Spin (IMAGE) Moscow Institute of Physics and Technology Caption The term 'spin' refers to the intrinsic angular momentum of a particle. The spin of a particle has both a magnitude and a direction. In the case of the electron, the magnitude is 1/2 times Planck's constant, and the direction is either up or down. Credit 10.1103/PhysRevLett.119.107601 Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.