The rotation of stars in galaxies such as the Milky Way is puzzling. The orbital speeds of stars should decrease with their distance from the center of the galaxy, but in fact, stars in the middle and ...

Colloids—mixtures of particles made from one substance, dispersed in another substance—crop up in numerous areas of everyday life, including cosmetics, food and dyes, and form important systems within ...

An international team has developed spherical colloidal particles for the visualization of rotational dynamics. The two-color fluorescent particles have an off-center core that allows tracking of ...