Experimental Evidence for Mixed Reality States Alfred Hubler and Vadas Gintautas Center of Complex Systems Research, Physics, UIUC Funding: NSF DMS Grant for the UIUC Material Computation Center We study the dynamics of a virtual system coupled with its real-world counterpart – an inter-reality system. We find a phase transition in the dynamics when the system parameters are close. This phase transition is from an uncorrelated small amplitude state (dual reality state) to a state in which the two systems move with a large amplitude as a coherent unit (mixed reality state). This synchronized motion of the real and virtual system is similar the synchronized electron-dynamics of real molecules in a LASER.

We study the dynamics of a virtual pendulum coupled to its real-world counter part with a instantaneous bi-directional interaction, 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: Synchronization of electron dynamics of molecules- 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)

This work: We use fast computers to simulate the virtual system in real time, fast probes & actuators to couple a real pendulum and its virtual counter part, with an instantaneous, bi-directional coupling. We observe a sudden synchronization of the real system and the virtual system, when their parameters are close. Photo: A. Hubler and V. Gintautas at the inter- reality system

Experimental Setup Real pendulum with actuator and probe (actuator lever arm not pictured) Virtual pendulum on computer Feedback to virtual pendulum depends on position of real pendulum and vice versa. Instantaneous Feedback Natural period of real pendulum ≈ 710ms Feedback and integration ≈ 35ms 35ms is effectively instantaneous for this system (verified by numerical simulation)

Inter-reality system and its simulated counter part

Dimensionless control parameters

Observables

Two different limiting behaviors

Phase transitions

Linear Theory

Phase diagram

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.

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. Example: Dynamical 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: Real System  Real System (LASERs, Millennium Bridge) Now: Real System   Virtual System (coupled real & virt. pendulum) Future (faster computers, probes & actuators): Simulated Real System   Simulated Virtual System (time travel?) || || Real System   Virtual System

Experimental Evidence for Mixed Reality States Alfred Hubler and Vadas Gintautas, Physics, UIUC (contains this 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, then the distinction between past, present, and future may fade away. Publication: "Experimental evidence for mixed reality states in an inter-reality system" by Vadas Gintautas and Alfred Hubler, in Phys. Rev. E 75, (2007) Funding: NSF DMS Grant for the UIUC Material Computation Center

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

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

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