  We provide experimental evidence of universal dynamics far from equilibrium
during the relaxation of an isolated one-dimensional Bose gas. Following a
rapid cooling quench, the system exhibits universal scaling in time and space,
associated with the approach of a non-thermal fixed point. The time evolution
within the scaling period is described by a single universal function and
scaling exponent, independent of the specifics of the initial state. Our
results provide a quantum simulation in a regime, where to date no theoretical
predictions are available. This constitutes a crucial step in the verification
of universality far from equilibrium. If successful, this may lead to a
comprehensive classification of systems based on their universal properties far
from equilibrium, relevant for a large variety of systems at different scales.
