Breakthrough of This Year:Areas to Watch in 2007(excerpt from Science)

World-weary? Hardly. Four fledgling spacecraft will give planetary scientists plenty to ponder in 2007. Europe's COROT orbiting exoplanet hunter, scheduled for launch 27 December, should detect dozens of new "hot Jupiters" around other stars and may even bag its big quarry: signs of rocky planets just a few times the size of Earth. Closer to home, the Mars Reconnaissance Orbiter will take the sharpest-ever pictures of the martian surface and will use radar to look for rock layers--and ice--as much as 1 kilometer deep. The Venus Express orbiter will be going full tilt, and in February, New Horizons will send back snapshots of Jupiter en route to its 2015 rendezvous with Pluto.

Skulls and bones. In recent years, paleoanthropologists have uncovered new skulls, teeth, and lower limbs of the earliest members of our genus Homo at sites in the Republic of Georgia, China, and Kenya. In 2007, the first descriptions of these fossils should give clues to the identity of the first human ancestors to leave Africa about 1.8 million years ago--such as whether the bones all belong to one species (Homo erectus) or to two or more. Meanwhile, the long-awaited partial skeleton of Ardipithecus ramidus, an early human ancestor that lived in Ethiopia 4.4 million years ago, promises to shed light on how upright walking evolved in early hominids.

Loads of new primate genes. With the human and chimpanzee genomes sequenced, genetic research into our evolutionary past is scrambling up other branches of the primate family tree. Lowresolution maps of gorilla, rhesus macaque, orangutan, marmoset, and gibbon genomes are already available, and refined, error-free versions should be ready in 2007. In addition, look forward to rough drafts of the genomes of the galago, tree shrew, and mouse lemur. If things go as planned, a comparative analysis of all these genomes might finally begin to explain what sets humans apart.

A climate of change? The case for human-induced warming will grow even more ironclad as the Intergovernmental Panel on Climate Change releases its report in February. Meanwhile, the International Polar Year, opening in March, will feature climate research on Earth's coldest climes. And the world is watching the U.S. Congress, which, under Democratic control, is expected to pass some sort of mandatory emission regime, and President George W. Bush, whose response will be sure to shape the debate.

Whole-genome association studies. The trickle of studies comparing the genomes of healthy people to those of the sick is fast becoming a flood. Already, scientists have applied this strategy to macular degeneration, memory, and inflammatory bowel disease, and new projects on schizophrenia, psoriasis, diabetes, and more are heating up. But will the wave of data and new gene possibilities offer real insight into how diseases germinate? And will the genetic associations hold up better than those found the old-fashioned way?

CREDIT: CIRAC AND ZOLLER/SCIENCE (2003)
Light crystals. Ultracold atoms continue to be one of the hottest areas in physics. Now researchers are loading the atoms into corrugated patterns of laser light known as optical lattices. The lattices work like artificial crystals, with the spots of light serving as the ions in the crystal lattice and the atoms playing the role of electrons moving through it. Optical lattices could help crack problems such as high-temperature superconductivity and seem sure to produce interesting new physics. Look for rapid progress in this burgeoning effort.

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Fastest Waves Ever Photographed!

Pictures of the fastest moving waves ever photographed were presented this morning at APS Division of Plasma Physics meeting in Philadelphia. These shots are more than your typical pretty pictures – they represent a major advance in wakefield accelerator technology, a technology that could make tabletop high-energy particle accelerators a reality.



The matter waves, which are oscillations moving through a plasma, are known as wakefields because they are created in the wake of an ultra-intense laser pulse. The waves travel at 99.997% of the speed of light and generate electric fields exceeding 100 billion electron volts/meter.


The ability to create huge electric fields makes wakefields a promising method for shrinking the size of accelerators from miles long (like those at the Stanford Linear Accelerator Center, FermiLab and CERN) to tabletop. Small accelerators would allow universities and hospitals to take advantage of the research and medical applications afforded by an accelerator without competing for time at a major particle accelerator facility.



Much work remains before tabletop accelerators can be a reality – particularly in understanding the interactions between a wakefield, the accelerated electrons, and the laser pulse. The ability to photograph wakefields is exciting news for scientists because it allows them to explore these interactions and compare theoretical predictions to real data.



Researchers from the University of Texas designed a holographic-strobe camera to take these pictures. Their method, called Frequency Domain Holography, sends two additional laser pulses though the plasma along with the ultra-intense pulse. The additional pulses detect the oscillations and then travel through a spectrometer where they interfere and are analyzed.An abstract of the talk and a lay language paper describing the research are available online.

