Astronomers of the 20th and 21st Century

  • Henrietta Swan Leavitt

    Henrietta Swan Leavitt
    Leavitt found a connection between how often Cepheid variable pulsed and its brightness. A Cepheid variable is a star whose magnitude changes throughout its life.
  • Einstein published his Theory of Relativity

    Einstein published his Theory of Relativity
    Einstein publiches his highly regarded Theory on relativity. The theory says that acceleration distorts the shape of time in space. This theory is still used in today's study of the cosmos.
  • Einstein Wins Nobel Prize

    Einstein Wins Nobel Prize
    Einstein wins the Nobel Prize for science for his work with light. His discovery was called the photelectric effect. It stated that light is made particles called photons
  • Edwin Hubble's findings about the universe are published

    Edwin Hubble's findings about the universe are published
    Hubble identified Cepheid variables in stars. By doin so he was able to see that these stars were many many light years away outside of the milkyway galaxy. This dispproved the previously accepted theory which theorized that the milkyway galxy took up the entire universe.
  • Hubble's law

    Hubble uses the redshift to figure that the galaxies are moving away from each other. This was the first big proof for the Big Bang Theory. Einstein had thought of the idea previously but had thought it impossible since there was not enough evidence at the time. Einstein later visits Hubble that the decision to leave his theory out of the theory of General Relativity was the biggest mistake of his life.
  • Stephen Hawking Born

    Stephen Hawking Born
    Stephen Hawking is born in England. He is born exactly 300 years after the death of Galileo Galilee. He went on to Oxford to study physics and went into the study of cosmology.
  • William K. Hartmann's theory on Creation of the moon

    Hartmann proposes his collision theory. The theory says that a large body collided with the earth and the remaining debris solidified into the body we know as the moon. This theory is widely accepted as what actually occured.
  • Period: to

    Carl Sagan's Cosmos

    Carl Sagan creates a 13 part series of shows. They are about the universe and galaxies and cosmology in general. The show did a lot to popularize science, astronomy in particular.
  • Stephen Hawking appointed Lucasian Professor at Cambridge

    Stephen Hawking appointed Lucasian Professor at Cambridge
    Stephen Hawking is appointed the head Lucasian Mathamatics Professor at Cambridge University. This is a very prestigious title as the same post's second holder was Sir Isaac Newton. Cambridge was the school Hawking had attended.
  • Hawking's "A Brief History of Time" published

    Hawking's "A Brief History of Time" published
    The book was a international best seller. The book aimed to explain the beginning of the universe and the supposed end. Hawking did this all in a way that a lay person could comprehend it.
  • Hubble Telescope Launched

    Hubble Telescope Launched
    In honor of Edwin Hubble, NASA launches the Hubble Space Telscope. The Hubble Space telescope is not the first telescope to be launched into space. However, it is the largest and most versatile.