New method of stealth

There is now a new method of stealthing objects by placing them between two pieces of calcite crystals (CaCO ₃ ).

The new system developed by the Massachusetts Institute of Technology and the Singapore Coalition Technology and Research Center (SMART) can lead to the disappearance of relatively large objects (visible to the eye) in a medium of light often.

A sample of calcite crystals in nature(photo: matsmineral)

This invisibility system is made of 2 pieces of calcite crystals (carbonate mineral, the most stable polymorph of CaCO ₃ ) which is joined together in a certain form. Calcite has a high inertia, meaning that the light coming from one side will disappear at another angle than going through the other side.

By using two different calcite samples, the researchers can bend light around a solid object placed between two crystals.

A pink object seems to disappear behind a crystal of calcite in the water environment illuminated with blue light (photo: George Barbastathis).

However, the new stealth system still has its limitations, in which the system works well in blue light and only works to hide objects from a certain direction. Observing the object in another direction will make it "show up" again, said George Barbastathis, the new stealth system developer.

In addition, the system can only cover physical paper about 2 mm tall, but larger calcite crystal samples can hide larger objects.

Barbastathis is confident that his team will complete the real 3D stealth system and come up with an application for it.'I live in Boston, where there are many roads that converge to a sharp angle, so when looking at traffic lights, it is difficult to know which lights to look at. With the current stealth system, you can hide certain lampposts and the driver is not difficult to identify. '