This article uses the idea of Kulturtechnik (Kulturtechnik) which is developed in Germany in the late 1990s to explore the different forms of "doors" in history and the multiple roles which they play. As an intermediary between the inside and the outside, the sacred and the secular, the public and the private, the city and the wilderness, the "door" not only establishes a social, political, and religious order, but also transforms space into a carrier of cultural codes. (Excerpt)

As early as in 1950, Morton Hielig had already created the prototype of the “Sensorama,” a machine that could effectively encompass multiple senses (senses of seeing, hearing, smelling and touching); and later in 1960, Hielig invented the first display head set of virtual reality (VR).

mage cannot be placed in front of or behind reality (Realität) because they help constitute reality.