Mathematicians Hoard Hagoromo Chalk Before Korean Firm Revives Brand

Great Big Story

Academics hoarded decades of Hagoromo chalk following a factory closure, only for a South Korean buyout to resume production and remind scholars that the tool's true value lies in using it up.

AI-assisted summary of Why the World’s Best Mathematicians Are Hoarding Chalk — original source. Check the original for full context.

Source published: 2019-05-02

Key ideas

Japanese Hagoromo chalk developed a legendary status among mathematicians worldwide as the 'Rolls-Royce of chalk,' prized for its dense composition, effortless glide, and clean lines. (0:00)
When the original Japanese manufacturer announced it was going out of business, mathematicians panicked and hoarded massive stockpiles—some acquiring up to 1,500 sticks or 15-year supplies. (1:23)
The supply shock spurred an informal black market within university departments, where hoarder professors acted as unofficial chalk dealers for their colleagues. (1:53)
The chalk was saved from extinction when a South Korean company acquired the original machinery and proprietary formulas to resume production. (2:34)

Detailed notes

## Background Published by the YouTube channel Great Big Story on May 2, 2019, this short documentary explores why elite academics fell deeply in love with Hagoromo chalk. The video description recounts the story of this irreplaceable Japanese writing tool—humorously rumored to be made from angel tears—which became so treasured that professors stockpiled massive reserves.

## TL;DR Japanese Hagoromo chalk achieved cult status among top mathematicians due to its dense texture, smudge-free erasing, and effortless glide across blackboards. When the original Japanese factory announced its closure, a panicked 'chalk apocalypse' ensued as professors hoarded massive multi-year stockpiles and covertly distributed boxes out of campus office cupboards. The tool was ultimately saved from extinction when a South Korean firm acquired the original formulas and machinery, reflecting how blackboard mathematics remains a physical craft where superior tools inspire confidence and intellectual artistry.

## Atmosphere & style The video carries a whimsical, affectionate, and lightly conspiratorial tone, blending dry academic humor with sincere reverence for a humble classroom tool. Watching distinguished scholars seriously discuss office 'chalk dealing,' personal burn rates, and 'angel tears' lends an eccentric, charming energy to the narrative. The emotional arc transitions playfully from mythic awe to apocalyptic panic, ultimately landing on a warm, thoughtful meditation on craftsmanship and teaching.

## Bulletin - [00:00](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=0s) Japanese Hagoromo chalk developed a legendary status among mathematicians worldwide as the 'Rolls-Royce of chalk,' prized for its dense composition, effortless glide, and clean lines. - [01:23](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=83s) When the original Japanese manufacturer announced it was going out of business, mathematicians panicked and hoarded massive stockpiles—some acquiring up to 1,500 sticks or 15-year supplies. - [01:53](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=113s) The supply shock spurred an informal black market within university departments, where hoarder professors acted as unofficial chalk dealers for their colleagues. - [02:34](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=154s) The chalk was saved from extinction when a South Korean company acquired the original machinery and proprietary formulas to resume production.

## Key takeaways - [00:08](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=8s) Hagoromo chalk attained mythic status among mathematicians, inspiring folklore that it was made from angel tears or made it impossible to write a false theorem. - [00:25](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=25s) Mathematicians universally dubbed Hagoromo the 'Rolls-Royce of chalk' due to its distinct performance advantages over standard commercial chalk. - [00:31](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=31s) Originally available only in Japan, the chalk was a closely guarded secret spread internationally through visiting scholars and luggage imports. - [00:57](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=57s) The physical properties of Hagoromo include extreme density, clean erasability, and smooth glide that requires minimal pressure compared to cheap alternatives. - [01:12](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=72s) Instructors note that the superior tactile quality of Hagoromo translates into tangible confidence and energy during blackboard lectures. - [01:23](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=83s) The announcement that Hagoromo's factory was closing sparked what academics termed a 'chalk apocalypse.' - [01:38](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=98s) Academics calculated personal daily burn rates to secure stockpiles meant to last through the remainder of their teaching careers. - [01:58](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=118s) Informal distribution networks formed in academic departments, with professors discreetly supplying cartons out of office cupboards to dependent colleagues. - [02:34](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=154s) A South Korean company rescued the product by purchasing the original factory machinery and proprietary recipes. - [02:46](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=166s) Mathematicians who hoarded lifetime reserves felt mixed emotions upon learning production would continue, recognizing their panic buying was largely unnecessary. - [03:02](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=182s) The chalk obsession highlights that mathematics lectures involve high-level physical craftsmanship and artistry, requiring reliable tools. - [03:24](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=204s) Mathematicians ultimately concluded that the true value of Hagoromo lies in actually using it on the board rather than hoarding it away.

