History Timeline

  • 276 BCE

    Eratosthenes is born in Cyrene, Libya.

  • Period: 276 BCE to 195 BCE


  • 240 BCE

    Eratosthenes determines the circumference of the Earth.

    Eratosthenes noticed that a well in Swenet, Egypt did not produce shadows when the sun was directly above it during the summer solstice. In another well in Alexandria, 5,000 stadia away, the sun casted a shadow, showing that the Earth had a curvature to it. Using basic trigonometry, he set up a ratio to determine the circumference of the Earth. His calculations were only 2% off from the actual circumference of the Earth. His discoveries were later published by Ptolemy.
  • 236 BCE

    Eratosthenes becomes chief librarian of the Library of Alexandria.

    As a skilled librarian, geographer, mathematician, astronomer, historian, and poet, Eratosthenes was called on by the Greek ruler of Egypt to serve as the new chief librarian after the previous librarian died. Along with this, Eratosthenes made many discoveries about the world, such as the tilt of Earth's axis and the distance to the sun and the moon. He also created a catalog of stars, a calendar with leap years, and the Sieve of Eratosthenes, a chart for finding prime numbers.
  • 195 BCE

    Eratosthenes dies in Alexandria, Egypt.

  • 85

    Claudius Ptolemy is born in Hermiou, Egypt.

  • Period: 85 to 165

    Claudius Ptolemy

  • 140

    Ptolemy creates the “geocentric” view of the world.

    Using Greek knowledge and Aristotle’s theory that the Sun and the planets revolve around a spherical Earth, Ptolemy creates the geocentric view. Borrowing Hipparchus’s theory of epicycles, small orbits that a planet made around an imaginary axis as it revolved, Ptolemy’s theory accurately predicts how celestial objects move across the sky. His theory is accepted for over 1400 years by many scientists.
  • 165

    Ptolemy dies in Alexandria, Egypt.

  • 641

    Ptolemy’s book is translated into Latin.

    After Muslim Arabs conquer Egypt, Muslim scholars begin to accept Ptolemy’s geocentric view of the universe. They call his book on astronomy “al-Magisti” or “The Greatest”, the translation of Ptolemy’s book to be named “The Almagest”.
  • Feb 19, 1473

    Copernicus is born.

  • Period: Feb 19, 1473 to May 24, 1543


  • 1514

    Copernicus releases “Little Commentary”.

    This work of Copernicus’s publishes his views on the heliocentric view of the world and helps to spread his ideas throughout society.
  • 1532

    Copernicus finishes “On the Revolutions of Celestial Spheres”.

    Copernicus finishes his second book on the heliocentric theory, but doesn’t publish the work for others to read.
  • May 24, 1543

    Copernicus dies.

    Upon Copernicus’s death, his work “On the Revolutions of Celestial Spheres” is published.
  • Isaac Newton is born in Lincolnshire, England.

  • Period: to

    Isaac Newton

  • Newton attends King’s School at Grantham.

    Newton attended school from 1654 to 1661. When he was not in school, Newton spend most of his time tinkering with small inventions and wondering about the world. When he was 15, his mother tried to take him out of school to become a farmer, but the headmaster saw Newton’s potential and insisted that he stay in school.
  • Newton studies at Cambridge University.

    After finishing his schooling at King’s School, Newton goes to Cambridge University to continue his studies. After 4 years of hard work, he obtains a degree just before the school closes temporarily due to the Black Plague.
  • Newton retreats from the Black Plague.

    As the plague spreads, Newton travels to his grandparents’ home in Lincolnshire. There, he performs studies on light to prove that white light is a combination of all colors and begins to create calculus. Newton gets his first thought about the forces of gravity when an apple drops from a tree beside him.
  • Newton returns to Cambridge University.

    After the plague, Newton returns to Cambridge to earn a master’s degree in mathematics. He later becomes a professor at Cambridge to teach others about his ideas.
  • Newton publishes “Mathematical Principles of Natural Philosophy”.

    Newton’s book is one of the most influential books in the history of science. Inside its pages, Newton presents the three Laws of Motion, The Law of Universal Gravitation, and adds on to Johannes Kepler’s Laws of Motion. Newton backs up his ideas using calculus, his new method of math that was able to accurately predict the movement of planets.
  • Newton is knighted by Queen Anne.

    Newton is knighted for his substantial contributions to science and mathematics.
  • Newton dies in London, England.

  • Marie Curie is born “Maria Sklowdowska” in Warsaw, Poland.

  • Period: to

    Marie Curie

  • Maria’s family becomes increasingly poor.

    In 1877, Maria’s mother dies and her father loses his job as a professor of math and physics. Despite their poverty, Maria is still fascinated by science and the scientific instruments her father keeps at their house, leading her to work hard at her studies.
  • Alfred Wegener is born in Berlin, Germany.

  • Period: to

    Alfred Wegener

  • Maria graduates from high school.

