Did they get you to trade
Your heroes for ghosts?
Hot ashes for trees?
Hot air for a cool breeze?
Cold comfort for change?

斯人已逝，生者如斯。

蔡老师，一转眼一年时间了，似乎直到最近才开始慢慢接受您离我们远去的事实，这一年里多少次驻足在531门口，多少次回忆起和您在办公室畅谈，您让我看到了什么是对科学事业的热爱，什么是纯粹的科学家，什么是真正的为人师表，您的身体力行将指引着我继续前行。

We miss you. We love you.

已经一年了，希望您在那里也好，您身后的世界也好

David was a great spirit, great mind, and a great guy! He inspired us all. We should try to carry his torch as best we can.

蔡老师，您离开我们已经整整一年了，学生很想念你。

今天是你的生日，朦朦想你了。

一晃就过去一年，映像反而越发深刻。想来在自然院已经待了四年，貌似也成长起来了，无论是否是您希望看到的结果。但感谢您让我看到了一个纯粹的科学家的例子。我觉得自己是做不了了，至少现在做不了。其实不难，只是要放弃的太多，不舍得。

I am flattered for the fact we had an opportunity working such a great scientist like you!

愿你在天上快乐。

Xiaxi turns 15 today!

每次遇到困难我就想起你的笑容。

Rest in peace.

Dear David
  Jack informed me that you are gone to HEAVEN. I missed you since I believed in that you could recover from the disease.  Now I am reminding happy good days with you in Los Alamos, Shanghai and Tokyo. 
  At Los Alamos, you were communicating frequently with me about mathematical physics, statistical physics and nonlinear wave phenomena during my stay there. We also exchanged the philosophical thinking on Chinese culture and Japanese one there. 
  At Shanghai, I observed that you were conducting many research projects, teaching many excellent students and inspiring young researchers. Also, you treated me many times in excellent Chinese restaurants. Conversations with you and your excellent young researchers were one of my treasures in my life.
  At the Institute of Statistical Mathematics, Tokyo, you kindly gave an excellent invited talk on ``multi-scale modeling of the primary visual cortex’’ in our meeting on biomedical engineering. Your talk was quite impressed for all of us. Also you kindly encouraged our PhD students during the stay in Tokyo. Reminding is also the cheerful time of visiting Sushi-Bar with me.
  Thank you very much David for everything done for me during in the past. I am sure that you will be living in our minds with the persons who met you and communicate with you here. I pray that you are with GOD in HEAVEN, and your wishes and dreams for your family members, your excellent students and all of your friends will be realized in the near future.

Hidetoshi

今天因为没有收到临时变动追思会地点的通知，所以赶到的时候已经不让进了，所以一直等到最后领导退场的之后才有机会进去献了花。希望能看到今天追思会的视频。

David was an incredibly influential person during my time as an undergraduate and Ph.D. student at RPI. His insights in the fields of computational neuroscience and applied mathematics are beyond impressive and he has left an everlasting mark on the academic world. His advisory guidance through my Ph.D. was more than appreciated and respected. David’s influence extended much further than my academic life, his sincere care about our well-being as students and people was always apparent. I learned just as many life lessons as I did mathematical ones from David. He will be truly missed by all of those who knew him and had the honor of spending time with him.

Rest in Peace.

I didn’t know David or your family but wanted to share some words of encouragement. From your comments I can see he accomplished many things in life. Although death just seems to be a part of life it doesn’t make it any easier to see our loved ones pass away. We can take comfort in knowing that it wasn’t God’s original purpose for people to die. We can look forward to a time when John 5:28, 29 will be fulfilled and there will be a resurrection. Until that time deep sympathy—-Julia

表哥：
我们虽然不常见面，但你的卓越才华我一直以你为傲，你的离去让我久久无法接受......
天堂之上愿你能健健康康、永无疾病。

I had Professor Cai for my Networks and Dynamics class in Shanghai, China. He only taught for around four weeks of the course before the next circulation, but in that time you could tell he had a power and confidence about him. He would wear a chain and a tank top to class, a sight not much seen, but a sight that again let you know his life was one of a straightshooter - a mind deep in his work, relishing in the excitement of it. He always seemed young in spirit yet old in wisdom. He never harbored any animosity, nor do I know of any student that held any against him. Beyond his impressive research and intellectualism, his absolute line of sight is something he's left behind that we can all be inspired by in his name. And although I only knew him from the ever-present eye contact in the class where we talked of chaos and nonlinear dynamics, there was a fire passed on through that.

