Astronomer Royal Martin Rees discusses the most extraordinary aspects of his distinguished career, from black holes to billionaires in space and the prospects of life beyond Earth

英国皇家天文学家马丁·里斯讨论了他杰出职业生涯中的一些最非凡的方面，从黑洞到太空中的亿万富翁，以及对地球以外的生命的推测。


AS ASTRONOMER Royal, you have to assume Martin Rees isn’t in it for the money: £100 a year is the reward for advising the UK monarch on all matters astronomical.
It is just one of many hats Rees has worn, though – including president of both the Royal Astronomical Society and the Royal Society and, since 2005, as an appointed member of the UK’s House of Lords. His work as a government adviser and public face of science has come on the back of an equally distinguished career in cosmology stretching back more than half a century, encompassing seminal research on the nature of the big bang and black holes, extreme phenomena throughout the cosmos, the search for life elsewhere in the universe and, latterly, humanity’s own fate within it.

“英国皇家天文学家”这个头衔，必须承认马丁·里斯不是为了钱而获得的：每年100英镑的报酬 是为英国君主就所有天文问题提供建议的奖励。不过，这只是里斯戴过的众多头衔之一——包括皇家天文学会主席和皇家学会主席，以及自2005年起成为英国上议院的成员。他作为政府顾问和科学家形象出现在公众面前工作是在半个多世纪以来同样杰出的研究宇宙学的职业生涯的背景下完成的，包括对大爆炸和黑洞本质的开创性研究，以及整个宇宙的极端现象，寻找宇宙其他地方的生命，以及以后人类在其中的命运。

Richard Webb: When you started out in cosmology, the idea that the universe began in a big bang wasn’t even accepted science. How have things changed in the past half-century?
Martin Rees: Amazingly. When I started research in the mid-1960s, the [late] astronomer Fred Hoyle was still advocating the idea of a steady state universe that had existed from everlasting to everlasting. Evidence for the big bang theory was very weak. The debate was settled in most people’s minds in 1964 when cosmic microwave background radiation was found – a relic of a hot, dense, early phase of the universe.
It was a good time to be starting research. obxts such as black holes and neutron stars were being found where Einstein’s general relativity was important, not just a tiny correction as it is in our solar system. At the same time, theorists like Roger Penrose were developing new techniques to solve Einstein’s equations, which was a big leap forward.

【1】理查德·韦伯：当你开始研究宇宙学时，宇宙起源于大爆炸的想法甚至没有被科学接受。在过去的半个世纪里，情况发生了怎样的变化？
马丁·里斯：令人惊讶。当我在1960年代中期开始研究时，[已故的]天文学家Fred Hoyle仍在倡导一个从永恒存在到永恒的稳态宇宙的想法。大爆炸理论的证据非常薄弱。1964年，当宇宙微波背景辐射被发现时，争论在大多数人的头脑中得到了解决——宇宙微波背景辐射是一个炽热、密集的早期阶段的遗迹。
这是开始研究的好时机。在爱因斯坦的广义相对论的重要帮助下，科学家发现了黑洞和中子星等物体，而不仅仅是对我们太阳系中的微小修正。与此同时，像罗杰·彭罗斯这样的理论家正在开发求解爱因斯坦方程的新技术，这是一个巨大的飞跃。

Is the big bang theory set in stone now?
As in all of science, every advance opens up new questions. We can understand the physics of the universe right back to when it was a microsecond old. That’s an amazing achievement. But why is the universe expanding the way it is? Why does it contain the mixture of atoms, radiation and dark matter that it does? And why did it have the kind of irregularities that resulted in it not remaining a uniform gas, but developing clusters of galaxies?
The answer to those questions lies before the first microsecond, when the entire universe was just the size of a tennis ball. As yet, we’ve got no experimental foothold on the very extreme physics involved.