## Detailed walkthrough ### [00:00](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=0s) The Rolls-Royce of Chalk and the Legend of Angel Tears

Within the mathematics community, Japanese Hagoromo chalk achieved an almost mythical reputation. Long considered one of the best-kept secrets among researchers, it developed a devoted cult following across the world’s leading universities. Professors and scholars spoke of its properties in hushed, reverent tones, circulating fanciful folklore about its qualities. As one mathematician remarked, “The legend around this chalk is that it's impossible to write a false theorem.” Another jokingly speculated about its recipe: “I assume the special ingredient was angel tears.” For those who tried it, the impact was immediate and irreversible; it was universally deemed “the Rolls Royce of chalk,” turning skeptics into instant converts.

The chalk was originally manufactured in Japan and was notoriously difficult to acquire abroad. Foreign academics generally had to rely on traveling colleagues or visitors from Japan to bring cartons back in their luggage. One professor recalled traveling to the University of Tokyo, where a local colleague boasted that Japan possessed far superior chalk to anything available in the United States. Dismissive at first, the visitor replied, “chalk is chalk,” only to test it out and discover that the claim was entirely true. The physical distinction comes down to performance: Hagoromo is remarkably dense, erases cleanly without smearing, and creates exceptionally crisp, vivid lines. Unlike cheaper, lower-grade chalk that forces instructors to exert heavy physical pressure just to make their handwriting legible, Hagoromo glides effortlessly across a good blackboard. As one professor explained, “When I'm teaching I get a feeling of energy, confidence, and the chalk absolutely helps.”