“申瓯：
得知你离去的消息时，心情万分悲痛，往事件件的从记忆深处浮现。自从你去了美国以后，我们就没有再见过面。
看到人们对你的追思留言，了解到你对科学和教育的热爱和执著，这也使我联想到学生时代的你。记得小时候暑假我们邻居小孩子们一起在党校校园玩耍，而你每次总是先画完画才跟我们玩，你坚持画画，几乎把校园里每个景色都画过了。当时我们只看到你画得逼真，而且不厌其烦地画树枝和建筑。现在看到你在学术界的高深造诣，我才明白你在小小的年纪就学会对事物从不同的角度去观察和理解。
记得开学的时候，因为你刚搬到温州，第一天上学我和姐姐还绕道去你家带你去学校。现在想来，我还曾经给你这位大师当过‘引路人’ 呢。记得小时候经过你家门口时，常常听到你父亲和你一起讨论《参考消息》上的内容，小小年纪已经开始关心起国际大事，而当时我们这些同龄人还沉浸在小人书，连环画的世界里。
虽然在学校各方面你都是第一，但是你在我们小伙伴当中也有个‘倒数第一’的名誉。因为你小时候跑得特别慢，伙伴们分组做游戏竞赛时，你总是最后一个才被大家挑选。后来我们在高中时曾经打过羽毛球，你那时的扣杀力已经让我乖乖地甘拜下风。
在北京上大学时，我们曾经一起讨论各自的专业和今后的发展方向。记得有一次你拿了我的一本书翻阅，马上就里边的内容提出了自己不同的观点，你认为从物理学的观点来看，书本上有些内容不符合自然规律。对于当时习惯于灌输式教育的我，根本就没想到课本上的内容还有疑问，当时我们争论不休。后来你把自己的物理课本拿来给我，上面密密麻麻地写着你的注释和自己的独特见解，还希望我阅后也写上自己的理解和意见。当时我觉得北大的物理书对我来说就像天书，根本看不懂，再说，我的专业跟物理没关，所以就把书原封不动的还给了你。回想起来，当时确实辜负了你的好意，没有利用这个近水楼台先得月的优势，拓宽自己的视野，培养自身的跨学科技能。现在自己作为一个教育工作者，才领悟到其中的意义。你在学生时期就先知先觉，知道从不同的视角去观察社会，以质疑的态度去阅读书本，并把不同的学科融汇贯通在一起，在科学领域驾轻就熟。这些正是我们现代社会知识日新月异，社会不断创新的背景下对人才的技能需求。这也使我更好地理解你为什么对科学研究和培养人才如此敬业，忘记自我。
你对别人的关爱也是人人皆知。记得有一次在大学篮球比赛时我不小心崴了脚，没有去参加我们温州同学的周末聚会。第二天你就来学校看我，还给我带来了一袋水果。我当时大吃一惊，因为那时我们互相串校，就地吃学校食堂，从来不带东西。当时我同宿舍的杭州同学（也知道你的大名）就说了：‘我还以为他就知道读书呢，还挺懂人情杂事的！’
回忆往事是美好的，回到现实是残酷的。到现在我还是难以相信，在社会急需你大显身手，施展才华的时候，你却早早地离开了我们。愿你在天堂一切安好！以后我回国时会去看望你的父母，为你尽一份孝心，让你少一份牵挂。
晓楠

