The team found that people have large numbers of neural stem cells and progenitors early in life — an average of 1618 young neurons per square millimeter of brain tissue at birth. (sciencemag.org)
If this is the case, then, my logical conclusion is that the relative hotness between chile peppers is determined by the concentration or density of the capsaicinoids per square millimeter of the pepper bodies. (fieryfoodscentral.com)
The temperature sensor is integrated into a small chip measuring 0.15 × 0.15 square millimeters in area. (sciencedaily.com)