F. Vedovato1, C. Agnesi1, M. Schiavon1, D. Dequal1,2, L. Calderaro1, M. Tomasin1, D. G. Marangon1, A. Stanco1, V. Luceri3, G. Bianco2, G. Vallone1, P. Villoresi1

1Department of Information Engineering, University of Padova, via Gradenigo 6/B, 35131 Padova, Italy
2Matera Laser Ranging Observatory, Agenzia Spaziale Italiana, Matera 75100, Italy
3e-GEOS spa, Matera 75100, Italy

One of the most surprising and counterintuitive aspects of Quantum Mechanics is the wave-particle duality, more precisely the impossibility of describing the fundamental elements of nature exclusively as waves or as particles. In fact, Quantum Mechanics requires all elementary particles to be treated contemporaneously as waves and as particles, but forbids both characters to be observed simultaneously. In 1978 John Archibald Wheeler developed a Gedankenexperiment, or thought experiment, that takes the implications of Quantum Mechanics to the extreme, and demonstrates that a classical description would lead to a seeming inversion of the temporal order and thus a violation of the causality principle. Building upon the results of our research group in Quantum Satellite Communications and as part of the collaboration between the Mater Laser Ranging Observatory of the Italian Space Agency, we have posted a manuscript ( https://arxiv.org/abs/1704.01911) were we perform a satellite version of Wheeler’s Gedankenexperiment. By exploiting the polarization degree of freedom and the temporal modes of photons reflected by satellites in a low earth orbit, we demonstrated the necessity of a quantum treatment in the hostile spacial environment. Furthermore we have paved the way for further tests and applications of the quantum theory in Space.