Download The Big Bang and Early Astronomers

The Big Bang and Early
Astronomers
A SCIENTIFIC THEORY is an explanation of some aspect of the natural
world that is acquired through the scientific method and repeatedly
tested and confirmed through observation and experimentation.
• Theories can be modified or rejected as more evidence is gathered
• Theories are testable
ASTRONOMY: The scientific study of the universe and the objects in
it, including stars, planets, nebulae, and galaxies. Astronomy deals
with the position, size, motion, composition, energy, and evolution of
celestial objects. Astronomers analyze not only visible light but also
radio waves, x-rays, and other ranges of radiation that come from
sources outside the Earth's atmosphere.
Not So BIG, No Bang!
• Big Bang Theory: state that approximately 15 billion years ago, the
universe began expanding out from a Primeval atom due to some
type of large energy release like an explosion.
• It was proposed by Georges Lemaitre, French physicist
• Greeks were the first people to use mathematics to interpret the
night sky
• At the time; they could only see 5 planets
• What were they?
Nicoles Copernicus
• After the fall of the Roman Empire, much of the knowledge of
astronomy was lost. Copernicus was a Polish astronomer who made
the next big discovery about the motion of our Solar System.
• Copernicus moved the Earth form the center of the solar system and
replaced it with the Sun. The movement of the planets as seen form
Earth is due to the rotation of Earth.
• Geocentric : having the Earth as the center of the solar system or
universe
• Heliocentric: having the Sun as the center of the solar system
Kepler
• Kepler used calculations to explain how the universe moves.
• He proposed that the planets revolve around the Sun which is offset
from the center; and that they do so in an elliptical pattern.
Galileo
• Used technology to observe the planets, stars, and solar system
• He developed a more accurate telescope which allowed him to see
the planets more clearly.
• He observed that Venus went through phases like our moon
• What could this mean?