Life on this earth seems to be calibrated in some mysterious way to the number seven. We humans operate under the cadence of a seven-day week—a cycle of activity that doesn’t even follow the cosmic timing of the stars, the sun, or the moon.
The number seven even governs the music world. Most people think there are eight notes in an octave, just as there are eight sides to an octagon. But no, an octave has only seven notes. Count them: do, re, me, fa, so, la, ti—and then we start over again with do. That eighth note, the octave, begins a new cycle of seven. There are as many notes in the scale as there are days in a week.
Six around one
The hexagon (a six-sided object) provides the most efficient use of space. Just ask a bee busily building its honeycomb. Mathematicians and architects insist that a hexagonal room (six walls built around a floor—the “six around one” principle) provides the most efficient ratio of perimeter to area and requires the least amount of wall material per square foot of floor space.
Like that central space set in the middle of six workdays, the Sabbath is God’s original prescription for allowing His people to enjoy optimum health, spirituality, and longevity. “Six days you shall labor,” He says in Exodus 34:21, “but on the seventh day you shall rest; even during the plowing season and harvest you must rest.”
It seems that all life moves in seven-day rhythms. A growing number of scientists have embraced a new field of study known as chronobiology that examines repeating phenomena in living organisms. These cycles are known as biological rhythms.
Franz Halberg is widely considered the “father of chronobiology.” This tall gentleman from Romania worked at the University of Minnesota in an office crammed with bookshelves that were stacked with copies of journals and papers he produced over the years. He insisted that we humans don’t just experience circadian rhythms of approximately 24 hours; we operate under circaseptan (weekly) rhythms.
Halberg first became interested in the subject when, as a high school student, he accompanied physician friends of his parents in their practice. He began to notice that patients with pneumonia either recovered or died in seven days.
Franz Halberg proposed that body rhythms of that length—far from being passively driven by the social cycle of the calendar week—are innate, self-governing, and perhaps the reason why the calendar week arose in the first place.
Research has uncovered many conditions about humans that seem to rise and fall in seven-day cycles. These include heartbeat, blood pressure, body temperature, hormone levels, acid content in the blood, red blood cell count, oral temperature, female breast temperature, urine chemistry and volume, the ratio between the brain’s neurotransmitters called epinephrine and norepinephrine, and the flow of several body chemicals such as the stress-coping hormone cortisol. Even the common cold is circaseptan.
Doctors have long observed that response to a malaria infection or pneumonia crisis peaks at seven days. Chicken pox symptoms (a high fever and small red spots) usually appear almost exactly two weeks after exposure to the illness. And surgical patients tend to have an increase in swelling on the seventh and fourteenth days after their surgery.
Organ transplants face similar a crisis as the body’s immune system attacks the newly introduced foreign object.
In the blood
God knew all of this, because He created us. Perhaps that’s why He commanded, in Genesis 17:12, that baby boys were to be circumcised one week after they were born. (Some scholars still don’t realize that “on the eighth day” is the Hebrew way of saying “one week later,” because the eighth day of the Jewish week was also the first day of the following week [Leviticus 23:39]). The Hebrews used inclusive reckoning when speaking of time, just like we use inclusive reckoning when speaking of the notes of the octave. In other words, God told the Israelites to circumcise their children on the octave of the day they were born.
So why wait a week to circumcise a baby boy? Prothrombin is what causes the blood to clot, preventing endless bleeding, and doctors tell us that’s when the prothrombin is at its maximum. It’s never that high again.
The week in history
Today, we take the seven-day cycle for granted, but in ancient cultures the “week” varied in length from three to nineteen days. However, in the millennium before Christ, Israel’s seven-day week took over the then-known world. And their weekly cycle revolved around something very unique. It was the Jews—those careful keepers of God’s time—who preserved one day as a period of rest and reflection, a “Sabbath” during which they focused on spiritual matters.
As the centuries rolled on, the Jewish Sabbath became an accepted part of Roman society. According to the ancient historian Josephus, writing in his book Against Apion, “The masses have long since shown a keen desire to adopt our religious observances; and there is not one city, Greek or barbarian, nor a single nation, to which our custom of abstaining from work on the seventh day has not spread.”
We live in a universe, not a multiverse. All of life is a symphony, and we’re each players in God’s great orchestra. Every song has a cadence, a rhythm. When we’re “in the groove” with the conductor, our lives experience a certain serenity, a familiar flow. Once we get out of step with the cadence of the song—the rhythm of time—our lives falter.
Imagine what it would be like if you tried to follow a 30-hour day. You’d soon find yourself completely out of step with society. Human nature is locked into that natural, God-created 24-hour circadian rhythm.
The same is true of the weekly circaseptan rhythm. That means that if you’re working on the Sabbath, you’re breaking yourself.
Maybe that’s one of the reasons why Seventh-day Adventists—a denomination of Christian believers who observe the seventh-day Sabbath—tend to live seven to ten years longer than the average citizen. They’re simply in sync with the rhythm of life.
Custom or creation
One final question. How do we know that these rhythms aren’t just social or religious customs? Perhaps, after several thousand years, the weekly cycle has simply been bred into us.
The problem with such a social convention explanation is that it can’t explain circaseptan rhythms in algae, Dahl rats, mice, guinea pigs, honeybees, beach beetles, and face flies.
In his writings, author Jeremy Campbell reports that circaseptan rhythms “are of very ancient origin, appearing in primitive one-celled organisms, and are thought to be present even in bacteria, the simplest form of life now existing.”
And here’s something really intriguing: While human teeth are growing, small lines or ridges form on the dental enamel about every seven days. The growing tooth might even be said to exhibit a weekly “rest” as it leaves behind a dark marker, just as trees show darker rings where their growth pauses in the winter. According to scientific researchers A. Mann, J. Monge, and M. Lampl in their book Investigation Into the Relationship Between Perikymata Counts and Crown Formation Times, these lines—30 to 40 microns apart—are called striae of Retzius. These stria are found even on the teeth of fossil hominids that lived before our modern culture existed.
Why should all living things have an innate seven-day cycle? I’d like to suggest a not-too-wild theory. It’s found in Exodus 20:11: “In six days the Lord made the heavens and the earth, the sea, and all that is in them, but he rested on the seventh day. Therefore the Lord blessed the Sabbath day and made it holy.”
I believe that God put within us rhythms that flow from the internal logic of our bodies.
Isaiah 58 contains some powerful health secrets. The first is a promise that God will bless those who bless the less fortunate (verses 5–12). The second is that God will bless those who honor His holy day. “If you keep your feet from breaking the Sabbath and from doing as you please on my holy day, if you call the Sabbath a delight and the LORD’s holy day honorable, and if you honor it by not going your own way and not doing as you please or speaking idle words, then you will find your joy in the LORD, and I will cause you to ride on the heights of the land” (verses 13, 14).
Just as we tune our radios to receive our favorite musical broadcasts, so every living cell has embedded in its primal genetic material a resonant frequency—a clock, a beat—that puts us in sync with the universe. And that powerful, mysterious beat revolves around the number seven.
Right now, God is calling you to tune your life to His heavenly broadcast and join in the song!