OT:Tempted to get this book

[douglas]

I'm reading the first chapter, which is available Online for free and I have a few observations:

The Geometric Orbit Equation he makes such a big deal of is actually Kepler's Third Law in disguise.

In his brief discussion of an alternative "rock-and-spring" model on page 44, as far as static orbits are concerned there is no difference at all between that and the "rock-and-string" model.

On page 56, the "mysterious" issues of equal acceleration independent of mass and absence of stress on the object are resolved very simply by the facts that gravitational force is proportional to the object's mass, and the force is not applied to any particular part of the object. The only reason other forces do not exhibit these characteristics is that their strength is independent of mass.

He completely ignores the fact that Newtonian Gravitation is a unifying theory for all of the other equations he deals with in the chapter.

He almost completely ignores the fact that Newtonian Gravitation is no longer the model of gravity generally accepted as correct - General Relativity is. Newtonian Gravitation is still taught only because it is much simpler than relativity and gives negligible error in all cases that most people will ever have to use it for.

The power source/energy tracking device that he points out is missing is, IIRC, present as the mass of the object(s) in question. When you lift something up, you increase its mass by a very small amount. When it drops, it's mass decreases.

His analogies using people in place of various objects are flawed in that a person is a very complex and inefficient organism and is constantly expending energy in ways not strictly necessary to do work.