Extending Wheeler's delayed-choice experiment to Space

DelayedChoice

F. Vedovato¹, C. Agnesi¹, M. Schiavon¹, D. Dequal^1,2, L. Calderaro¹, M. Tomasin¹, D. G. Marangon¹, A. Stanco¹, V. Luceri³, G. Bianco², G. Vallone¹, P. Villoresi¹
Science Advances 3, e1701180 (2017)
DOI:10.1126/sciadv.1701180

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 conceived a Gedankenexperiment, or thought-experiment, that takes the implications of Quantum Mechanics to the extreme, demonstrating that a classical description would lead to a seeming inversion of the normal order of time and thus a violation of the causality principle. Building upon the results of our research group in Satellite Quantum Communications and as part of the collaboration between the Matera Laser Ranging Observatory of the Italian Space Agency, we published a manuscript ( Vedovato et al, Sci. Adv. 2017;3:e1701180) where we perform the first 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 the quantum treatment in the hostile space environment. Furthermore we have paved the way for further tests and applications of quantum theory in Space.

Some related articles in non-specialistic magazines:

New Scientist: Light’s quantum weirdness survives after going to space and back

Scientific American: Space-Based Test Proves Light's Quantum Weirdness

Phys.org: Reflecting light off satellite backs up Wheeler's quantum theory thought experiment

Space.com: There and Back Again: Scientists Beam Photons to Space to Test Quantum Theory

Gizmodo: Scientists Confirm Light's Crazy Quantum Mechanical Properties in Space

Science Alert: Quantum Weirdness of Light Was Just Confirmed by Shooting Photons Into Space

Forbes.com: Quantum Thought Experiment Works In Space

Daily Mail: Light's quantum weirdness works in SPACE: Scientists send photons 2,170 miles towards a satellite to confirm it behaves as both a particle and a wave

Alcuni articoli di divulgazione in italiano:

Le Scienze: Una conferma spaziale per il dualismo del fotone

Focus: La natura quantistica della luce sopravvive ai viaggi nello spazio