- **Reputation**: Regarded as an essential secret weapon across top mathematics departments worldwide. - **Physical properties**: Distinctly dense composition, exceptionally smooth line delivery, easy erasability, and minimal writing effort required. - **Scarcity**: Historically available only in Japan, requiring personal imports and luggage space.

```mermaid flowchart TD accTitle: The Hagoromo Chalk Phenomenon accDescr: Flowchart illustrating the discovery, hoarding crisis, and eventual continuation of Hagoromo chalk. subgraph CultStatus["Cult Status"] A["Japanese Hagoromo chalk"] --> B["Word spreads at top universities"] B --> C["Prized for clean lines & effortless glide"] end subgraph Crisis["Supply Shock"] C --> D["Company announces closure ('Chalk Apocalypse')"] D --> E["Mathematicians hoard multi-year stockpiles"] E --> F["Office 'chalk dealing' among colleagues"] end subgraph Resolution["Continuation"] F --> G["Korean company buys original machinery & formula"] G --> H["Craft tradition continues on the blackboard"] end ```

---

[01:23](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=83s) The "Chalk Apocalypse" and Secret Department Deals

Around four years before, panic swept the mathematical community when word broke that the Japanese manufacturer of Hagoromo was shuttering its operations and going out of business. The impending extinction of their beloved tool triggered what one academic dubbed a full-blown crisis: “I sort of jokingly referred to it as a chalk apocalypse.” Realizing that the supply would permanently dry up, faculty members immediately rushed to buy every box they could find. While some faculty conservatively secured two or three boxes to stash in their university desks and rationed it out with extreme caution, others treated the event as a career-defining logistical problem and placed massive bulk orders.

Hoarding became widespread across academic corridors, with mathematicians calculating the exact burn rate of sticks required to sustain their teaching and research until retirement. One collector tallied up a reserve of roughly 1,500 sticks, concluding that at a burn rate of four sticks a day, “I think I'm gonna make it.” Others secured ten- to fifteen-year supplies. This panic buying gave rise to an informal underground economy within academic departments. One hoarder admitted: “I didn't wanna become a chalk dealer, but I did like the idea that I could be the first stick is free chalk dealer on the block in my department.” Secretive transactions became routine, with the hoarder pulling boxes out of an office cupboard to supply a regular roster of eight to ten colleagues who were desperate for their supply: “Yeah, we all had a chalk fix. And we still do.”

- **Stockpile metrics**: Calculations ranged from stockpiles of 1,500 sticks down to multi-box emergency reserves meant to last 10 to 15 years. - **Campus chalk dealing**: Regular distribution networks emerged in faculty hallways, with colleagues quietly buying and trading boxes out of office cupboards.

---

[02:34](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=154s) Korean Rebirth and the Craft of Mathematics

