Weihnachten customs held upon returning from church leading to the gift giving vary across the German-speaking countries. One of the most common situations sees the returning children wait to enter into their (locked) living room until a little bell rings. This bell marks the departure of the one delivering gifts. In the more Catholic regions - primarily South Germany and Switzerland - this is considered the Christ Child ("Christkind"), while those in North Germany commonly consider it to be the "Weihnachtsmann" (Saint Nicholas or Santa Claus) who is exiting. The children then enter to see the decorated Weihnachtsbaum (Christmas tree), with
Emmanuel David Tannenbaum Emmanuel David Tannenbaum Emmanuel David Tannenbaum (June 28, 1978 – May 28, 2012) was an Israeli/American biophysicist and applied mathematician. He worked as a professor and researcher in the Department of Chemistry at the Ben-Gurion University of the Negev and the Department of Biology at the Georgia Institute of Technology, specializing in the fields of mathematical biology, systems biology, and quantum physics. Tannenbaum's initial work was in quantum chemistry as part of his Harvard University doctoral thesis where he developed a novel partial differential equation approach to the EBK quantization of nearly separable Hamiltonians in the quasi-integrable regime. Emmanuel Tannenbaum