Tree-D printing for Christmas

This 3D-printed Christmas tree was made by researchers at the University of Amsterdam in the Netherlands. The system makes use of the same evaporative cooling effect used by some temperature control units. Under a vacuum, water evaporates at much lower temperatures than normal, with each molecule transferring a small amount of heat away from the remaining water reserve. This means that the liquid water becomes colder and colder until it is supercooled.