(IMAGE) Bielefeld University Caption In this experimental design, the sample is stretched between two copper blocks. One is hot; the other, cold. The coils generate the magnetic field; the contact pins measure the tension. Credit Photo: Bielefeld University Usage Restrictions The image may only be used with appropriate caption or credit. 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.