对牛顿定律进行终极检验的实验

对牛顿定律进行终极检验的实验

奥地利的一名物理学家最近提出了一个实验，有可能揭示牛顿万有引力定律的一个缺陷。如果该缺陷确实存在，那么解释银河系的运动就不需要被迫引入暗物质了。

Experiment sets the ultimate test for Newton's laws (Mar 16)
http://physicsweb.org/article/news/11/3/12
A physicist in Australia has come up with an experiment that could
potentially reveal a flaw in Newton's law of gravitation. If the flaw
exists, it would be the first evidence in support of theories that
explain the movement of galaxies without having to introduce "dark
matter" (Phys. Rev. Lett. 98 101101).

双负性媒质的频率范围已经接近可见光波段了

美国研究人员最近制作的一种材料，在波长为813纳米的红外光波段，其导磁率和介电率都为负值。这是目前为止能实现双负性的材料所达到的最短波长，并且已经与可见光谱380-780纳米非常接近。之前的纪录为1500纳米。这个结果朝着实现可见光波段双负性材料(DN-NIMs)的目标前进了一大步。

Double-negative metamaterial edges towards the visible (Mar 16)
http://physicsweb.org/article/news/11/3/13
Researchers in the US have created a metamaterial that has a negative
magnetic permeability and negative electric permittivity for infrared
light with a wavelength of 813 nm. This is claimed to be the shortest
wavelength yet for such a metamaterial and lies just outside of the
visible spectrum at 380-780 nm. The previous record had been about 1500
nm, and the result is an important step towards the creation of
double-negative negative-index metamaterials (DN-NIMs) that operate in
the visible range.