1. The Materials Computation Center, University of Illinois Duane Johnson and Richard Martin (PIs), NSF DMR-03-25939 www.mcc.uiuc.edu Objective: Understand synchronization between virtual and real systems. Approach: Couple a real dynamical system (a pendulum in this experiment) to its virtual counterpart with an instantaneous bi-directional coupling. Measure the amplitudes of both systems and their phase difference, and then detect synchronization. Determine the phase diagram for dual reality states (when the two pendulums are not connected and not in sync), and mixed reality states (when the two pendulums move together) and reproduce the results with a numerical simulation of the inter- reality system. Significant results: We found experimental evidence for a phase transition from dual reality states to mixed reality states. The phase diagram of the inter-reality system is in good agreement with the phase diagram of the simulated inter-reality system. Principal Investigator: Alfred Hubler (UIUC), Student: Vadas Gintautas Phase diagram of the inter-reality system: amplitude of the coupling versus the frequency ratio of the real and the virtual system. The phase boundary between mixed reality states (I) and dual reality states (II). The solid, dashed, and dotted lines indicate the critical points in the experiment, simulation, and analytic theory, respectively. Experimental evidence for mixed reality states in inter-reality systems

2. The Materials Computation Center, University of Illinois Duane Johnson and Richard Martin (PIs), NSF DMR-03-25939 www.mcc.uiuc.edu Why it matters: With the rapid advance in computer technology, virtual systems match their real counter parts with ever-increasing accuracy. If virtual systems are coupled to their real counterparts, mixed reality states may occur. In mixed reality states there is no clear boundary between the real and the virtual system. Mixed reality states can be used to analyze and control real systems with high precision. Broader Impact: The paper received a lot of media attention, exploring the phenomenon that a virtual world can affect objects in the real world. “The unknown factors in the real system can be determined by changing the virtual system until they shift from dual reality to mixed reality. Then, the physicists will have good estimates for the values of the unknown parameters.” -PhysicsCentral.com Publication: The paper "Experimental evidence for mixed reality states in an inter- reality system" by Vadas Gintautas and Alfred Hubler, in Phys. Rev. E 75, 057201 (2007), was selected for the APS tip sheet: http://www.aps.org/about/tipsheets/tip68.cfm http://www.aps.org/about/tipsheets/tip68.cfm Photo: A. Hubler (left) and student V. Gintautas at the inter-reality system

3. The Materials Computation Center, University of Illinois Duane Johnson and Richard Martin (PIs), NSF DMR-03-25939 www.mcc.uiuc.edu Applications of mixed reality: This example demonstrates the possibilities of mixed reality to overcome friction on a pendulum’s movement. Mixed reality is also exhibited in experiments which involve human perception: generating out-of-body experiences. Volunteers wore virtual-reality googles to view their own bodies from a camera’s location. When the volunteers were prodded at the same time an object approached the camera, they felt their body was at the camera’s location. In such experiments, the virtual system is the video image. As with the virtual/real pendulums, there is instantaneous, bi-directional feedback: when the person moves, the image of the person moves; as the video image is changed, the person feels a change. The authors are curious about the possibilities of mixed-reality economies, for example how Second Life gold can be purchased with real dollars.