No because no "run away" effect. "inverted" mass means that the mass goes on the other side... gravity works the same there.
> ... **Not Judging** ...
> ...
> Despite it all, I hope to have achieved a truthful text that illustrates the
> **unclassifiable** person Grothendieck was.
> ...
> The quite unusual style of writing—with sentences, subsentences, and the
> excessive use of cross references—intrigued me. One of my friends, a
> professional psychoan-alyst, declared that **the author was paranoiac**.
it's faster than other scripting languages, allowing
you to have the rapid development of Python/MATLAB/R
while producing code that is as fast as C/Fortran"