Every year, people all over the world try to make the biggest artificial Christmas tree, like the Gubbio Christmas Tree, formed by thousands of lights on the slopes of Mount Ingino, or the illumination of the 372-meter high transmission mast at Lopik in The Netherlands. Maura Willems, a student of Applied Physics at Delft University of Technology (TU Delft), decided to do the opposite. She created what is probably the world's smallest Christmas tree.

For her graduation, Willems works with a scanning tunneling microscope, a complex device that is capable of scanning individual atoms and even changing their position. She uses this microscope to build small structures, literally atom by atom, in order to study their quantum mechanical properties.

But sometimes, you can also use technology for something more fun.

Willems came up with the idea of making a Christmas tree by removing 51 atoms from a perfect crystal lattice. The tree is exactly 4 nanometers tall, or 4 millionths of a millimeter. But that is, admittedly, without counting the tree-topper.

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