与师同行 | 以数学为爱好？所授课程被冠为“白学”课？这是怎样一位神仙老师！

*Scroll down for the English version

 在ZJUI有两门课

被同学们戏谑的冠以“白学”头衔

即“学了一晚上，依然全不会，学了也白学”

上这课程的老师也被推上“人气”榜首

即被同学们日复一日念叨的“老白”

以数学为最大爱好的Thomas Honold教授

虽则“白学”课难得大家叫苦连天

可课程结束后，大家又对“老白”爱莫能止

下面就让小编和大家一起领略

Thomas Honold教授的“反差”魅力！

Thomas Honold

毕业于德国慕尼黑工业大学，接受过纯粹的理论数学教育，致力于代数编码理论的研究。他治学严谨，坚守初心，竭力培养学生的系统性思考和全局视野。

治学严谨 vs 允许考试带“小抄”

Thomas教授的板书

作为一名纯粹的数学家，Thomas Honold教授将严密的数理假设与推论证明带进了课堂，课件中充满 “定义—定理—证明” 的无限循环。他认为“证明”是不可或缺的一个过程，它能将各个零散的知识编织成一个完整的体系，是只能通过面对面教授习得，而无法通过啃书本自学得来。只有通过证明，将各种知识联成网络，坚持系统性学习，逐步形成系统性思维，才能在将来真正遇到实际问题时快速做出反应。他指出，朦胧的知识碎片也许足以应付考试，但对知识转化和实际应用并没有太多帮助。因此他坚持在课堂上详尽证明出每一个定理，为同学们揭示定理背后的故事和逻辑，鼓励同学们养成系统性思考的习惯，培养全局视野。这也就是Thomas教授的数学课最难和最令人难以忘怀的地方，只要你跟上证明的逻辑，就能享受逐步解析与构建万物间联系的乐趣，打开一扇新世界的大门！

对于ZJUI这些非数学专业的学生，Honold教授给出的最低学业要求是掌握数学的基础应用技巧，而非课程中的全部细枝末节。为了更好地考察同学们对知识点的掌握，在一学期两次的主观题考试里，同学们被允许携带一张A4大小的手写“小抄”。这上面可以写上所有你认为有用的定义定理与例题。对此，Honold教授表示，这与将来结课之后的实际情况十分类似，你可以参考已有的笔记或文献来解决遇到的问题，但是判断什么有用则非常必要且重要。

“最大爱好是数学”

Honold教授表示，他个人的业余生活非常简单，假期也常常被用来工作。当被问及平时有什么兴趣爱好时，他坦言，“Actually, Mathematics is my hobby”。

但这么热衷于数学的Honold教授最开始进入大学时候学习的却不是数学，而是主修计算机科学辅修物理学。在微积分课程的学习中，他深深地爱上了数学，于是将辅修的物理学换成了数学，并在两年后，完全转向了数学学习。

自十二年前加入浙江大学后，他逐渐由纯粹的理论数学家转向应用，进行工业通信的错误检测代码等方向的研究。这一研究的一大应用领域是存储纠错，可以利用代码来实现查找并纠正光盘中的记录错误。目前，他的主要研究方向为代数编码理论，完美地将数学与计算机结合在了一起。

同时，他对数学的工程应用教授也颇有经验。他在采访中指出，数学与工程学有两点最重要的联系：严谨的证明与近似的模型。只有通过严密逻辑达成的数学证明才是百分之百正确的，他喜欢这种百分百的笃定与确信。而利用数学建模可以忽略微小变量得出复杂问题的一般表达形式，世间万物几乎都能被数学模型概括和解释，他将数学建模称之为一种无与伦比的艺术。这两点相互交织构成了工程的理论框架。

采访过程中，只要聊到数学，冷静的Honold教授眼里都闪烁着热情的光芒。出乎我们意料，却也在情理之中。若非对数学有着异常深厚的情感，谁又能年复一年地与这一门艰深的学问为伍又乐此不疲呢？

中国缘与ZJUI缘

十二年前，Honold教授与妻子来到中国定居，成为浙江大学信电学院副教授。由于他本人不太会说中文，每次与学院行政人员的交流都必须抓上一个研究生才能正常进行。于是4年前ZJUI一成立时，他就提交了申请，获取了这仿佛为他量身定制的岗位。到ZJUI后，就再也不用担心语言的问题了。

12年的中国生活经历和4年ZJUI教学经历，不断加深着Honold教授对中国和对ZJUI的认识。他表示，虽然西湖还是那个西湖，但周围条件却在不断改善，无论是城际铁路交通系统还是杭州城内的地铁系统都经历了跨越式的发展。而ZJUI的发展更是肉眼可见。

