６月６日早６时０８分（美国东部时间６月5日晚６时０4分）一场激动人心的“金星凌日”盛宴将在天空上演。这一罕见天象两次一组，两次相距８年，两组之间相距１００多年。上一次“金星凌日”是２００４年６月８日，下次要等到２１１７年１２月１１日，距今１０５．５年。因此，对大多人来说这将是观看“金星凌日”的最后一次难得的机会，千万不要错过。 请看新华网和CBC的有关报道。 http://news.xinhuanet.com/tech/2012-06/03/c_112103530.htm 6日天宇上演“金星凌日” 天文专家指点观“小日食” 资料图片：2006年6月8日发生金星凌日天文现象，这是在宁夏境内观测到的凌始内切景象。 新华社记者 余福卿摄 新华网 天津６月３日电（记者帅安宁、周润健）６月６日，一场激动人心的天空盛宴将上演，这就是“金星凌日”。那么，对此次罕见的天象奇观该如何观测？怎样才能拍摄出效果绝佳的照片？如何与“小日食”合影呢？ 我国天文教育专家、天津市天文学会理事赵之珩介绍说，金星将影子投在太阳圆面上，缓慢地从明亮的日面上经过，这种天象称为“金星凌日”。由于日面被金星遮挡，因此，“金星凌日”也被看做是一次“小日食”。这一罕见天象两次一组，两次相距８年，两组之间相距１００多年。上一次“金星凌日”是２００４年６月８日，下次要等到２１１７年１２月１１日，距今１０５．５年。 ６月６日上演的“金星凌日”，我国各地都可以看到，其中在东部可见到完整凌日过程，西部地区则可见太阳“带凌而出”。 “金星凌日”分为“凌始外切”“凌始内切”“最小角距离”“凌终内切”和“凌终外切”５个阶段。赵之珩提示说，本次“金星凌日”整个过程持续６个多小时，但“凌始外切”和“凌终外切”时间在全国各地略有不同，前者在６时０８分至６时１１分之间，后者在１２时４８分到１２时５２分之间。因此，各地公众在观测时要提前做好相应的案头工作。 为了更好地观测本次“金星凌日”，赵之珩建议公众要在早上６点之前起床，提前赶到能够看到日出的地点，争取看到从“凌始外切”到“凌终外切”的全过程。 赵之珩提醒说，观看“金星凌日”时，公众一定要使用滤光片，不可裸眼观看，电焊工头盔上的滤光片是首选，也可使用专用太阳观测镜等工具，每看一次不可超过１０秒钟，否则会伤害眼睛。 爱好天文摄影的公众要提前准备好相机，数码或胶片的都可以，并提前选好能看到日出地平线的地点。在拍摄时，一定要在相机镜头前加上滤光片，采用适当的曝光量。“可用长焦镜头摄影，每隔１０分钟－１５分钟拍摄一张，入凌和出凌（开头和结尾）期间可以连续拍摄。如能选取一些有特色的背景物，比如高塔、古建筑、树木等，将更有观赏和纪念价值。”赵之珩说。 天文专家表示，今年是太阳活动高峰年，日面上经常有太阳黑子出现。如有太阳黑子，最好把“金星凌日”与太阳黑子拍摄在同一张照片上，这将是难得的天文摄影佳作。 http://www.cbc.ca/news/technology/story/2012/05/16/f-venus-transit.html Last Chance to see Venus transit across sun June 5 alignment of Earth, sun and Venus won't happen again for 105 years By Kazi Stastna, CBC News Posted: Jun 1, 2012 5:34 AM ET Last Updated: Jun 1, 2012 3:06 PM ET V enus transits across the sun as seen over Hong Kong on June 8, 2004. There have only been seven such transits since 1631. The eighth will take place on June 5, 2012, and will be the last chance that people alive today will have to witness the rare celestial event. The next transit won't occur until 2117. (Bobby Yip/Reuters) If you happen to glance at the sun in the early evening next Tuesday and notice a black dot moving across it, fear not, that's not dust in your eye or an early sign of glaucoma — it's Venus. Our nearest planetary neighbour will be passing between the Earth and the sun starting at 6:04 p.m. ET on June 5 and will be aligned in such a way that its passage will be visible with the naked eye. The transit, as it's known, will last about six hours, but in most parts of Canada, it will be visible for only a few hours before sunset. "The view is best the farther west you go, but, actually, it's pretty good for most of Canada," said Mike Reid, a lecturer in the department of astronomy at the University of Toronto and a public outreach co-ordinator at the university's Dunlap Institute for Astronomy and Astrophysics . Eastern Australia, Asia will have best vantage points The best view of the transit will be in the middle of the Pacific Ocean, but people in eastern Australia, New Zealand, Japan, Philippines, Korea, parts of China and Russia and Pacific nations like Papua New Guinea will also be able to see Venus's entire journey across the sun — although for them it will be occurring the morning of June 6. Europeans, and people in eastern Africa, the Middle East, India and places in between will have to get up very early to catch a glimpse of the transit. West Africa, Portugal and parts of Latin America and Spain will miss it altogether. For people on