  This is prepared for a featured article in Nuclear Physics News. Recently,
the global polarization of \Lambda and \bar{\Lambda} hyperons in heavy-ion
collisions (HIC) has been observed by the STAR Collaboration at the
Relativistic Heavy Ion Collider in Brookhaven National Laboratory. The
discovery confirms the theoretical prediction made more than ten years ago and
indicates that the quark gluon plasma (QGP) produced in HIC possesses a
vorticity as high as 10^21s^-1, much higher than any other fluid observed in
nature. This opens a new window to study properties of QGP and a new direction
in high energy heavy ion physics. This featured article is aimed to report the
basic idea, current status and outlook.
