  I put forth a scenario of jet-driven jittering-jets in cooling flows in
galaxies and clusters of galaxies. By uplifting cool gas from the center of the
cluster jets and the bubbles they inflate cause the direction of later jets to
substantially change. Some uplifted cool clumps fall back to feed the active
galactic nucleus, in what is termed the cold feedback mechanism, but with an
average angular momentum that is largely inclined to that of the original jets.
The proposed jittering jets scenario allows, over the cooling time of the
intracluster medium (ICM), the heating by the mixing of hot jet-inflated bubble
gas with the ICM to operate in all directions. The proposed scenario further
supports the heating by mixing mechanism of the ICM. The feedback heating
mechanism of the ICM chiefly refers to the energy cycle. The cold feedback
mechanism introduces mass as another ingredient of the feedback cycle, as the
mass accretion of future activity cycles is determined by the formation of
perturbations by the present activity cycle. The jittering jets scenario that I
propose here brings angular momentum to be another ingredient of the feedback
cycle.