Earth to be able to see Venus transiting the sun, the planet has to cross the plane of Earth's orbit at the precise time that Earth, Venus and the sun are lined up. That doesn't happen very often because most of the time when Venus crosses Earth's orbital plane , Earth is somewhere else in its orbit, so there is no direct sight line from Earth to Venus and the Sun "Earth orbits the sun slower than Venus. If they both orbited in the same plane, like runners running around a track, then every time Venus 'lapped' Earth, there would be a transit," Reid said. "However, Venus's orbit is 'tilted' relative to Earth's orbit, so the only way Venus and Earth can line up with the sun is if Venus laps Earth exactly when Venus happens to be passing through the plane of Earth's orbit. "That only occurs at two points in Venus's orbit (the two points where the ring of Venus's orbit 'punctures' Earth's orbit). The odds of Venus happening to be at one of those two points when it 'laps' Earth are small." Children in Bombay watch the June 8, 2004, transit of Venus. Special eye protection must be worn when looking directly at the sun to avoid eye damage. (Arko Datta/Reuters) When transits do occur, they occur in pairs, with each transit in a pairing separated by eight years, and then not again until 105.5 or 121.5 years later. The last transit was in June 2004, and after this year's transit, the next one won't occur until December 2117. (Learn why the timing of transits follows this pattern.) "It's very similar to the reason why we don't see a solar eclipse every time there is a new moon," Reid said. "You'd think that every time the moon comes between Earth and the sun, it would block out the sun, but sometimes, it's a bit above the sun, sometimes it's a bit below the sun." Mercury also occasionally aligns with the Earth and the sun, and does so more frequently than Venus, but its transits can't be seen with the naked eye, because Mercury is much smaller and farther away from Earth than Venus. Transits used to measure distance to sun This will be the eighth transit of Venus since the invention of the telescope in 1609. The earliest record of a transit we have is from 1639 (the transit prior to that, in 1631, was known about but not visible in Europe). The 1639 transit of Venus was documented by a young amateur astronomer in Lancashire, England, named Jeremiah Horrocks (sometimes spelled Horrox) and his friend William Crabtree. Horrocks used his observations to measure the diameter of Venus and to obtain a crude estimate of the distance between the Earth and the sun. In later years, astronomers, most notably Edmond Halley, refined the method of using transits to estimate the distance to the sun by measuring the differences in how long the transit appeared to take depending on where the observer was located on Earth and applying the principles of the displacement effect known as parallax . Getting a precise measurement of the distance preoccupied many researchers in the 18th and 19th centuries and was in part the motivation behind Captain James Cook's first expedition to the South Pacific. Cook was tasked with observing the 1769 transit of Venus by Britain's Royal Society and did so from Tahiti. Today, the distance between the Earth and the sun, referred