Suarez and Valerio Scarani, inspired by discussions with Bell, proposed in 1997 the "before-before" experiment. They proposed to use moving measurement devices to test quantum entanglement and nonlocality (the EPR experiment) to see whether there is some ordering process behind the nonlocal correlations. Suarez hoped to find something wrong with standard quantum mechanics.

The "before-before" experiment used the idea of hyperplanes of simultaneity from the special theory of relativity. Back in the 1960's, C. W. Rietdijk and Hilary Putnam argued that physical determinism could be proved to be true by considering experiments and observers moving at high speed with respect to one another. Roger Penrose developed a similar argument in his book The Emperor's New Mind called the Andromeda Paradox.

Suarez and Scarani showed that for some relative speeds between two observers A and B, observer A could "see" the measurement of observer B to be in his future, and vice versa.

Because the two experiments have a "spacelike" separation (neither is inside the causal light cone of the other), each observer thinks he does his own measurement before the other.

In 2001, Suarez collaborated with Nicolas Gisin on these tests. Suarez and Gisin described the situation as some influence coming "from outside space-time" to cause the 100% correlations found in their tests of Bell's Theorem.

They tested the limits on this effect by moving mirrors in one of the paths in a path-length (Mach-Zehnder) interferometer. They showed that, like the other Bell inequalities, the "before-before" suggestion of Suarez and Scarani could not eliminate nonlocality and entanglement. Their tests confirmed quantum mechanics and refuted the Suarez temporal explanation.

In his recent essay "Does Free Will Require New Physics," Suarez explores the possibility that the brain contains a generator of the random bits seen in his nonlocality experiments, and that the will might in some way control the order of those bits to make "pieces of information". This resembles the idea of downward causation.

Like many physicists proposing specific free will mechanisms, Suarez imagines a physical process in the brain related to the work in physics that he is most familiar with. In his case it is a path-length interferometer.

the decision about which detector clicks (in an interference experiment, like that represented in the Figure) does not happen when "one photon encounters a detector" but only subsequently, after a virtual cascade involving billions of electrons has been triggered. Only then an irreversible registration of a result happens and a human observer can become aware of it.

An event is "measured", i.e. irreversibly registered, only if it is possible for a human observer to become aware of it.

Conscious free will implies irreversibility and therefore requires new physics capable of well defining this concept. But quantum mechanics itself requires such a new physics. Quantum theory does not define at all which conditions determine when measurement happens and a result becomes irreversibly registered. This state of affairs clearly shows a point where the theory can and must be completed.

Suarez cites the Free Will Theorem of John Conway and Simon Kochen as making free will an axiom, without which science itself could not proceed. Suarez does not believe that his current movements can be "explained by a chain of temporal cause going back to the Big Bang."

With the support of Carlos Cavallé and his Social Trends Institute, Suarez organized an experts meeting on the question "Is Science Compatible With Our Desire For Freedom?" in October 2010. Several philosophers and scientists interested in the the problem of free will attended, including Robert Kane, Alfred Mele, Bob Doyle, and Martin Heisenberg.