Transcript The History of Astronomy

The History of Astronomy
Part 5
Copernicus
Copernicus (1473-1543)
Copernicus was a Polish
physician, lawyer and astronomer,
he questioned the Ptolemaic System.
It just didn’t pass the test of “Ockham’s Razor”
that
“the simplest explanation is usually best.”
The Copernican System
Copernicus proposed a simple heliocentric system
with circular orbits
• The planets orbit in the right order (though without
Uranus and Neptune).
• He even got the relative distances from the sun
correct (see chart on page 49).
• Moon orbits Earth
To avoid religious persecution he published his work
“de revolutionibus orbium coelestium” posthumusly.
This system explains retrograde motion easily,
The Earth was simply passing the by!
The lack of observable parallax could be explained
with simple geometry.
A star far enough away would have a parallax too
small to see
Recent discoveries had shown that stars might be far
enough away (see Tycho)
At first Copernicus's Simple Heliocentric
model met opposition from great
astronomers such as Tycho Brahe .
But some agreed,
Like: The Astronomer Kepler
And the mathematician/philosopher:
Rene Descartes
A Great Debate ensued
Crazy Talk!
Thomas Diggs and Giordano Bruno both
proposed that:
Stars are other Suns and planets may orbit
them!