  Spinning objects which move through air or liquids experience a Magnus force.
This effect is commonly exploited in ball sports but also of considerable
importance for applications and fundamental science. Opposed to large objects
where Magnus forces are strong, they are only weak at small scales and
eventually vanish for overdamped micron-sized particles in simple liquids. Here
we demonstrate an about one-million-fold enhanced Magnus force of spinning
colloids in viscoelastic fluids. Such fluids are characterized by a
time-delayed response to external perturbations which causes a deformation of
the fluidic network around the moving particle. When the particle additionally
spins, the deformation field becomes misaligned relative to the particle's
moving direction, leading to a force perpendicular to the direction of travel
and the spinning axis. The presence of strongly enhanced memory-induced Magnus
forces at microscales opens novel applications for particle sorting and
steering, the creation and visualization of anomalous flows and more.
