  To the naked eye, turbulent flows exhibit whirls of many different sizes. To
each size, or scale, corresponds a fraction of the total energy resulting from
a cascade in five dimensions: scale, time and three-dimensional space.
Understanding this process is critical to modeling strategies of geophysical
and industrial flows. By tracking the flow regions containing energy in
different scales, we have evidenced the statistical predominance of a
cross-scale link whereby fluid lumps of energy at scale $\Delta$ appear within
lumps of scale $2\Delta$ and die within those of scale $\Delta/2$. Our approach
uncovers the energy cascade in a simple water-like fluid, offering new insights
to turbulence models while paving the way to similar analysis in conducting
fluids, quantum fluids and plasmas.