回忆起8年前在蔡老师的指导下完成本科毕业设计的日子，好像还近在眼前。听到噩耗当天，虽然心里也有所准备，却也无法相信是真的，直到得到松挺的亲自确认。记忆里的日子还在脑里播放着，无法释怀。愿蔡老师在另一个地方一切安好。您的学生们一定会继续在科学的道路上为社会和中国多做贡献。

While at Los Alamos, David was first my collaborator, then also my postdoc, and always my inseparable friend, from whom I learnt invaluable scientific and personal traits that are still with me today. He had a remarkable presence of competency, perfection, and warmth in everything from science, to political and philosophical discussions, to food and art, and even to lifting weights, which was a significant part of our weekly routine. I am professionally proud to have been part of David's early career, and I am immensely grateful for his close friendship, which he readily extended to my family and our cat. As our careers eventually took us in different geographic directions it was expected that we would naturally reconnect and reunite one day. The anticipation of that day always gave a bright outlook. The change in this outlook has left a deep void.
David, you will be sorely missed by many, including me.

Has anyone here seen my old friend David?
Can you tell me where he's gone?
You know, he freed a lot of people
but it seems the good die young
I just looked around and he was gone...

I never met with David or talked to him before. In 2015, I submitted many applications to universities around the world for a faculty position.
One of them reached to David's desk. He carefully read it and decided not not give me a chance at his institute but he forwarded my materials to Prof. John Hopcroft, which helps me to open the door of SJTU.
When got the invitation letter from Jiao Tong University, I was really surprised. I can hardly image how many emails he could recive everyday. Even though he is very busy, he still carefully process every email for his university.

I knew he had been illed for quite a long time. But i was really shocked to know this sad news. It is a great loss for China academics.

叔叔，虽然见面次数不多，但可可常常念叨着您——数学家爷爷。您工作太辛苦太累了………愿天堂没有病痛，一路走好！想念您的时候，我们会去南塘的“数学家博物馆”看看您，安息！

蔡教授是我的表舅公。

从小父亲就一直以温州蔡家兄弟的传奇事迹激励我们好学上进，可以说蔡舅公一直是我们家兄弟姐妹心目中的一盏明灯和精神偶像！

前几年，得知舅公作为长江学者和千人计划专家，受聘回交大报效国家，父亲还让我写Email给蔡舅公，本欲趁全家去上海游览世博会期间去拜访舅公，让我们晚辈得以亲炙舅公的教诲；可惜当时行程匆忙，也怕打扰教授繁忙的工作，未能成行。

不意父亲去年不幸病逝，今日又闻舅公噩耗，父亲之愿，终无实现的可能，真真乃人生中巨大的遗憾和伤痛，令人不胜唏嘘悲涕！

这些天，一直无法接受和相信舅公离去的事实！

人生有尽，宇宙无穷，叹苍天为何不能护佑这样一个高贵伟大的灵魂、这样一颗充满睿智博爱的雄心、这样一位充满激情的探索者和慈爱的导师，让他能够实现满腔滚烫的报国雄志？？？天妒英才，雄鹰折翅，痛何如哉，痛何如哉！！！

这些天，拜读舅公在交大开学典礼上的演讲，深为叹服，您的视野和胸怀原来自小就驰骋在自由的时空万维，有包罗万象的格局！我愿意相信，您只是去了另外一个时空，继续探索您所热爱的真理科学！

斯人虽逝，雄业永在；
斯人虽去，求真务实、博爱仁慈之风范长存；
斯人虽远，您的征途，必有后继，永是您爱的星辰大海！

“每当我找不到存在的意义，每当我迷失在黑夜里”，
您永是我们夜空中最亮的星！

请舅公家人及堂上二位老人节哀保重！
愿舅公三位孩子健康茁壮成长！

舅公安息！愿巴赫的音乐永伴您！


   ---  晚辈后学 章显洲 及钱库章家 哀悼

沉痛悼念敬爱的蔡申瓯教授！我作为一名2009级致远学院毕业生家长，与蔡教授见面是在致远学院2013届学生毕业典礼那天。我女儿孟昭仪本科阶段有幸跟学术大师蔡教授做科研，期间得到蔡老师的培养、教育、关心、关照和关爱，刻骨铭心。蔡老师您为人师表，深受家长和学生敬仰、崇拜。蔡老师，您永远活在我们心中。