【2】大爆炸理论现在已经被确认了吗？
与所有科学一样，每一次进步都会带来新的问题。我们可以从宇宙仅一微秒年龄的时候开始了解宇宙的物理性质。这是一项了不起的成就。但是为什么宇宙会以现在的方式膨胀呢？为什么它包含原子、辐射和暗物质的混合物？为什么它有那种不规则性，导致它没有保持均匀的气体，而是发展出星系团？
这些问题的答案存在于宇宙生命的第一微秒之前，那时整个宇宙只有网球那么大。到目前为止，我们在所涉及的非常极端的物理学上还没有实验立足点。

Clearly, our knowledge is incomplete. We know dark matter behaves like neutral particles in a swarm that don’t collide with each other. We notice about five times as much mass in that form as within atoms, and that allows us to get a good model of how galaxies form. What it is, we don’t know. But it is easy to envisage particles we haven’t discovered yet and that are harder to discover. There’s no reason why everything in the universe should shine.
Dark energy is telling us something we don’t understand about space itself. It’s saying that the vacuum itself has properties: it exerts a force that causes the universe to accelerate when you’d expect it to be decelerating through gravity’s pull. I think this is one of the big challenges related to the very, very early universe. With dark matter, I think there’s a reasonable hope, within the next 20 years, of making progress. With dark energy, I think it will be much longer.

【3】当宇宙的95%以我们无法解释的形式出现时，我们能声称有任何理解吗？也就是说，暗物质和暗能量？
显然，我们的知识是不完整的。我们知道暗物质的行为就像一群不会相互碰撞的中性粒子。我们注意到这种形式的质量大约是原子内部的五倍，这使我们能够获得一个很好的星系形成模型。它是什么，我们不知道。但是很容易想象我们还没有发现的粒子，而这些粒子更难被发现。没有理由宇宙中的一切东西都会发光。
暗能量告诉我们一些我们对空间本身不了解的事情。据说真空本身具有特性：它施加的力会导致宇宙加速，而你预计它会因重力的拉动而减速。我认为这是与非常非常早期的宇宙相关的重大挑战之一。对于暗物质，我认为在未来 20 年内取得进展是有合理希望的。而对暗能量的研究，我想需要更长时间。

Meanwhile, cosmology is increasingly embracing outlandish concepts such as the multiverse. Do you subscribe to that idea?
The multiverse comes from the theory of inflation, the best theory we have to explain why the universe is as large and uniform as it is now. It implies that it started off small enough that quantum fluctuations could have shaped the entire universe. One idea developed out of that, mainly by the cosmologist Andrei Linde, is eternal inflation, this idea that inflation might go on, producing many big bangs and many universes.
I was once at a panel discussion with Linde. Someone asked: would you bet your goldfish, your dog or your life on the multiverse? I said I was dealing with a dog level. Linde said he had spent 25 years on this theory, so he would almost bet his life. When asked his views at a later conference, [physics Nobel laureate] Steven Weinberg said he would happily bet Martin Rees’s dog and Andrei Linde’s life. But I think Andrei Linde, my dog and I will all be dead before it’s settled.

【4】与此同时，宇宙学越来越多地接受诸如多元宇宙之类的古怪概念。你同意这个想法吗？
多元宇宙来自宇宙大爆炸理论，这是我们必须解释为什么宇宙像现在这样大而均匀的最佳理论。这意味着它开始时足够小，以至于量子涨落可以塑造整个宇宙。主要由宇宙学家安德烈·林德（Andrei Linde）由此产生的一个想法是永恒的膨胀，这个想法认为膨胀可能会继续，产生许多大爆炸和许多宇宙。
我曾经和林德一起参加小组讨论。有人问：你会把你的金鱼、你的狗或你的生命赌在多元宇宙上吗？我说我处理的是狗级别的。林德说，他在这个理论上花了25年时间，所以他几乎赌上性命。在后来的一次会议上，当被问及他的观点时，[诺贝尔物理学奖获得者]史蒂文·温伯格说，他很乐意以马丁·里斯的狗和安德烈·林德的生命为赌注。但我认为安德烈·林德、我的狗和我都会在一切尘埃落定之前死去。
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One idea associated with the multiverse is the anthropic principle – that certain features of the universe are just so because if they were any different, we wouldn’t exist to observe them. Isn’t that a bit of a cop-out?
One of the theories that would explain what happened under the extreme conditions of the big bang – string theory – suggests that empty space, the vacuum, is not simple. It’s got a microstructure, so there may be many different versions of it. Many big bangs might cool down in such a way that they ended up with a space with different conditions – a different strength of gravity or nuclear forces, a different mass of the electron. Only a subset of them would have had the properties that allowed life to emerge: for example, if gravity was very strong, obxts as big as us couldn’t exist without being crushed, so we need gravity to be important, but very weak. It’s all speculative, but what it’s saying is that reality is very complicated. There are many things we can’t predict: the weather a month ahead, for example, because of chaos theory. What we now regard as universal laws prevailing throughout the observable universe may, in the grander perspective of the multiverse, be just parochial bylaws applying in our cosmic patch. I don’t think you can call that a failure, just as you can’t blame weather forecasters for not giving an exact weather forecast.

