This article mentions latencies in the order of magnitude of 50 to 100ms. For reference, the speed light takes to travel 3m/10ft is 0.00001 ms. For the problem being considered (latency in user interfaces), it IS insignificant, and rounded to zero.
Not sure what you're measuring with 3m/10ft, and what would travel that distance at the exact speed of light. For the reference, electrical signals travel at about 2/3c through fiber, a bit faster that that through copper.
I was simply pointing out that even interaction of atoms to proximity is propagated with a speed of light, and should not be called zero. Nothing to do with the rest of the article or the excellent app idea.