蔡老师，一路走好。

两个月前发邮件请蔡老师帮忙做为申请的reference, 他很快回复说愿意写。半个月前找他写推荐信时，他说很抱歉，由于身体疾病无法胜任。那时才知道蔡老师已经癌症晚期，以致到了临终关怀期。而两个月前他竟然在如此严重的病痛折磨下依然愿意帮忙。。。天妒英才，让这样一位伟大的老师早早离开了我们！祈祷蔡老师在天堂一切安好。

初见David，是14年之前鄂维南在北大组织的第一期暑期班讲授统计力学的班上，穿着紧身背心，裸露性感肌肉，脖子还有粗粗的金项链，彻底颠覆我对大学教授的认知下限。然而，一旦接触，就知道蔡老师是那么温暖、平和、热心的人，毫无架子。后来蔡老师有段时间又在北大给本科生开常规课程和接触研究生，教授了很多北大应数出来的学生，其中不少后来一直受益蔡老师的指点。我在读博士期间，在北大访问时请教过David非线性动力学的基础知识，蔡老师事无巨细，很有耐心，当时给我了很大的信心。后来，常去Courant, 也常去交大，每次见到David跟他打招呼聊天，都是非常开心。David Cai温暖的人格魅力，耐心育人的品格，渊博而独特的知识视角，令每一个有过接触的人都难以忘怀。
如今一番病魔搏斗之后，斯人已去留余念，秋风飘瑟也致远。
愿David安息，愿家人节哀。

最近几天，蔡申瓯教授被越来越多的人知道，他的天才和纯粹，他的英年早逝，让所有人感到惋惜和缅怀！我很有幸与蔡申鸥同学同窗五年，从城南初中到温州中学高中毕业，他渊博的知识面和天赋一直是我们无可企及的，他一直是我们的偶像，但他又是那样平易近人，没有架子，是我们的小老师。今天，打开这个纪念网站，听到“长亭外，古道边，芳草碧连天....”，我的眼泪止不住往下流，看见他的这么多学生的深情留言，真的很感动，想象得出来，回国报效祖国的这些年，他是多么呕心沥血鞠躬尽瘁！虽然毕业以后我们没有见过几面，记得五年前为我儿子申请美国大学的时候邮件咨询过他，他也是有问比回，而且每次回的邮件都是凌晨时间。最近几年我们同学群里一直在找他，可是我们等来的确是这样一个不幸的消息！震惊！惋惜！愿申瓯同学在天堂里再建一个数学王国！

第一次见到蔡老师是在夏天，他从数学楼二楼下来，穿着一个背心，扛着一辆自行车，看上去非常健壮，他面带微笑，我们一起打了个招呼，后来在一起参加的活动多了，发现，蔡老师非常幽默、睿智，对很多问题都有一些独到的见解，特别是在新生开学典礼上的发言至今印象深刻，他希望同学们要热爱数学、做事要专注。近些年来，数学学院应用数学的发展可以说蔡老师倾注了毕生心血。蔡老师虽然离开了我们，感觉他的音容笑貌一直在眼前出现，仿佛我们还在交流。您的奋斗、奉献精神将永远激励着我们努力工作，蔡老师您一路走好。

状元年少万人英，
致远何堪负重行。
学有所成真教授，
心无旁骛是书生。
悟得天上一时事，
换取凡间亘古名。
下蔡风华终复去，
申江瓯水此悲同。

I LOVED working with David during his years at the Center for Nonlinear Studies at Los Alamos in the 1990s.

Ostensibly, David was the student and I was the mentor. I was indeed 15 years older but most of the time I felt he was 15 years my senior in mathematical dexterity and physical insights! Those years of partnership and productivity -- and friendship -- shine brightly in my memory. It has been a delight to follow his wonderful career since leaving Los Alamos.

David's life has been cut short cruelly but his impact will survive for many years to come in the lives of those he taught and helped. A life too short, but a life so well lived.

