From GRENVILLE NEEDHAM
John Gribbin’s description of the ‘centrifugal force’ acting on a spacecraft
is simply nonsense (‘Spinning backwards for Christmas’, Science, 22/29 December).
His discussion of the curvature of space-time may be post-Einsteinian, but
his understanding of circular motion can only be described as pre-Newtonian.
In which direction were your editors spinning when they passed Gribbin’s
piece and its diagram? I suggest they have a new-year re-read of Newton’s
first and second laws and then rewrite the article before the beginning
of next term.
Grenville Needham Ackworth School Pontefract Yorkshire
