这几天在看文献的时候发现我做笔记的地方非常分散：纸上写了一点，PDF上做了一些标记，evernote上也记了一点。我一直想能不能有一样设备能够代替纸笔，来做电子化的笔记，而不丧失纸笔已有的体验呢？
这个想法变的强烈和清晰是在老板买了一个“e人e本”以后，每次组会都能看到他不亦乐乎地拿着那只号称体验极佳的电磁笔在屏幕上奋笔疾书。
当然，三星和苹果的官司也让我关注起三星的产品，特别是它的那款galaxy note 10.1，和那支神奇的s-pen，看了它的review video，很惊讶于那种书写的顺畅，当我看到它把手写的方程式识别成电子格式的后，都震惊了！
但是，这些似乎离代替纸笔的功能还很远，特别是那种无法替代的书写感觉。
也许，能够真正实现这个梦想的并不只是靠技术进步，还得从下一代开始从小培养这种电子书写的体验和习惯。
其实我很佩服图拉鼎，很多时候我自己也很想在我的领域成为像他那样的布道者，传播我的理念和想法。但这不仅需要我对我的领域各种知识的了解，尝试着去做各种新的东西，也需要我能够静下心了，坚持做好几件重要的事，拓展自己的视野，积累自己的经验。
Project Euler 里很多题目要用到pandigital number，这里记录一下产生此数列的算法：
#using sagemath
#遍历0-9的所有组合，包括以0开头的数字
l=permutations('0123456789')
l1=[''.join(each) for each in l]
#去掉以0开头的数字
l2=l1[len(l1)/10:]
前天（10.2）骑车去的十三陵，现在有空记录一下。
流水帐：
早上九点从保福寺桥出发，经过健翔桥上G6辅路，11：15左右到达昌平城区。骑得较为轻松，只是中间有一段路跟一个人飙车花了不少力气。这次骑行的平均速度达到了20码，虽然我主要是跟骑，但是看来跆拳道的练习还是很有帮助，第二天腿部并没有明显的酸胀感。
误闯高尔夫球场：
在环水库骑行的时候，已是中午，无意中进入了一个入口，骑了一段时间发现竟然有种世外桃源般的感觉——路边栽满了各种果树，然后眼前全是起伏有致、异常平整的草坪。当我们看到一个旗杆标志的时候才意识到这是个高尔夫球场。最后，球场的管理人员看到了我们，将我们请出了球场（貌似我们的到来要使那个门卫的奖金给泡汤了）。
定陵机场：
去定陵的路上发现了这个机场，貌似是华北电网巡视用的。
http://www.nature.com/nature/journal/v426/n6965/full/426389a.html
Steven Weinberg*
When I received my undergraduate degree — about a hundred years ago — the physics literature seemed to me a vast, unexplored ocean, every part of which I had to chart before beginning any research of my own. How could I do anything without knowing everything that had already been done? Fortunately, in my first year of graduate school, I had the good luck to fall into the hands of senior physicists who insisted, over my anxious objections, that I must start doing research, and pick up what I needed to know as I went along. It was sink or swim. To my surprise, I found that this works. I managed to get a quick PhD — though when I got it I knew almost nothing about physics. But I did learn one big thing: that no one knows everything, and you don’t have to.
Another lesson to be learned, to continue using my oceanographic metaphor, is that while you are swimming and not sinking you should aim for rough water. When I was teaching at the Massachusetts Institute of Technology in the late 1960s, a student told me that he wanted to go into general relativity rather than the area I was working on, elementary particle physics, because the principles of the former were well known, while the latter seemed like a mess to him. It struck me that he had just given a perfectly good reason for doing the opposite. Particle physics was an area where creative work could still be done. It really was a mess in the 1960s, but since that time the work of many theoretical and experimental physicists has been able to sort it out, and put everything (well, almost everything) together in a beautiful theory known as the standard model. My advice is to go for the messes — that’s where the action is.
My third piece of advice is probably the hardest to take. It is to forgive yourself for wasting time. Students are only asked to solve problems that their professors (unless unusually cruel) know to be solvable. In addition, it doesn’t matter if the problems are scientifically important — they have to be solved to pass the course. But in the real world, it’s very hard to know which problems are important, and you never know whether at a given moment in history a problem is solvable. At the beginning of the twentieth century, several leading physicists, including Lorentz and Abraham, were trying to work out a theory of the electron. This was partly in order to understand why all attempts to detect effects of Earth’s motion through the ether had failed. We now know that they were working on the wrong problem. At that time, no one could have developed a successful theory of the electron, because quantum mechanics had not yet been discovered. It took the genius of Albert Einstein in 1905 to realize that the right problem on which to work was the effect of motion on measurements of space and time. This led him to the special theory of relativity. As you will never be sure which are the right problems to work on, most of the time that you spend in the laboratory or at your desk will be wasted. If you want to be creative, then you will have to get used to spending most of your time not being creative, to being becalmed on the ocean of scientific knowledge.
Finally, learn something about the history of science, or at a minimum the history of your own branch of science. The least important reason for this is that the history may actually be of some use to you in your own scientific work. For instance, now and then scientists are hampered by believing one of the over-simplified models of science that have been proposed by philosophers from Francis Bacon to Thomas Kuhn and Karl Popper. The best antidote to the philosophy of science is a knowledge of the history of science.
More importantly, the history of science can make your work seem more worthwhile to you. As a scientist, you’re probably not going to get rich. Your friends and relatives probably won’t understand what you’re doing. And if you work in a field like elementary particle physics, you won’t even have the satisfaction of doing something that is immediately useful. But you can get great satisfaction by recognizing that your work in science is a part of history.
Look back 100 years, to 1903. How important is it now who was Prime Minister of Great Britain in 1903, or President of the United States? What stands out as really important is that at McGill University, Ernest Rutherford and Frederick Soddy were working out the nature of radioactivity. This work (of course!) had practical applications, but much more important were its cultural implications. The understanding of radioactivity allowed physicists to explain how the Sun and Earth’s cores could still be hot after millions of years. In this way, it removed the last scientific objection to what many geologists and paleontologists thought was the great age of the Earth and the Sun. After this, Christians and Jews either had to give up belief in the literal truth of the Bible or resign themselves to intellectual irrelevance. This was just one step in a sequence of steps from Galileo through Newton and Darwin to the present that, time after time, has weakened the hold of religious dogmatism. Reading any newspaper nowadays is enough to show you that this work is not yet complete. But it is civilizing work, of which scientists are able to feel proud.
*Department of Physics, the University of Texas at Austin, Texas 78712, USA. This essay is based on a commencement talk given by the author at the Science Convocation at McGill University in June 2003.