Illustration par défaut

Quantum technologies challenged by microgravity

5 January 2017

Physicists from the Laboratoire photonique numérique et nanosciences (CNRS/Université de Bordeaux/Institut d’optique graduate school), from the Systèmes de référence temps-espace department of the Paris Observatory (Observatoire de Paris/CNRS/UPMC) and of the CNES have for the first time compared the free fall of two matter wavess in microgravity. These results were published in the December 12th 2016 issue of /Nature Communications/.

The work involves atoms cooled to a temperature of almost absolute zero, which behave as waves.

Done on board an Airbus A310 the experiment showed that potassium and rubidium atoms in free fall fell at the same speed in spite of a mass difference of a factor of two.

The double interferometer installed on board a zero-G aircraft, whose parabolic flight provides 20 secondes of microgravity. The on-board system compensates for the rotation of the plane and the Earth .
© Barrett et al. 2016

The objective was to verify Einstein’s equivalence principle [1] énoncé par Einstein.

These results prefigure future measurements made in space where, in spite of numerous technical problems, microgravity will enable the current precision of 10-13 to be considerably improved.

Even an infinitesimal difference would open the door to theories such as string theory which violate the principle of equivalence.

Reference

  • Dual Matter-Wave Inertial Sensors in Weightlessness, Brynle Barrett,
    Laura Antoni-Micollier, Laure Chichet, Baptiste Battelier, Thomas
    Lévèque, Arnaud Landragin, Philippe Bouyer. Nature Communications,
    12 décembre 2016. DOI : 10.1038/NCOMMS13786

[1According to this principle, the inertial mass of a body (its resistance to a change in its mouvement) is equal to its gravitational mass (its reaction to gravity). To date, all measurements of these two quantities have shown them to be identical.