Higgs particle could be found by Christmas By Pallab Ghosh Science correspondent, BBC News Hunt for Higgs gains momentum as the rate of collisions inside the LHC exceeds expectations Continue reading the main story Related Stories Higgs boson range narrows at LHC LHC 'has two years to find Higgs' Guide to the Large Hadron Collider The hunt for the Higgs particle is well ahead of schedule, say researchers at the Large Hadron Collider (LHC). Earlier this year they said they would either discover the Higgs or confirm it does not exist by the end of 2012. Now, because the machine is working so well, an LHC spokesman, Professor Guido Tonelli, has told BBC News that the search could be completed much sooner. The Higgs Boson is the particle that in the physics "Standard Model" allows other particles to have mass. Discovery or elimination of the particle is one of the LHC's major objectives; and it could come as early as Christmas 2011. "We could discover the Standard Model version of the Higgs Boson or exclude it earlier than expected. Could we discover it by Christmas? In principle, yes," said Professor Tonelli The Higgs particle was postulated by physicists in 1964 to explain how other sub-atomic particles have mass, and remains the only major particle in the Standard Model, the dominant current theory of sub-atomic physics, yet to be observed. The collider is a giant accelerator machine housed in a 27km-long (17 miles) circular tunnel under the French-Swiss border. Two beams of proton particles are fired around this subterranean "ring" and smashed together at crossing points. Continue reading the main story Big detectors are located at these points to look for new particles in the sub-atomic wreckage of the collisions. The physicists measure the number of collisions they see in units called "inverse femtobarns", and were aiming to collect 5 inverse femtobarns' worth of data by the end of 2012. But, said Professor Tonelli who speaks for LHC's CMS experiment, the LHC has already collected 2.5 inverse femtobarns - the equivalent of 175,000 billion collisions. So in the space of a few months, the machine has collected half the data it was expected to collect in two years. Fairly quickly The current run of collisions designed to detect the Higgs will be completed by the end of October. Professor Tonelli believes that if this rate of progress continues and nothing goes wrong, there is an outside chance of gathering sufficient data by then and analysing it fairly quickly. The possibility of an early Christmas present for the physics community was raised at the beginning of the week by PhD student Richard Ruiz in the highly respected physics blogsite Quantum Diaries . He wrote: Continue reading the main story “ Start Quote This would be the first time that we would have scientific evidence that this theory which has been so successful in the last 40 years must be definitely abandoned” Professor Guido Tonelli LHC Spokesman "What this means is that by the end of this year, not next year, we will definitely know whether or not the Higgs Boson as predicted by the Standard model exists." But although the discovery of the Higgs by Christmas is possible, it is by no means assured. Five inverse femtobarns of data may not be enough to make a definitive statement on the Higgs, according to Richard Hawkings, who speaks for the LHC's Atlas experiment. "It's a bit optimistic. If the Higgs had been in an easy to find area then yes, we may have been able to have discovered it by Christmas," he said. "But what we have discovered in the past couple of months is that its in a region that's much harder to find. This will require more data and more time." Triumph Even so, if nothing goes wrong with the supercollider, researchers will have collected the 10 inverse femtobarns of data they need to make a cast iron statement about the existence of the Standard Model version of the Higgs by next summer. If they do discover the Higgs, it would be a triumph for the Standard Model, making it a complete theory. If they do not, it would be an even more exciting outcome, according to Professor Tonelli. "This would be the first time that we would have scientific evidence that this theory which has been so successful in the last 40 years must be definitely abandoned and we should look for another theory." 