#1 | Approaching Kokkuri-san with Equations of Motion! Taking on Animation from Scratch

My eldest son is in
the upper grades of elementary school.

His daily life is
surprisinglySASUKE all the way...

At home, he spends
all his time practicing SASUKE.

When he has a Switch, he creates his own SASUKE courses inMario Maker 2 or
Minecraft.

On YouTube, he watches past tournament footage,
studying it with intense focus.

As for playing outside...
he spends his days planningRun for Money games.

Recently,
he seems to be aiming to expand the scale of his events
by increasing participants in a pyramid scheme fashion.

If only he would put that motivation into his studies or lessons...
As a parent,
I am impressed by that motivation.

Watching my eldest son like that,
I suddenly remembered myself at that age.

Back then, I had many lessons,
and my memories of free time
were just playing Dragon Quest on the Famicom,
or playing soccer.

And then,
there was a game I vividly remembered.

That was,
Kokkuri-san!

The younger generation today
might not be familiar with it.

Kokkuri-san is a game
using paper and a coin (like a 10-yen coin),
a kind of fortune-telling or
spirit summoning ritual.

You draw 'Yes/No' or a hiragana chart on a white sheet of paper,
and place a 10-yen coin on it.

Then,
all participants gently place their fingertips
on that 10-yen coin.

In this state,
after calling out, 'Kokkuri-san, Kokkuri-san, please come...', and asking a question, the 10-yen coin, which no one is supposed to be moving, slides across the paper and begins to speak.

The real thrill of this game
was that the 10-yen coin would start moving on its own,
and reveal secrets like the love lives of classmates
one after another.

While pretending to be a spooky ritual,
in reality, it was the ultimate communication tool
for boys and girls to get excited together.

On the other hand,
I have never believed in spirits.

Even back then,
I looked at it with a somewhat cynical eye, thinking,
“Someone is just pushing it on purpose to make it move the way they want, right?”

However, things are different now that I am an adult.

I have become able to imagine
the principles behind that phenomenon.

Could the movement of a 10-yen coin in Kokkuri-san be reproduced using mathematical formulas?

That curiosity is
what sparked this series.

I plan to proceed with this series
in the following order.

1. Identify the factors that make the 10-yen coin speak the answer

2. Formulate the physical factors among them into equations

3. Solve the equations in Excel cells
   *No macros will be used
   *Might switch to Python along the way

4. Use Python to animate the movement of the 10-yen coin
   in real-time

I don't know if I can do it well.

But,
wouldn't it be quite interesting to try animating a 10-yen coin that moves on its own
using high school physics?

Note that the Excel files and Python scripts created in this series will be distributed sequentially within a single paid article, but I will set it up so that everything becomes free if you repost on X (formerly Twitter).

You are welcome to create the Excel files and Python scripts along with me while reading the article, or download the finished products and just look at them and think, 'I see.'

Of course,
I would also be happy if you just
skim through the process of this attempt.

Something you can't learn at school,
something you can enjoy precisely because you are an adult:
The Physics of Kokkuri-san

Please stay with me until the end!

🔗 Continues to the next article

If you found this even a little helpful or
are curious about what comes next,
please give it a like or follow,
as it encourages me to create the next article!

• Subject: #Kokkuri-san

• Theme: #Introduction

• Usage Scenarios: #IndependentResearch #Reviewing #Relearning #ClassroomMaterial #Physics

• Topics: #ILovePhysics #TriedIt