I give an account of the Machian approach to dynamics,
from Mach's critique of Newton to the work of Barbour, Bertotti, York and
O'Murchadha, which culminated in the theory of Shape Dynamics, a new and
original way of thinking about General Relativity. I conclude commenting on the
present research lines in Shape Dynamics, and the opportunity it offers to
solve the problem of time in quantum gravity.
Support
for this colloquium is provided by The Templeton Frontiers Program.