The statement is about the viability of learning all gotchas of C++, and to make a credible point on this you just need to know there exists a large number of them.
(Indeed knowing all, or merely many, of the gotchas would speak against the conjecture.)
No, the circumstantial evidence of the book title was placed along with the shallow exposition that made up the "analysis" and was found to point in the same way: towards a not very objective assessment by the author.
I mean, this is a the text where a teacher relates anecdotes of the japanese actively sabotaging their learning (answering "yes" even when they don't understand) in a positive context.
You're absolutely right, of course. I was talking about the "time-gravity" component they subtract in the article to circularize the orbit, not all of gravity.
During an orbit, gravity is of course stronger when you're near the planet, and weaker when you're away from the planet. So they equalize the gravity by subtracting the relative time/gravity differential and calling it a separate dimension.
This leaves a constant gravity force and velocity, making certain calculations and transformations more natural in this model.
Ethanol is "environment friendly" when compared to gasoline, the latter having no good environmental aspects making it a bit of a low standard to beat.
The fact that rain forests are destroyed for corn plantations is probably independent of ethanol consumption, the ethanol driven investment mostly just increasing the existing rate at which deforestation happens. Corn is not only used for ethanol after all.
We can argue right and left here. Fact is, that there are multiple studies (somebody also cited some here) come to the result that ethanol when every effect is taken into account is worse than mineral oil for the environment -- and who says different, is most likely paid by the ethanol lobbies.
And to your "rain forests are destroyed anyway"-argument: You argue without any proof just by guessing. (BTW: rain forests where only one example, in fact, I don't know what areas are destroyed by fuel plants, but fact is, that there are areas destroyed and they are mono-cultures that grossly harm nature).
He mentions a 10% error in energy conservation, so not too great.
Probably he should have done research before he started, he would have found one of the several lecture notes that tell you how to integrate orbits. They tell you that symplectic methods are great for time reversible problems.
Or he would have found one of the public codes for integrating the solar system very far into the future.
(Indeed knowing all, or merely many, of the gotchas would speak against the conjecture.)