尽管我个人对标准模型不看好，觉得不够美，希望彻底打破重建。 但如果真的能在圣诞节，见证上帝粒子的存在，或者彻底证明不存在，那都是无比激动人心的事情，是神的启示。
看到一篇科普文章，讨论动物是怎样预报地震的，下面给出开头和链接，稍后会抽时间翻译成中文，文中观点不代表本博主认同或者同意。 池塘里的动物能够找出地震先兆吗？ 奇怪不奇怪？ 2009年7月，美国圣地亚哥大地震发生几个小时后，当地居民发现上百只鱿鱼搁浅在沙滩上。这些深海鱿鱼通常生活于水面下200到600米之间。 1992年6月28日凌晨5点58分，美国加州一个沙漠的地面开始晃动，这是40年来最大的一次地震，刚好此时一队人正在此处研究沙漠蚂蚁。观测揭示出，在地震过程中这些蚂蚁的行为并无任何异常。 在2009年的地震前几天内，所有的蟾蜍都离开了原来的生活地。 当你想到地震中这么多而复杂的事情发生在岩石上，如果动物们不受影响的话，这简直太奇怪了。 STRANGE OR NOT In July 2009, just hours after a large earthquake in San Diego, local residents discovered dozens of Humboldt squid washed up on beaches. These deep sea squid are usually found at depths of between 200 and 600m At 5.58am on 28 June 1992 the ground began to shake in the Mojave Desert, California, right in the middle of a scientific study on desert harvester ants. Measurements revealed the ants did not change their behaviour at all during the earthquake, the largest to strike the US in four decades. All of the toads left the breeding colony days before the 2009 earthquake When you think of all of the many things that are happening to these rocks, it would be weird if the animals weren't affected in some way” Rachel Grant How animals predict earthquakes By Victoria Gill， Science reporter Can pond-dwelling animals pick up pre-earthquake signals? Animals may sense chemical changes in groundwater that occur when an earthquake is about to strike. This, scientists say, could be the cause of bizarre earthquake-associated animal behaviour. Researchers began to investigate these chemical effects after seeing a colony of toads abandon its pond in L'Aquila, Italy, in 2009 - days before a quake. They suggest that animal behaviour could be incorporated into earthquake forecasting. The team's findings are published in the International Journal of Environmental Research and Public Health . In this paper, they describe a mechanism whereby stressed rocks in the Earth's crust release charged particles that react with the groundwater. Animals that live in or near groundwater are highly sensitive to any changes in its chemistry, so they might sense this days before the rocks finally "slip" and cause a quake. The team, led by Friedemann Freund from Nasa and Rachel Grant from the UK's Open University hope their hypothesis will inspire biologists and geologists to work together, to find out exactly how animals might help us recognise some of the elusive signs of an imminent earthquake. Strange behaviour The L'Aquila toads are not the first example of strange animal behaviour before a major seismic event. There have been reports throughout history of reptiles, amphibians and fish behaving in unusual ways just before an earthquake struck. In 1975, in Haicheng, China, for example, many people spotted snakes emerging from their burrows a month before the city was hit by a large earthquake. This was particularly odd, because it occurred during the winter. The snakes were in the middle of their annual hibernation, and with temperatures well below freezing, venturing outside was suicide for the cold-blooded reptiles. But each of these cases - of waking reptiles, fleeing amphibians or deep-sea fish rising to the surface - has been an individual anecdote. And major earthquakes are so rare