Southman

I am In Nam, the editor of glu.kr. Under the mission “God Loves U: learn, discuss, and explain all things that God created,” I write across six areas — culture, history, science, plants, animals, and climate. Every article begins as an AI-assisted draft, then goes through source checks, numerical verification, and terminology review before I read and edit it myself for publication. Images carry their source and license, with freely licensed material preferred. If you find an error, write to south-man@daum.net. I verify it, correct the article, and note the change.

A Cicada Sings With Its Belly, Not Its Throat

2026-07-102026-07-22

The summer sound everyone hears but no one quite understands: a cicada makes its call not with vocal cords, but with a ‘drum’ on its… Read More »A Cicada Sings With Its Belly, Not Its Throat

How One Fire Keeps a Whole Room Warm All Night — The Heat Design of the Ondol

2026-07-082026-07-22

You light a fire only briefly in the evening, yet the floor stays warm until dawn. The ondol is an ingenious heat-storing system: it detours… Read More »How One Fire Keeps a Whole Room Warm All Night — The Heat Design of the Ondol

Why a Whole City’s Cherry Blossoms Open in the Same Week — The Temperature Math Hidden in Bloom

2026-07-072026-07-22

Every spring a whole city’s cherry trees burst into bloom within days and fall together about a week later. This synchrony is no accident —… Read More »Why a Whole City’s Cherry Blossoms Open in the Same Week — The Temperature Math Hidden in Bloom

Cherry Blossoms and Their Look-Alikes — Telling Apart Five Spring Blossoms of the Genus Prunus

2026-07-062026-07-22

In spring, whole neighborhoods turn pink — but the Japanese apricot, apricot, peach, and plum are all different trees, not cherries. They look alike because… Read More »Cherry Blossoms and Their Look-Alikes — Telling Apart Five Spring Blossoms of the Genus Prunus

A Cloud Weighs as Much as 100 Elephants, Yet It Doesn’t Fall — The Physics Hidden in a Single Droplet

2026-07-062026-07-22

A single fair-weather cumulus cloud weighs about 500 tonnes — as much as 100 elephants. So why doesn’t it fall? We look at the terminal… Read More »A Cloud Weighs as Much as 100 Elephants, Yet It Doesn’t Fall — The Physics Hidden in a Single Droplet

Why the Moon Always Shows the Same Face — The Design Behind Tidal Locking

2026-07-032026-09-21

보름달 앞면을 고해상도로 담은 사진으로 어두운 바다와 밝은 고지대, 크레이터가 보입니다

The Moon shows us the same face not because it ‘doesn’t rotate’ but because its rotation is perfectly synchronized with its orbit. We explore the… Read More »Why the Moon Always Shows the Same Face — The Design Behind Tidal Locking