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Industrial Postdocs(by Rick H Fields)

Industrial Postdocs: The Pros and Cons of Doing an Industrial Postdoc (by Rick H Fields)
United States6 August 1999

Rick H. Fields is a Thin Film Materials Science postdoc working in a large industrial research center in California. His name has been changed to protect his identity.
As long back as I can remember, I always intended to obtain a doctorate degree in the sciences. As my father had done, I planned on joining the ranks of industrial researchers to advance technology for the profit of the company, the benefit for consumers, and possibly society. During my graduate career, I visited and interacted with many researchers from industrial, national, and university laboratories. I was truly fortunate in that I had numerous possibilities after graduation. However, my goal of obtaining a permanent research staff position at a California company limited my choices to a handful of companies. From the beginning, my job search focused on a particular company. Let's call them Company X. I was attracted by the productivity of numerous highly respected scientists of Company X's research center.
Despite being actively recruited by Company X, I was unable to secure a permanent research position as I had hoped. Instead, I was offered a postdoctorate position by a reputable researcher at the company. Despite my high ambitions, I decided that an industrial postdoc would provide me with extensive exposure within the company and potentially lead to a permanent position. The experience would also make me attractive to other potential future employers. Eighteen months have passed since I made the decision. I will try to shed light on the positives and negatives of pursuing an industrial postdoc position based on my experience and that of fellow industrial postdocs.

High-tech companies hire industrial postdocs as a recruitment tool and to do exploratory research beyond the scope of the designated program. If one has not decided whether to pursue an academic or industrial career, an industrial postdoc position is an excellent opportunity to observe the environment and demands of an industrial researcher. The secrecy and motivations behind industrial or applied research is an entirely foreign world for most graduate students when emerging from an academic environment. You will be reeducated in terminology and processes not listed in graduate textbooks or academic journals. You may find yourself operating state-of-the-art research and manufacturing equipment supported by an active supporting staff of technical engineers. The competitive race for cutting-edge technology requires large-scale but selective capital investment by high-tech companies. The highlight of my postdoc experience is my professional and personal associations with the collection of motivated and talented engineers and scientists. These experts were readily available to dispense advice regarding a wide variety of disciplines and problems. An advantage of the "temporary employee" status of postdocs is that I was "excused" from most of the bureaucratic requirements imposed by corporate management. Financially, industrial postdocs are paid competitively with similar positions at national labs and considerably more than academic postdocs. Industrial postdocs are also invited to participate in the company stock purchase plan and other employee discount programs.

The disadvantages of being an industrial postdoc are numerous and complicated. Your experience may vary greatly from mine depending on the industry, corporate culture, your attitude, and your supervisor. Being in industry, one must naturally expect to focus on an aspect related to commercial technology. Basic science research does exist within industry, but such opportunities are few and with limited funding due to marginal interest from management. Because you are regarded as a temporary employee, the company is obliged to protect its many industrial secrets by denying you access or exposure. I found this unbelievably frustrating and detrimental to my scientific development. Despite the availability of experts and equipment, I became aware very quickly of the limits and closed doors. I am not permitted to attend the weekly group meetings nor other internal discussions. I flourished in the openness of the academic setting, but wilted in this stifling environment. After some time, one simply loses interest in the projects of the other group members. To avoid disclosure problems, you may be assigned projects only distantly related to product level technology; however, if your research results suggest a new area of unlicensed technologies, you will experience great difficulty in publishing or disclosing your work outside of the company. All external publications and presentations must go through a process of managerial approval to determine if the research results are proprietary. Similarly, internal collaborations are encouraged but limitations to external collaborations exist due to financial and proprietary constraints.

There are a number of more subtle and circumstantial disadvantages to the industrial environment. If you design and construct an analytical or characterization tool, your association with the equipment can create the dangerous situation of being reduced to a glorified technician. Postdocs in this position resented the narrow focus of their position and felt abused. In the industrial management scheme, a hierarchy of decision-making and control exists where the focus of research is often dictated from above. The external control can create situations of unwanted interference. I soon also realized that my position placed me at the bottom of the pyramid of power. The progress of my work was impeded by delays because my samples were often deemed "low priority." As a postdoc, you are granted a limited travel budget to attend conferences in your field which is subjected to managerial approval. Despite the competitive pay as a postdoc, the postdoc salary is only 50% to 70% of that of the researchers and supporting engineering staff. Due to the temporary employee status, I am denied certain benefits given to permanent employees such as a dental plan and contributions to a retirement account. Postdocs are not eligible for pay increases during the length of their contract and ineligible for variable pay such as bonuses. Finally, working for 2 years for a company does not guarantee any position, let alone a research position. Many of the retained postdocs are often placed in engineering positions due to the lack of new research positions.