【5】与多元宇宙相关的一个想法是人择原理——宇宙的某些特征之所以如此，是因为如果它们有任何不同，我们就不会存在那里和观察它们。这不是有点逃避吗？
可以解释大爆炸极端条件下发生的事情的理论之一——弦理论——表明空旷的空间，即真空，并不简单。它有一个微观结构，所以它可能有许多不同的版本。许多大爆炸可能会以这样一种方式冷却下来，最终形成一个具有不同条件的空间——不同的重力或核力强度，不同的电子质量。它们中只有一部分具有允许生命出现的特性：例如，如果重力非常强，那么像我们这样大的物体不可能存在而不被压碎，所以我们需要重力很重要，但是很弱。这都是推测性的，但它所说的现实非常复杂。有很多事情我们无法预测：例如，由于混沌理论，未来一个月的天气。我们现在所认为的普遍存在于可观测宇宙中的普遍规律，从多元宇宙的更宏大的角度来看，可能只是适用于我们宇宙补丁的狭隘章程。我认为你不能称之为失败，就像你不能责怪天气预报员没有给出准确的天气预报一样。
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（图：“地球升起”——在阿波罗 8 号登月任务上拍摄的标志性照片，美国国家航空航天局/比尔安德斯）

We have just seen the launch of the James Webb Space Telescope. What answers will it give us?
There are two important fields that it’s going to illuminate. One is the very early stages of galaxy formation. About a half a million years after the big bang, the universe enters a literal dark age until the first stars form and light it up again. We’d like to know whether these first stars form already in galactic structures or separately.
The second is the search for life in the universe. One of the most exciting developments in the past two decades has been the realisation that our solar system isn’t that special. If there were an Earth-like planet around one of the nearest stars, the Webb telescope might be able to take a crude spectrum of its light.
We might be able to use this to show evidence of life. It is probably just about the limit of what it can do. But if I look ahead 50 years, I would hope there will be large telescopes in space that will not merely detect light from extrasolar planets, but even a blurred picture revealing their surface features. It would be great if by 2068 – 100 years after the famous ‘Earthrise’ – we could display an image of another Earth.

【6】我们刚刚看到了詹姆斯韦伯太空望远镜的发射。它会给我们什么答案？
它将阐明两个重要领域。一是星系形成的早期阶段。大爆炸后大约50万年，宇宙进入了真正的黑暗时代，直到第一颗恒星形成并再次点亮它。我们想知道这些第一颗恒星是在银河结构中形成还是单独形成。
二是在宇宙中寻找生命。在过去的二十年中，最令人兴奋的发展之一是我们意识到我们的太阳系并不是那么特别。如果最近的一颗恒星周围有一颗类地行星，韦伯望远镜或许能够获取其光的粗略光谱。
我们也许可以用它来展示生命的证据。这可能只是它可以做的极限。但如果我展望未来50年，我希望太空中会有大型望远镜，它们不仅能探测到来自太阳系外行星的光，甚至还能通过模糊的图片来揭示它们的表面特征。如果到2068年——著名的“地球升起”100周年后——我们可以展示另一个地球的图像，那就太好了。

Is not just life, but intelligent life, out there?
My view is that any intelligent life is unlikely to be a flesh-and-blood civilisation, but some exotic and possibly malfunctioning electronic entity. The timespan of our technological civilisation is just a few thousand years, and it could be less than another 1000 before it’s usurped by electronic entities. That is a very thin sliver of time, not only compared with the three and a half billion years of Darwinian evolution, but also to the billions of years that lie ahead. If there were another planet in the galaxy that had evolved like ours, it would be most unlikely we would catch it in this sliver.

