  The fundamental equation describing the rotational dynamics of a rigid body
is ${\vec \tau}=d{\vec L} / dt$ which is a straightforward consequence of the
Newton's second law of motion and is only valid in an inertial coordinate
system. While this equation is written down by an inertial observer, for
practical purposes, it is worked out within a non-inertial ancillary coordinate
system which is typically fixed in the rigid body. This results in the famous
Euler equation for rotation of the rigid bodies. We show that it is also
possible to describe the rotational dynamics of a rigid body from the point of
view of a non-inertial observer (rotating with the ancillary coordinate system
fixed in the rigid body), provided that the non-inertial torques are taken into
account. We explicitly calculate the non-inertial torques and express them in
terms of physical characteristics of the rigid body. We show that the resulting
dynamical equations exactly recover the Euler equation.