    Maria graduated from high school when she was 15 and wished to continue her education in science and math. However, the University of Warsaw did not accept women, so she knew she had to travel to get into a college. As their family was extremely poor, her and her sister Bronya made a deal that Maria would work to support Bronya’s medical school, and when she graduated, she would do the same for Maria.
  • Maria moves to Paris to study at the Sorbonne.

    After Bronya finishes her education, Marie moves to Paris to study at the Sorbonne, where she could learn from the best minds of the era. Because people still believed that women should not be educated, there were only a handful of women at the university. Despite this, Maria worked hard to learn French and signed her name as Marie. She rented a small house and studied hard in her classes.
  • Marie earns a degree in physics.

    Marie takes a test to get her degree in Physics, a science dealing with natural laws, and passes with the highest marks in her class. She is the first woman to ever get a Physics degree from the Sorbonne.
  • Marie marries Pierre Curie.

    Marie marries Pierre Curie, a French scientist of Physics. Together, they begin researching radioactivity.
  • Marie discovers radium and polonium.

    Marie performs tests on pitchblende, a material that produced higher x-ray levels than uranium. She heated the material, ground it into powder, and added chemicals to isolate the elements. From this, the Curies discovered polonium, which is 400 times more radioactive than and other, and radium, which is 900 times more radioactive than polonium.
  • Marie is awarded the Nobel Prize in Physics.

    Shortly after earning her doctorate degree in Physics, Pierre is nominated for the Nobel Prize in Physics, but without Marie. He convinces the committee to consider her with him for the award, and together, with Antoine Henri Becquerel, they share the Nobel Prize. Marie becomes the first woman to ever be awarded a Nobel Prize.
  • Wegener recieves a PhD in astronomy.

    Wegener receives PhD from the University of Berlin.
  • Pierre Curie dies.

    Soon after the birth of their second daughter, Pierre is struck by a horse-drawn carriage and dies. After many months, the Sorbonne offers Marie his job as a professor due to her help in discovering polonium and radium. She become the first woman to ever be a professor at the Sorbonne.
  • Harry Hess is born in New York, New York.

  • Period: to

    Harry Hess

  • Wegener teaches at the University of Marburg.

  • Marie receives second Nobel Prize in Chemistry.

    As she continued her research on radium and polonium, Marie concentrated on finding their place in Mendeleev’s recently-made Periodic Table of Elements. By isolating radium and finding its molecular weight, Marie proved that polonium is number 84 while radium is number 88. She becomes the first person to win 2 Nobel Prizes as a result of this research, being awarded her second Nobel Prize in Chemistry.
  • Wegener co-writes "The Thermodynamics of the Atmosphere".

    Wegener publishes this textbook along with Vladimir Köppen, a famous climatologist.
  • Marie creates the Radium Institute.

    During WW1, Marie uses radiology cars to help wounded soldiers in hospitals. In doing this, she also creates the Radium Institute and establishes over 200 radiology machines in hospitals.
  • Wegener publishes "The Origin of Continents and Oceans".

    In 1910, Wegener began to realize that parts of the world map fit next to each other smoothly, such as how West Africa seemed to match up with the East Coast of South America. By gathering evidence of similar fossils, mountain ranges, and rock strata, Wegener proved that the continents were once all connected in a giant landmass. He called this landmass "Pangaea" and explained that this landmass existed over 300 million years ago.
  • Wegener teaches at the University of Graz in Austria.

    Wegener is offered a professorship of meteorology and geophysics.
  • Wegener's theories are mocked by geologists.

    Although he provided sufficient evidence to prove his theory, Wegener could not explain how the continents had moved, so his theory was discounted.
  • Wegener dies in Clarinetania, Greenland.

    Wegener led several dogsled teams carrying supplies to his colleagues at the isolated inland station, which did not have enough provisions. After delivering the supplies, Wegener and his companion, Rasmus Villumsen, died on their return trip west to the coast.
  • Marie dies of leukemia in Savoy, France.

    Marie developed leukemia throughout her lifetime, a cancer caused by extended exposure to radiation. At the time of her research, doctors did not know the effects of radiation and did not have any safety measures when handling it.
  • Hess discovers landforms on the seafloor.

    During WWII, Hess was a geology student from Princeton University who was drafted into the war. While at war, however, he continued his studies by keeping his sounding gear on his ship on all the time. The map produced from this revealed canyons, trenches, volcanic sea mountains, and even a huge rift that ran along the top of the Mid-Atlantic Ridge.
  • Hess publishes "History of Ocean Basins".

    Hess publishes his theories on "seafloor spreading", stating that the Earth's crust has been moving apart in the center of the ocean, forming a chain of volcanoes along this fault line.
  • More evidence is found to prove Hess' theories.

    Dating of ocean-core samples helps to prove that the seafloor had been spreading. Geophysicists also realized that Earth’s magnetic field had reversed polarity many times, with each reversal lasting less than 200,000 years. This was shown in rocks near either side of the Mid-Atlantic Ridge that had symmetrical polarity stripes on them.
  • Hess dies in Woods Hole, Massachusetts.

    Hess dies of a heart attack after helping to plan the U.S. space program and the Apollo 11 mission to the moon.