Windows that can automatically adjust from transparent to opaque to keep out the sun can already be found in use all over, including Boeing's new 787. But while they provide shade, the glass still absorbs and transmits heat to a room. So researchers at Japan's National Institute of Advanced Industrial Science and Technology have developed an easy-to-apply transparent film that can turn into a mirror to blocks and reflect light away.

So not only will it reduce annoying glare, it can also make it easier for an air conditioner to cool a room since the heat from the sun's rays is not being absorbed by the surrounding windows. And, it's cheaper to implement since the film can be applied to existing windows, instead of having to replace them all with the tintable kind. And while the current version of the film takes about ten minutes to go from a mirror finish to transparent, the researchers at AIST have developed an improved version that can make the change in 30 seconds, and are confident that when commercialized the film would eventually work its magic in just five seconds. [DigInfo TV]