How Did the World Agree on a Seven-Day Week? 5 Things to Consider

Why No Teeth?
A baby enters the world complete with all its external and internal organs, including hair and nails. This is a wonder and a great miracle, yet there's one missing part that develops later—teeth!
I ask myself: Why does the baby arrive with all organs intact, but without teeth? The answer is that the baby cannot eat solid food and relies entirely on breast milk. This way, it prevents the baby from causing pain to its mother during breastfeeding by coming toothless...
Here's another question: Why do baby teeth, which appear later, fall out? Why don't they stay permanently like other organs such as the nose or ears? After all, these parts don’t fall off and regrow. So why just teeth fall out and grow back?
If we observe, baby teeth are small and fit the size of the baby's head. If they stayed, they wouldn’t fit the larger head of an adult, making it impossible to talk or chew properly. Therefore, baby teeth fall out early in childhood, replaced by new teeth that are proportional to an adult's head size...
Is this by accident? Could this process happen without a creator or planner?...

 There Is Such an Animal!
I had the chance to visit a zoo. An amazing wonder, animals of countless types and kinds, one incredible creation after the other: Elephant, giraffe, rhino, crocodile, lion... The sight etched in my memory is of visitors looking with curiosity and wonder at the animals surrounding them.
People are amazed by animals that lie around all day, that can't speak, and relieve themselves anywhere... Sure, some intelligent animals surprise us with their wisdom, but they are quite limited. However, there are creatures that speak, communicate, think, remember, and create, capable of inventing sophisticated devices, like transportation on land, in the air, and sea, build buildings, and invent devices of high technological level...
What creature am I speaking about? The human!
So, why aren't we amazed by humans as we are with zoo animals? Why does a creature that lounges around unwisely garner so much attention, while humans—the most astonishing creation on earth—are taken for granted? It's because we are accustomed... We rarely see animals, maybe on a holiday zoo trip... whereas humans are our natural environment, and we've grown accustomed to seeing their talents and abilities as everyday things. Thus, we don't marvel or ask the big question: Who is responsible for the astonishing creation, the crown of creation—humanity?
May it be God's will that we learn to look at the human body, the strengths within it, its material and spiritual achievements, and understand that our very existence in this world is a miracle and a grace from the Creator. As King David phrased in Psalms: "What is man that you are mindful of him, and the son of man that you visit him? You have made him a little lower than Hashem..."
 
Automated Cleaning System
Anyone who wears glasses is familiar with the daily routine of cleaning the lenses with water, a cloth, or tissue to avoid blurry vision. What a hassle for us!
In contrast, for those who don't wear glasses, have you ever had to clean and wipe the eye with cloth and water to see clearly? Of course not! Yet all day, we look non-stop, and our view remains clear!
How does our eye see clearly without washing and cleaning as we do with glasses? It turns out the eye indeed undergoes cleaning: there's a lubrication mechanism with a pouch of tears washed by the eyelids, which move up and down continually, cleaning the human camera—the eye. This happens in the blink of an eye...
And I ask, who "designed" the automatic cleaning system of our eyes? Who programmed the constant movement of the eyelids that allows for eye cleaning? Who is "responsible" for the existence of the tear pouch meant to produce special fluids that constantly maintain the eye’s moisture and cleanliness?

 Oh My!
When we suddenly spot a threatening dog, snake, or even a "roach"—cockroach, we experience fear or panic. What process occurs in our body?
The structure in the brain that mediates emotions, especially fear, is called the "amygdala" (amygdale). Monkeys with damaged amygdalas showed a marked decrease in fear. People with similar damage can't recognize facial expressions that depict fear or learn new fear responses.
We might ask, what does fear contribute to us? Does the Creator want us to be afraid?!
The answer is yes—in certain situations, and why? Out of endless care and love for us.
Damage to the amygdala can lead to dull responses to danger, resulting in reckless behavior in unknown, hostile environments. For example, people with impaired amygdalas might approach a threatening animal like a snake with a wish to exhibit "positive" behavior such as petting the animal instead of stepping away immediately, as expected and usual.
Thus, the fear mechanism is fundamentally designed to save our lives from dangers and harmful situations!
The wonder grows considering there are two separate systems in our brain that work in perfect synchronization: the memory system with the emotional system. The connection between the amygdala and the hippocampus ties emotion to memory and explains why we remember emotional events far more than mundane happenings. We will remember a traumatic event in detail, and as a result, we will know to avoid it in the future.
Undoubtedly, the intelligent and wondrous function of the brain testifies to a guiding and caring hand. 
 
Why Not Ten Days a Week?
What day is today in the week? Suppose today is Friday...
My question to you is this: We take it for granted, but who decided today is Friday? What was the basis for this decision? We all agree today is Friday and tomorrow is *Shabbat*! So, I ask: How do we know today is really Friday? Could it be it's actually Wednesday, and someone "got the count wrong"?
Think about it. Who created the weekly count of seven days? How did the division and count of the week: Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, and *Shabbat*—begin at all? And why did the whole world start counting the week this way? And why seven days a week, not, say, ten days?
The big question: How does the whole world agree there are seven days in a week? How did it happen that our count matches theirs, i.e., Monday here is also Monday there, and so on? How can it be that this count is universally accepted and agreed upon?!
And let's say today is *Shabbat*...

Though we observe Shabbat and are accustomed to the weekly seventh day being *Shabbat*, who decided today is the seventh day of the week? The seventh day of what exactly? Who decided today is *Shabbat*? How are we sure today is indeed *Shabbat* and not, for example, Tuesday? How are we so sure?... Have you ever thought about this?
If influential leaders like Barack Obama or Benjamin Netanyahu decided to "reset the week" and start the count anew on a day convenient for them—do you think anyone would listen? Could they even enforce such a decision? Clearly not! Such an instruction cannot bind the whole world!
Logic suggests that likely there was an "historical event" in the past that started the count, leading everyone to willingly agree to this. Following that "historical event," the Israeli people began observing Shabbat precisely on the seventh day of the week, which a whole nation wouldn't have been ready to impose many of the constraints stemming from Shabbat observance if the event hadn't occurred!
Can you imagine what "world historical event" could convince all people on earth? Perhaps the creation of the world or the revelation of the Creator to an entire nation at the giving of the Torah... What do you say?