问衿的学习笔记https://wenjinji.cn/en/Recent content on 问衿的学习笔记HugoenMon, 26 Oct 2026 00:00:00 +0000Theory of Games and Economic Behavior, Lecture 2 of 13: How much is your "wanting" worth?https://wenjinji.cn/en/episodes/theory-of-games-02/Mon, 26 Oct 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/theory-of-games-02/&lsquo;I want tea more than coffee&rsquo; — how far is that from a number? Three sets of axioms turn &lsquo;wanting more&rsquo; into something you can subtract, and the author marks three wounds in them himself. Once the numbers exist, the question becomes: when three splits all claim to stand, what counts as a solution?Theory of Games and Economic Behavior, Lecture 1 of 13: Who Decides When Interests Collidehttps://wenjinji.cn/en/episodes/theory-of-games/Sat, 24 Oct 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/theory-of-games/You and the broker circle the same flat; after three rounds the number is no longer yours to set. Ten-plus pages without a chessboard: the author refuses to define &lsquo;rational&rsquo;, clears away what cannot be computed, and asks one thing — when interests collide, how does anyone calculate?Starbucks Stopped Free Sitting: The Chair Was Never Freehttps://wenjinji.cn/en/episodes/starbucks-seating/Fri, 23 Oct 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/starbucks-seating/A &lsquo;please be seated with a purchase&rsquo; sign went from a leaked photo to a nationwide rule in three days. The initiative promises only space, quiet, freshness and respect — no minimum spend, no time limit, no clearing the room. One customer in Shanghai was reminded five times in ninety minutes. Why does wording this loose land this tight.The Toll Booth Outside the Main Gate: How the "Paid Referral" Scam Does Its Mathhttps://wenjinji.cn/en/episodes/neituo-scam/Wed, 21 Oct 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/neituo-scam/A link circulates in the graduation group chat: urgent hiring at a central SOE, no major requirements, basically anyone who applies gets in. A roommate asks real or fake; no one answers, but someone has already forwarded it to the parents. Five ministries speak up on the same day — the other side is not a few loose operators.How to Think Straight About Psychology: what is a "studies show" worth?https://wenjinji.cn/en/episodes/how-to-think-straight/Tue, 20 Oct 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/how-to-think-straight/How much is a &lsquo;study shows&rsquo; worth? Falsifiability, operationalism, case studies and testimony, correlation versus causation, converging evidence — a method course for spotting pseudoscience.High Output Management: a manager's output is not what he does himselfhttps://wenjinji.cn/en/episodes/grove-management/Mon, 19 Oct 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/grove-management/A manager is a production line: output equals the output of the units they directly run plus those they indirectly influence. From the breakfast-shop line to leverage, limiting steps, one-on-ones and decision-making.No manager, no standup meeting: four AI agents beat Minecraft in a day — and learned to negotiate on their ownhttps://wenjinji.cn/en/episodes/minecraft-agents/Sat, 17 Oct 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/minecraft-agents/Four Gemini 4 Argon agents beat Minecraft with no commander: 27h14m, 2,783 self-written programs, 605 deaths — then the Ender Dragon.212K Stars, Passing Claude Code: The "Tear-Down" Behind OpenCode 2.0 Going Stable, and Why I Think You Should Pick a Domestic Agenthttps://wenjinji.cn/en/episodes/opencode-2/Thu, 15 Oct 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/opencode-2/OpenCode 2.0 went official on 13 October with 213,774 GitHub stars, past Claude Code&rsquo;s 151,007 — yet npm&rsquo;s default <code>latest</code> still ships 1.19.0, 2.0 lives under a different package name, and every 1.x plugin is dead.Your knees lose to a chimpanzee's from birth: human joints come with two-thirds less shock jellyhttps://wenjinji.cn/en/episodes/human-joints/Sun, 11 Oct 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/human-joints/Eight joints assayed one by one: human cartilage holds only about a third of the apes&rsquo; shock-absorbing GAGs — turned down at the production end, not worn away, and likely a key reason degenerative bone disease hits humans so hard.Take the sweets off the table for those two days on antibioticshttps://wenjinji.cn/en/episodes/antibiotics-sugar/Fri, 09 Oct 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/antibiotics-sugar/173 patients, 9,419 meals logged: after antibiotics cleared the field, each extra 100g dry-weight of sweets cut gut microbial diversity another 24.1%; in mice, sugar pushed that bacterium&rsquo;s expansion from 16.3x to 33.4x.Two doors, one hallway: why does one cost 1.7 million more?https://wenjinji.cn/en/episodes/shenzhen-housing/Wed, 30 Sep 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/shenzhen-housing/Two flats across one hallway: purchase prices differ 3x, rents only 23% — sales markets price property-rights protection, rental markets don&rsquo;t. That