During the 18 months of my postdoc, I often asked myself if I would have made the same decision. Although I am very happy with my fellow co-workers, I continually suffered from an overwhelming sense of frustration that never abated. I found the environment to be confining and it limited my productivity. I wanted to contribute more, but my enthusiasm was often doused by the policy of confidentiality. In hindsight, I probably should have increased my options and pursued my goal of a permanent industrial position to greater lengths. In the months remaining in my postdoc, I will seek a permanent position at an industrial research center. The change in status may eliminate the frustration of closed doors, but I realize that many of the limitations I listed are intrinsic to the industrial environment

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The All-around Geniuses in Physics-Landauer & Feynman

朗道（Lev Landau，1908-1968，出生于前苏联的巴库，1962年诺贝尔物理奖）和费曼（Richard Feynman，1918-1988，出生于美国纽约，1965年诺贝尔物理奖）都是公认的最有个性的理论物理学家并且各自拥有大量的崇拜者。作为冷战时代两大敌对阵营的天才骄子，把朗道和费曼拿到一起对比是很有戏剧性的。令人惊讶的是除一个是前苏联人（朗道），另一个是美国人（费曼）外，我们发现在他们的身上有很多共同点，简直就像是孪生兄弟。
年青的朗道
在物理学上，朗道的贡献是多方面的，借用摩西十诫之名，人们把朗道在物理学上的贡献总结为“朗道十诫”，这10项成果是：量子力学中的密度矩阵和统计物理学(1927)；自由电子抗磁性的理论(1930)；二级相变的研究(1936～1937)；铁磁性的磁畴理论和反铁磁性的理论解释(1935)；超导体的混合态理论(1934)；原子核的几率理论(1937)；氦Ⅱ超流性的量子理论(1940～1941)；基本粒子的电荷约束理论(1954)；费米液体的量子理论(1956)；弱相互作用的CP不变性(1957)。
这是费曼，朗道的美国“弟弟”，他总是喜气洋洋的

