1916年4月30日诞生于美国密西根州的Petoskey。在Gaylord小镇长大,当时镇里只有三千居民。父亲是该镇的法官,他们父子的姓名完全相同,都是Claude Elwood Shannon。母亲是镇里的中学校长,姓名是Mabel Wolf Shannon。他生长在一个有良好教育的环境,不过父母给他的科学影响好像还不如祖父的影响大。香农的祖父是一位农场主兼发明家,发明过洗衣机和许多农业机械,这对香农的影响比较直接。此外,香农的家庭与大发明家爱迪生(Thomas Alva Edison,1847-1931)还有远亲关系。
香农的大部分时间是在贝尔实验室和MIT(麻省理工学院)度过的。在“功成名就”后,香农与玛丽(Mary Elizabeth Moore)1949年3月27日结婚,他们是在贝尔实验室相识的,玛丽当时是数据分析员。他们共有四个孩子:三个儿子Robert、James、Andrew Moore和一个女儿Margarita Catherine。后来身边还有两个可爱的孙女。
1938年香农在MIT获得电气工程硕士学位,硕士论文题目是《A Symbolic Analysis of Relay and Switching Circuits》(继电器与开关电路的符号分析)。他已经注意到电话交换电路与布尔代数之间的类似性,即把布尔代数的“真”与“假”和电路系统的“开”与“关”对应起来,并用1和0表示。于是他用布尔代数分析并优化开关电路,这就奠定了数字电路的理论基础。哈佛大学的Howard Gardner教授说,“这可能是本世纪最重要、最著名的一篇硕士论文。”
1940年香农在MIT获得数学博士学位,而他的博士论文却是关于人类遗传学的,题目是《An Algebra for Theoretical Genetics》(理论遗传学的代数学)。这说明香农的科学兴趣十分广泛,后来他在不同的学科方面发表过许多有影响的文章。
在读学位的同时,他还用部分时间跟温尼法·布什(Vannevar Bush)教授进行微分分析器的研究。这种分析器是早期的机械模拟计算机,用于获得常微分方程的数值解。1941年香农发表了《Mathematical theory of the differential analyzer》(微分分析器的数学理论),他写道:“大多数结果通过证明的定理形式给出。最重要的是处理了一些条件,有些条件可以生成一个或多个变量的函数,有些条件可使常微分方程得到解。还给出了一些注意事项,给出求函数的近似值(不能产生精确值)、求调整率的近似值以及自动控制速率的方法。”
香农与John Riordan一起工作,1942年发表了一篇关于串并联网络的双终端数的论文。这篇论文扩展了麦克马洪(Percy A. MacMahon,1854-1929)1892年在Electrician上发表的论文理论。1948年则创立了信息论(information theory)。
在漫长的岁月,他思考过许多问题。除在普林斯顿高等研究院工作过一年外,主要都在MIT和Bell Lab度过。需要说明的是,在二次世界大战时,香农博士也是一位著名的密码破译者(这使人联想到比他大4岁的图灵博士)。他在Bell Lab的破译团队主要是追踪德国飞机和火箭,尤其是在德国火箭对英国进行闪电战时起了很大作用。1949年香农发表了另外一篇重要论文《Communication Theory of Secrecy Systems》(保密系统的通信理论),正是基于这种工作实践,它的意义是使保密通信由艺术变成科学。
1948年香农在Bell System Technical Journal上发表了《A Mathematical Theory of Communication 》。论文由香农和威沃共同署名。前辈威沃(Warren Weaver,1894-1978)当时是洛克菲勒基金会自然科学部的主任,他为文章写了序言。后来,香农仍然从事技术工作,而威沃则研究信息论的哲学问题。
香农在普林斯顿高级研究所(The Institute for Advanced Study at Princeton)期间,开始思考信息论与有效通信系统的问题。从1948年6月到10月,香农在《贝尔系统技术杂志》(Bell System Technical Journal)上连载发表了影像深远的论文《通讯的数学原理》。1949年,香农又在该杂志上发表了另一著名论文《噪声下的通信》。在这两篇论文中,香农解决了过去许多悬而未决的问题:阐明了通信的基本问题,给出了通信系统的模型,提出了信息量的数学表达式,并解决了信道容量、信源统计特性、信源编码、信道编码等一系列基本技术问题。两篇论文成为了信息论的基础性理论著作。那时,他才不过刚刚三十出头。
As the 1952 maze solver was recently at the MIT Museum.
Picture from Life Magazine 28 July 1952. Top trace is showing the first pass of the maze solver learning the maze. The second run showing that it has learnt the maze and the mouse goes direct to the cheese.
Detail of a trace showing to mouse rotations and making contact with the wall.
Picture above from Popular Science March 1952 showing another pair of time-lapse photos showing the learning of the maze in the first run, and the solving of the maze. A modified mouse is also shown. It included a lamp to ensure a trace showed in the time-lapse photography. Full pdf here.
The above maze photograph from Electrical Engineering July 1952. It took two minutes to learn the maze, and between 12-15 seconds to reach the "cheese" once solved.
Problem-Solving Electric Mouse Aids in Improved Telephone Equipment Research
An electric mouse with a man-made super-memory is busily at work these days, repeatedly threading its way through a series of complicated mazes at Bell Telephone Laboratories. The handiwork of Dr. C. E. Shannon, a mathematician associated with the Bell Telephone Laboratories, Inc., the mouse uses for its "brain" some of the same kind of switching relays found in dial telephone systems. The reason it exists is to provide fundamental knowledge which will help improve telephone service. The mouse, in reality a 2-inch bar magnet with three wheels and copper whiskers, can solve quickly more than a million million different mazes, learning each new one rapidly, then instantly forgetting it in order to be ready to learn the next one. Its goal is an electric terminal with a bell which rings when the mouse nudges it with its copper whiskers. The maze is about half the size of a desk top. It has aluminum fences which can be rearranged at will in 40 different slots to create the hardest possible problems for the mouse. The mouse is placed at some arbitrary point in the maze and the goal at a different arbitrary point. After a brief pause to get its bearings, the mouse goes up and down corridors, bumping into walls, backing up and turning, and exploring until, a minute or two later, it reaches its goal and rings the bell. Having learned the correct path to the goal, the mouse now can be set down at any point that it visited during its explorations and, without making a single false move, it will proceed directly to the goal in 12 to 15 seconds. If it is placed in a part of the maze not previously visited, it will explore until it reaches a known part and then move directly to the goal. After this, if the maze is altered, the mouse will have to learn the new paths by further exploration, but it readily will remember those parts of the path which remain unchanged. This is the way the mouse works. When it is set down on the metal floor of the maze, it trips an electric switch which signals its position to a mechanism under the floor. A motor-driven electromagnet moves swiftly to the spot directly beneath the mouse and from then on holds it in a magnetic grasp. The magnet turns through a 90-degree angle, carrying the mouse with it, then guiding it forward. If the mouse hits a barrier and detects, by means of its copper whiskers, that it is in a dead end, the magnet will back away, shift the mouse to another direction, and start it forward to try again to find an open path. It keeps trying until it finds the way to the goal. Then it remembers the successful path and can solve the maze directly without error. To regulate the sequence of movement, a "programming" circuit has been built, consisting of 40 electric relays. Another part of the mouse's "brain," which serves as its memory, contains 50 relays. Two small motors complete the equipment. By working with such problem-solving equipment, it is hoped that more will be learned about what man can do with machines. Many of the techniques by which machines are able to remember are currently being applied in the Bell System in dial switching, in automatic accounting, and in other equipment. The real significance of this mouse and maze, lies in the four unusual operations it is able to perform. It has the ability to solve a problem by trial and error means, remember a solution and apply it when necessary at a later date, add new information to the solution already remembered, and forget one solution and learn a new one when the problem is changed.
The above two sequences are interesting in that the 'learnt' maze is altered (2nd panel before the finish), and the mouse is still capable of re-learning the change and solving the maze.
Shannon with the mouse.
The original mouse was carved from wood hollowed out to take a two-inch magnet bar of aluminium, nickel, and cobalt. It has two beady, button eyes, three small brass wheels for legs, and an pipe cleaner for a tail. Two copper whickers guide it through the maze to the "cheese" which is an electrical terminal that rings a bell when toughed by the whickers.
Bell built several versions of Theseus for demonstrations of the technology. One of them was known as Philbert as used by Southwestern Bell Telephone Company. As late as November 1976 they were still being demonstrated.
Time-Life have about 70 images of Shannon, the mouse, and time-exposures of the maze. They can also be found in Google images by adding the option source:life .