to as the astronomical unit , is well known and can be measured using radar, and transits have instead begun serving another purpose: they are helping astronomers locate planets outside our solar system, known as exoplanets. When these planets pass between Earth and the star they are orbiting, they block out some of the light the star is emitting, causing it to dim slightly. By observing the nature of this dimming, astronomers can learn about the planet causing it. "You look for the same pattern of dimming to repeat over and over again, and you can deduce from that what kind of planet it is, how far from the star it is, whether it's a big planet or a small planet, and now, we're getting to the point where we can measure some elements of the atmospheric composition of the planet," Reid said. Public viewings planned across Canada To mark this year's transit of Venus, events are being held across Canada at which the public will be able to observe the transit safely and learn more about the phenomenon. The Slooh Space Camera , a robotic telescope that transmits live images of space online, will have real-time feeds of the transit from solar telescopes in Australia, Japan, New Zealand, Hawaii, Norway, Arizona and New Mexico. Other sites, including those of the San Francisco-based Exploratorium museum and the group Astronomers Without Borders , will also carry live webcasts of the event. Children in Vienna watch an image of the sun and Venus projected onto a cardboard box on June 8, 2004. Simple devices like pinhole projectors can be made to view the transit indirectly. (Heinz-Peter Bader/Reuters) Users of Apple and Android smartphones can download a free transit of Venus app created by Astronomers Without Borders and ESRI, a company that works with geographic information system, or GIS, technologies. The app, available at iTunes App Store and Android Market , allows users to find out when and where the transit will be visible, follow transit-related tweets, download photos and videos and learn about the history of the transit. In Toronto, the Dunlap Institute for Astronomy and Astrophysics will be holding a public transit viewing at Varsity Stadium, starting at 5:30 p.m. ET. It will distribute 5,000 pairs of specially treated glasses that will allow people to look directly at the sun without damaging their eyes and will have telescopes on hand equipped with solar filters that show the sun in greater detail than can be seen with the naked eye. Astronomers will be present to answer questions and provide information about transits and their use in contemporary astronomy. Participants will also be able to view live streams of the transit from around the world. The Institute has distributed another 43,000 pairs of "transit glasses" to universities and Royal Astronomical Society of Canada chapters across the country, and similar glasses are being sold through Sky News magazine and on various websites. Eye protection needed For those who can't get their hands on a pair of glasses, Reid suggests crafting a simple device like a pinhole projector to project an image of the sun onto the ground or another surface. (The Exploratorium science museum in San Francisco suggests a variation on this using binoculars.) Learn more Listen to author