在德国参加Alcoma 15国际会议

求学德国，又曾在美国等地开展过教学工作的Honold教授认为，如果仅以大一入学时的知识水平来判断，中国与德国的高中教学相对更好，中国与德国学生的挂科率更低，退学率也同样较低。他表示，虽然在英文课堂上中国学生由于语言等原因仍不够活跃，一开始他们往往写完所有过程却一言不发，但这种情况随着课程的推进与对专有单词的了解会逐渐改善。ZJUI大部分同学都会非常认真地提升英语水平来适应教学的需求，这让他感到十分欣慰。中国学生对于学习的钻研精神，也令他印象深刻。他说在ZJUI最有趣的经历还是跟学生做学术探讨，他表示非常喜欢这样的深入探讨。

不少同学说他的考试太难

不少同学回过头才发现他的好

无论时代如何变迁，

Honold教授始终保持初心

他对数学的热情与执着 

他对系统性学习的推崇与践行

他数十年如一日的坚守与深爱

鼓励和感动了ZJUI师生

他也想对同学们说：

Don’t be discouraged by the many obstacles the Covid-19 pandemy has put in your way. Once you will be back and running in the same, or even a stronger, way than before.”无论何时，回归平常，坚持不懈，现在努力的一点一滴终将成为通往高处的垫脚石！

Swipe up for the English version

Professor Thomas Honold

He takes Math both as profession and hobby, his classes are viewed as demanding (to say the least) by many students.

What an amazing professor!  

Let us have a closer look into this man’s life as we interview Professor Thomas Honold.

In ZJUI there are two undergraduate classes students perceive as particularly difficult. Some  would even jokingly say “we are learning in vain”, realizing that they haven’t made much progress towards understanding the subject after grinding on the notes for a whole night. Thomas Honold, the teacher of these classes, gained fame among students as they banter about the high difficulty of the courses. Interestingly, although students often struggle in Prof. Honold’s classes, they also find themselves lured into and in love with the subject in inexplicable ways.

To unravel the mystery behind these apparently contradicting views on Prof. Honold’s classes, we shall introduce this Math geek to you in more detail.

Introduction

Prof. Thomas Honold studied Mathematics and Computer Science at Technical University of Munich. After obtaining his PhD degree in Mathematics 1994, he worked there for several years as assistant professor and obtained his Habilitation (the qualification for university teaching in Germany) in 2000. Since then he has held various appointments at universities in Germany, Singapore, and since 2007 in China. Focusing in his research on Algebraic Coding Theory and related areas of Mathematics (Combinatorics, Finite Geometry), Prof. Honold is a dedicated and passionate educator who strives to nurture his students as individuals thinking holistically.

Rigorous Teaching vs Allowing Bringing Notes to Exams

Although a considerable part of his work is in applied mathematics, Prof. Honold rates himself as a pure mathematician. He brings the rigor of mathematics into his lectures, as his classes rely  heavily on the fundamental concepts of ‘definition’, ‘theorem’, and ‘proof’. Prof. Honold believes that proving mathematical assertions forms an essential part when learning Mathematics, because only with a rigorous proof at hand we can be sure that we haven’t been fooled by our perceptions and (perhaps unjustified) assumptions about the matter.  To quote an example from his Calculus III lecture: If one side of a rectangular cardbox with prescribed surface area is made infinitely large, does it follow that the volume of the cardbox becomes infinitely small? Proving a mathematical theorem is a process where one puts together all the tiny fact (“bricks”) known about the subject and combines them into an established logical structure (“building”). Prof. Honold sees mastering Mathematics as something that can be taught only in face-to-face lectures with dedicated examples and then by assigning lots of exercises where students can practise and interact with tutors and with each other, but not through reading textbooks having a thousand pages. It is only through this long and often painful process that students will develop the habit to connect the “knowledge dot” and embody the mindset of conceptual learning and eventually develop systematic thinking. Prof. Honold believes that the ultimate goal of teaching is to turn students into masters of the subject. Dispersed “knowledge dots” might be good at acing exams; in real life applications, however, this is a pointless skill. That’s why Prof. Honold insists on precise reasoning at each step, in the hope that students will cultivate a beneficial learning habit. That is also the secret why his classes make learning a magical journey of exploration. If students can successfully follow his reasoning, they will be rewarded by the beauty of mathematics of and the creativity to advance it.

For students not majoring in Mathematics, Prof. Honold has the expectation that they should  at least understand the basic mathematical concepts underlying his courses and be able to apply these concepts successfully to selected exercises/problems. But they are not required to reproduce proofs in an examination. As a noteworthy aside, Prof. Honold usually allows students to bring an A4-sized handwritten cheating sheet to his exams, which are otherwise closed-book. When preparing for the exam, students can write on the sheet whatever they consider as important. Prof. Honold explains that the purpose of these notes is to organize the exam preparation process rather than having the cheating sheet available during the examination.

A life that revolves around numbers

Prof. Honold said his life is mostly occupied by work, even during holidays. When asked about what he would do to kill time, he said “think about mathematical problems or theories, because Mathematics is also my hobby”. One might think someone so in love with Mathematics certainly studied it from the earliest days. But Prof. Honold told us  that he discovered his interest in Mathematics only during his last two years at high school (after an earlier focus on languages like Latin and Greek) and started off in university with a major in Computer Science and a minor in Physics/Astronomy. Then, while learning Calculus, he fell into love with it and changed his minor from Physics to Math, and two years later delved completely into the study of Mathematics.

