In the plane rectangular coordinate system xOy, O is the coordinate origin, the circle P centered on P( 1, 1) is tangent to point M and point N respectively, and point F starts from point M and moves at the speed of 1 unit length per second along the positive direction of X axis, connecting PF, and the intersection point PE is perpendicular to the intersection point of PF and Y axis at point E, and a point is set.
(2) During the movement of point F, let OE=a and OF=b, and try to represent b with an algebraic expression containing a;
(3) Let point F be the symmetrical point {F}' about point M, and connect QE by intersecting the parabola symmetry axes of three points M, E and {F}' with point Q.. Is there a moment in the movement of point F, which makes the triangle with points Q, O and E similar to the triangle with points P, M, F, M and F? If it exists, write the value of t;