Mark Anderson discuss his book about the history of the study of the Venus transit, The Day the World Discovered the Sun , on Quirks and Quarks , June 2 at noon ET. As with the annular eclipse that dazzled millions of people around the world on May 20, the key to viewing the transit of Venus safely is to avoid looking directly at the sun without a protected lens. Sunglasses or ordinary telescope lenses are not enough to protect the eyes. To be safe, lenses must be treated with something like an aluminized film like Mylar or have a strong filter such as the type found on some welder's glasses. The Royal Astronomical Society of Canada lists a number of safe lens options in a special section of its website devoted to the transit. Whatever viewing method you choose, the key, says Reid, is to not miss what will be your last chance to see Venus in transit. "It will not occur again until 2117, so it's worth trying to see it," Reid said.
Richard 何许人也？ Richard 者，狂人也，全名 Richard Axel 。这家伙本科就读于哥大，随后到霍普金斯读医学。美国的医学生可都不是等闲之辈啊，可惜 Richard 是个不误正业的医学生，去临床实习的第一天，老师跟他说， Richard 啊，你要是答应我这辈子不做医生，我现在就可以让你毕业，大概他在病人身上犯了极大的错误；在病理科实习的第一天，不知道他又在病人尸体上搞什么鬼，老师说， Richard 啊，你要是答应我一辈子不做尸体病理解剖，我现在就让你通过病理科的实习。 Richard 就是这样的一名医学生，他能做医生吗？没有！ 这是第二次听 Richard 讲故事，是最近的 PDA 组织的渡假，他过来作陪，开场白就是说的他作为医学生的丑事。还记得第一次是在 Caspary ，纪念学校的第五任校长 Joshua Lederberg ，他的哥大校友，他从哥大档案馆里把 Joshua 的大学成绩单扫描出来呈现给大家看，大多数科目的成绩是 B 和 C ，只有极少数是 A ，看样子 Joshua 学习成绩平平。 Joshua 的经历可以看看维基百科， http://en.wikipedia.org/wiki/Joshua_Lederberg ，他也读过医学，读了二年之后，对细菌的表型改变感兴趣，就放弃了医学，搞研究去了。没想到，在 33 岁的时候因为发现细菌质粒就拿了个诺贝尔医学奖。 Richard 的不务正业表现很广泛。听他的报告，必须能够欣赏美，因为他的幻灯基本上由近代艺术作品组成，我不知道他怎么收集到哪些超具代表性的近代艺术，然后又将近代艺术作品跟他热衷的荧光体系展示在一起。这种超现代的艺术表现手段让我这种只能看古典艺术的人感到蓦然，我没法理解。 他的报告是种难于让我理解的艺术，他的经历表现的更为神奇，正是因为他的不误正业，他的研究方向在他人生的早期一直在更换，从研究质粒转染， DNA 重组，到研究逆转录病毒的复制，然后又搞起了免疫，发现了 CD4 与 MHC-II 分子相互结合在免疫学上的关键作用，已经够多的了，从分子生物学、到病毒学、再到免疫学，他在这些方面的研究结果可以跟这些领域的权威科学家相媲美，让人想不到的是，他在 45 岁之后还在更换领域，搞嗅觉。 1991 年，他和他的博士后 Buck Linda 克隆到嗅觉相关受体，文章发表在 cell 上，正是这篇文章，奠定了他在神经生物学研究的地位， 2004 年他和 Buck 共享诺贝尔医学奖。 Richard 的嗅觉神经生物学的报告，对于我来说实在太难跟上他的表现节奏，他用 Drosophila 作为模式动物，因为大概只有几十个神经元细胞，比较容易研究嗅觉脑皮层的激发和抑制过程，他用漂亮的颜色勾勒出神经突触种种漂亮风姿，展现低等生物嗅觉中的 Innate 和 acquired 嗅觉激活，还谦虚的说： I do nothing, all of these experiments were done by post-doc fellows in the lab. 其实听他的艺术还是挺乏味，不仅我没有听懂，我周围几个搞免疫的也没有听懂。不过他的 live show 是听懂了。在 Richard 介绍完研究之后，就是跟一批博后交流他怎样做研究，他自己怎样改自己的研究领域等等。其中我觉得他对一个独立的研究人员，怎样脱离以前老板的束缚，开展新的研究领域有非常精彩的阐述。他认为一个优秀的科学家，应该养成自己的 perception ，这是最重要的。如果你有 Perception ，你做什么都会成功，当然他还交代了一些如何在新的领域申请基金，如何发展等等细节性的问题。他说的话，是要有点底气的，因为他是一成功的人士。比如他说的 perception ，可能就是说你要有灵感，可是年轻的科学人员们，有几个人敢确定自己是有灵感的。 一帮博后座在一起聊更有趣，其中就聊到很多科学家都要经历困难期，有人怀疑 Richard 有没有经历过困难，我说ldquo; sure rdquo;，但是很多人都说ldquo; Not sure rdquo;，想想看 Richard 在他 30 岁左右的时候就掌握了一个核心专利，即 DNA 的细胞转染，或者称为ldquo; axel 专利rdquo;，他的这个专利给他带来了数以百万计的收入。他自己有了钱，想换换方向还不容易吗？想招几个聪明的博士后还不容易吗？不过之后，最大的话题转移到我，一个以色列的朋友介绍我，说我是第七十八代的孔夫子后人，美国人的都惊呆了， 78 代，他们最多也就只知道 2-3 代的历史而已，他们怎么知道早在 2500 多年前的中国就开始有了这样传奇的家谱。让他理解什么是2500年前，我只能说俺们家老祖宗是跟柏拉图是差不多年代的，比后者还要早100年左右。大家又聊到所有的孔性男子都应该具有相同的 Y 染色体，不知不觉中说到 Paul Nurse ，这位新的英国皇家科学院的新院长，说到他的私生活。他在最近接受 Science 杂志采访时说到的。为了申请美国的绿卡，他了解了一下自己的家系，结果发现，他的爸爸妈妈原来是他的外公外婆，而他的姐姐是他的妈妈！！！他们都已经去世，他现在不知道他的爸爸是谁。他当然不会放弃，打听到他可能的生物学父亲是个吉他手，后来他找到那个吉他手，但吉他手已经去世，留下几个孩子，现在 Paul 估计正在分析他是不是已经找到了他生物学上的父亲。这样的交流活动还是挺有意思的，比如听他们吹一个卡车驾驶员怎样错过了诺贝尔奖，而且还觉得做个卡车驾驶员没有什么好遗憾的。
标签: 2004
