Cause 1. The Printing Press- The printing press was developed to make the copying of writing much much faster. Before the printing press everything had to be written by hand. Also during this time period, people who could read and write legibly, wasn't very common. To copy a 100 page book 12 times the writer would have to hand copy each individual page 12 times. With the Printing Press it could be done much faster, making books more common.
Cause 2. The Caravel- As the Europeans began exploring the ocean more and more, it was taking way too long to travel because if the wind wasn't in the right direction you were either stuck or back-tracked, which wasn't what you wanted. The Caravel was a small, fast sailing ship. The sail of the Caravel could be moved into the direction of the wind.
Cause 3. Canons- With the Europeans traveling more, they were bound to find enemy's at some point, so they developed the canon, which was extremely effective. The canons were able to fit on the bottom deck of the ships, making the Europeans superior in the ocean. They also developed a more effective compass and an Astrolabe, which was a device used to measure the altitude between the horizon and bodies of stars.