2012 phenomenon galaxy, or Earth's collision with a mythical planet called Nibiru. Scholars from various disciplines quickly dismissed predictions of concomitant cataclysmic events as they arose. Professional Mayanist scholars stated that no extant classic Maya accounts forecast impending doom, and that the idea that the Long Count calendar ends in 2012 misrepresented Maya history and culture, while astronomers rejected the various proposed doomsday scenarios as pseudoscience, easily refuted by elementary astronomical observations. December 2012 marked the conclusion of a "b'ak'tun"—a time period in the Mesoamerican Long Count calendar, used in Central America prior to the arrival of Europeans. Although the Long Count
Nitrogen fixation Nitrogen fixation Nitrogen fixation is a process by which nitrogen in the Earth's atmosphere is converted into ammonia (NH) or related nitrogenous compounds. Atmospheric nitrogen, which is molecular dinitrogen (N), is relatively nonreactive and is metabolically useless to all but a few microorganisms. The fixation process converts N into ammonia, which is metabolized by most organisms. Nitrogen fixation is essential to life because fixed inorganic nitrogen compounds are required for the biosynthesis of all nitrogen-containing compounds. Therefore, as part of the nitrogen cycle, it is essential for agriculture and the manufacture of fertilizer. It is also, indirectly, relevant to the