Peace to your family David and rest well.   Alan.

落叶时节，闻君乘风而去。不曾想你与撒但已抗争了三年有余，四月份还曾在网上看到过有你的春季授课，现实有时真的无语。
自从高中毕业后，我们再无见过面。你在我脑里留下的永远是那个在九山河畔的青年才俊；甜甜的微笑，能看穿空气似的眼神。
记得大学时曾去信请教，你那沉甸甸的回信里是满满的朋友与兄长之爱。
03年我们曾有一次通话。你大侃从一个数学模型看美国两党的政治走向，也大赞地球另一边的高效发展。最后曾相约有机会见个面吃顿饭。
相信地球是我们的短途之旅。相信你是到另一个世界去了。依你的性格，你可能还是会大步流星往前走。给自己算个小数学题；没必要分秒必争，没必要废寝忘食，更没必要经常熬夜。
哪天追随而去，必先要与你补了那顿饭。希望到时别找不到北。
窗外满眼的红叶，黄叶，绿叶，感觉全是对你的思念。一路走好。

I got to know David at Los Alamos. Besides we were apprentice-fellows under Dr. Alan Bishop at T-11, his formal B.S. adviser at Peking Univ., Prof. Danhua Qin, is also the wife of my Ph.D. adviser, Prof. Zhao-bin Su at CAS. We were friends since.

David taught me many things, and we had lots of fun together. We shared many friends, and I had the chance to meet his parents. As my wife recalled my last Christmas at Los Alamos, we had a party at Dr. Zukun Chen's house. All the other parties at the table are still alive and well, only David parted forever!

The car he sold me was wrecked in a snow storm at Los Alamos, but I am still driving the way David taught me. The music clubs he had me joined were all out of business, but I am still listening to the same classical music he introduced me to. David might paint or draw no more, but the paintings he painted are still hanging somewhere in my house.

Some people live after their death because they are remembered.

We couldn't find a proper way to send our condolences to his grieving parents and family, and hope in this way David could be remembered as we shall always do.

先生之风，山高水长

此生很有幸能够成为蔡老师的学生，知道消息的时候，心里特别不好受，更多的也有颇深的感触。认识蔡老师的时候还是在我大三暑假2009那年，正值蔡老师刚回国开始创立自然科学研究院的时候，当时蔡老师来给了个神经科学方面的报告，虽然听的不是太懂，不过感觉挺有意思。后来联系申请做了蔡老师的博士。在我第一次给报告介绍色散波时，发现自己只给了一些波数、频率、色散关系的数学定义，其背后的物理自己根本没有理解，然后蔡老师补充介绍了它们的物理意义，那时发现原来数学表达式的背后可以这样来理解它们的意义。学术上如此，生活中也是，很多时候，我们获取的信息是类似的，但是蔡老师总是能够给出他自己独到的一些见解和看法。

博士阶段开始做研究了，第一次做出的数值模拟结果，然而自己并不能读懂自己所模拟的结果，而当我把模拟结果给蔡老师看的时候，他通过不断的放大图像，还发现了更深层的水波结构。蔡老师对结果的观察力，对物理的洞察力，对问题的直觉理解，一直是我非常钦佩的。

在博士期间，和蔡老师在深夜有过多次的讨论，也偶尔有过几次激烈的学术争论，也经常听蔡老师讲解一些数学物理和生物知识，讲解的最后，一般都会有句“make sense to you？”至今记得蔡老师说那句话时的语音语调。一般每次学术讨论完后，蔡老师也会给我们讲一些美国的文化，他自己的留学经历，以及一些轶事。

以前听蔡老师讲起，开始以为是玩笑话：柯朗所的学生，一般如果学术做不好，就去华尔街挣钱了。后来发现在我以前的学长Boris还真是去了华尔街。蔡老师也经常和我们分享他早年在做高能物理时的一段经历，当年杨老师告诉蔡老师，学术要做自己喜欢的，如果做的好那当然好，即使没做出什么大成果，那至少那段时间自己也乐在其中，我也很相信这句话。蔡老师也很喜欢和我们开玩笑，快临近毕业的时候，蔡老师常叮嘱我们要锻炼身体，毕业时要体格达标。

