"3주 동안 안 떠오른다"는 말, 처음엔 그게 그렇게 대단한 얘기인지 잘 모릅니다, 햇빛도 공기도 없는 강철 통에서 사람이 버티는 과학

At first, you might not realize just how extraordinary the phrase "not surfacing for three weeks" truly is. However, it actually means "not being detected even once for three weeks." The moment you surface to breathe is the moment of death. So, not surfacing doesn't simply mean staying submerged; it means you must survive without air for those entire three weeks. In this video, we take a closer look at the four scientific elements that made this seemingly impossible survival possible. Air-Independent Propulsion (AIP) Fuel Cell — Generating electricity by transforming into water without sparks A smartphone battery scaled up to submarine size (Lithium-ion) — If a Note 7 were to surface, that would be correct, but imagine it being carried hundreds of meters underwater Oxygen and drinking water produced directly from seawater — Extracting enough air from within to breathe for 50 people for three weeks Acoustic stealth that silences even footsteps — Because the moment you are detected, it is the end And the submarine that incorporates all four of these elements into a single vessel is the only one in the world—the Jang Yeong-sil, which we built, is the first of its kind. A country that used to buy from Germany until the 1990s has now become a nation where Canada stands in line with 60 trillion won. If you were curious about the cutting-edge science inside that steel container, we will explain it all here today. Chapter 00:00 Three Weeks Inside a Steel Container — Why This Makes No Sense 01:00 The Principle of How Submarines Rise and Sink (Using the Tube Analogy) 03:30 An Engine Running Without Air — The Chemistry of AIP Fuel Cells 06:15 Putting Note 7 Batteries in a Submarine? — The True Role of Lithium-Ion 08:30 Where Does the Oxygen Come From, Where Does the Water Come From? — The Chemistry That Saves 50 Lives 11:00 Silence Your Footsteps — Acoustic Stealth and Co-array Sonar 12:45 Why the Buying Country Became a Selling Country — The Jang Yeong-sil Ship and the Bidding War with Canada 14:00 What Remains Longer Than the Technology — The People Inside That Steel Container