysics, Subrahmanyan Chandrasekhar is perhaps best known for his work on the evolution of massive stars. Today known as *Chandrasekhar limit*, it contributed to final understanding of supernovas, neutron stars, and black holes. A prolific writer, he also did significant work on energy transfer by radiation in stellar atmospheres and convection on solar surface.

24

J. J. Thomson

(British Physicist Who is Credited With the Discovery of the Electron)

J. J. Thomson was a British physicist credited with the discovery of the electron, the first subatomic particle to be discovered. He was awarded the Nobel Prize in Physics in 1906 for his work on the conduction of electricity in gases. In 1884, he was appointed Cavendish Professor of Physics at the University of Cambridge.

25

Rachel Carson

(Marine biologist)

Rachel Carson was a conservationist, marine biologist, and author. She is credited with authoring an influential book titled *Silent Spring,* which played a significant role in advancing the global environmental movement. Carson is also remembered for her book, *The Sea Around Us, *which earned her a *U.S. National Book Award.* She was posthumously honored with the *Presidential Medal of Freedom.*

26

Linus Pauling

(One of the Greatest Scientists of All Time & Winner of Two Nobel Prizes)

Only person to win two unshared Nobel Prizes, Linus Carl Pauling was an American theoretical physical chemist, who received the **1954** **Nobel Prize in Chemistry** for his work on nature of chemical bond and **1962 Nobel Prize for Peace** for his efforts to stop nuclear weapon testing. Also a prolific writer and educator, he has published 1,200 books and papers.

27

Claude Shannon

(Mathematician, Engineer & Cryptographer Known as a 'Father of Information Theory')

Claude Shannon was an electrical engineer, mathematician, and cryptographer. He is credited with publishing the article *A Mathematical Theory of Communication* which gave rise to the field of information theory. Hence, Shannon is considered the ** father of information theory.** He is also credited with founding digital circuit design theory. During

28

Kurt Gödel

(Mathematician, Philosopher and One of the Most Significant Logicians in History)

Hailed as one of the greatest logicians since Aristotle, Kurt Gödel was Austrian-born American mathematician, logician, and philosopher, who earned international stardom for his *incompleteness theorem*. Also credited with developing a technique called *Gödel numbering*, he later started working on *Mathematical Platonism, *a philosophical theory that failed to attract wide acceptance.

29

Richard Dawkins

(British Evolutionary Biologist Who Contends that a Supernatural Creator Almost Certainly Does Not Exist)

Richard Dawkins is a British ethologist, author, and evolutionary biologist. He first achieved popularity after publishing his book, *The Selfish Gene*, which is credited with popularizing the* gene selection theory*. The book is also credited with introducing the term *meme*. In 2006, he established the *Richard Dawkins Foundation for Reason and Science* to promote secularism and scientific literacy.

30

Tim Berners-Lee

(Computer Scientist and Inventor of the World Wide Web)

Widely known as ten inventor of the world wide web, Tim Berners-Lee made the first communication between an HTTP client and server through the internet in 1989. He is associated with various organizations, such as the **W3C** and the **World Wide Web Foundation**, and has received the knighthood, too.

31

Max Born

(German Physicist Who Won Nobel Prize for His Contribution to Quantum Mechanics)

From being home-schooled for being too sickly to attend school, Max Born went on to win the **Nobel Prize in Physics** for his contribution to quantum mechanics. Being a Jew, with the rise of the **Nazi **power, he lost his professorship at the **University of Göttingen**, and moved to Cambridge.

32

Wilhelm Rontgen

(German Mechanical Engineer and Winner of the 1901 Nobel Prize in Physics)

Wilhelm Rontgen was a German physicist and mechanical engineer. He is best remembered for producing and detecting X-rays for which he was honored with the first Nobel Prize in Physics* *in 1901. His discovery of X-rays remains one of the greatest achievements in the field of medical science.

33

Francis Crick

(Co-discoverer of the Structure of the DNA Molecule, Nobel Prize Winner)

**Nobel Prize**-winning British biophysicist Francis Crick is best known for his ground-breaking work to determine the structure of the DNA, along with James Watson, Maurice Wilkins, and Rosalind Franklin. He taught at various institutes, such as the **Salk Institute**, and was also awarded the **Order of Merit**.

34

Paul Dirac

(One of the Most Significant Physicists of the 20th Century and Nobel Laureate)

English theoretical physicist and Nobel laureate Paul Dirac *OM FRS*, counted among leading physicists of the 20th century, made fundamental contributions in the early development of quantum electrodynamics and quantum mechanics. He derived the *Dirac equation* while the modern theory of antimatter began with one of his papers. His book *The* *Principles of Quantum Mechanics* remains an influential monograph on the subject.

35

G. H. Hardy

(English Mathematician Known for His Contributions in Number Theory and Mathematical Analysis)

English mathematician G. H. Hardy is best recognised for his work and achievements in number theory and mathematical analysis, and also as mentor of distinguished Indian mathematician Srinivasa Ramanujan. He is noted for his essay on mathematics titled *A Mathematician's Apology*. He also made his mark in biology formulating a basic principle of population genetics called *Hardy–Weinberg principle*.