that the events surrounding them are almost impossible to study in detail. This is where the case of the L'Aquila toads was different. Toad exodus Ms Grant, a biologist from the Open University, was monitoring the toad colony as part of her PhD project. "It was very dramatic," she recalled. "It went from 96 toads to almost zero over three days." Ms Grant published her observations in the Journal of Zoology . "After that, I was contacted by Nasa," she told BBC Nature. Scientists at the US space agency had been studying the chemical changes that occur when rocks are under extreme stress. They wondered if these changes were linked to the mass exodus of the toads. Their laboratory-based tests have now revealed, not only that these changes could be connected, but that the Earth's crust could directly affect the chemistry of the pond that the toads were living and breeding in at the time. All of the toads left the breeding colony days before the 2009 earthquake Nasa geophysicist Friedemann Freund showed that, when rocks were under very high levels of stress - for example by the "gargantuan tectonic forces" just before an earthquake, they release charged particles. These charged particles can flow out into the surrounding rocks, explained Dr Freund. And when they arrive at the Earth's surface they react with the air - converting air molecules into charged particles known as ions. "Positive airborne ions are known in the medical community to cause headaches and nausea in humans and to increase the level of serotonin, a stress hormone, in the blood of animals," said Dr Freund. They can also react with water, turning it into hydrogen peroxide. This chemical chain of events could affect the organic material dissolved in the pond water - turning harmless organic material into substances that are toxic to aquatic animals. It's a complicated mechanism and the scientists stress that it needs to be tested thoroughly. But, Dr Grant says this is the first convincing possible mechanism for a "pre-earthquake cue" that aquatic, semi-aquatic and burrowing animals might be able to sense and respond to. "When you think of all of the many things that are happening to these rocks, it would be weird if the animals weren't affected in some way," she said. Dr Freund said that the behaviour of animals could be one of a number of connected events that might forecast an earthquake. "Once we understand how all of these signals are connected," he told BBC Nature, "if we see four of five signals all pointing in direction, we can say, 'ok, something is about to happen'. *********************
与国内年轻PI共勉 【序：对每一位刚刚在清华大学生命科学学院或医学院建立独立实验室的年轻PI（Principal Investigator），我都会不止一次地忠告：至少要在前三年，你们一定要把自己当成超级博士后，身先士卒、尽全力地在实验室做研究、做自己的课 题，同时训练培养博士生、实验员和博士后。只要能够重复你们博士生和博士后阶段的辉煌，你们就不愁在清华拿不到tenure！】 普林斯顿的offer 1997年3月27日下午，在纽约市Memorial Sloan-Kettering Cancer Center的实验室里，我接到了来自普林斯顿大学分子生物学系教授Tom Silhavy的电话，“Yigong, I am calling to tell you a piece of good news. Our faculty voted unanimously to offer you a position, at the level of Assistant Professor.”我喜不自胜，“Great！” Tom接着说，“We will be happy to discuss with you about what you may need to set up your independent lab. We hope you will let us know whether you accept our offer by July 1st”我想也没想地就马上回复，“I am very happy to accept your offer.” Tom似乎很意外听到我直截了当的当场回复，竟不知如何反应；他迟疑了片刻，才提醒我，“Well, Yigong, please think it over. You may use this period to negotiate with us about your start-up package.”那天下午是我一生中最高兴的时刻之一！我把好消息与Nikola Pavletich（我的博士后导师）以及实验室的同事们分享。Nikola善意地告诫我，“If I were you, I would NOT tell them that I would accept their offer now. This is your time to cut a better deal!”Nikola故意在“NOT”上加重了语气。 其实，我何尝不知道拿到offer后争取更好待遇的重要性，但普林斯顿大学是我梦幻中的学术圣地，怎能在这种地方讨价还价呢？！这是我的性格。更何况，拿到这个offer实在是惊喜，因为这是我第一次正式的工作面试，事先是做好了失败准备的！ 