A property of a material that changes the speed of light, computed as the ratio of the speed of light in a vacuum to the speed of light through the material. When light travels at an angle between two ...

The original goal was to investigate biological samples on a molecular scale – but this soon led to stubborn technical problems. Eventually, however, the researchers realized that the very source of ...

Recent experiments that demonstrate the negative refraction of light could bring a heated scientific debate to a close, and give negative-index materials a positive future Figure 1: Negative-index ...

Physicists at Harvard University in the US have built a silicon waveguide that exhibits a refractive index of, or close to, zero when operating at near-infrared telecom wavelengths. The waveguide can ...

The World Health Organization (WHO) recommends that babies be exclusively breastfed for the first six months of life, since ...