Although supplies of the original Japanese-manufactured Hagoromo are steadily dwindling, the chalk was spared outright extinction. A Korean company stepped in to purchase the original machinery and proprietary formulas, successfully recreating the exact manufacturing process in South Korea. For the mathematicians who had spent significant sums of money stockpiling lifetime reserves during the panic, the news prompted a bittersweet reaction. As one hoarder admitted, “I was happy to know that it would still be made. But I was a little disappointed that I was less clever than I thought I was.”

The obsession with Hagoromo ultimately reflects the deeper culture of mathematics itself. While math is an abstract discipline, delivering an intricate proof or lecture live on a blackboard involves physical artistry and rigor. As one scholar reflected: “In many ways mathematics is like craftsmanship, in some ways it's like artistry; in some ways it's like science. But there's a real high craft side to getting a beautiful lecture on a blackboard.” Mathematicians respect that craft in one another and insist on using tools that honor it. Yet hoarding the sticks defeats the purpose of why they were made in the first place, leading to the concluding insight: “There's incredible value to this but the value is in using it up, not hoarding it.”

## Notable quotes > [02:34](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=154s) In many ways mathematics is like craftsmanship, in some ways it's like artistry; in some ways it's like science. But there's a real high craft side to getting a beautiful lecture on a blackboard.

## Mentioned Hagoromo, University of Tokyo, Japan, South Korea, United States

## Video description Once upon a time, not long ago, the math world fell in love ... with a chalk. But not just any chalk! This was Hagoromo: a Japanese brand so smooth, so perfect that some wondered if it was made from the tears of angels. Pencils down, please, as we tell the tale of a writing implement so irreplaceable, professors stockpiled it.

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[Source](https://www.youtube.com/watch?v=PhNUjg9X4g8)

中文简报

韩国企业复活羽衣粉笔前数学家曾疯狂囤货一家工厂停产后，学者们囤积了可用数十年的羽衣粉笔，随后一家韩国公司完成收购并恢复生产，提醒学者们这一工具的真正价值在于将其用尽。日本羽衣（Hagoromo）粉笔凭借细腻致密的质地、易擦无痕的特性以及在黑板上流畅顺滑的书写感，在顶尖数学家中赢得了近乎狂热的崇高地位。当最初的日本工厂宣布关闭时，一场恐慌性的“粉笔末日”随即爆发，教授们囤积了大量可用数年的库存，并在大学办公室壁橱里秘密分发粉笔盒。最终，一家韩国公司收购了原始配方和机械设备，使这一工具免于消亡。这也体现出黑板数学依旧是一门实体技艺，卓越的工具能够激发信心与学术艺术感。日本羽衣粉笔在全球数学家中享有传奇地位，被誉为“粉笔界的劳斯莱斯”，因其质地致密、书写极其流畅且线条清晰而备受推崇。 (0:00) 当最初的日本制造商宣布停业时，数学家们陷入恐慌并大量囤积——有些人购入了多达1500支或可供使用15年的存货。 (1:23) 供应冲击在大学院系内部催生了一个非正式的黑市，囤积粉笔的教授们成了同事眼中的非官方粉笔贩子。 (1:53) 一家韩国公司收购了原始机械设备和专利配方并恢复生产，使该粉笔免遭停产绝迹的命运。 (2:34)

Detailed notes — zh

## Background 该视频由 YouTube 频道 Great Big Story 于 2019 年 5 月 2 日发布。视频简介讲述了全球数学界对日本顶级粉笔品牌羽衣（Hagoromo）的狂热痴迷——这种粉笔因极致顺滑而被戏称为“天使的眼泪制成”，甚至在其面临停产时引发了教授们疯狂囤货的故事。 ## TL;DR 视频讲述了被誉为“粉笔界劳斯莱斯”的日本羽衣（Hagoromo）粉笔在顶尖数学家圈子中引发的传奇狂热。由于其密度极高、书写流畅省力且擦除干净，它成为了学者们黑板推演不可或缺的利器。当日本原厂宣布停产关闭时，学界爆发了被称为“粉笔浩劫”的囤货狂潮，教授们纷纷精确计算教学生涯消耗量大批量抢购，甚至在系内形成了半开玩笑的秘密分销网络。最终一家韩国公司收购了配方与设备让其重获新生，而这场风波也折射出数学家对黑板板书这一精湛工匠精神与教学艺术的极致追求。 ## Atmosphere & style 全片基调幽默诙谐、温情而充满知性色彩，将看似枯燥的数学家群体描绘得生动可爱。严谨冷静的学者们在镜头前带着孩童般的热忱与自嘲，讲述自己像“粉笔贩子”般囤货和交易的趣事，形成了一种奇妙的反差萌。观众在观看时既能感受到学界对极简书写工具近乎宗教般的执念，也能体会到黑板演算背后那种纯粹、严谨而浪漫的工匠精神。 ## Bulletin - [00:00](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=0s) 日本羽衣文具（Hagoromo）生产的粉笔因其极致顺滑、字迹清晰且易于擦除的特性，被全球顶尖数学家赞誉为“粉笔界的劳斯莱斯”，甚至戏传其配方加入了“天使的眼泪”。 - [01:23](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=83s) 四年前羽衣文具宣布停产在日本本土引发全球学术界的“粉笔浩劫”，多位数学教授恐慌抢购，甚至有人按每日 4 支的消耗量囤积了 1,500 支以支撑整个职业生涯。 - [02:34](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=154s) 一家韩国企业随后收购了羽衣粉笔的专利配方与生产设备并在韩国成功复产，令早前大举囤积的学者们心情复杂。 - [02:34](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=154s) 数学家视黑板演算为科学、艺术与手艺的结合，尽管羽衣粉笔极其珍贵，学者们强调其真正价值在于推导过程中被使用消耗，而非长期囤积。 ## Key takeaways - [00:00](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=0s) 日本羽衣（Hagoromo）粉笔在数学界享有崇高声誉，被公认为“粉笔界的劳斯莱斯”。 - [00:00](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=0s) 学者们流传着“不可能用羽衣粉笔写出错误定理”的传说，戏称其丝滑质感源自“天使的眼泪”。 - [00:00](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=0s) 与普通粉笔相比，羽衣粉笔密度极高、擦除干净且几乎不留残影，书写毫不费力即可呈现清晰饱满的线条。 - [00:00](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=0s) 早期羽衣粉笔流通渠道极为有限，海外数学家通常需借赴日学术访问或同行人肉代购才能获得。 - [01:23](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=83s) 约四年前日本原厂宣布停产关闭，直接引发了席卷各大数学系的“粉笔浩劫”（Chalk Apocalypse）。 - [01:23](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=83s) 由于担心未来教学无粉笔可用，多所顶尖学府的数学家展开了精确计算消耗速率的疯狂囤积潮。 - [01:23](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=83s) 有教授囤积了多达 1,500 支粉笔以覆盖直至退休的教学需求，部分学者家中的存量足以支撑 10 至 15 年。 - [01:23](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=83s) 大学数学系内部自发形成了非正式的分销网络，部分学者在办公室充当“粉笔贩子”，向走廊同仁秘密提供配额。 - [02:34](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=154s) 一家韩国企业收购了羽衣粉笔的核心配方与机器设备，成功在韩国复产并还原其原始品质。 - [02:34](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=154s) 得知粉笔重获新生后，此前大量囤货的数学家既感到庆幸，又对当初过度恐慌的囤积行为感到一丝自嘲与失落。 - [02:34](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=154s) 在黑板上呈现逻辑严谨、推演工整的板书，被数学界视为极具工匠精神（craftsmanship）的艺术表达。 - [02:34](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=154s) 数学家最终达成共识：粉笔的终极价值在于板书推演中化作粉末并启发思维，而非深藏在柜子中作为收藏品。 ## Detailed walkthrough ### [00:00](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=0s) 数学界的“劳斯莱斯”：羽衣粉笔的神话与魔力在顶级数学家的圈子里，流传着一种近乎神圣的教学工具——日本羽衣文具（Hagoromo）生产的粉笔。数学界甚至为此诞生了一条半开玩笑的传说：“关于这种粉笔的传说之一，就是你绝不可能用它写出错误的定理。”有学者甚至调侃道，羽衣粉笔之所以如此顺滑神妙，恐怕配方里添加了“天使的眼泪”。长期以来，这款粉笔成了全球顶尖高校数学家之间心照不宣的秘密武器与小众狂热信仰，一旦有人偶然上手试用，就会立刻彻底沦陷，成为它的忠实拥趸。正如多位学者赞誉的那样：“它是粉笔界的劳斯莱斯。” 羽衣粉笔的笔触在黑板上划过时的行云流水，是一种难以用言语确切描述的愉悦感。然而在早期，这种粉笔极难获取，学者们通常只能通过前往日本出差、或是拜托日本同行人肉代购才能带回几盒。一位教授回忆起自己与羽衣粉笔的初遇：当时他前往东京大学访问，当地的一位日本教授自豪地对他说，日本的粉笔比美国的好用得多。起初这位教授不以为然，心想“粉笔还不就是粉笔”，但当他亲自拿起羽衣粉笔在黑板上书写的一瞬间，立刻被其惊艳的表现彻底折服。学者们一致认为，羽衣粉笔质地最为紧密厚实，擦除时极其干净利落不留残影，落笔时又能勾勒出最清晰优美的线条。使用劣质粉笔时，讲者必须使出全身力气使劲按压，台下的听众才能看清字迹；而在优质黑板上使用羽衣粉笔，书写几乎毫不费力。这种顺畅的触感为讲台上的数学家注入了源源不断的活力与自信，使板书与推演变成一种纯粹的享受。 - **行业声誉**：羽衣粉笔被数学界普遍誉为“粉笔界的劳斯莱斯”（Rolls Royce of chalk），成为顶尖学府数学家极高频使用的标配。 - **书写特性**：密度极高、书写阻力极小、字迹线条饱满鲜明、擦拭干净且极少扬尘。 - **早期流通门槛**：主要产自日本本土，美国及海外学者多依靠学术交流互访或托人海外代购才能获得。 ### [01:23](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=83s) “粉笔浩劫”下的全球囤货潮与地下交易随着羽衣粉笔的口碑在数学圈内逐渐扩散，它在一部分学者之间演变成了一种不可阻挡的潮流。然而大约在四年前，一个犹如晴天霹雳的消息在学界炸开：生产羽衣粉笔的日本母公司即将停产关闭。这一突发事件被数学家们戏谑而又心痛地称为“粉笔浩劫”（Chalk Apocalypse）。恐慌迅速席卷了各大数学系，学者们为了保住自己未来的学术教学生涯，立即掀起了一场疯狂的抢购与囤货狂潮。正如一位数学家所描述的那样：“我开玩笑地把它称作‘粉笔浩劫’，所以我立刻开始尽可能多地囤积它。” ```mermaid flowchart LR accTitle: 羽衣粉笔浩劫与囤货链条 accDescr: 展示羽衣粉笔停产消息传出后数学家囤货与系内分销的流程 subgraph Origin["停产危机"] A["日本原厂宣布停产"] --> B["引发学界‘粉笔浩劫’恐慌"] end subgraph Hoarding["恐慌囤积"] B --> C["教授精确计算职业生涯消耗量"] C --> D["大批量购入数百乃至数千支"] end subgraph Distribution["院系内部流通"] D --> E["办公室成为地下交易据点"] E --> F["向同事限量分销粉笔维持日常教学"] end ``` 在这场囤积狂潮中，每位数学家都展现出了惊人的算计与狂热。