aristarchus of samos was the first to suggest that the earth moved around the sun.
who was the first to suggest that the earth moved around the sun?
aristarchus of samos
a primitive way to determine the distance to the sun in terms of the distance to the moon was already proposed by aristarchus of samos in his book "on the sizes and distances of the sun and moon". he noted that the sun, moon, and earth form a right triangle (with the right angle at the moon) at the moment of first or last quarter moon. he then estimated that the moon, earth, sun angle was 87°. using correct geometry but inaccurate observational data, aristarchus concluded that the sun was slightly less than 20 times farther away than the moon. the true value of this angle is close to 89° 50', and the sun is actually about 390 times farther away. he pointed out that the moon and sun have nearly equal apparent angular sizes and therefore their diameters must be in proportion to their distances from earth. he thus concluded that the sun was around 20 times larger than the moon; this conclusion, although incorrect, follows logically from his incorrect data. it does suggest that the sun is clearly larger than the earth, which could be taken to support the heliocentric model.
parallax
bullet::::- an argument based on the behavior of swirling lumps of material like in a sieve, where the heavier ones accumulate at the center









































bullet::::- an argument from tycho brahe on the behavior of falling bodies









































bullet::::- an argument from tycho brahe on the flight of cannonballs fired east or west









































bullet::::- an argument from tycho brahe on the positions of stars being changed if earth moved









































bullet::::- an argument from tycho brahe on the positions of the celestial pole being changed if earth moved









































bullet::::- an argument from tycho brahe on the day length being changed if earth moved
francesco ingoli