  In a broad class of complex materials a quench leads to a multi-scaled
relaxation process known as aging. To explain its commonality and the
astounding insensitivity to most microscopic details, record dynamics (RD)
posits that a small set of increasingly rare and irreversible events, so called
quakes, controls the dynamics. While key predictions of RD are known to concur
with a number of experimental and simulational results, its basic assumption on
the nature of quake statistics has proven extremely difficult to verify
experimentally. The careful distinction of rare ("record") cage-breaking events
from in-cage rattle accomplished in previous experiments on jammed colloids,
enables us to extract the first direct experimental evidence for the
fundamental hypothesis of RD that the rate of quakes decelerates with the
inverse of the system age. The resulting description shows the predicted growth
of the particle mean square displacement and of a mesoscopic lengthscale with
the logarithm of time.
