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生命的尽头 - 少年人的天堂, 中年人的战场, 老年人的坟墓 

The above Chinese subtitle which contains a lot of truth is a well known saying about life in the United States. Yet the will to survive is a basic instinct of human beings. As one approaches the end stage of life, one cannot help but face this somewhat depressing thought. In the past several years, quite a few of my lifelong friends passed away, some unexpectedly too soon, others more or less expected. Just before we departed for our annual trip to China/Tsinghua, another friend died after a long illness at age of 84 (the doctors privately gave him six months, but he lasted one month). He had a family, wife, five children, many grand children and lived a full life. Everyone was still talking about him returning home from hospital. Plans were underway about remodeling his home so that he can live out his remaining time comfortably with assistance in his own home. But I guess he just used up his life reserve and stopped breathing in his sleep alone in the hospital late at night without anyone at his side. In a way, one can say this is a good death and that it is a form of release for his family and children who spend months at his bedside rallying for his recovery. But nevertheless it is sad nor what was expected even by himself.

I held my Mother’s hand while she drew her last breath 16 years ago. But even in the end she wanted to live on to see her great grand children grow up. Other friends who were not religious converted to Catholicism in their last days. Most of us do not wish to face the last moments alone. God and religion are sources of comfort. I know I said that I shall die a very happy man (http://www.sciencenet.cn/m/user_content.aspx?id=279300) . But do I really know how I would feel when that moment comes. Selfishly, you hope it would come suddenly without much pain and suffering. But do you really want to know the exact date of your death sentence? How many of us really look forward to our own demise.

Nowadays every morning I look to my incoming e-mails and for any comments about my blog articles. Those feedbacks make me feel connected. I still have several titles of blog articles I wanted to write, talks I can and wanted to present, and occasionally even entertain the thought of getting some results worth writing another technical paper. But as the saying goes “sometimes the spirit is willing but the flesh is weak 心有余而力不足”. At night after dinner my wife and I would sit, talk, and reminisce about my lives together. We are both still healthy and can plan forthcoming trips and visits. Such are the stuffs that keep us going. But looking at our garden and the Spring flowers on a bright morning we know that such seasons are dwindling down to a precious few. We are grateful, happy, and content but can’t help to want more time to enjoy life.

The Chinese characterize life as 生,老,病,死. The Greeks say “You are born, you get sick and you die” Such is life. I envy those truly religious persons who seem to be totally at peace with the end of life – Buddhists attain nirvana, Christians are going to a better place. What do philosophers think?

So long we are on this depressing subject, I jotted down some of my own observations.

Some down sides of growing old

1.    `You can no longer rent cars in Ireland and several other countries after the age of 70

2.    Many public surveys lump everyone over 65 into one category not distinguishing that many over-65ers are still active and working

3.    Major organ donations are no longer accepted from anyone over 60 for transplant. However, cornea donation and donation for research purposes are still OK.

4.    Of course, you can no longer do many of the physical things you used to do with ease when younger

5.    You circle of interest shrinks. Novels of 金庸 no longer have the same hold on my attention.

6.    It takes longer to keep up scholastically even when your research efforts shrink.

7.    The 13 hour one way trip from New York City to Beijing and back as well as the resultant jet lags at both ends become the worst parts of my annual trip to Tsinghua and China.

8.    Your short term memory is no longer so good (what is often called the “senior moment”). I walk into a room to tell my wife something but can no longer remember what it is when I got there. Nor can you remember what you had for breakfast yesterday morning. Without your appointment calendar you can no longer function.

9.    You often do not remember what day of the week it is and try to do transact business on weekends or vice versa since everyday is the same to you.

10.     Your golden age does seem to be too short .夕阳无限好, 只是近黄昏.

On the other hand,

1.    Many former “life-and-death” matters no longer seem that important to you anymore.

2.    You can stay up to watch your favorite old movie as late as you want and not have to worry about keeping an early breakfast meeting the next day.

3.    You don’t need many business attires. You can wear the most comfortable clothing all day.

4.    If you still have your health and old friends, you can reminisce all day long and relive the good old days

5.    If you managed your finances right, you never have to worry about outliving your savings.

6.    You have few obligations to anyone except to yourself

7.    You say what you feel and are not worried about offending someone or governments.

8.    You not only do what you please but what you damn well please. You do things not because you have to but because you wanted to.