有的教授谨慎下单了三盒，藏在办公室里精打细算、极其节俭地省着用；还有的数学家则一次性买下了堆积如山的库存，直接储备了足以支撑其整个职业生涯的用量。一位数学家透露自己足足囤了大约 1,500 支粉笔，他按照每天消耗四支粉笔的速率精确计算，胸有成竹地表示这些库存完全能支撑自己安然退休；另一位学者家中至今仍藏有足够使用 10 年的存量。更有趣的是，有些教授甚至在系里扮演起了半开玩笑性质的“粉笔贩子”角色。一位教授坦言，自己虽然不想真正成为非法商贩，但他十分享受那种在系里提供“第一支免费试用”的神秘毒贩式体验。他定期向办公室走廊里的八到十位同事暗中供货，每当同事需要时，他便神神秘秘地打开办公室的储物柜掏出一盒完成“交易”，大家彼此心照不宣地维持着对羽衣粉笔的深刻依赖。 - **囤货规模**：部分学者囤积了 1,500 支粉笔（按每日 4 支的教学高强度计算），许多人储备了 10 至 15 年的教学用量。 - **系内“黑市”**：大学数学系内部自发形成了调剂分销网络，个别教授自嘲像街头贩子一样，在办公室柜子里存货并向 8 到 10 位同事分销。 ### [02:34](https://www.youtube.com/watch?v=PhNUjg9X4g8&t=154s) 配方转让、重获新生与黑板上的工匠精神原厂日本羽衣粉笔的库存虽然仍在不可逆转地日渐减少，但这门手艺并没有彻底消失。几年之前，一家韩国公司全盘收购了羽衣粉笔的专利配方与生产设备，并竭尽所能地在韩国忠实还原了其原始品质与书写触感。面对羽衣粉笔在韩国的复产，当年大举囤货的数学家们的心情却十分复杂而微妙。一方面，大家为这种顶级书写工具得以薪火相传而感到庆幸；但另一方面，许多人又为自己当初自作聪明的囤积行为感到一丝滑稽。一位曾大量囤货的教授笑着坦白道：“那种心情很复杂。得知它还会继续生产我固然很高兴，但我也感到有一点失落，因为我发现自己并没有自己想象的那么聪明。” 在这场关于粉笔的传奇背后，折射出的是数学家对板书这一传统教学形式的极致敬畏。对于数学研究者而言，数学在许多层面既是一门严谨的科学，也是一种充满灵感的艺术，但更是一门讲究精雕细琢的手艺。在黑板上呈现出一堂结构严谨、推导工整、视觉优美的板书讲座，本身就代表着极高的工匠造诣与职业素养。数学家们由衷地欣赏同仁展示出的这种黑板技艺，也自然渴望拥有世上最好的工具去实现它。然而正如一位教授在反思中所总结的那样，无论粉笔多么珍贵稀缺，它的真正宿命终究是在黑板上化为粉末，正如他所强调的：“这东西确实有着难以置信的价值，但它的价值在于把它用完，而不是把它囤积起来。” - **品牌传承**：韩国公司买下羽衣（Hagoromo）的核心配方与机器，在韩国实现了对原版品质的高度忠实再造。 - **数学美学核心**：黑板演算被视为科学、艺术与精湛手艺（craftsmanship）的三位一体，顶级工具服务于完美的逻辑与板书展示。 - **价值归宿**：粉笔的真正价值在于在黑板上被书写消耗、启迪思维，而非锁在柜子里作为藏品。 ## Mentioned 羽衣粉笔（Hagoromo）, 羽衣文具, 东京大学, 劳斯莱斯（Rolls-Royce）, Great Big Story ## Video description Once upon a time, not long ago, the math world fell in love ... with a chalk. But not just any chalk! This was Hagoromo: a Japanese brand so smooth, so perfect that some wondered if it was made from the tears of angels. Pencils down, please, as we tell the tale of a writing implement so irreplaceable, professors stockpiled it. Got a story idea for us? Shoot us an email at pitch [at] GreatBigStory [dot] com 📧 Get exclusive GBS items from our online store 🛒 👉 https://shop.greatbigstory.com/ SUBSCRIBE: https://www.youtube.com/channel/UCajXeitgFL-rb5-gXI-aG8Q?sub_confirmation=1 NOTIFICATIONS: Make sure you enable the 🔔 to get notified about our latest video publishes. Follow us on Instagram: https://www.instagram.com/greatbigstory Check us out on TikTok: https://www.tiktok.com/@greatbigstory Follow us on Facebook: https://www.facebook.com/greatbigstory Give us a shout on Twitter: https://twitter.com/greatbigstory Sign up to our newsletter: https://greatbigstory.com/signup/ #Chalk #Teacher #Mathmatics #GreatBigStory [Source](https://www.youtube.com/watch?v=PhNUjg9X4g8)

Source quotes

[2:34] In many ways mathematics is like craftsmanship, in some ways it's like artistry; in some ways it's like science. But there's a real high craft side to getting a beautiful lecture on a blackboard.

Original transcript

[0:00] (upbeat music) [0:01] - The legend around this chalk is that it's impossible [0:04] to write a false theorem. [0:06] - I assume the special ingredient was angel tears. [0:09] - Mathematicians from all of the top schools very [0:12] frequently use it. [0:13] - It's a cult favorite. [0:16] - As soon as I use it I was a convert. [0:18] - The chalk is one of the best kept secrets in [0:22] the math world. [0:23] - It's the Rolls Royce of chalk. [0:25] (gentle music) [0:29] (chalk