Examine how the following men built upon Copernicus' ideas:
1. Tycho Brahe
2. Johannes Kepler
A. By refining and improving upon Copernicus' heliocentric model
B. By conducting detailed observations and collecting accurate data
C. By formulating laws of planetary motion
D. By challenging and critiquing Copernicus' ideas
E. By popularizing and spreading Copernicus' ideas to a wider audience
