This will open up a world of possibilities if they can find a way to manufacture it at a reasonable price. Imagine consumer level telescope eye-pieces with no energy loss .
As they say. "Those who learn from history are doomed to watch it repeat"
Its kinda cool that they are attempting it with visible light now. The negative refraction index still bothers me as it implies that light moves faster through this whatever than the supposedly maximum speed of the universe. Interesting implications for causality.
186,000 miles/sec It's not just a good idea; It's the law.