带领中国进入世界天文学俱乐部的何子山

摘要

在北大任教的美籍天文学家何子山说，天文的魅力之一在于它与世俗世界无关。但探索宇宙的面貌，需要世俗的投入。他看好中国在科学领域的大举投资，并希望为之做出贡献。

今年48岁的何子山(LUIS HO)是北京大学科维理天文与天体物理研究所(KAVLI INSTITUTE FOR ASTRONOMY AND ASTROPHYSICS)所长，北京大学教授。作为已在中国工作两年多的美籍研究人员，他对这个国家在科学方面的抱负有独到的见解。

何子山在加州帕萨迪纳的卡内基科学研究院天文台(CARNEGIE OBSERVATORIES)工作，目前休假中。今年夏天，我们在他位于那里的办公室(也曾是爱德文·P·哈勃[EDWIN P. HUBBLE]的办公室)交谈了近三个小时，之后还通过电话。以下是访谈内容经过编辑的摘要版本。

问：你是在哪儿长大的?

答：我在莫桑比克长大，那时莫桑比克还是葡萄牙的殖民地。在我童年时代的非洲，就存在关于出身背景的冲突。葡萄牙人并不是很乐于接纳我们，有许多外在的种族主义表现。然后，在1970年代末，在那个国家独立，而且不可避免地陷入一场丑恶的内战之后，我们被迫离开了那儿。他们没收了我父亲的全部财产，我们是拎着手提箱走的。

问：你们去哪儿了?

答：由于运气好，我们不知怎么就获得了美国签证，因此去了东波士顿。当时我12岁，在一所很恶劣的学校里，我是唯一的亚裔学生。我的父亲在餐馆洗盘子。在学校里，人们都取笑我。这让我决心迅速学会英语，以便能到更好的学校去。我做到了。我进了这个城市中最好的学校，波士顿拉丁中学 (BOSTON LATIN SCHOOL)。我从那儿去了哈佛大学;在那里，我似乎是唯一一个不富裕，并且还要打工的人。我觉得好像自己无论去哪儿，都是一个局外人。

问：这种情况是什么时候结束的?

答：有一天，我在哈佛碰巧参加了一次关于银河系中黑洞的讲座。我完全被迷住了。我找到演讲者贺曾朴(PAUL HO)，他立即就给了我一个研究项目。

我喜欢天文学的诸多事情之一，就是它跟世俗世界没有关系。它甚至与我们所在的星球也没有关系。也许，这是对我的家庭不得不为之奋斗的所有日常琐事的一种反应。

问：你从事的的天文学领域是什么?

答：黑洞。我是证明黑洞其实很常见的第一批人中的一个。这是我1995年博士论文中的结论之一。在那之前，人们认为黑洞应该存在，但很罕见。我证明了每个大星系都有一个核心，其中包含超大质量黑洞。之前人们只是怀疑，但我做到了证明这一点。

问：你是如何做到的?

答：通过寻找间接的方式来证明其存在。我寻找能量的迹象，结果我发现，几乎每个星系都有一个黑洞，只是我们之前没有看到。

在我修完博士学位后，哈勃太空望远镜(HUBBLE SPACE TELESCOPE)已经修复。我可以利用它来测算这些黑洞周围星体和气体的旋转速度。哈勃望远镜印证了我论文中的许多观点。

问：对于了解宇宙的面貌，黑洞有多么重要的意义?

答：据我们当前的了解，应当认为黑洞是让各个星系呈现当前面貌的关键因素之一。一个很大的问题是，像黑洞这么小的东西，如何能影响整个星系本身?目前人们相信，它们之间能够互动。

问：我们生活在一个宇宙知识取得巨大突破的时代。为什么我们现在了解得这么多?

答：很大程度上得益于技术的推动。天文学家有了许多很棒的新玩具。天文学的快速发展完全得益于大型天文望远镜的使用。我之所以敦促中国领导人，参与一个新的大型国际天文望远镜的建设，其中一个原因就在于此。

中国在科学方面有很大的抱负。有一条不成文的规则：要想加入天文学俱乐部，就需要参与某个大型天文望远镜的建设。说服他们并不容易，三座新建的天文望远镜全都在外国领土上，这一点很难让他们接受。他们最终选择与加州理工学院(CALTECH)、加州大学(UNIVERSITY OF CALIFORNIA)、加拿大和印度合作建造三十米天文望远镜(THIRTY METER TELESCOPE)。

问：在成长过程中，你想过将来会到中国生活和工作吗?