9.    You still have your life time partner. ( as they sing in the Rogers-Hammerstein musical : “every night my honey lamb and I, sit alone and talk , and watch . . “, “ life is a bowl of cherry”

10.     As your ambition and life style stabilize, “ENVY 红眼病” is no longer part of your emotion and vocabulary

11.     You are still passionate about something whether is seeking new knowledge or writing blogs

On Being 76 (七十六岁了)

As an academic, I did some research on the age of 70s. The first book I consulted is the poor Richard’s almanac which is an old book with many wise sayings of Benjamin Franklin. In it, 20 is defined as the age of ambition, 30 of will, 40 knowledge, 50 experience, then it is strangely silent on 60 or 70. Confucius, however, said at 60 everything you hear is mellow to your ears ( 六十耳顺) in the sense that you have made peace with the world and nothing can really bother you anymore. But nothing was available for the 70s (七十古稀) (Note added 6/26/10 several readers have corrected me below by poiting out that Confucius did say something about 70s. I thank them for the correction). I guess in olden times, it is an accomplishment to just have lived this long . Life spans were different in those days. But two thousand years later, Frank Sinatra sang the modern version in his signature song in which he says : “regrets I have a few, but they are too few to mention”. These sentiments I certainly share.

Personally, I find 70s are the times you are old enough to treasure the moments your children and grandchildren spend with you but not yet so old as to demand them. 76 is when you are old enough to enjoy reminiscing but not so old as to become repetitive. 76 is when you are old enough to find that your body parts need more frequent repairs but not so old as to require replacement.

In academia and research you live for those moments of intellectual ecstasy when you discover a bit of scientific truth and for those grudging admiration from a few of your colleagues. 76 is the age when you appreciate even more those moments not only because those moments come less often but also because you have learned better to tell the difference between what is a passing fancy and what may stand the test of time. Yet you are not so old as to be totally incapable of the latter (Note my most recent technical book was published in the Fall of 2007 and technical paper in June 2009).

76 is the time if you have your personal affairs more or less in order and you still have your health and partner, you can sit back and say like the comedian, Bill Cosby, “man, I did it all”. Or as R. Browning wrote much earlier “the best is yet to be”. It IS your golden age.

But, 76 is also the time when you realize the future is definitely finite and short. The golden years are few and limited which brings to mind the subject of real retirement or “call it a day”. The Boston Celtic great basketball star Bob Couzy said it best when the reporter asked him why did he retire at a relative young athletic age and near the top of his form. He replied that ”yes while I may be able to do most of the things that I did when younger and even fake those I no longer can. But in my heart, I know I am a fraction of seconds slower here and there and I pass up few more risky shot that I used to make. It is far better not to over stay your welcome.” Thus while few of us will have the opportunity, we should try to emulate the great baseball player, Ted Williams, who hit a home run his last time at bat and inspired the novelist John Updike to write that poignant prose about “God does not answer curtain calls” That is going out in style.

But above all 76 is a time to reflect upon your life, I am grateful for four things in my life: The country I live in which I am a citizen by choice. The family I have, from parents, to my lifelong partner, and to my children. The Institution I work for all my life – Harvard who gives you exhilarating intellectual stimulation. And last but not least, the student and colleagues I had. Modesty defines research as standing on the shoulder of giants which is certainly true. But cynics have another way of putting it. They say to steal idea from one person is plagiarism. But to steal from many is called research. In this sense I am indeed fortunate and am not at all ashamed to admit that I had such a brilliant group of former students and colleagues to steal ideas from. I am deeply honored and enormously grateful to all of them, my adopted country, my family, and the institution where I spent all my adult life.

Last year, my former students organized a 75^th birthday celebration for me which took place simultaneously with the annual international conference of my field in Shanghai, China December 14-17 2009. http://www.sciencenet.cn/m/user_content.aspx?id=279300 They say, “living well is the best revenge”. Thus, it was the occasion of my victory lap or the farewell tour, like a retiring athlete or performer.

