Artificial Crystal Creates First-Time Event: Reverse Doppler Effect

Doctors Xiangping Li and Baohua Jia, together with Professor Min Gu and their fellow researchers in Shanghai have created a demonstration of the reverse Doppler Effect, which is not known to occur naturally. Namely, what they managed to do was to decrease the wavelength from blue to red as the object got closer, and to increase it from red to blue as it got further away. In other words, the object was less visible at close range, while it was easier to see at longer distance.