答：从未想过。有很多事情对我产生了影响，其中之一是遇到了很多有才能的年轻中国科学家。我帮助其中一些人进入了美国的大学。他们在美国的拼搏，让我感同身受。当他们回到中国时，并不能总是取得成功，他们的才能和机遇并不匹配。

在过去十年中，情况开始发生变化。中国在科学领域大举投入，这些人现在回来有事可做。2013年，科维理的工作人员联系我时，我感觉自己或许可以为那样的环境做些贡献。

问：该研究所的邀请有什么吸引你的地方?

答：实际上吸引力很小。研究所提出邀请时，可能是我最不可能接受的时候。我和妻子刚刚生了小孩，其他孩子也已经读高中了，他们没办法离开。这份工作意味着我要住在北京，那里污染严重，交通堵塞，房间狭小。我的妻子留在了加州，她说，“我们必须做到。”我妻子不希望我失去这个机会。

其中涉及了很多琐碎的问题。为了节省通勤时间，我睡在北京大学的办公室里。我早晨5点起床，跟女儿通过SKYPE交流，我还通过网络辅导我儿子。

我每两个月回加州看望他们一次。

问：中国教育以机械和死板著称，你觉得是这样吗?

答：他们有一套非常死板的制度，因为这在以前的效果不错。

我知道卡内基天文台为何能在天文学研究领域成为一个卓有成效的中心，那里允许很多自由讨论和头脑风暴。我正努力将这些做法，带到我们在中国的研究所。

我的梦想是，从今往后的20年，哈佛和普林斯顿最好的学生希望来到北京大学，而不是相反。我们研究所能做的就是提供一片绿洲，由于我在这一小片地方拥有较大的控制权，我可以加速这个过程。

我认为中国的体系可以逐步演进，科维理就提供了一个样板。我们会开展平等的互动讨论。我们吸引了很多水平很高的访问者来授课教学。科维理研究所已经吸引了很多外籍博士后，他们希望来到这里，因为他们看到了这里正在酝酿什么。

另一方面是，中国现在有钱投资科学领域，而且愿意投资!即使在那些最先进的国家，基础天文学都只是一种兴趣学科。但在中国，他们愿意投资发展这门学科。有了资金和这些优秀的人才资源，现在的要诀就是将两者结合。

问：经历了一生的流离劳顿之后，你在北京找到家的感觉了吗?

答：我希望能在这里找到家的感觉。所以我努力工作，想推动项目取得成功。我来这里是抱有长远计划的。我在学习说汉语写汉字。有趣的是，我上次回去的时候，实际上很想念这里。一年前，这里对我来说还是最陌生的地方。

Luis Ho Pushes China Into World Astronomy Club

Luis Ho, 48, is the director of the Kavli Institute for Astronomy and Astrophysicsand a professor at Peking University in Beijing. As an American researcher who has worked for more than two years in China, he has a unique perspective on the country’s scientific ambitions.

Dr. Hois on leave from Carnegie Observatoriesin Pasadena, Calif. We spoke for nearly three hours this summer at his office there — it once belonged to Edwin P. Hubble— and later by telephone. A condensed and edited version of the conversation follows.

Q. Where did you grow up?

A. In Mozambique, which during that time was still a colony of Portugal. In the Africa of my childhood, there was a clash of backgrounds. The Portuguese were not very accepting. There were many outward expressions of racism. Then, in the late 1970s, after the country became independent and essentially deteriorated into a very ugly civil war, we were forced to leave. They confiscated all my father’s properties. We left with our suitcases.

Q. Where did you go?

A. By a stroke of good fortune, we somehow got visas for the U.S., so to East Boston. I was 12, the only Asian in a very rough school. My father washed dishes. At school, people made fun of me. That made me determined to learn English quickly enough to get into a better school, which I did. I got into the best one in the city, the Boston Latin School. From there I went to Harvard, where it seemed as if I was the only person who wasn’t rich and worked. It felt like wherever I went I was the outsider.