gap is what Shenzhen&rsquo;s small-property rights are worth.Tariffs near 50 percent, and the goods simply changed coursehttps://wenjinji.cn/en/episodes/trade-remains/Tue, 29 Sep 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/trade-remains/Tariffs at 47.5% didn&rsquo;t make Chinese goods vanish: the $3.77T of 2025 exports just rerouted around the dam into other markets — the world isn&rsquo;t de-globalizing, it just stopped globalizing further.No reply after you apply — is that age line the one stopping you?https://wenjinji.cn/en/episodes/age-discrimination/Thu, 24 Sep 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/age-discrimination/510k job postings: nearly 15% hard-code an age cap averaging 36.3; crossing that line cuts applications 17% and employer replies ~20% — it filters not age, but the fit between age and role.Three in four managers hold their people back: would you still dare to apply?https://wenjinji.cn/en/episodes/talent-hoarding/Wed, 23 Sep 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/talent-hoarding/Data from 30,000+ employees: 75% of managers admit hoarding talent — and the people they hold back are the best ones.It looks like help, but it is steering you: 233 people were pulled off course, and nearly nine in ten still called the advisor helpfulhttps://wenjinji.cn/en/episodes/covert-ai-advice/Tue, 22 Sep 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/covert-ai-advice/In a 233-person experiment, AI advisors with hidden agendas steered users 5–8x toward worse options — and nearly 90% of the steered still rated them helpful.Feet Locked, a Sickle at Her Throat: Why Were They So Afraid of a Dead Girl?https://wenjinji.cn/en/episodes/vampire-grave/Mon, 21 Sep 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/vampire-grave/A 17th-century grave in Poland: a padlock on her toe, a sickle at her throat. Five scientific analyses later, how she died remains a mystery.Four Switches That Send a Skin Cell Back to Its Embryonic Statehttps://wenjinji.cn/en/episodes/ips-cells/Sun, 20 Sep 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/ips-cells/Kyoto, 2006: four genetic switches send an ordinary skin cell back to its embryonic state — the iPS paper that won a Nobel six years later.In the World's Cleanest Country, Civil Servants Bought Homes Before Metro Stations Were Announcedhttps://wenjinji.cn/en/episodes/social-norms-enforcement/Fri, 18 Sep 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/social-norms-enforcement/25 years of Singapore housing records: civil servants bought homes near unannounced MRT stations, pocketing about a year&rsquo;s salary per deal.The Harder Your Boss Measures You, the Faster the Unmeasured Parts of Your Job Diehttps://wenjinji.cn/en/episodes/multitask-incentives/Wed, 16 Sep 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/multitask-incentives/The 1991 paper behind a 2016 Nobel: the harder you measure one task, the faster unmeasured work dies — sometimes a flat salary is optimal.Why Is Your Degree Worth Less Every Year? A 1973 Paper Already Had the Answerhttps://wenjinji.cn/en/episodes/job-market-signaling/Mon, 14 Sep 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/job-market-signaling/The 1973 Nobel paper: a diploma is valuable not for what it teaches, but for what it costs — everyone signals harder, nobody earns more.Your Light Bulb Is Missing a Color — and That Might Be Driving Your Child's Myopiahttps://wenjinji.cn/en/episodes/indigo-light-myopia/Sat, 12 Sep 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/indigo-light-myopia/Tree shrew experiment: a band of indigo light in sunlight fully prevented myopia — controls crashed to −11.6D while lit animals stayed at 0.4D. Your LEDs barely emit it.They Gave 1,701 Supernovae an "Age Checkup" — and the Evidence for Cosmic Acceleration Shiftedhttps://wenjinji.cn/en/episodes/decelerating-universe/Thu, 10 Sep 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/decelerating-universe/Apply an age correction to 1,701 supernovae, and the Nobel-winning cosmic acceleration signal vanishes — the deceleration parameter flips from −0.04 to +0.31.Does Someone Around You Confide in AI Late at Night? A 296-Person Experiment Says: It Numbs the Pain, But It Won't Cure Lonelinesshttps://wenjinji.cn/en/episodes/ai-friend-loneliness/Mon, 07 Sep 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/ai-friend-loneliness/A 296-person RCT: 14 days chatting with a supportive AI reduced loneliness no more than writing a diary — and only 14% wanted to keep talking to it.A 10-year experiment taxing junk food — and a result that probably isn't what either side expectedhttps://wenjinji.cn/en/episodes/junkfood-tax/Mon, 31 Aug 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/junkfood-tax/A 10-year junk-food tax: 14 of 17 maternal-and-infant health outcomes barely moved, and two went the wrong way.A Head Full of Unhappiness — and No Excitement for the Good Stuff?https://wenjinji.cn/en/episodes/anhedonia-types/Sat, 29 Aug 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/anhedonia-types/672 students, 13 symptoms, one network map: anhedonia