Radiating Glass Fiber (image) Vienna University of Technology Caption An ultra-thin glass fiber emits light of different wavelengths. Theories going beyond Planck's law can describe this emission very accurately. Credit Vienna University of Technology Usage Restrictions None 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.