Embarking on a PhD to test Bell’s inequalities in 1974: the most exciting subject I had ever encountered*

When I read Bell's paper[1] in 1974, it was like love at first
sight. I immediately decided that this would be the subject of my PhD thesis.
The paper clearly explained that one could experimentally settle the debate
on the interpretation of Quantum Mechanics, between Einstein's position,
which was totally convincing, and Bohr's point of view, which was the main
stream. A young professor at Institut d’Optique, Christian Imbert, allowed me
to perform a Bell’s test it in his lab.
At that time, two pioneering experiments, one in Harvard (Holt and Pipkin)
and one in Berkeley (Clauser and Freedman) had provided opposite results.
[2] Beyond settling that contradiction, my goal was to work out an improved
experimental scheme, in which the tension between quantum mechanics and
relativity would be tested[3]. After some time, it was clear that this tension
was subtle: even if standard quantum mechanics would be vindicated, it did
not mean that one could use quantum non-locality to transmit “operational”
information faster than light[4]. It had become clear to the physicists
interested in that question, and I was one of them, that this “no signaling”
was linked to the fundamental randomness of each individual quantum
measurement and to the impossibility to duplicate a photon without
perturbing its state.
[1] J.S. Bell, On the Einstein-Podolsky-Rosen paradox, Physics, 1 (1964)
195-200.
[2] For a general review of the tests of Bell’s inequalities, see for instance A.
Aspect, Viewpoint: Closing the Door on Einstein and Bohr’s Quantum
Debate, Physics, 8 (2015) 123. 10.1103/Physics.8.123

[3] A. Aspect, Proposed Experiment to Test Nonseparability of Quantum-
Mechanics, Physical Review D, 14 (1976) 1944-1951.

[4] A. Aspect, Expériences basées sur les inégalités de Bell, Journal De
Physique, 42 (1981) 63-80.
https://doi.org/10.1051/jphyscol:1981203