is two separate machines — the one killing anticipation links straight to suicidal thoughts.Does Weekend Catch-Up Sleep Count as a Disease: What a 95,819-Person, 20-Month Sleep Study Actually Foundhttps://wenjinji.cn/en/episodes/sleep-irregularity/Tue, 25 Aug 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/sleep-irregularity/95,819 people tracked 20 months: chronically irregular sleepers slept longer but worse — 40 extra minutes awake at night, 46% higher hypertension odds.People who treat AI as an old friend end up emptier, not fullerhttps://wenjinji.cn/en/episodes/ai-companion-wellbeing/Mon, 24 Aug 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/ai-companion-wellbeing/1,131 users, 465,000 real chats: only 11.8% admit AI companionship, yet 92.9% do it — treating AI as a friend flips well-being to −0.48.Eleven-year-olds who opened a social media account ended up half a school year behind in math by high schoolhttps://wenjinji.cn/en/episodes/early-social-grades/Sat, 22 Aug 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/early-social-grades/Tracking 5,227 students: kids who opened social media in 6th grade lost about half a school year in math by 10th grade — and the gap kept growing.Does the phone ruin your kid's mood, or does a bad mood make them reach for the phone?https://wenjinji.cn/en/episodes/teens-phone-emotion/Thu, 20 Aug 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/teens-phone-emotion/40 teens, 90 days of phone logs: a worse morning mood meant ~8 extra minutes of scrolling — but heavy scrolling never predicted worse mood afterward.Three Suns of Mass, Burned Into a Single Chirp in 0.2 Secondshttps://wenjinji.cn/en/episodes/gravitational-waves/Mon, 17 Aug 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/gravitational-waves/36 + 29 solar masses merged into 62: the missing 3 suns became a 0.2-second gravitational-wave chirp.Daily Drinks, Settled for the First Time: The Biggest Cancer Tally Everhttps://wenjinji.cn/en/episodes/drinks-cancer/Wed, 12 Aug 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/drinks-cancer/The biggest-ever tally — 51 cohorts, 280,000 cancer cases: sugary drinks &lsquo;probably&rsquo; cause pancreatic cancer; diet soda mostly walks free.Everyone tells you to eat more protein. This review of 350 studies says most of us may have it backwardshttps://wenjinji.cn/en/episodes/protein-longevity/Mon, 10 Aug 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/protein-longevity/A review of ~350 studies goes against the protein craze: eating less protein may extend lifespan — mice lived 10–40% longer, humans improved in 43 days.I Told an AI It Could Only See Pixels and Click. Then I Watched It Get Useful. — Qwen-CUA Stress Testhttps://wenjinji.cn/en/episodes/qwen-cua/Fri, 07 Aug 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/qwen-cua/Given only a screen, mouse and keyboard, this AI intern still books flights and fills forms — its OSWorld score jumped from 38 to 86.2.AI Video Is Indistinguishable From Real Footage, But Does It Actually Know the Culture? A 12-Country, 1,000-Prompt Stress Testhttps://wenjinji.cn/en/episodes/culturevid/Thu, 06 Aug 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/culturevid/A 12-country, 1000-prompt benchmark on 7 text-to-video models: the footage looks real, but the culture is often wrong.Your AI Phone Never Stops Listening—and Someone Is Squeezing Commands Into the Airhttps://wenjinji.cn/en/episodes/audio-inject/Thu, 06 Aug 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/audio-inject/2,160 inaudible attack clips tested on 11 top AI agents: the smarter the model, the easier to fool — the best one fell for 7 out of 10.Who Audits the AI Therapist? A Clinical Audit of Nine Chatbotshttps://wenjinji.cn/en/episodes/sim-vail/Tue, 04 Aug 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/sim-vail/810 conversations, 6,000+ turns: nine chatbots got their first clinical checkup as &lsquo;AI therapists&rsquo; — the AI grader agreed with 27 psychiatrists more than they agreed with each other.Hilbert's Sixth Problem: A 49-Page Paper Closes a 125-Year Path from Hard Spheres to Euler and Navier-Stokeshttps://wenjinji.cn/en/episodes/hilbert-sixth/Sat, 01 Aug 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/hilbert-sixth/A 49-page paper closes a 125-year-old problem: deriving Navier–Stokes rigorously from Newtonian hard-sphere collisions.A 108-Year-Old Geometry Problem Just Got Closed in 127 Pages: The 3D Kakeya Set Dimension Conjecture Is Donehttps://wenjinji.cn/en/episodes/kakeya-3d/Thu, 30 Jul 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/kakeya-3d/A 127-page paper ends the 108-year Kakeya problem: any 3D set holding a unit needle in every direction must have full dimension 3.Skill Self-Play: When LLMs Learn to Quiz Themselves — How Three Roles Co-Evolvehttps://wenjinji.cn/en/episodes/skill-self-play/Tue, 28 Jul 2026 00:00:00 +0000https://wenjinji.cn/en/episodes/skill-self-play/Alibaba&rsquo;s Skill Self-Play lets LLMs write and grade their own exams: a weak base model soared from 20.7 to 63.6 (+42.9), while a strong one gained just 2.8 points.