普林斯顿大学分子生物学系1997年共有两个助理教授（Assistant Professor）的位置，但却有四百多名年轻的博士后科学家申请。经过层层筛选，确定了六个面试人。我作为六人中的一员在2月27日最后一个到普林斯 顿面试。去世界著名的普林斯顿，心情既紧张又激动，26日一晚上基本没能睡着，脑子里一遍遍地全是精心准备的介绍我的科研进展的幻灯片。早晨6点起床，赶 上了七点从纽约Penn Station开往南方的火车，七点五十抵达普林斯顿。九点整开始面试。 27日上午分别与四位教授举行一对 一的每人45分钟面谈，其中一人是2001年成为普林斯顿大学校长的Shirley Tilghman。因为我已经对他们的科研事先有所了解，所以面谈还算顺利；但Shirley在认真讲述了她的科研进展后很意外地考了我一个相关问题，我 极为紧张地思考后做了还算得体的回答，她点头称对，我才收了一身冷汗。中午与几位博士生一起午餐。下午一点半午餐后，又与三位教授进行面谈，其中第一位是 时任系主任的Tom Shenk，第二位是前系主任、后曾任洛克菲勒大学校长的Arnold Levine。下午4点整，我在系报告厅LTL003给了50分钟的学术报告。我发挥得很好，效果出乎自己的意料，回答问题时已经完全自信。原定晚餐由 Tom Silhavy及另外两名教授参加；我的学术报告后Tom Shenk和Arnold Levine两位重量级教授临时决定共进晚餐，而且Shenk很有暗示意味地对我说，“I think you will become a superstar at Princeton.” 晚餐安排在普林斯顿小城著名的法国餐馆Lahiere’s Restaurant。 Levine介绍说这是爱因斯坦在普林斯顿22年中最喜欢的餐馆；Shenk则指着一张爱因斯坦挂像下面的桌子说，“In a few years, if I invite you to dine at that table, then you will soon receive tenure at Princeton.”。晚餐聊得很开心，根本不象是面试的一个环节。当天晚上我下榻Nassau Inn，由于白天面试的顺利进行，我激动得几乎彻夜难眠，直到凌晨4点多才入睡。第二天继续与8位教授的一对一面谈，包括后来接Shenk做系主任的 Lynn Enquist和1995年的诺贝尔奖得主Eric Wieschaus。由于连续两天没休息好，午餐后我已经筋疲力尽，居然在与Wieschaus面谈时差点打盹，害得我红着脸坦白没有休息好。面试直到 28日下午4点结束，也结束了持续整整两天的面试。老实说，第二天的感觉远不如第一天，心里也有点儿忐忑不安。还好，最终拿到了offer。 创业：做个超级博士后 尽管我可以在1997年的夏天开始普林斯顿的独立实验室，我选择推迟六个月，在1998年1月才正式报到，其中的主要原因是完成我博士后阶段的科研工 作，也让自己做更充分的准备。尽管如此，我心里还是感觉诚惶诚恐，不知今后几年的学术生涯能否继续自己博士阶段和博士后训练的辉煌。 Shenk和Levine对我各说了一句让我终生难忘、至今想与每一位年轻PI分享的忠告。和每一位刚刚开始独立实验室的助理教授一样，我担心自己能否顺 利申请到科研基金，尤其是NIH的项目经费；这种担心对英语非母语的外国人尤其真实和迫切。1998年1月，初到普林斯顿，我对Shenk表达了这种担 心；Shenk回答道，“Yigong，please focus on your research and apply for NIH grants only when you have significant preliminary results. If you fail to obtain any external funding but are doing fantastic research, we will support you! Please don’t worry.”Shenk的这句话打消了我所有的疑虑！只要我的科研出色，即使拿不到外面的经费，系里也会支持我！ 不可否认，每一位 助理教授都对能否拿到tenure耿耿于怀；我也一样，从在普林斯顿正式报到的第一天起，就常常想这个问题，而且常常想得很紧张。在1991至1997的 六年中，七位年轻的助理教授试图在分子生物学系拿到tenure；可惜，只有一位成功，其他六人都被迫离开普林斯顿、另谋它职。Levine看透了我的担 心，直截了当地告诉我，“Yigong, think about it: getting tenure is not so difficult. If you can reproduce your track record as a graduate student and a postdoc in the next 5 years, you will get your tenure at Princeton or any other top-notch university in the US.”如果说Shenk的表态打消了我对申请基金的担心，Levine的忠告则让我看清了为拿到tenure而需要努力的目标。Levine进一步提醒 我，“The difference is that you were alone as a grad student or postdoc. But now you have a lab full of people to help you. That’s why it should not be difficult to get tenure.”这句话让我信心充足！是啊，我至少会有三、四个人的实验室，加上我，如果这么一批人在一起还不能重复我一个人做博士生和博士后期间的工作 分量，我也太笨了，不值得普林斯顿的tenure！ Levine又对我做独立PI提出了具体建议，“Treat yourself as a super-postdoc in the lab during the first 3 years. You must work on your own projects at the bench and supervise your students. This way, you will get your research take off immediately.”我完全接受Levine的建议，不仅天天在实验台上做自己的课题、还尽全力指导博士生和博士后做研究，科研工作很快形成局面， 仅用三年就顺利拿到了普林斯顿大学的终身教职。在庆祝我顺利tenure的party上，Levine又一次忠告我，“I know you’ve been working hard on the bench for 3 years. Now your lab is fully established, and you need to shift your focus from bench work to supervision. Some people believe, and I agree, that spending the vast majority of your time on the bench work after being a PI for 5 years won’t make you fantastically successful.” 当时对这条建议我从心里有点不认同，但回望过去十几年的科研经历，这个建议是很有道理的。 我对清华年轻PI的忠告 对每一位刚刚在清华大学生命科学学院或医学院建立独立实验室的年轻PI，我都会不止一次地忠告：至少要在前三年，你们一定要立足于自己是一个超级博士 后，身先士卒、尽全力在实验室做研究、做自己的课题，同时帮助训练培养博士生、实验员和博士后。只要能够重复你们博士生和博士后阶段的辉煌，你们就不愁在 清华拿不到tenure！当然，我也有信心自己可以像Shenk和Levine一样做好对年轻人的支持工作。只要你们做的研究工作出色，即使在外面拿不到 经费，清华也会尽最大的努力支持你们！ 我还告诫这些优秀的年轻人：不要花时间去拉关系，尽全力做研究，以实力取胜！其实，一个人的尊 严、学术地位、以及别人发自内心的尊敬，永远不可能靠拉关系获得，只能来源于自己真正的学术修养和贡献。那些天天热衷于拉关系的浮躁科学家，如果没有实实 在在的学术成果，即使表面风光，事实上也会被同行（包括一些他拉过关系、关照过他的人）从心里看不起。在学术界，这永远是真理！在美国是，在中国是，在世 界上任何国家都一样！ 与所有的年轻PI共勉！
