"I think it is significant, especially for experimental physics, that measurement errors and disturbances are clearly distinguished from quantum fluctuations in Ozawa's formulation," said Shogo Tanimura of Nagoya, who is independent from Ozawa's group. "Physicists thought that the only way to reduce errors is to suppress fluctuations. But Ozawa's inequality suggests that there is another way to reduce errors by allowing an object system to have larger fluctuations, although it may sound contradictory."
Ozawa's formulation confirms an emerging trend in probing the foundations of physics: to hew closely to what experimenters directly see in the lab—a so-called operational approach. "The error–disturbance uncertainty relation is much more important than that of fluctuations," says Akio Hosoya, a theoretical physicist at Tokyo Institute of Technology, "because in physics the final say comes from experimental verification." Heisenberg would be pleased that the limitation we can know about the world, which he aimed to expressed, was this time clearly revealed with the new rigorous, experimentally verified formulation. The new uncertainty relation between measurement error and disturbance is no more just conjecture, but physical law.