费曼的科学工作也同样涉及到多个领域。其中最重要的是量子力学路径积分理论以及他以路径积分的形式写出的整个量子电动力学（QED），使之具有相对论协变的形式，并且通过重整化的方法避开了发散的困难，解决了电子的自能问题。利用这样的理论，就可以相当精确地计算出兰姆位移和电子的反常磁矩等用旧有的理论无法处理的问题。在此过程中，他还发展了在场论中十分重要的费曼图技术。今天，路径积分、费曼图已经成为理论物理学家通用的语言，恰似微积分对牛顿力学的重要性一样。 朗道和费曼都不约而同的用女人和性来表达自己对物理学的热爱。费曼表示研究物理对他来说就象是性，虽然很少有功利的用途，但又绝对不能缺少。朗道也曾经酸溜溜地表示：“漂亮姑娘都和别人结婚了，现在只能追求一些不太漂亮的姑娘了。”这里漂亮姑娘指的是量子力学，量子力学是现代物理学的基础，于上世纪30年代由海森堡、薛定谔和狄拉克三个幸运儿建立，朗道因为比他们小几岁所以没能赶上这次物理学史上最关键的淘金行动。
朗道虽然很帅，但却没追到最漂亮的姑娘
从朗道和费曼的科学工作看，我们很难区分出哪一个更厉害一些。朗道的工作大多集中在凝聚态物理学，被认为是凝聚态物理学这一物理学最大分支的创建者（这也和前苏联在低温物理学方面的深厚传统有直接关系）。不过朗道对自己“生不逢时”，没能赶上量子力学的创建，感到极度惋惜。而费曼的工作则主要集中在量子场论，他的量子力学路径积分理论被认为是量子力学的第三种等价理论形式（除此之外还有海森堡的矩阵力学、薛定谔的波动力学；狄拉克的贡献是建立了表象理论从而证明了矩阵力学和波动力学的等价性）。这个工作是足够让朗道羡慕的，可以说朗道想把自己的名字与量子力学创建者联系起来的愿望部分地被费曼实现了。
费曼是一个以教书为乐的物理大师
朗道和费曼同时又都是优秀的教师，如果我们走进任何一个大学的图书馆，我们会发现以朗道或费曼为作者的物理教材和讲义是最多的并且是最热门的。这其中朗道的《理论物理学教程》和《费曼物理学讲义》是最被大家津津乐道的。除此之外，朗道还有一套《大众物理学》专门写给高中生和大学低年级水平读者的；而费曼也有《统计力学讲义》、《量子电动力学讲义》等研究生水平的教材。看来两个人都有使用自己风格叙述“全部”物理学的嗜好。但有趣的是，朗道和费曼几乎从未执笔去“写”过这些书，他们更像是布道者在讲坛上或研究组内去讲自己的物理。就像圣经是上帝的门徒根据其言行编纂出的经典一样，朗道书的执笔者主要是其学生及合作者；费曼书则是根据讲课录音及学生笔记整理出来的，费曼上课一般就是拿张纸神侃。 朗道作为前苏联理论物理学的象征，是著名朗道学派的领导者，在这个科研组里学生必须先读完朗道的《理论物理学教程》才可以进入研究。据说朗道本人是从不读文献的，他的学生会把自己读过的文献拿来与他讨论，而朗道学派培养出的大师级人物也特别多，象2003年诺贝尔奖得主阿布里科索夫和栗弗席兹等。相比之下，费曼作为一名导师，却没有培养出在物理方面特别成功的学生。但费曼很热心物理学在公众中的传播，经常给世界各地的大学本科生上课、给公众做各种讲演等。聪明伶俐、活泼好动的费曼生活在传媒发达的美国显然吸引了更多物理学以外大众的注意力，就象是生活在物理世界中的传奇浪子。而朗道的声名则主要限制在学术圈内，在学术上朗道还多少有些“学阀”作风，有些被朗道枪毙掉的论文，后来被证明是极重要的。
上了年纪的朗道，深邃的眼神中透出淡淡的悲哀
1938年，朗道因被怀疑是德国间谍而入狱，关押一年后，被包括玻尔在内的国内外物理学家所营救，但那段日子一定是他刻骨难忘的，他写道：I spent a year in prison and it was clear that I would be unable to live for even another half year.（在狱中我呆了一年，显然再有半年我就会死掉。） 1962年朗道又遭遇严重车祸（这很可能是前苏联克格勃精心策划的），在车祸中朗道断了11跟骨头并头骨骨折，在经历数次临床死亡判决之后，医生又把朗道从死神手里抢救了回来，但他已经失去了做物理学研究的能力，6年后朗道过早的离开了我们，时年仅60岁。朗道可以说是一个悲剧人物，他虽然在科学上取得了空前的成功，但也留下了太多的遗憾，让后人为他惋惜。
狱中的朗道而费曼则显然是个喜剧人物，他的才华在各方面得到了充分发展和展示，费曼玩鼓、研究古埃及的象形文字、到舞会上找女大学生玩、俨然一副天才顽童形象。当然费曼的最爱还是理论物理，在他去世前，在他办公室的小黑板上画的是 Bethe Ansatz 这一超级难题。但费曼的好出风头也不是每个人都喜欢的，夸克之父盖尔曼就毫不掩饰他对费曼的敌视，通常，费曼如果讲点什么，盖尔曼会立即讽刺性地抨击费曼，费曼又会立马反击。对这种激烈得近乎“残忍”的交锋，费曼通常觉得有些荒唐而一笑了之，但盖尔曼却会事后越想越生气而暴躁起来。盖尔曼想避免生气，后来就尽力避开费曼，如果盖尔曼在做讲座时看到费曼就会开始用单调的语气读起笔记，只有当费曼离开后，他才会重新生动地讲起来。令人惊讶的是，费曼和朗道一样都是犹太人，并且都是来自前苏联地区的犹太人。朗道的故乡是今天阿塞拜疆共和国的首都、里海边上的石油城巴库市。费曼虽然出生在美国的纽约，但他的父亲麦尔维尔则是白俄罗斯的明斯克人。费曼的父亲爱好物理，并是小费曼的启蒙，朗道的父亲则是一位工程师，俄罗斯民族及犹太人的学术及数理传统无疑是催生两个物理天才的真正父亲。朗道和费曼对物理学的影响永远不会过去。

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