36

Lord Kelvin

(Mathematician, Physicist)

Lord Kelvin was a British mathematical physicist and engineer. He studied at the Glasgow University and proceeded to teach there as well. Besides his academic career, he also had a career as an electric telegraph engineer and inventor. He received the Royal Society's Copley Medal in 1883. Absolute temperatures are stated in units of kelvin in his honor.

37

Guglielmo Marconi

(Inventor of 'Radio' and Winner of 1909 Nobel Prize in Physics)

Guglielmo Marconi was an Italian electrical engineer and inventor best remembered for his work on long-distance radio transmission. Marconi, who is credited with inventing the radio, was honored with the 1909 *Nobel Prize in Physics *for his work in the field of wireless telegraphy. Also a businessman, Marconi founded the *Wireless Telegraph & Signal Company* in 1897.

38

Emmy Noether

(German Mathematician Who Made Many Important Contributions to Abstract Algebra)

Emmy Noether was a German mathematician best remembered for her contributions to abstract algebra. She is credited with discovering *Noether's theorem*, which is regarded as a fundamental theorem in mathematical physics. One of the most important mathematicians of her generation and **the most important woman in mathematics history**, Emmy Noether developed theories of algebras, fields, and rings.

39

Grace Hopper

(Computer Scientist, Mathematician and One of the First Programmers of the ‘Harvard Mark I’ Computer)

Computer scientist and **U.S. Navy **rear admiral Grace Hopper was one of the first programmers of the **Harvard Mark I** computing system. She pioneered the machine-independent programming language technique, and the **FLOW-MATIC** language used by her was later used to create **COBOL**. She received a posthumous **Presidential Medal of Freedom**.

40

Paul Erdős

(Mathematician)

Hungarian mathematician Paul Erdős spent most of his childhood at home, due to his mother’s overprotectiveness after his sisters died of scarlet fever. Known for his eccentricity, he used his own vocabulary. His contributions include the *Ramsey theory*, and he skipped many university job offers to continue working independently.

41

Vint Cerf

(Computer scientist)

42

Henri Poincare

(French Polymath and Mathematician Known as One of the Founders of the 'Field of Topology')

Known as *The Last Universalist *for his expertise in a variety of domains, French mathematician Henri Poincare conducted research that formed the basis of the modern chaos theory. Apart from his work on relativity and the three-body problem, he also laid the foundation of algebraic topology.

43

E. O. Wilson

(Biologist)

E. O. Wilson is an American naturalist, biologist, and writer. An influential biologist, Wilson has earned several nicknames, such as** The Darwin of the 21st century.** He has also been referred to as

44

John Horton Conway

(British Mathematician Known for His Contributions to 'Combinatorial Game Theory (CGT)')

57

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Remembered as versatile mathematician, game wizard and polymath, John Horton Conway had limitless curiosity, which matched with his scientific originality. Although he is best known for devising the cellular automation called *Game of Life, *he made significant contributions to group theory, number theory, algebra, geometric topology, theoretical physics, combinatorial game theory and geometry. Conway published many outstanding papers in these fields.

45

Wolfgang Pauli

(One of the Pioneers of Quantum Physics and Winner of 1945 Nobel Prize for Physics)

**Nobel Prize**-winning Austrian physicist Wolfgang Pauli is remembered for his contribution to quantum physics and for laying down the *Pauli principle*. While he was initially married to a cabaret dancer, the marriage ended in a divorce after a year. His written works are considered classics in science.

46

Nikola Tesla

(Inventor, Engineer & Futurist, Who Obtained Over 300 Patents)

Inventor, engineer and futurist, Nikola Tesla, is best remembered for his contribution to the development of the modern alternating current (AC) electricity supply system. A prolific inventor, he had around 300 patents for his inventions. Even though he earned a considerable amount of money, he had poor money management skills and died a poor man.

47

Alexander Grothendieck

(French Mathematician and a Pioneer in the Field of 'Modern Algebraic Geometry')

Alexander Grothendieck was a 20th-century mathematician who was a leading figure in the creation of modern algebraic geometry. With his so-called "relative" perspective, he revolutionized many areas of pure mathematics. During his later career, he became a professor at the University of Montpellier. He is counted among the greatest mathematicians of the 20th century.

48

Katherine Johnson

(Mathematician and One of the First African-American Women to Work as a NASA Scientist)

Katherine Johnson was a physicist and mathematician, remembered as the first African-American female **NASA** scientist. Her calculations helped launch the space missions of Alan Shepard and John Glenn. She was crucial to the **Apollo **program and won a **Congressional Gold Medal** and a **Presidential Medal of Freedom** for her achievements.

49

A.P.J. Abdul Kalam

(Aerospace Scientist & 11th President of India)

A. P. J. Abdul Kalam, India’s 11th president, had earlier been an aerospace scientist at **DRDO** and **ISRO**. Known as the “People’s President” and the “Missile Man of India,” he was instrumental in India's **Pokhran-II **nuclear tests. He died of a cardiac arrest while delivering a lecture at **IIM Shillong**.

50

Alexander Graham Bell

(Inventor of Telephone & Co-Founder of 'American Telephone and Telegraph Company (AT&T)')

Alexander Graham Bell was a scientist, inventor, and engineer. He is credited with inventing the first functional telephone. He is also credited with co-founding America's major telephone company *AT&T*, which has been going strong since 1885. Bell's later life was marked by his groundbreaking work in aeronautics, hydrofoils, and optical telecommunications. He was also an ardent supporter of compulsory sterilization.