“Johannes Kepler was born on December 27, 1571 poor and sickly in what is now Germany. His father left home when Johannes was five and never returned. It is believed he was killed in a war. While Johannes was pursuing higher education his mother was tried as a witch. Johannes hired a legal team which was able to obtain her release, mostly on legal technicalities.
Although …show more content…
Unlike Kepler's first and second laws that describe the motion characteristics of a single planet, the third law makes a comparison between the motion characteristics of different planets. The comparison being made is that the ratio of the squares of the periods to the cubes of their average distances from the sun is the same for every one of the planets. As an illustration, consider the orbital period and average distance from sun (orbital radius) for Earth and mars. The T2/R3 ratio is the same for Earth as it is for mars. In fact, if the same T2/R3 ratio is computed for the other planets, it can be found that this ratio is nearly the same value for all the planets. Amazingly, every planet has the same T2/R3 ratio.
Kepler's third law provides an accurate description of the period and distance for a planet's orbits about the sun. Additionally, the same law that describes the T2/R3 ratio for the planets' orbits about the sun also accurately describes the T2/R3 ratio for any satellite (whether a moon or a man-made satellite) about any planet. There is something much deeper to be found in this T2/R3 ratio - something that must relate to basic fundamental principles of motion.” (The Physics