  We report observations of vortex formation as a result of merging together
multiple $^{87}$Rb Bose-Einstein condensates (BECs) in a confining potential.
In this experiment, a trapping potential is partitioned into three sections by
a barrier, enabling the simultaneous formation of three independent,
uncorrelated condensates. The three condensates then merge together into one
BEC, either by removal of the barrier, or during the final stages of
evaporative cooling if the barrier energy is low enough; both processes can
naturally produce vortices within the trapped BEC. We interpret the vortex
formation mechanism as originating in interference between the initially
independent condensates, with indeterminate relative phases between the three
initial condensates and the condensate merging rate playing critical roles in
the probability of observing vortices in the final, single BEC.
