VR - Past, Present and Future

VR has come a long way - from clunky, mechanically-tracked HMDs driven by multi-million dollar computers - to sleek wireless HMDs driven by commodity PCs and graphics cards - and many purported VR applications don't use HMDs at all. Applications have expanded from scientific, engineering and military to entertainment and social networking. The meaning of VR has changed. In this talk I ask (and endeavor to answer) questions such as: "What is the essence of VR?"; "What is the future of VR?"; "How has VR changed?"; "What is the science behind VR?"; and "What are open VR research questions?"