The History of Cosmic Ray Studies
- c. 4500 BC
- Science of astronomy first recorded
- c. 2000 BC
- Mesopotamian and Egyptian astronomers began to map the heavens.
- 1223 BC
- First eclipse record
- c. 800 BC
- First recorded sunspot observation, noted in the Chinese
"Book of Changes"
- c. 700 BC
- A common view in Greece was that the Universe is a rational place following universal, natural laws.
- c. 600 BC
- Greek philosophers describe the magnetic properties of natural
- c. 450 BC
- The Greek philospher Empedocles announces that all matter is
formed from earth, air, fire, and water
- 440 BC
- Leucippus introduces the concept of the atom as an indivisible
unit of matter
- c. 400 BC
- Magnetic compass invented by the Chinese
- c. 350 BC
- Aristotle discovers that free fall is a form of acceleration
- c. 300 BC
Aristotle theorized that the Earth was the center of the Universe.
- c. 260 BC
Aristarchus of Samos proposed a heliocentric Universe.
- Roman philospher Anicus Boethius is beheaded for his use of
"magic" to determine the speed of light
- Chinese astronomers observed a supernova in Taurus. These supernova remnants are now known as the Crab nebula (M1). This image of the Crab nebula is courtesy of NASA.
- Roger Bacon suggested that a light vessel filled with some (hypothetical) fluid lighter than air could use the flotation principle in the atmosphere.
- Nicolaus Copernicus published De Revolutionibus Orbium Coelestium in which he provided mathematical evidence for the heliocentric theory of the Universe. He was the first European to claim that the Earth is not the center of the Universe.
- Tycho Brahe witnessed a supernova in the constellation Cassiopeia, and cited it as evidence that the heavens are not without change.
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