Motivated by his mentor Prof. W. Heise, an incidence geometer and coding theorist at TU  Munich, Prof. Honold started to work on Algebraic Coding Theory as a master student and later obtained his PhD in 1994 with a thesis on QR codes (at that time referring to so-called quadratic residue codes and not to the ubiquitous quick response codes we now use every day). Algebraic codes are used to detect, and if possible correct on the fly, errors when transmitting messages over noisy communication channels, such as the low-bandwidth channels used for communication with distant space satellites or the more reliable (but still many errors producing) channels involved when recording/playing audio CDs, writing/reading data CDs, or scanning a quick response code with a smartphone. By using algebraic error-correcting codes it is possible to make such transmissions virtually error-free, at the expense of modestly lowering the transmission rate, respectively, in the case of a data CD or quick response code modestly decreasing its storage capacity/number of data pixels.  

Since moving to Zhejiang University twelve years ago, Prof. Honold gradually shifted his focus from theoretical aspects of Coding Theory (weight functions for codes, codes and geometry over so-called finite chain rings) to more applicable areas, for example codes for Random Linear Network Coding. Currently, when time permits, he does research on the so-called  Main Problem of Subspace Coding, an area linking Network Coding to Finite Geometry and where progress relies heavily on number crunching, computer calculations and experiments - the perfect combination of Geometry, Combinatorics, and Computer Science.

Through his work at ZJUI, Prof. Honold is now also experienced in teaching Engineering Mathematics. He commented that Mathematics and Engineering Science share similar  impeccable proofs and conceptions. Prof. Honold enjoys the certainty and reliability of strict mathematical reasoning. According to him, good mathematical models ignore the many irrelevant aspects of a complex problem and focus only on a few key aspects. This often allows for a relatively simple yet representative solution. But finding a good mathematical model is normally not easy and can be considered as a form of art. It also provides the foundation for engineering applications.

During the interview, the “calm” professor’s eyes shine repeatedly when talking about Mathematics, which is quite understandable since nobody could work for a long time in such a tough and for outsiders dry subject without profound passion.

What brings Professor Honold to China and ZJUI

More than 12 twelve years ago, Prof. Honold immigrated with his wife to China, taking the position of Adjunct Professor at the College of Information Science and Electronics Engineering of Zhejiang University. Initially planned only for a few years, the visit to China has turned into a long-term stay and job, sometimes paved with difficulties because of the language problem – Prof. Honold recalls that he had to rely on his master students when doing the paperwork for his courses and other administrative things in Chinese –, but now continued in the fully internationalized  environment of ZJUI.

Twelve years’ life and teaching in China have deepened Prof. Honold’s understanding and personal connections towards China and ZJUI. Regarding the change of  environment he recalls, somewhat nostalgically, that although the West Lake is still the West Lake, the surrounding metropolitan area of Hangzhou has delevoped dramatically over the past 12 years. Among the many new infrastructure projects completed during this time he rates the metro transportation system as particularly useful. Asked about his vision for the next few years, Prof. Honold is confident about the eventual growth of ZJUI and its partner institutes at the International Campus into a world-renowned university.

As someone who has studied in Germany and taught students from several other countries, Prof. Honold feels that in terms of mathematical skills and knowledge, students from China are on a par with those from Germany and other European countries, and often have had  a better  high school math education to build upon than their counterparts in the US. Also he recalls being very surprised when holding his first final examination for students of Zhejiang University that virtually all students showed up for the examination, whereas in Germany they would always discover a certain percentage of “non-active” students on that occasion. 

Prof. Honold observes that although Chinese students are initially quite shy when enrolled in English-based classes, the situation improves greatly over time as students build up their vocabulary and become more comfortable with interacting in English. The efforts Chinese students put in learning English deserves high praise, Prof. Honold says. Another thing that impressed Prof. Honold is the engagement of Chinese students during work and discussion of intellectual topics.  

There are students who found Prof. Honold’s classes too difficult, but many realized his good intentions and how blessed they were to have him as a teacher in retrospective. Prof. Honold stands firm by his beliefs and keeps his academic standards high despite the fundamental changes universities have undergone during the past decaces. His passion and  persistence in Mathematics shapes him into a great mentor, not just in class but in other aspects of university life as well.

ZJUI is proud to witness that lives of students have been changed by Prof. Honold ’s integrity and love, and is grateful to have Prof. Honold in our team.

At the end, Prof. Honold leaves a message for all the students out there: “Don’t be discouraged by the many obstacles the Covid-19 pandemic has put in your way. Once you will be back and running in the same, or even a stronger, way than before.”

文 | 陈圣伟 谢臻   采访 | 谢臻 陈圣伟 林航正 牛逸群

翻译 | 赖树弦 朱欣然

本期编辑 | 张旖   责任编辑 | 张旖

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