【7】不只是生命，还有智慧生命，存在吗？
我的观点是，任何智能生命都不太可能是有血有肉的文明，而是某种奇异的、可能出现故障的电子实体。我们科技文明的时间跨度只有几千年，再过1000年就被电子实体篡夺了。与达尔文进化的35亿年的达尔文进化相比，与未来的数十亿年相比，那是非常短的时间。如果银河系中还有一颗像我们一样进化的行星，我们不太可能在这块碎片中捕捉到它。

Why stop at electronic organisms?
I completely agree. Since we are not the culmination of intelligence, we’ve got to be mindful that there could be aspects of reality of which we are unaware, which our brains couldn’t grasp. And so it could be that there is complexity and intelligence out there of a kind different from anything we can envisage.

【8】为什么要停留在电子有机体上？
我完全同意。由于我们不是智力的顶峰，我们必须注意现实中可能存在我们不知道的方面，而我们的大脑无法掌握这些方面。因此，可能存在与我们所能想象的任何事物不同的复杂性和智能性。

Talking of lifespans, two decades ago, you put the probability of our own extinction by 2100 at about 50 per cent.
I’ve since refined the arguments. I think the chance of something wiping out every human is small. On the other hand, I think the chance of some serious global setback to civilisation is quite high. This century is special: it’s the first in which one species has the power to determine the future of life on Earth. Of course, we started saying things like that when nuclear weapons were developed. But they are expensive, they need special facilities to build and we can monitor them. Now we have bio and cyber weapons and genetic modification, for example “gain of function” experiments to make a virus more virulent or transmissible. Threats that can cause a serious setback to our interconnected civilisation can be created in labs, or even in someone’s bedroom.

【9】谈到寿命，二十年前，你认为我们自己到2100年灭绝的概率约为50%。
我已经完善了这些论点。我认为某种东西消灭每个人的可能性很小。另一方面，我认为全球文明严重倒退的可能性很高。本世纪很特别：这是第一个物种有能力决定地球生命未来的世纪。当然，当核武器研制出来时，我们就开始这么说。但是它们很昂贵，需要特殊的设施来建造，我们可以监控它们。现在我们有了生物和网络武器以及基因改造，例如“功能获得”实验，以使病毒更具毒性或传播性。可能对我们相互联系的文明造成严重挫折的威胁可以在实验室甚至某人的卧室中制造。

How should we be responding to these threats?
One thing we need is more resilience. Covid-19 has shown how dependent we are on networks: suppose the internet had failed during lockdown. We shouldn’t depend on supply chains where a single lix disrupts manufacturing, and we should keep a lot more slack in our hospitals.
But the ability of a few disaffected people to create a global catastrophe means we’re also going to have to contend with a tension between three things we want to preserve: freedom, privacy and security. We may be forced to accept more intrusive surveillance as the price we have to pay to minimise the risk of catastrophe.

【10】我们应该如何应对这些威胁？
我们需要的一件事是更有弹性。Covid-19显示了我们对网络的依赖程度：假设互联网在封锁期间出现故障。我们不应该依赖可能被单一环节扰乱生产的供应链，同时我们应该在医院增加更多床位。
但少数心怀不满的人制造全球灾难的能力意味着我们也将不得不应对我们想要保护的三件事之间的紧张关系：自由、隐私和安全。我们可能被迫接受更具侵入性的监视作为我们必须付出的代价，以尽量减少灾难的风险。
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（图：英国剑桥郡伊利大教堂，伊万·沃多文/阿拉米）

Climate change and biodiversity loss represent a different form of existential threat that we are failing to tackle…
The problem is that when something sudden like covid-19 happens, politicians and the public are immediately aware that they must do something about it, whereas, with these slow-burners, we are rather like the frog in the pot of water that is being heated – not taking action until it is too late to escape.

【11】气候变化和生物多样性丧失代表了我们未能解决的另一种形式的生存威胁……
问题是，当像covid-19这样的突发事件发生时，政客和公众会立即意识到他们必须对此采取措施，然而，有了这些慢热的人，我们就像是锅里温水中的青蛙，正在被加热——一直不采取行动，等想要逃跑时为时已晚。
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Do you despair at our inability to think longer term?
There’s a paradox that strikes me whenever I visit Ely Cathedral, an amazing building just a few miles away from where we are sitting. It was built by masons as a structure that wasn’t to be finished in their lifetime, but which still inspires us 800 years later. We can’t think long term like they did. I think the reason is that those masons thought their grandchildren would live similar lives to them. Now, however, the pace of technological change means we don’t know enough about the preferences of people half a century in the future to be able to make confident plans. Although our horizons in space and time have hugely expanded, our capacity to do reliable long-term planning is less than it was in medi times.