Q. When did that end for you?

A. One day at Harvard, I stumbled into a lecture about the black holes in the Milky Way. I was absolutely captivated. I sought out the lecturer, Paul Ho [no relation], and he immediately gave me a research project.

One of the things I loved about astronomy was that it was not tied to the mundane. It was not even tied to our planet. Maybe this was a reaction against all the day-to-day things my family had to struggle with.

Q. What area of astronomy did you work in?

A. Black holes. I was one of the first people to show how common they are. This was one of the results of my doctoral thesis in 1995. Before, the thinking was that they should exist but that they were really very rare. I was able to demonstrate that every big galaxy has a nucleus containing supermassive black holes. This was suspected before, but I was able to prove it.

Q. How did you accomplish that?

A.By searching for an indirect way to show their existence. I looked for signs of energy, and what I found was that basically every galaxy had a black hole. We just hadn’t seen it before.

After I finished my doctorate, the Hubble Space Telescopewas repaired. It made it possible to measure the rotation speed of the stars and gas around those black holes. The Hubble confirmed many of the points of my thesis.

Q. How central are black holes to understanding what the universe looks like?

A. We’re learning they are to be considered to be one of the key ingredients that make galaxies look the way they do. The big question is, how can something so tiny like a black hole influence the entire galaxy itself? The belief now is that they know how to talk to one another.

Q. We are living in an era of tremendous breakthroughs in our knowledge of the universe. Why are we learning so much now?

A. A lot of it is technology-driven. Astronomers have a lot of very nice new toys. The rapid development of astronomy is completely tied to access to big telescopes. That’s one reason why I urged China’s leaders to partner on one of the big new international telescopes.

China has great scientific ambitions. It’s an unwritten rule that to be part of the astronomy club, you need to be part of a big telescope. It wasn’t an easy sell. The three new telescopes that were coming were all to be on foreign soil, and that was a difficult concept. They eventually choose to join with Caltech, the University of California, Canada and India on the Thirty Meter Telescope.

Q. When you were growing up, did you ever think you’d come to live and work in China?

A. Not ever. One of the things that influenced me was meeting so many talented young Chinese scientists. I helped some get into American universities. I could relate to their struggles here. When they returned to China, it wasn’t always possible for them to succeed. There was a mismatch between their talents and opportunities.

Over the past decade, things have begun to change. China has made large science investments, and these people now have something to go back to. In 2013, when the Kavli people approached me, I felt I might have something to contribute to an environment like that.

Q. What appealed to you about the foundation’s offer?

A. It actually was very unappealing. It came at the worst possible moment. My wife and I had just had a baby. There were older kids in high school. They could not be uprooted. The job meant living in Beijing, with its pollution, traffic and cramped apartments. My wife, who stayed behind, said, “We’ll just have to make it happen.” My wife didn’t want me to lose this opportunity.

It involves a lot of juggling. To save commuting time, I sleep at my Peking University office. I get up at 5 a.m. to Skype my daughter. I tutor my son via the Internet.

I return to California every two months to see them.

Q. Chinese education has a reputation for being mechanistic and rigid. Have you found it that way?

A. They had a very rigid system because, in a different time, that’s what worked.

I know what made Carnegie an effective center for astronomy research. It was an environment that allowed a lot of free discussion and brainstorming. I’m trying to bring some of that to our institute in China.

My dream is that 20 years from now, the best students from Harvard and Princeton will want to go to Peking University, not the reverse. What my institute can do is provide an oasis where I can expedite the process, because I have more control over this little patch.

I think the Chinese system can evolve, and Kavli is providing one model. We have nonhierarchical interactive discussions. We’ve attracted very high-level visitors to lecture and teach. Already, our Kavli Institute attracts many non-Chinese postdocs, and they want to come here because they see the ferment.

The other thing is that China now has the means to invest in science. And it is willing to do so! Even in the most advanced countries, basic astronomy is a hobby science. Yet in China they are willing to spend on it. With that and these great human resources, the trick is to combine them.

Q. After a lifetime of travel and displacement, do you feel at home in Beijing?

A. That’s where I hope I can find a home. That’s why I work so hard to make the program successful. I am there for the long haul. I’ve been learning to speak and write the language. Funny thing: The last time I returned I actually missed the place. A year ago, it was the most alien place to me.