Sometimes when you look into a swimming pool it’s difficult to tell how deep the water actually is. If you grab something long, like a stick, you can use it to test the depth of the water. Upon ...

Well, OK, not exactly. A beam of light could pass through air all day long (as long as you have a layer of air 26 billion kilometers long) and not deviate a whit. But if the density of that air ...

For the first time, scientists have demonstrated that negative refraction can be achieved using atomic arrays - without the need for artificially manufactured metamaterials. Scientists have long ...