H. It's the door to curiosity.

December 29, 2022

Until the Edo period, the day was divided into 12 periods, called the Hour of the Rat, the Hour of the Ox, etc.

24 divided by 12 means that 1 hour is about 2 hours, and the hour of the Rat is from midnight to 2 o'clock... you'd think so, right?

Actually, the day was divided into two parts: "sunrise to sunset" and "sunset to sunrise," and each part was further divided into six parts, and each part was assigned an animal from the zodiac, such as the Hour of the Rabbit, the Hour of the Dragon, etc.

Hmm? What do you mean?

In Japan, the sun doesn't rise at 7am and set at 7am when you're directly on the equator, so sunrise varies from 4am to 7am depending on the season. The length of the day is also completely different between the summer solstice and the winter solstice.

So, even though it was called "the hour of the tiger," it didn't refer to a specific time lol

For example, in a period drama, a thief

"I'm going to sneak into Echigoya at midnight tonight!"

Even if they arranged to meet up, how on earth did the thief manage to meet at the exact time?

...

As can be seen from the 12 animals of the Chinese zodiac, 12 is a number commonly used in time and calendars.

This obviously comes from the lunisolar calendar, in which the moon waxes and wanes 12 times per year (Earth's orbital period) .

There's an interesting story.

In the past, the lunar cycle was 29.5 days (its orbital period was 27 days) , so multiplied by 12 months was 354 days in a year.

But we know that there are 365 days in a year.

To adjust for this, 30 days ÷ 10 days (error) = 3. So, one month every three years, there is a "leap month" instead of a leap year lol

This means!

In modern times, a bonus would normally be six months' salary.

There was no such thing in the Edo period, but once every three years there were 13 months in a year.

In years with leap months, my salary increased by one month. I feel like I've gained something!

If you think about it calmly, you only get what you work for lol

Well, if you think about it in terms of annual income, the punchline was that it was an increase in income, which is a lame punchline lol

...

The calendar is calculated based on the laws of motion of the Earth and Moon in the solar system .

In the past, the geocentric theory based on Catholic thought was dominant, and the view was that "the sun revolves around the earth."

This is,

"The Earth revolves around the sun"

It seems that observations based on the heliocentric theory began only about 300 years ago , when Newton discovered the law of universal gravitation .

The heliocentric theory, which was proposed in ancient Greece, began to emerge in 15th century Poland.

Later, with the advent of Copernicus and the printing press, knowledge became widely disseminated.

It took Kepler and Galileo, and then Newton in the late 17th century, for this to be scientifically proven .

This film depicts the people who risked their lives in the pursuit of the heliocentric theory, or scientific truth, in Poland during the period when the heliocentric theory was first established.

"Thi. About the movement of the Earth."

This science manga was incredibly popular this winter. I ended up buying all nine volumes.

Hmm. This is truly a modern version of "candle science."

Recommended for children in fifth grade and above who can tolerate some brutal depictions of medieval Europe.

That's why, Mom and Dad.

When you return to Seongju, instead of rice, please try packing "Chi. About the Movement of the Earth" in your suitcase.

It's the blossoming of curiosity. An invitation to science. A door to the future.