Biological cycles with relatively long and some unusual periods in the
   range of the half-week, the half-year, years, or decades are being
   discovered. Their prior neglect constituted a confounder in aging and
   much other research, which then "flew blind" concerning the
   uncertainties associated with these cycles when they are not assessed.
   The resolution of more about 10-year and other cycles, some reported
   herein, replaces the admission of complete unpredictability, implied by
   using the label "secularity." Heretofore unaccounted-for variability
   becomes predictable insofar as it proves to he rhythmic and is mapped
   systematically to serve as a battery of useful reference values. About
   10-year cycles in urinary 17-ketosteroid excretion and in heart rate
   and its variability, among others, are aligned with cycles of similar
   length in mortality from myocardial infarction. Associations accumulate
   between cycles of natural physical time structures, chronomes such as
   the 10.5-year (circadecennian) Schwabe and the 21-year
   (circavigintunennian) Hale cycles of solar activity, and chronomes in
   biota. There are about 50-year (circasemicentennian) cycles in
   mortality from stroke in Minnesota and in the Czech Republic and also
   in human morphology at birth, the latter result reducing the likelihood
   that these cycles are purely human made. Associations among large
   populations warrant long-term systematic coordinated sampling of
   natural physical and biological variables of interest for the design of
   countermeasures against already documented elevated risks of stroke,
   myocardial infarction, and other catastrophic diseases, notably in
   elderly adults. New findings will be introduced against the background
   of the documented value of mapping rhythms in medicine and gerontology.
   In both these fields, rhythms promise the seeming paradox of better
   care for less.