I conclude by listing my own life (so far) in numbers:

1.    76 years old, 15 in China, 61 abroad and in the US

2.    Married to my wife for 50+ years

3.    Officially retired, but still active, reasonably healthy, happy, and content for 9 years

4.    Earliest memory – 7/7/1937 of the bombing/shelling of Shanghai by Japan – an errand projectile landed near our home.

5.    Publications and Presentation (actual from 1987-2009, estimated or actual 1961-2009)

a.     4 books and 5 chapters in book

b.    199 papers

c.     21(25) invited plenary speeches

d.    211 (330) oral presentations

6.    53 Ph.d supervised (50 at Harvard, 3 at Tsinghua) in 47 years

7.    Over 1,400,000 visitors to my blog since 2007

8.    One job, one wife, and one home since starting out, one set of K-12-college for all my children

9.    Visited 70 of the countries and localities of the Traveler’s Century
Club http://travelerscenturyclub.org/ ; 258 of the 1000 places to visit before you die http://www.1000beforeyoudie.com/ . 49 0f the 50 states.

10.     Countless friends and colleagues all over the world .

11.     41^st anniversary of the publication of the SCI Classic text book Applied Optimal Control by Bryson and Ho (in English, Chinese and Russian)

12. One wonderful ride in life.

(Note added 7/11/2010. The Sunday New York Times today in the "Week in Review" section has a page one article on being over 70 listing many statistical and interesting facts, both uplifting and depressing, about this old age http://www.nytimes.com/2010/07/11/weekinreview/11zernike.html)

生命的尽头 - 少年人的天堂, 中年人的战场, 老年人的坟墓

       题文中的中文副标题是美国的一句关于生命的名言，它包涵着诸多真理。然而，求生是人类的本能。当一个人步入生命的尾声，他不得不面对这个令人沮丧的想法—死亡。在过去几年中，我的终生好友有不少都去世了，有的人走的太快，出乎意料，有的则或多或少在预料之中。就在我们正准备和往年一样前往中国/清华时，另一位朋友永远地离开了，他长期患病，享年84岁（医生们私下告诉他还有6个月的寿命，但他最终只熬过了1个月）。他有家庭，妻子，五个孩子，还有满堂的孙子孙女，过着充实的生活。大家原本还在讨论把他从医院接回家里，而且正计划改造房子，让他可以在家人的帮助下舒适地度过剩下的日子。但是我猜想他只是耗尽了生命的储蓄，在深夜的病房里，在睡梦之中停止了呼吸，身边没有任何人。从某种程度上说，这也算是一个好的离去，甚至是一种解脱，他不再需要家人和孩子整日守在他身边，竭尽全力让他康复。但无论如何，他的离去让人悲痛，甚至连他自己也没有预料到这一天会来得这么快。

      16年前，在我母亲最后一次呼吸的时候，我紧握着她的手。但即便是在那最后一刻，她还是希望能够活下去，看着她的曾孙子女长大成人。还有些朋友在生命的最后几天开始信仰天主教。我们大多数人都不希望独自面对自己生命的最后时刻，上帝和宗教给我们带来些许安慰。我知道我曾经说过，我会非常快乐地离去，(http://www.sciencenet.cn/m/user_content.aspx?id=279300)但是我不知道当那一刻真的到来时，我会怎么样。你总会自私地希望死亡突如其来，就不会有太多的痛苦和挣扎。但是你是否真的想知道你将要离去的确切日期呢？究竟有多少人真正期待着自己的消亡？

       现在我每天早上都查看电子邮件，浏览我博客的评论。这些评论和反馈让我觉得我和很多人都联接在了一起。我还想写几篇博客文章，题目我都想好了，还有一些谈话希望能够放在博客上与大家分享，有时还希望能取得一些科研成果，可以再写一篇技术论文。但是真的常常如谚语所说：“心有余而力不足”啊！

      吃过晚饭后，我总会和妻子坐下聊天，一起回忆我们的生活。我们的身体都还不错，可以计划出去旅行或探亲访友。正是这些才让我们能够继续活下去。但是当我们在明亮的清晨凝视着花园和春天的鲜花，我们知道，春天这个季节对于我们来说是越来越少了。我们心怀感激，快乐满足，但也情不自禁地希望能有更多时间来享受生活。

