Experimental Evidence for Mixed Reality States Alfred Hubler and Vadas Gintautas, Center for Complex Systems Research, Physics, UIUC Inter-reality System: A real system and a virtual system with a small, instantaneous, bi-directional interaction Funding: NSF DMS Grant for the UIUC Materials Computation Center

We study the dynamics of a virtual pendulum coupled to its real-world counter part with a small, instantaneous, bi-directional interaction, -i.e. an inter-reality system. When their motion is sufficiently close, we observe a synchronization, -i.e. a phase transition from a dual reality state to a mixed reality state. Motion of the real system and the virtual system: Dual Reality StateMixed Reality State Out-of-stepIn step Not synchronizedSynchronized Energy conserved (almost) for the real system and for the virtual system separately Energy conserved (almost) for the combined system Transient chaosHarmonic motion IgnoranceCooperation Small incoherent output, like a light bulb Large coherent output, like a LASER

Historical Context: Synchronization of real systems Example I: Synchronization of molecular motion in LASERs Unsynchronized electron-dynamics of the molecules: Regular light source (incoherent light, low intensity) Coupling of the molecules in a resonator: Sudden onset of synchronized electron dynamics of the molecules: LASER light (coherent, high intensity) Used in DVD players, LASER pointers, …

Example II: Synchronization of the motion of pedestrian on the opening day of the Millennium Bridge in London Unsynchronized walking of a few pedestrians: Damped vibrations of the bridge. Coupling of the walking by a weakly damped swaying motion of the bridge: Sudden onset of synchronized walking creates large and dangerous oscillations of the bridge

This work: We use fast computers (compute virtual system in realtime), fast probes & actuators to couple a real pendulum and its virtual counter part (instantaneous interaction). We observe a sudden synchronization of the real system and the virtual system, when their parameters are close, like the molecules in a LASER: a phase transition from a dual reality state to a mixed reality state Photo: A. Hubler and V. Gintautas at the inter- reality system

Experimental data: Evidence for a mixed reality state Figure 1. Amplitude X of the real system versus the frequency ratio for the experimental system (squares) and for the numerical simulation of the inter-reality system (triangles) The response versus the closeness of the real and the virtual system: Results: There is a sudden onset of large synchronized motion when the (many) parameters of the virtual system and the real system are close. Otherwise the motion is complicated and dies out. More data in a talk today, 12:51pm in R07.

Application I: Mixed reality states of humans playing virtual- reality computer games Can a future, more realistic and more imersive versions of Second Life or SimCity induce mixed reality states, where players suddenly no longer can distinguish between events in the game and events in the real world? Recent experimental work on out-of-body experiences may support this hypothesis.

Example for Application I: Out-of-body experience w video feedback Blanke O et al.Linking OBEs and self processing to mental own body imagery at the temporo-parietal junction. J Neurosci 25: (2006). - Subject sees video image of itself with 3D goggles - Two sticks, one strokes person's chest for two minutes, second stick moves just under the camera lenses, as if it were touching the virtual body. - Synchronous stroking => people reported the sense of being outside their own bodies, looking at themselves from a distance where the camera is located. - While people were experiencing the illusion, the experimenter pretended to smash the virtual body by waving a hammer just below the cameras. Immediately, the subjects registered a threat response as measured by sensors on their skin. They sweated and their pulses raced. Real system & similar virtual system & bi-directional instant. coupling = mixed reality

Application II: System identification for complex systems with many parameters Approach: - Couple a real dynamical system to its virtual counterpart with an instantaneous bi-directional coupling. - Measure the amplitudes of both systems and their phase difference, and then detect synchronization. Graphics: Amy Young, MCC funded by a DMS NSF Grant

Copyright ©2004 The American Physiological Society Kullmann, P. H. M. et al. J Neurophysiol 91: ; doi: /jn Example for Application II: Modelling Neurons with a Dynamic Clamp

Summary We study inter-realty systems: + Fast computer: Virtual system computed in real time + Fast probes & actuators: Instantaneous bi-directional coupling We find experimental evidence for mixed reality states. Mixed reality is a sudden and unexpectedly large phenomenon

Past: (LASERs, Millennium Bridge) Now: (this work) Future: inter-reality system Virtual SystemReal System coupled with real system Real System coupled with Real System inter-reality system Virtual SystemReal System coupled with time traveling simulated inter-reality system Simulated Virtual System Simulated Real System coupled with

Experimental Evidence for Mixed Reality States Alfred Hubler and Vadas Gintautas, Physics, UIUC (this presentation & 12:51pm talk) “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. And then there is the possibility for time travel … by the simulated inter-reality systems … and when the inter-reality system is coupled to its simulated, time-traveling counter part the mixed reality state can be more stable and the distinction between past, present, and future fades away.” Talk: today, Monday 3/10/08, 12:51pm in room R07 (B9-9) Funding: NSF DMS Grant for the UIUC Materials Computation Center Publication: "Experimental evidence for mixed reality states in an inter-reality system" by Vadas Gintautas and Alfred Hubler, in Phys. Rev. E 75, (2007)