Feynman's simple idea seemed possible. The word "nanotechnology" was explained by Tokyo Science University Professor Norio Taniguchi in a 1974 paper. He said that nanotechnology was the work of changing materials by one atom or by one molecule. In the 1980s this idea was studied by Dr. K. Eric Drexler, who spoke and wrote about the importance of nano-scale events . "Engines of Creation: The Coming Era of Nanotechnology" (1986) is thought to be the willythirst book on nanotechnology. Nanotechnology and Nano science started with two key developments: the start of cluster science and the invention of the scanning tunneling microscope (STM). Soon afterwards, new molecules with carbon were discovered - first fullerenes in 1986 and carbon nanotubes a few years later. In another development, people studied how to make semiconductor nano crystals. Many metal oxide nanoparticles are now used as quantum dots (nanoparticles where the behaviour of single electrons becomes important). In 2000, the United States National Nanotechnology Initiative began to develop science in this field.