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.

How Do Jumping Spiders Judge Distance from a Blurred Image?

2026-07-302026-09-21

A jumping spider’s lens and layered retina produce defocus cues that can help it judge distance. Explore the behavioral evidence and the questions that remain.

How a Gecko’s Foot Became NASA’s Solution for Gripping in Space

2026-07-292026-09-21

In the vacuum of space, suction cups have no pressure to grip with and adhesives freeze solid almost instantly — so NASA and Stanford engineers… Read More »How a Gecko’s Foot Became NASA’s Solution for Gripping in Space

There Was a Smartphone 13 Years Before the iPhone

2026-07-282026-09-21

1994년 출시된 IBM 사이먼 실물 사진. 4.5인치 저항식 터치스크린과 키패드가 보인다.

It’s famous that the iPhone opened the smartphone era in 2007. But a commercial product combining phone calls, email, and touchscreen apps in one device… Read More »There Was a Smartphone 13 Years Before the iPhone

Hot Muscle in Cold Water: The Great White Shark’s Regional Endothermy

2026-07-272026-07-27

The great white shark is often called “warm-blooded,” but more precisely it is a regionally endothermic (mesothermic) animal that warms only specific parts of its… Read More »Hot Muscle in Cold Water: The Great White Shark’s Regional Endothermy

Launched 16 Days Later, It Arrived First: Voyager 1 and 2’s Diverging Paths

2026-07-252026-09-21

Voyager 2 launched first in August 1977, with Voyager 1 following 16 days later — yet Voyager 1 reached Jupiter and Saturn first. Behind that… Read More »Launched 16 Days Later, It Arrived First: Voyager 1 and 2’s Diverging Paths

The Real Reason the Ocean Sunfish Lies on the Waves Like It’s Dead: Rewarming After the Hunt

2026-07-242026-07-24

The ocean sunfish floats on its side on the waves as if dead. But it’s actually diving into the deep sea several times a day… Read More »The Real Reason the Ocean Sunfish Lies on the Waves Like It’s Dead: Rewarming After the Hunt