scratching) [0:31] - Hagoromo is a brand of Japanese chalk. [0:34] The way it flows on a board is a bit hard to describe [0:37] in words. [0:38] - It's really hard to get. [0:39] You can only get it from Japan, you need a Japanese [0:41] person to bring it back for you. [0:43] - I discovered it when I went to visit the [0:45] University of Tokyo and one of the professors there [0:48] said to me, you know, we have better chalk [0:50] than you do in the States and I said, oh go on, [0:53] chalk is chalk. [0:54] And so I tried it out, and I was surprised to find [0:57] that he was right. [0:58] - I tried it, and I thought it was phenomenal. [1:02] It's the densest, it erases the cleanest, [1:04] it leaves the nicest line. [1:06] - If you use bad chalk often you have to press [1:08] really hard for anyone to see what you're writing [1:10] so using Hagoromo on a good board, it doesn't really [1:12] feel like you're working hard to write. [1:14] - When I'm teaching I get a feeling of energy, [1:17] confidence, and the chalk absolutely helps. [1:20] (chalk clacking) [1:23] - Slowly the math world has become aware of this, [1:26] and it became a bit of a fad in some circles. [1:30] (upbeat music) [1:33] - It was like maybe four years ago the word came out [1:36] that the company was going out of business. [1:38] I sort of jokingly referred to it as a chalk apocalypse. [1:40] So I immediately started hoarding up as much as I could. [1:43] - I ordered three boxes of Hagoromo and kept it in [1:46] my office and used it very sparingly. [1:49] - I should've bought more but I have friends that bought [1:51] boxes and boxes and boxes of the stuff. [1:53] They might very well be set for the rest of their career. [1:56] - We've got like 1,500 sticks. [1:59] That's a lot of days, four sticks a day. [2:01] I think I'm gonna make it. [2:02] - I have probably a 10-year supply still at home. [2:05] - I calculated how many boxes would I need to last for [2:07] 10 or 15 years. [2:09] I didn't wanna become a chalk dealer, but I did like the [2:12] idea that I could be the first stick is free [2:15] chalk dealer on the block in my department. [2:17] - I was probably selling it regularly to maybe [2:20] eight to 10 colleagues. [2:21] I would reach into my cupboard in my office [2:23] and pull out another box and we'd do the deal [2:26] in my office. [2:27] Yeah, we all had a chalk fix. [2:28] And we still do. [2:30] (gentle music) [2:34] - The original Hagoromo chalk is slowly disappearing. [2:38] A few years ago, a Korean company bought their formulas [2:42] and did the best job of faithfully reproducing it [2:44] in Korea. [2:46] - It was mixed emotions. [2:48] I was happy to know that it would still be made. [2:50] But I was a little disappointed that I was less clever [2:53] than I thought I was. [2:54] (gentle music) [2:56] - In many ways mathematics is like craftsmanship, [2:59] in some ways it's like artistry; [3:01] in some ways it's like science. [3:03] But there's a real high craft side to getting [3:05] a beautiful lecture on a blackboard. [3:07] Mathematicians admire this in each other [3:10] and like to use the best tools for it. [3:14] - There's incredible value to this but the value [3:16] is in using it up, not hoarding it. [3:19] (gentle music)