      中文将生命描述成“生，老，病，死”。希腊人说：“你出生了，你生病了，然后你死了”，这就是生活。我很羡慕那些真正的宗教人士，他们在生命的尽头时显得那么平静，似乎完全泰然处之——佛教徒涅槃，基督徒则将去往那个更美好的地方。哲学家们是怎么想的？

       既然我们在谈论这个令人沮丧的话题，我也不妨写下一些我自己的想法。

变老的一些缺点 

1. 你70岁之后就不能再在爱尔兰和其它一些国家租用汽车。

2. 虽然很多65岁以上的人还在工作且很活跃，但是许多民意调查都将65岁以上的人归为并不出色的一类。

3. 在移植中，人们不再接受60岁以上人的主要器官捐赠。但是捐献眼角膜和用于研究目的的捐赠还是可以接受的。

4. 当然，你在年轻时可以轻轻松松做的很多体力活，现在再也做不了了。

5. 你所感兴趣的东西越来越少。金庸小说现在对我来说不再那么有吸引力了。

6. 即使你的研究工作减少了，可你还是需要更多时间才能赶上科研的进度。

7. 我每年去中国清华大学，从纽约到北京的13小时路程和下飞机后的时差都让我难受。

8. 你的短时记忆力已大不如前（这往往被称为“年纪大了，一时失忆”）。我本来进屋想跟妻子说点什么事，但张口又想不起来要说什么。我也记不起昨天早餐吃的什么。如果没有记事日历，你就做不了任何事情。

9. 你常常忘记今天是星期几，甚至在周末办理业务，或反之亦然，因为每一天对你来说都没有任何区别，日复一日而已。

10. 夕阳无限好，只是近黄昏。



变老的优点 

1. 许多关于以前觉得是“生死大事”的问题对你来说已经不再那么重要了。

2. 你可以熬夜看你最喜欢的老电影，不必担心会耽误第二天的早餐会议。

3. 你不需要很多的正装，可以整天穿着最舒适的衣服。

4. 如果你的老朋友身体还健康，你们可以整天回忆过去的美好时光。

5. 如果你年轻时理财有道，就永远不必担心退休存款不够。

6. 除了对你自己之外，你对其他人几乎没有什么责任。

7. 你可以畅所欲言，不必担心会得罪他人或得罪政府。

8. 你可以做任何你乐意做的事，没有必须要做的事，只有你想要做的事。

9. 你的老伴还在你身边。（正如罗杰斯-汉默斯坦歌剧里所唱到的：“每天晚上我和我亲爱的坐着聊天，观看…”，“生命是一碗樱桃(英文俗语意思一切快乐丰美)”。
10. 当你的壮志雄心和生活方式都稳定了下来，“嫉妒（红眼病）”将不再出现在你的情绪和字典里。

11. 你仍热衷于某些事情，比如学习新知识或者写博客。

七十六岁了 

       作为一个学者，我对70多岁年龄做过一些研究。我查阅的第一本书是本杰明·富兰克林所著的”可怜的理查德”年鉴，这是一本老书，里面记录了本杰明·富兰克林的很多名言。书中将20岁定义为充满雄心壮志的年龄，30岁则为富有意志的年龄，40岁为满腹经纶的年龄，50岁是经验充足的年龄，可奇怪的是，书中并没有对60岁或70岁做出任何定义或描述。但孔子曾说过 “六十耳顺”，意思是60岁时，你已经与世无争，没有什么事情可以让你心烦。但是，对于70多岁似乎没有什么描述。（七十古稀）（这是我在2010/6/26补充的，因为有几位读者说孔子曾这么说过。对此，我非常感谢）。我猜想，在古代，如果一个人能够活到70岁，这本身就是个成就。人的寿命在那时与现在大不相同。但是两千年后，弗兰克·西纳特拉在演唱他代表作的现代版时唱到：“我有几个遗憾，但是很少，根本不值一提”。对此我非常赞同。

       就我个人而言，我认为在70多岁时，你应该珍惜你和子孙们共度的时光，但还没有老到需要去要求他们陪伴你；76岁时你可以享受回忆，但还没有老到需要不断重复地回忆； 76岁时你会发现身体的某些部位需要更频繁的治疗，但还没有老到需要更换它们。

