Hi Akinbo,
I've learned that strokes are funny things. While my verbal skills have declined (I stutter), my cognition and focus have benefitted. Maybe the speech impediment is a blessing -- it relieves me of the burden of having to engage in small talk. I am sad that the same level of health care is not available worldwide (or even in the U.S.) -- I strongly believe that free health care (and free lifelong education as well) are absolute entitlements.
Yeah, stubborn and incorrigible fit.
Anyway, I get access to Science articles through my AAAS membership. I don't know if you can access it; I would shoot you a copy if I could.
The crux of the experiment is the creation of an artificial superposition of states of time so that one state lags due to gravitational influence. The first two paragraphs of the (exceptionally well-written) article give the gist:
"Two-slit interferometry of quanta, such as photons and electrons, figured prominently in the Bohr-Einstein debates on the consistency of quantum theory (1, 2). A fundamental principle emerging from those debates--intimately related to the uncertainty principle--is that 'which path' information about the quanta passing through slits blocks their interference. At the climax of the debates, Einstein claimed that a clock, emitting a photon at a precise time while being weighed on a spring scale to measure the change in its mass-energy, could evade the uncertainty principle. Yet Bohr showed that the clock's gravitational redshift induces enough uncertainty in the emission time to satisfy the uncertainty principle. Inspired by the subtle role time may play, we have now sent a clock through a spatial interferometer. Our proof-of-principle experiment introduces clock interferometry as a new tool for studying the interplay of general relativity (3) and quantum mechanics (4).
"Time in standard quantum mechanics is a global parameter, which cannot differ between paths. Hence in standard interferometry [e.g., (5)], a difference in height between two paths merely affects their relative phase, shifting their interference pattern without degrading its visibility. General relativity, by contrast, predicts that a clock must 'tick' slower along the lower path; thus if the paths of a clock through an interferometer have different heights, a time differential between the paths will yield 'which path' information and degrade the visibility of the interference pattern (6). Consequently while standard interferometry may probe general relativity (7-9), clock interferometry probes the interplay of general relativity and quantum mechanics. For example, loss of visibility due to a proper time lag would be evidence that gravitational effects contribute to decoherence and the emergence of a classical world (10)."