There are three kinds of philosophic position holdingas the empiricism of John Locke and the idealism of George Berkeley aswell as the skepticism . of David Hume . Empiricism, philosophical doctrine holding that all knowledge is derived from experience , whether of the mind or of the senses. Thus it opposes the rationalist belief in the existence of innate ideas . A doctrine basic to the scientific method, empiricism is associated with the rise of experimental science after the 17th cent. It has been a dominant tradition in British philosophy , as in the works at John Locke , David Hume , and George Berkeley . Most empiricists acknowledge certain a priori truths (e.g., principles of mathematics and logic ), but John Stuart Mill and others have treated even these as generalizations deduced from experience. From the Concise Columbia Encyclopedia. Copyright ?1991 by Columbia University Press. Idealism , in philosophy, the attempt to account for all objects in nature and experience as representations of the mind , and sometimes to assign to such representations a higher order of existence. It is opposed to materialism and naturalism . Early idealism (e.g., that of Plato ) conceived a world in which eternal ideas constituted reality; in modern times idealism (e.g., that of George Berkeley in the 18th cent.) has come to refer the source of ideas to the individual's consciousness. In Kant 's transcendental idealism, the phenomenal world of human understanding opposes a world of things-in-themselves, while the later German idealists (e.g., FICHTE, SCHELLING, and Hegel ) treated all reality as the creation of mind or spirit. More recent idealists include F.H. Bradley and CROCE. From the Concise Columbia Encyclopedia. Copyright ?1991 by Columbia University Press. Skepticism , philosophic position holding that the possibility of knowledge is limited , because of either the limitations of the mind or the inaccessibility of its object. The term is used more loosely to denote any questioning attitude. The earliest skeptics included the Greek Sophists (5th cent. B.C.) and Protagoras . David Hume is famous for his theoretical skepticism, but more closely linked to skepticism was the agnosticism of Kant , who demonstrated that certain problems are insoluble by reason. Descartes used skepticism as a methodology. The scientific method, which demands that all assumptions be questioned, is skeptical to a degree, although the of scientists assumes that material effect is impossible without material cause. From the Concise Columbia Encyclopedia. Copyright ?1991 by Columbia University Press.
Tenure-track Position The School of Civil and Environmental Engineering invites applicants to applyfor a tenure-track faculty position in Transportation Systems Engineering starting in Fall 2009. Click here for more info The School of Civil and Environmental Engineering at Cornell invites applicants for a tenuretrack faculty position in Transportation Systems Engineering starting in Fall 2009. Candidates must have a Ph.D. in civil engineering, systems engineering, or a closely related engineering discipline. An appointment at the Assistant Professor level is anticipated, but an Associate Professor appointment will also be considered. Applications must be submitted both by mail and on-line. Application must consist of a detailed resume, statement of professional research and teaching goals, official graduate transcript, 1-3 publications, and the names, mailing and e-mail addresses, and phone and fax numbers of at least three references. Mail to: Transportation Systems Engineering Search Committee Chair School of Civil and Environmental Engineering 220 Hollister Hall, Cornell University, Ithaca, NY 14853-3501. On-line submission: Electronic copies of all application materials must be submitted on-line at http://www.cee.cornell.edu/position_search/
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