Barium Ions (IMAGE) University of California - Los Angeles Caption A microscopic sample of barium ions, shown in teal, immersed in a cloud of calcium atoms whose temperature is 1/1,000th of a degree above absolute zero. Credit Alex Dunning 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.