In 1543, a Polish astronomer named Nicolaus Copernicus, published a book that contradicted (went against) what the ancient Greeks and Catholic Church had written.

Through his observations, Copernicus believed that the sun was at the center of the universe--known as the heliocentric theory.

Copernicus’ book marked the beginning of the Scientific Revolution. 

Tycho Brahe charted the positions of hundreds of stars, using careful observation and detailed recordings.

Galileo Galilei was the first person to study the sky with a telescope.  He also was the first to use experiments to test his theories/ideas.

He supported Copernicus’ heliocentric theory of the universe which got him into trouble with the Catholic Church.

Galileo was also interested in mechanics--the study of objects and motion.

Isaac Newton is best known for creating the laws of gravity and motion.

Zacharias Janssen invented the microscope to look at small plants and animals.

The Dutch were the first to build telescopes to study the sky, but Galileo improved it and was the first to use it to study the sky.

Evangelista Torricelli invented the barometer which measures air pressure and is used to predict the weather.