Planet Earth: Governed by Cycles
Cycles are a defining characteristic of all living things. We introduce this post by reminding readers that there is no persuasive evidence that any type of life exists anywhere else in this enormous universe. Given the truth of this statement, we devote this post to one of the defining characteristics of life on Earth—the existence of ubiquitous cycles.
Our last post highlighted solstices and equinoxes, cyclical astronomical phenomena which allow for changing seasons and create ideal agricultural conditions. These unique conditions are life-friendly. For instance, recurring cyclical seasonal changes together with the well-known water cycle and numerous chemical cycles support the lives of billions of individual humans and millions of animal and plant species. Sustaining miracles described in Genesis Chapter 1 supply hundreds of environmental conditions designed by The Creator of All Things. Cycles are vitally important for our planetary operating system.
Cycles are sequences of repeating events recurring multiple times in the same order. Cyclical events rule our daily lives even when we are not aware of them. We cite a few examples of cycles by categories:
Physical Science: energy cycles, chemical cycles
Biological Science: life cycles, agricultural cycles, carbon cycle, nitrogen cycle, oxygen cycle, water cycle
Earth Science: astronomy cycles, climate cycles, geological cycles, rock cycles
Without numerous interrelated and interlocking cyclical events the planet as we know it could not function. Knowledge of cyclical events in the natural world is an invaluable apologetic for the existence of the omniscient Creator of All Things, the Divine Designer of our intricately designed planetary home. An interesting phrase is “biogeochemical cycle” which describes interrelationships of many different types of cycles operating on our planetary home. Brittanica defines the term as “any of the natural pathways by which the essential elements of living matter are circulated.” The term is “a contraction of the biological, geological, and chemical aspects of each cycle. Elements within the biogeochemical cycles flow in various forms from the nonliving (abiotic) components of the biosphere to the living (biotic) components and back.
Human life and the lives of at least 8.7 million animal and plant species known on Earth depend on the operation of multiple cycles. Modern agriculture depends on a number of chemical cycles—the carbon cycle, the nitrogen cycle, the oxygen cycle, and the water cycle, to name only a few. Below, we recycle several posts from our 2012 archive. The cycle concept is highlighted in each post: