科学与翻译

Stephen Hawking has said that there is a 50-50 chance that we will find a complete unified theory in the next 20 years. Do you agree that the end of theoretical physics is in sight?

The most common criticism was equating the discovery of a theory that unified the four fundamental forces of nature - a so-called theory of everything - with the end of theoretical physics. Some theoretical particle physicists agreed with Hawking’s prediction about the chances of discovering a theory of everything, although several reckoned that it would take 50 to 100 years. Steven Weinberg, for example, said: “20 years is possible, but unlikely. I would guess 100 years for a ‘complete unified theory’. But a ‘complete unified theory’ would not be the end of theoretical physics.”

Kaku agreed that 20 years will be enough “to prove whether superstring theory is the theory of everything or the theory of nothing - there is no middle path. But even then, knowing the rules of chess does not mean we have become grand masters of chess. Similarly, knowing the rules of the unified field theory does not mean we have become grand masters of that theory. It may take us centuries before we exhaust the full implications and applications of a theory of everything”.

Gerard ‘t Hooft, however, was less optimistic about even the more limited interpretation of Hawking’s statement: “Absolutely not. He has been saying the same thing for more than 20 years. Physicists like him will say this again and again, always projecting the ultimate solution 20 years to the future. Although I do believe an ultimate theory is conceivable, we are many generations away from it.”

“Physics is not like getting to the top of Everest,” said Luciano Maiani, director general of CERN. “It is more like trying to get to absolute-zero temperature. As you get closer, new scales of phenomena appear and these call for a new effort and new understanding.”

Eugene Parker at Chicago was not convinced either. “The idea that when the last field equation is written down on paper, physics will come to an end is naive in the extreme,” he said. “In 1865, for example, Maxwell completed the electromagnetic field equations by adding the displacement current to Ampère’s law. That was the beginning of electromagnetism, not the end. When Schrödinger and then Dirac wrote down the quantum-mechanical wave equation, that was the beginning of quantum mechanics, not the end. When Einstein wrote down the equations of general relativity, that was the beginning of modern gravitational theory and cosmology, not the end.”

Many respondents pointed out that the discovery of a theory of everything will have little impact on the rest of physics “A unified theory would be a tremendous breakthrough,” said astronomer Alex Filipenko at the University of California at Berkeley, “but it would not, for example, lead to solutions of many important problems in condensed-matter physics, biophysics, astrophysics, and so on. It certainly won’t give us a much clearer picture of the origin of life or of intelligence. Much will remain to be done!”
摘自：http://physicsworld.com/cws/article/print/851

In October 1841 the 17-year-old Thomson entered St Peter’s College (Peterhouse), Cambridge, as a “pensioner” ­ in other words as a student who paid his own way. The formal tutoring in mathematics in his first year was of a very low level compared with what Thomson already knew. Indeed, by the time he reached Cambridge, Thomson had already published a paper in the Cambridge Mathematical Journal, in which he defended the mathematical rigour of Fourier series against the erroneous criticisms of Philip Kelland, a mathematician at Edinburgh University. During his time as an undergraduate he wrote a further 10 papers and was quickly tipped to be the “senior wrangler” (the student who would come first in the final mathematics examinations).

While Thomson was at Cambridge every member of his family regularly wrote to him. His father, who was footing all the bills, often advised him on the wise use of money and time. Yearly college maintenance fees alone came to £230, which would probably have accounted for as much as one-third of his father’s annual income. Thomson’s letters to his father often contained detailed lists of all expenditure. If writing to ask for extra money, he would sometimes include a mathematical theorem for possible use in exams to soften his father up.

In one early letter to his father, Thomson outlined how he planned to spend his days at Cambridge. His intention was to rise at 5 a.m. and light his fire; read until 8:15 a.m.; attend his daily lecture; read until 1 p.m.; exercise until 4 p.m.; attend chapel until 7 p.m.; read until 8:30 p.m.; and finally go to bed at 9 p.m. As Thomson’s modern biographers point out, it is doubtful whether he actually adhered strictly to this timetable, but it does illustrate his lifelong desire to minimize wasted time.

Thomson took part in many other activities at Cambridge besides studying. He rowed, becoming an excellent oarsman. He played the cornet and helped to establish the university’s music society. He also walked, skated and swam. Of all these activities it was Thomson’s rowing that his father disapproved of the most, fearing that it would bring his son into loose company, which would “ruin [Thomson] forever” with wine parties and time wasting.

Thomson’s final exams ­- the Senate House examinations ­- began on New Year’s Day 1845 and went on until 7 January. There were 12 papers, with morning papers lasting two and a half hours and afternoon papers three hours. The final result depended on both the quantity and quality of the answers to the questions. The exams were the toughest mathematical racecourse in the land, with the competitors trained like thoroughbreds to answer questions at top speed, and to use all possible short cuts to reach the answers.

To universal surprise Thomson came not first but second, behind one Stephen Parkinson of St John’s College. The family was disappointed, but justice was eventually done when Thomson came first in the Smith’s prize examination at the end of January. The papers for this exam were more suited to Thomson’s abilities, containing as they did more problem-solving questions and less of the bookwork that characterized the Senate House papers. Even though Thomson had come second in the Senate House examinations, the comments around Cambridge showed that he was by far the greater mind. As one examiner commented to a colleague: “You and I are just about fit to mend [Thomson’s] pens.” These successes meant that Thomson was elected a fellow of St Peter’s in June 1845 at the age of 21.

摘自：http://physicsworld.com/cws/article/print/16484

The year 1821 was in many ways one of the most important in Faraday’s life. On 21 May 1821 he was promoted in the Royal Institution to be Superintendent of the House. On 2 June he married Sarah Barnard who was a member of one of the leading Sandemanian families in London and on 15 July Faraday made his Confession of Faith in the Sandemanian Church. The year was also the one when he made his first major contribution to natural knowledge.

In 1820 the Danish natural philosopher Hans Christian Oersted had discovered electro-magnetism. This he announced in a paper written in Latin, but was quickly translated into the major scientific languages of Europe. It was immediately evident that Oersted had made a major discovery, but because he belonged to the German school of naturphilosophie his paper contained views which many of its readers found strange. Indeed writing later Faraday commented that “I have very little to say on M. Oersted’s theory, for I must confess I do not quite understand it”. What was clear was that Oersted had opened up a major field of scientific enquiry which was exploited by savants all over Europe. Faraday was part of this effort and on 3 and 4 September 1821 in his basement laboratory at the Royal Institution, he undertook a set of experiments which culminated in his discovery of electro-magnetic rotation - the principle behind the electric motor. Apart from the practical significance of this discovery, it was important as Faraday’s interpretation of the phenomenon indicated that he was not a Newtonian in supposing that forces had to act rectilinearly.

In the ensuing decade following this discovery, Faraday’s opportunity for doing original research was severely circumscribed, although he was able to liquefy chlorine in 1823 and discover bicarbuet of hydrogen (later renamed benzene by Eilhard Mitscherlich) in 1825. At Davy’s instigation he was the first secretary of the newly founded Athenaeum Club in 1824 and in the late 1820s undertook an extensive project on making optical glass for a joint committee of the Royal Society and Board of Longitude. In addition in 1826 he founded the Friday Evening Discourses and in the same year the Christmas Lectures for juveniles. In total Faraday gave 123 Friday Evening Discourses between 1826 and 1862 and 19 series of Christmas lectures between 1827 and 1861. These and other lectures that he gave served to establish his reputation as the outstanding scientific lecturer of the time. Both the Friday Evening Discourses and the Christmas lectures continue to this day. The latter series is televised each year.

It was not until nearly ten years to the day after his discovery of electro-magnetic rotations that Faraday was able to resume his work on electro-magnetism, when he discovered on 29 August 1831, electro-magnetic induction. This is the principle behind the electric transformer and generator. It was this discovery, more than any other, that allowed electricity to be turned, during the nineteenth century, from a scientific curiosity into a powerful technology. During the remainder of the 1830s Faraday worked on developing his ideas on electricity. He enunciated a new theory of electro-chemical action between 1832 and 1834 one of the results of which was that he coined, with William Whewell, many of the words now so familiar - electrode, electrolyte, anode, cathode and ion to name but five. In the later half of the 1830s Faraday worked on a new theory of static electricity and electrical induction. This work led him to reject the traditional theory that electricity was an imponderable fluid or fluids. Instead he proposed that electricity was a form of force that passed from particle to particle of matter.

摘自： http://www.rigb.org/heritage/faradaypage.jsp

In 1609, Galileo had set a telescope in the garden behind his house and turned it skyward. Never-before-seen stars leaped out of the darkness to enhance familiar constellations; the nebulous Milky Way resolved into a swath of densely packed stars; mountains and valleys pockmarked the storied perfection of the Moon; and a retinue of four attendant bodies traveled regularly around Jupiter like a planetary system in miniature.

“I render infinite thanks to God,” Galileo intoned after those nights of wonder, “for being so kind as to make me alone the first observer of marvels kept hidden in obscurity for all previous centuries.”

Galileo found himself lionized as another Columbus for his conquests. Even as he attained the height of his glory, however, he attracted enmity and suspicion. For instead of opening a distant land dominated by heathens, Galileo trespassed on holy ground. Hardly had his first spate of findings stunned the populace of Europe before a new wave followed: He saw dark spots creeping continuously across the face of the Sun, and “the mother of loves,” as he called the planet Venus, cycling through phases from full to crescent, just as the Moon did.

All his observations lent credence to the unpopular Sun-centered universe of Nicolaus Copernicus, which had been introduced over half a century previously, but foundered on lack of evidence. Galileo’s efforts provided the beginning of a proof. And his flamboyant style of promulgating his ideas–sometimes in bawdy humorous writings, sometimes loudly at dinner parties and staged debates–transported the new astronomy from the Latin Quarters of the universities into the public arena. In 1616, a pope and a cardinal inquisitor reprimanded Galileo, warning him to curtail his forays into the supernal realms. The motions of the heavenly bodies, they said, having been touched upon in the Psalms, the Book of Joshua, and elsewhere in the Bible, were matters best left to the Holy Fathers of the Church.

Galileo obeyed their orders, silencing himself on the subject. For seven cautious years he turned his efforts to less perilous pursuits, such as harnessing his Jovian satellites in the service of navigation, to help sailors discover their longitude at sea. He studied poetry and wrote literary criticism. Modifying his telescope, he developed a compound microscope. “I have observed many tiny animals with great admiration,” he reported, “among which the flea is quite horrible, the gnat and the moth very beautiful; and with great satisfaction I have seen how flies and other little animals can walk attached to mirrors, upside down.”

摘自：http://www.galileosdaughter.com/firstchapter.shtml

Spread over a 16 m-wide wall in the Palazzo Vecchio town hall in Florence, Leonardo da Vinci’s The Battle of Anghiari is a magnificent fresco depicting two horse riders in combat. Also impressive are la America Tropical by the Mexican muralist David Alfaro Siqueiros in the Italian Hall in Los Angeles, and the numerous frescos adorning the ancient Hagia Sophia church in Bulgaria. Unfortunately no one can see these paintings: they are all hidden beneath a layer of plaster.

If studies by a team of scientists from the US and France continue to prove successful, however, then it could be only a matter of time before such frescoes, which have often been covered for religious or political motives, are exposed. Although plaster is opaque to visible light, in the much lower frequency terahertz (10¹² Hz) it all becomes clear. “Most non-polar, dielectric materials are transparent in the terahertz spectral range,” says Bianca Jackson, a physicist at Michigan University in the US. “Therefore, with enough power, terahertz can penetrate ‘infinitely’ thick, optically opaque materials suchas concrete or wood.”

Jackson and her colleagues are collaborating with researchers from Picometrix — a photonics company based in Ann Arbor, Michigan —as well as the National Higher School of Advanced Techniques (ENSTA) and the Centre for Research and Restoration in the Louvre Museum, both in Paris. Their system involves scanning a pulse of terahertz light over a surface and then measuring how the amplitude of the reflected signal changes with time. Because materials have different dielectric properties, which determine how much light is reflected, these measurements can tell how dissimilar materials are layered on top of one another. This makes it ideal for imaging frescos — a technique that won favour during the Renaissance in which pigments are painted into wet plaster.

Although art historians regularly employ ultraviolet, infrared and Raman spectroscopy to examine the surfaces of murals, these techniques cannot probe deeper than a millimetre into plaster. On the other hand, X-rays and microwaves can penetrate many layers, but X-rays cannot distinguish between the layers and microwaves have a poor spatial resolution. Terahertz radiation has none of these drawbacks and, because it is non-ionizing, should not damage a painting either.

The Michigan team has already tested Picometrix’s “T-ray 4000” system on a graphite sketch of a butterfly imbedded in a 4 mm layer of plaster-of-Paris. After focusing the T-ray transceiver onto the back of the plaster, they found that they could make out the 2 mm wide graphite lines of the butterfly. The team is now planning to take the system next month to the St John the Baptist church in Vif, France, where there are believed to be many hidden frescoes.

Irl Duling, director of terahertz business development at Picometrix, says that the company is already shipping the T-ray system to customers. “T-ray 4000 is the only full-featured, portable time-domain terahertz system.”

原文：http://physicsworld.com/cws/article/news/32833

以下是我收集的一些《生物物理》方面参考书，不包括电子版。

Physics and Biology, M.V. Volkenstein (1982)

一本很精炼的概念书，国内有中文版；

生物物理学，赵南明等（2000）

不多的以生物物理为书名的中文书，适合研究生或本科生学习的入门书；

Mathematical Biology, J.D. Murray 2nd edition (1998)

已经是生物数学了，讨论了不少相关数学模型，大多属于微分方程或偏微分方程；

软物质物理学导论，陆坤权等（2006）

书名叫软物质，某些章节属于生物物理方面的，适合相关领域研究生入门阅读；

生物物理学概论，W. 休斯（1979）

这是我从yijun处借来的，一本很老的书，复旦大学译。

译自The impact of physics on biology and medicine中的表格，总结得很全面。

英国的物理网喜欢各种有趣的评选活动。比如他们曾在2002年评出了科学史上最漂亮的10个物理实验。

1. 单电子双缝干涉实验（Young’s double-slit experiment applied to the interference of single electrons）
2. 伽利略的落体实验（Galileo’s experiment on falling bodies），1600s
3. 密立根油滴实验（Millikan’s oil-drop experiment），1910s
4. 牛顿三棱镜分光实验（Newton’s decomposition of sunlight with a prism），1665-1666
5. 杨氏干涉实验（Young’s light-interference experiment），1801
6. 卡文迪什扭摆实验测量万有引力常数（Cavendish’s torsion-bar experiment），1798
7. 厄拉多塞测量地球的直径（Eratosthenes’ measurement of the Earth’s circumference），公元前三世纪
8. 伽利略斜面实验（Galileo’s experiments with rolling balls down inclined planes），1600s
9. 卢瑟福散射实验（Rutherford’s discovery of the nucleus），1911
10. 傅科摆（Foucault’s pendulum），1851

未上榜的著名实验还有：

• 阿基米德的王冠实验： Archimedes’ experiment on hydrostatics
• 罗默测量光速实验：Roemer’s observations of the speed of light
• 焦耳热功当量实验：Joule’s paddle-wheel heat experiments
• 雷诺层流实验：Reynolds’s pipe flow experiment
• 马赫声冲击波实验：Mach & Salcher’s acoustic shock wave
• 迈克尔逊-莫雷实验：Michelson-Morley measurement of the null effect of the ether
• 伦琴发现麦克斯韦位移电流：Röntgen’s detection of Maxwell’s displacement current
• 奥斯特电磁感应实验：Oersted’s discovery of electromagnetism
• 布拉格X-射线散射实验：The Braggs’ X-ray diffraction of salt crystals
• 爱丁顿观测到星光被太阳偏转实验：Eddington’s measurement of the bending of starlight
• 斯特恩-盖拉赫实验：Stern-Gerlach demonstration of space quantization
• 薛定谔猫理想实验：Schrödinger’s cat thought experiment
• Trinity test of nuclear chain reaction
• 吴健雄验证宇称不守恒：Wu et al.’s measurement of parity violation
• Goldhaber’s study of neutrino helicity
• 费曼O圈实验：Feynman dipping an O-ring in water，费曼在挑战者号航天飞机失事调查委员会上把O形密封圈丢进冰水中证明低温可使橡胶变脆，由此解开了失事的谜团。

虽然是物理学家发明了Internet，但在Web 2.0的潮流中，物理学家有点落后了。physicsworld（物理世界）2007年第一期花大量篇幅报道了物理学家和Web 2.0，以下是原文的链接。

1. Brave new Web
2. The open-access debate
3. Talking physics in the social Web
4. Blogging for physics
5. Blog life: Uncertain Principles

这 里面Talking physics in the social Web，是最值得一读的。根据IoP（Institute of Physics Publishing, physicsworld的出版者）的调查，2695名接受调查的物理学家中，有84%的人不知道什么是社会化书签（social tagging），仅有14%的人参与了维基百科中相关研究领域词条的编辑。

该文中还提到：60个回应调查物理学家中的16个阅读过物理博客，其中又仅有3人自己写博客。

牛津的理论物理学家Frank Close说：

I ignore blogs completely, I wouldn’t read what someone posts
on a notice board outside my local newsagent and putting it on
the Web doesn’t make it any more official.

针对维基百科的态度，物理学家们的态度可谓泾渭分明，超弦理论家Motl认为维基百科内词条质量是高的，尤其是那些被很多人编辑过的一般性词条。

但凝聚态理论家，诺贝尔物理奖得主Philip Anderson则承认：他不会在维基百科里读物理，即使他读了，他也不会相信。

当然文章也提到了很多积极拥抱网络的物理学家，除了年轻一代的物理学家外，还出现了Michio Kaku的名字，Kaku在MySpace上的主页竟然有多达2725个好友，显然这中间绝大部分不是物理学家。但当使用Myspace这一代人成长起来的时候，会有更多的物理学家拥抱Web 2.0。