Michael Wieser, University of Calgary (1 of 2) (image) University of Calgary Share Print E-Mail Caption Michael Wieser, a professor at the University of Calgary, is contributing to changes to the periodic table. He works with a thermal ionization mass spectrometer used to measure the isotope abundance of an element. Credit Riley Brandt/University of Calgary Usage Restrictions Please credit Riley Brandt Share Print E-Mail 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.