**7.2. Biology/medicine**

The uncertainty derives from the uncertainty of BioMedicine. The problem to be solved is how we interpret the meaning of SI. We agree that it could be a controversial issue for the people who read this article without doing experiments. Diagnosis/interpretation of data is never perfect, but SI calculation is accurate and perfect.

I recall my childhood: cicadas sing during the day of sunny summer days. It is like under perfect condition they sing. At night, I hear insects most of them were a cricket or a katydid. Whenever 'a boy of a curious nature' tried to capture them, he experienced, the insects stop singing if he approached too closer to them. Typically, animals do not love human approaching.

A few people have asked me if lobsters/crabs feel stress. My answer is 'yes' although there is a problem regarding the uncertainty and accuracy (see earlier text). The truth is not known yet, because animals never tell us how they feel. But they indeed sense a human. At least, the truth that we found is SI changes when they sense a human (**Figures 7** and **9**).

We can explain that SI measure is like temperature measure (Celsius, C degree). SI has a criterion value as temperature does. If C is 37°, our healthiness is fine as far as temperature is of concern. In the same way, if SI is one (1.0), healthiness is fine. 1/f is comparable to SI = 1. It has been shown by Kobayashi and Musha in 1982 [1] and Peng et al. in 1990s [2, 3]. In those days, when Kobayashi et al. worked, their computer never had enough power to quickly calculate/ handle the time series data.

In short, the scaling exponent (SI) is accurate. The uncertainty derives from our interpretation. For our guide line, believe it or not, you may have no problem for the heart if you have SI, ranging 0.8 < SI < 1.2.
