Arrow's Impossibility Theorem
Arrow's theorem proves that no ranked-ballot voting rule with three or more options can simultaneously satisfy every basic fairness condition—at least one must be sacrificed.
8 min 4 scenes
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Mind & Society
Psychology, education, sociology, politics, and economic behaviour.
噩梦在整理情绪
噩梦是睡眠在把白天的情绪记忆重新打开、降低强度再归档，大脑借此把情绪从「当下正在发生」搬到「已经发生」。
8 min 4 scenes
为什么有些梦记得清，有些忘光？
梦的留存不取决于梦本身有多强烈，而取决于醒来后那几十秒里你是否把梦境翻译成了语言——大脑只在“刚醒”这个极短的窗口里，把视觉化的梦境转写成可以长期储存的语言记忆。
8 min 4 scenes
Why Jokes Are Funny
A joke gets its laugh when the punchline flips a confident expectation into a harmless incongruity, and the size of the safe flip drives the size of the laugh.
8 min 4 scenes
이순신, 해류를 무기로 삼다
한반도 연안의 조류·풍향 특성과 이순신의 함선 배치·침로 선택이 어떻게 연결되는지를 한산도 해전을 중심으로 보여주는 설명.
18 min 9 scenes
When Rumors Die Out
A rumor dies out when fewer than one new person is infected per infected person before that person stops spreading — so survival depends on the reproduction ratio, not on how interesting the rumor is.
8 min 4 scenes
What Is a Filter Bubble?
A filter bubble is the personalized, algorithmically narrowed slice of information a platform shows you, and the clearest sign you're in one is when your feed feels uniformly agreeable and missing opposing views.
8 min 4 scenes
How the Voting Rule Changes the Outcome
A voting rule defines what 'most preferred' means, so changing the rule can change the winner without any voter changing their mind.
16 min 8 scenes
甜果实背后的演化密码
这场探索会讲清楚甜味果肉为什么能在进化中出现，以及甜味如何帮助植物把种子传播出去。
16 min 8 scenes
Why Stories Change When Retold
A story changes when retold because each act of remembering rebuilds it from fragments shaped by what the retelling feels meaningful.
8 min 4 scenes
Habits Without Willpower
Habits shift when you redesign the environment—hide the cue or raise the effort—so the old loop stops before willpower is ever needed.
8 min 4 scenes
How the Brain Measures Time
The brain tells time through a flexible, distributed circuit—not a single stopwatch—and its 'tick rate' can be changed by attention, emotion, and brain chemistry.
20 min 10 scenes
How the Brain Hears Emotion
Music feels emotional because separate brain systems track the melody's mood and the tempo's energy, then combine them into one feeling.
20 min 10 scenes
Sad + Upbeat: Why It Feels Right
Sad songs with an upbeat beat feel right because rhythm and melody send separate emotional messages—one lifts your energy, the other carries the sadness—and the brain blends them into a bittersweet feeling.
8 min 4 scenes
Why Jokes Fall Flat
Understand why jokes fail and how to read an audience, fix delivery, and recover gracefully when a punchline misses.
20 min 10 scenes
When Prices Can't Move
When the price cannot adjust, the market stays out of balance: a price stuck below equilibrium creates persistent shortages, and a price stuck above equilibrium creates persistent surpluses.
22 min 11 scenes
Real-Time Market Disequilibrium
A market in disequilibrium self-corrects in real time: shortages push prices up, surpluses push prices down, until quantity demanded catches up with quantity supplied.
8 min 4 scenes
Spotting Painterly Depth Cues
A practiced eye for the depth cues hiding in photos, films, games, and everyday screens.
22 min 11 scenes
Depth Without Perspective
Flat paintings feel three-dimensional because artists stack simple depth cues—overlap, size, position, atmosphere, color, and detail—without needing a vanishing point.
20 min 10 scenes
Depth Cues: How Paintings Fool the Eye
A flat painting creates depth by combining overlap, relative size, and converging lines—consistent cues our brain reads as spatial relationships.
8 min 4 scenes
How Majority Rule Makes Collective Decisions
Why majority rule can fail to produce a single clear winner, and why voting procedures matter.
14 min 7 scenes
The Illusion of Depth
A flat painting looks deep when it uses the same spatial cues our visual system uses in the real world: relative size, overlap, and converging lines—not by adding realism.
8 min 4 scenes
The Anatomy of a Joke
A joke becomes funny when its punchline violates a strong expectation in a way that feels safe and playful, not when the words are funny by themselves.
8 min 4 scenes
How Corals Capture Sunlight
Corals are animals that get most of their energy from microscopic algae living inside them; those algae capture sunlight and turn it into sugar.
18 min 9 scenes