Invisible Aluminum
Sci-fi fans may know of transparent aluminum from the movie "Star Trek IV." When Scottie needed to build a whale-transporting tank on the spaceship, instead of using six-inch thick plexiglass, which was the most modern technology available in 1986 America, he shared know-how from the future to create transparent aluminum, which meant the walls of the tank only needed to be one inch thick, saving both space and weight on the spaceship.
As reported in New Scientist and explained at the University of Oxford's website, the scientists used the FLASH laser in Hamburg, Germay to conduct their experiments. This laser is a free-electron laser that generates brief but extremely strong pulses of soft x-ray light-about 10 million gigawatts of power per square centimeter. In their experiments, the team took a thin piece of aluminum foil and pummeled it with the FLASH laser, focusing its power on one tiny spot that had a diameter less than a twentieth of the width of a human hair. In normal conditions, the chemical makeup of aluminum is a web of ions, with free electrons in between. The high heat and intensity of the FLASH laser managed to knock an electron out of each ion and free it before other electrons could replace it, absorbing the photon in the process. This resulted in the aluminum appearing and behaving like a new form of matter, even though it retained its crystalline structure. X-rays could now go straight through the aluminum. Although it's an exciting development, the Oxford team hasn't yet been able to make this new state of matter last very long. Their attempts have been successful in creating transparent aluminum that lasts about 40 femtoseconds (that's fractions of a nanosecond) before the energy gets to the ions and blows them apart. However, this discovery has created a material that mimics the center of a large planet, which these scientists believe can help us understand more about conditions inside of large planets. They also believe transparent aluminum can explain more about nuclear fusion in the creation of miniature stars. Perhaps one day they'll even be able to create a whale-sized fish tank with this new material. 