还有很多和蔡老师有关的记忆，仿佛就是昨天发生的很多事情，即使您离开了，但是相信，无论您对于生活的态度，还是执着学术的意志，将会永远长存，在黑暗中点亮一盏明灯，指引着我们向追求真理的道路上继续前进。

David gave the warmest encouragement and welcome to me as a young postdoc working in his field at NYU a decade ago or so. His office was a wonderland of advanced ideas and fantastical contraptions for making tea and, in the end, more ideas. All of this will live on in the memories of us in mathematical neuroscience and so far beyond.

生命虽然短暂，已经足够精彩！深切怀念申瓯同学！！！

回想起来，每一次和David的交谈都有收获，可惜无法再听到了。他在美国养病期间，心里牵挂着...为学生的事情打电话跟我讨论，看到感兴趣的学术报告，会让人录了给他看...他是我见过的最敬业的学者。去年David回学校时还见到他，几乎看不出是一个生着重病的人，当时为了他的顽强心里很感动。无意中看到的一句话“When the living could no longer fight, the dead will”, 让我觉得David仍和我们一起奋斗！愿David一路走好！愿天堂一切安好！

蔡老师，还记得北大暑假班时候您的大背心和金链子，还记得在北大南门喝茶的美好时光，您的温文尔雅、勤奋低调是学术圈的一缕清风，一抹阳光，R.I.P.

申瓯, 还是不敢相信你就这麼突然到那边去了。 六月见你时你还那麼精神！尤其是你那乐观的笑容，泰然的神态现在还浮在眼前！很幸运能跟你这样才华横溢，真正的奇才同窗亦友！想当初研一时一起去考托福，然后来美，多年后又有幸在纽约交集几年 。。。这麼多年一起的时光沥沥在目，也让我亲身感受到何是“上知天文，下知地理”。你这个全才还不只限于在学问上：六月份在你家吃馄饨时你据然记得我们几年前吃饭时我不能吃海鲜，特地让晓雁给我单独准备肉馅馄饨！每当想起此事，就感慨万分也深感预哭无泪。真实感到天妒英才，但你是名符其实的潇洒走一回！我尤其会永远记住你那对任何事情的淡定，坦然，镇定及乐观的精神！愿你在天堂那边一路走好！

带着满腹的学问英年早逝，深为痛惜，颇感震惊。高中学习期间，申瓯就是班级和学校的学霸，不论是智商还是情商，也不论是学习能力还是组织能力，用一句俗语：如果他说自已第二，估计没人敢说第一。记得他是10月10日的生日，比我小两天；也记得在高考临考前我拿着厚厚的一叠题目到南站党校来问他，他总是很认真的帮助解释，匆匆间高中毕业也已37年，期间也在温州见过几面，依旧是如此的健谈和充满活力，不想现在已天人相隔。申瓯，你永远是我们的学霸。

第一次见到您是11年春，您来RPI做一个Distinguished Lecture, 一个让我记忆深刻受益匪浅的学术报告，我们也一起度过了愉快的晚餐时光。转眼12年春，我很荣幸的得到您的邀请来交大参加了一个面试，由于各种原因，虽然最后没有成为您手下一员，但是我内心一直心存感激。回国后，一直计划邀请您来我工作的地方访问指导，您也欣然应允，但是您太忙了，未能成行，而今竟成我的终身遗憾。 愿您一路走好！

"愿天堂没有病痛，一路走好。"

蔡教授是位非常真诚认真的学者。和他虽然接触不多，但每次见面交谈都很享受，他太聪明了，脑袋里装满了想法。昨天听到这个消息，不禁泪如雨下，申瓯教授这些年太辛苦了！

蔡教授安息！ 怀念您！

还记得在IAS听他和鄂老师的课，收益至今。 音容笑貌，永远都不会忘记。一路走好。