      在学术和研究界，你陶醉在知识之中，特别是当你发现了一点科学真理，赢得了几位同事的难得的钦佩。76岁时，你应该更加珍惜这些时刻，不但因为这种时刻将会越来越少，也因为你已经清楚地知道什么只是昙花一现，什么能够经得起时间的考验。但你还没有老到无法取得经得起时间考验的成就（我最近的一本研究著作于2007年秋季发表，最近的研究论文在2009年6月出版）。

       在76岁时，如果你的个人事务仍井然有序，你的身体还健康，老伴还在身边，那么你可以悠闲地坐下来，像喜剧演员比尔·考斯比那样说道：“一切我都做到了。”或者像布朗宁曾经写道的“最好的还在后头”。这是你的黄金年龄。

       但是，在76岁时，你也应该意识到你的未来必定是有限且短暂的。黄金岁月已所剩不多，你会想到真正的退休或“收工”。正如波士顿凯尔特人队伟大的篮球明星鲍勃·库西，当记者问他为什么在比较年轻而且还在近事业顶峰的时候退休，他回答道：“不错，虽然我仍然可以做大部分年轻时做的事，甚至还可以假装我能够做那些做不了的事，但我自己心里清楚，很多时候我在球场上会稍慢一点，不会再像以前那样去尝试投一些比较冒险的球。在自己开始不再受欢迎之前离开是最好的。”虽然我们很少人会有这样的机会，但我们应该向伟大的棒球选手泰德·威廉姆斯学习，小说家约翰·厄普代克从泰德的最后一次本垒打中受到了启发，写了一篇有关“上帝从不会谢幕”的深刻散文。

       但最重要的是，在76岁时，你应该反思你的生活，我生命中的四件事情让我无比感激：我所居住的国家是我自己的选择；我的家庭，从我的父母到我的伴侣和我的孩子；我一生工作的机构——哈佛大学，它给了我知识的灵感；最后是我的学生和我的同事。谦虚的定义是站在巨人的肩膀上做研究，这说的很对。但是愤世嫉俗者并不这么认为。他们说，窃取一个人的思想是抄袭，而窃取多个人的思想则是研究。从这个意义上说，我确实很幸运，我毫不羞愧地承认我可以从一群才华横溢窃的学生和同事那里窃取思想，对此我深感荣幸和感激，对我所在的国家，我的家人，以及我一直工作的机构心怀感激。

       去年，我以前的学生为我庆祝了75岁生日，当时正值我所在领域的国际会议于2009年12月14日至17日在中国上海同时举行。http://www.sciencenet.cn/m/user_content.aspx?id=279300 人家说：“好好地生活就是最好的报复”。于是这生日庆祝会成了我的胜利之圈或告别之旅，就像一个退役运动员或表演者。



最后，我列出我生命中（迄今为止）的一些数字：

1. 76岁，15年在中国，61年在国外和美国

2. 和妻子结婚50多年

3. 正式退休9年，但仍然积极，健康，快乐，满足

4. 最早的记忆--- 1937年7月7日上海被日本炮击和轰炸—一枚弹射弹落在我家附近。

5. 出版物和演讲（实际从1987年至2009年，估计或实际从1961年至2009年）

    a. 4 本著作，著作中的5个章节

    b. 199篇论文

    c. 21(25)次应邀请发表大会演讲

    d. 211 (330)次口头演讲

6. 在47年中，指导了53名博士生（50名在哈佛，3名在清华）

7. 2007年以来，我的博客访问量超过1,400,000。

8.从一开始，我一生就只有一份工作，一位妻子，一个家，所有孩子都在同一个学校完成了幼儿园到大学的教育。


9. 去过“旅行者世纪俱乐部”中的70个国家和地区
http://travelerscenturyclub.org/  ； 在你去世前要去的1000处地方中的258处 http://www.1000beforeyoudie.com/ 美国50个州中的49个。

10. 在全世界有数不清的朋友和同事。

11. Bryson和本人合著的SCI经典教材《应用最优控制》（英语，中文和俄文）出版41周年。

12. 一次精彩的生命旅程。

 
（科学网 郑吉曼 译 /  梅进 校）