Waters' book inspired further speculation in the mid-1980s, including revision of the date by the McKennas, Argüelles, and John Major Jenkins to one corresponding with the winter solstice in 2012. Interpretations of the date became the subject of further speculation by José Argüelles in "The Mayan Factor: Path Beyond Technology" (1987), promoted for the 1987 Harmonic Convergence. It received further elaboration in the Novelty theory of Terence McKenna. The supposed prediction of an astronomical conjunction of the black hole at the center of the Milky Way galaxy with the winter solstice Sun on December 21, 2012, referred to by Jenkins in "Maya Cosmogenesis 2012: The True Meaning of the Maya Calendar End-Date" (1998) and "Galactic Alignment:The Transformation of Consciousness According to Mayan, Egyptian, and Vedic Traditions" (2002) as having been predicted by the ancient Maya and others, is a much-anticipated event in Mayanism. Although Jenkins suggests that ancient Maya knowledge of this event was based on observations of the "dark rift" in the Milky Way as seen from Earth (this "dark rift", it is said by some Mayan scholars, was believed by some Mayans to be one of the entrances to Xibalba), others see it as evidence of knowledge imparted via ancient contact with extraterrestrial intelligence. The relevance of modern "dark rift" observations to Pre-Columbian and traditional Maya beliefs is strongly debated, and academic archaeologists reject all theories regarding extraterrestrial contact, but it is clear that the promotion of Mayanism through interest in 2012 is contributing to the evolution of religious syncretism in contemporary Maya communities. Psychonaut author Daniel Pinchbeck popularized New Age concepts about this date, linking it to beliefs about crop circles, alien abduction, and personal revelations based on the use of entheogens and mediumship in his 2006 book "2012: The Return of Quetzalcoatl".