Kepler's Three Laws

When it comes to the study of gravity and its effect on orbits, familiarity with Kepler's three laws of planetary motion is essential. Any theory of gravity has to conform to these laws.

What's interesting to note is that the second law, although accurate to within 2% is not completely accurate. There is in other words something going on that doesn't conform completely to a simple mathematical function.

Interesting too, is the fact that Mercury and Jupiter deviate in the same direction. Both move marginally faster than expected. The largest and the smallest planet in our solar system are affected in the same way. Why is that? (This problem is known as the Mercury Anomaly.)

Mercury is very close to the Sun, the largest body in the solar system, and Jupiter is the second largest body in the solar system. Maybe that's a hint? Gravity is after all an interaction between two or more bodies. It is the combination that yields the total effect.

With the solar system awash with electrical activity in addition to gravity, the discrepancies are of course quite reasonable. Only in a completely sterile void would we expect things to conform neatly into simple formulas. Still, it's sometimes in the details that the truth is hidden. The discrepancies are telling us something, and it would be interesting to know exactly what that is.

Johannes Kepler

By Unidentified painter - Unknown, Public Domain, Link