Tangled (IMAGE) University of Vienna Caption This abstract illustration shows four particles of light can be produced and manipulated in such a way that one can later decide in which quantum state two of the particles have been. Credit Jon Heras, Equinox Graphics Ltd. 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.