【12】您对我们无法长期规划感到绝望吗？
每当我参观伊利大教堂时，都会遇到一个悖论，这是一座离我们坐的地方只有几英里远的令人惊叹的建筑。它是由泥瓦匠建造的，持续几代人才能完成，但在800年后仍然激励着我们。而我们却不能像他们那样长期规划。我认为原因是那些泥瓦匠认为他们的孙子会过着与他们相似的生活。然而，现在技术变革的步伐意味着我们对未来半个世纪的人们的偏好还不够了解，无法做出自信的计划。尽管我们在空间和时间上的视野已经大大扩展，但我们进行可靠的长期规划的能力却不如中世纪。

So meeting climate targets isn’t enough to plan for future generations?
Even if a country such as the UK meets its net-zero target by 2050, that is only a small contribution. What’s more important is what happens to the 4 billion people who will be in India or sub-Saharan Africa by 2050, and who are going to need more per-capita energy if they are to develop. If we can somehow enable them to leapfrog directly to clean energy, just as they’ve leapfrogged directly to smartphones having never had landlines, then that will be something which does more for the world than simply meeting our own targets.

【13】那么满足气候目标还不足以为子孙后代做长远规划吗？
即使像英国这样的国家到2050年实现净零排放目标，这也只是很小的贡献。更重要的是，到2050年，将在印度或撒哈拉以南非洲的40亿人发生什么变化，如果他们要发展，他们将需要更多的人均能源。如果我们能够以某种方式使他们能够直接跨越到清洁能源，就像他们从没有固定电话直接跨越到智能手机一样，那么这将比简单地实现我们自己的目标对世界更有帮助。

When you started out as a scientist, it was the middle of the space race. Now, we’re back there again. Is space the solution to our problems?
I think it’s a dangerous delusion to imply, as Elon Musk does, and as my late colleague Stephen Hawking did, that there could be mass migration to Mars to avoid Earth’s problems. Dealing with climate change on Earth is a doddle compared to terraforming Mars to make it habitable.

【14】当你开始成为一名科学家时，那是太空竞赛的中间阶段。现在，我们又回到了那里。太空是解决我们问题的方法吗？
我认为，正如埃隆马斯克和我已故同事斯蒂芬霍金所做的那样，暗示可能会有大规模迁移到火星以避免地球的问题，这是一种危险的错觉。与改造火星使其适合居住相比，应对地球上的气候变化是一件轻而易举的事。

Should we be sending astronauts to space at all?
If I was from the US, I wouldn’t want my tax money to go to NASA’s space programme for human space flight. Miniaturisation and robotics are advancing fast, so the practical case for astronauts is getting weaker all the time.

【15】我们应该把宇航员送上太空吗？
如果我来自美国，我不希望我的税款用于NASA的载人太空飞行太空计划。小型化和机器人技术正在快速发展，因此宇航员的实用价值一直在变弱。

What about Elon Musk, Jeff Bezos and the other billionaires attempting it?
They can do it more cheaply and can afford to take higher risks than NASA or any Western government could impose on publicly funded civilians. If you look back to the space shuttle, it was launched 135 times and failed twice, resulting in catastrophic crashes.
Each of those was a big trauma in the US. But a less than 2 per cent failure rate is acceptable to test pilots and thrill seekers. If Messrs Bezos and Musk want to have a programme of human space flight for thrill seekers prepared to take a risk, that is great. But they shouldn’t present it as tourism.
One reason why I wish them luck is that human enhancement is going to be strongly regulated on Earth. But if there are these guys in a hostile environment on Mars, they would have every incentive to adapt themselves to that environment and they’d be away from the regulators. So if there is to be a post-human species, then it could evolve fastest from the progeny of these bold pioneers.

【16】Elon Musk、Jeff Bezos和其他尝试这样做的亿万富翁呢？
与美国宇航局或任何西方政府对公共资助的平民施加的风险相比，他们可以以更便宜的成本和承受能力承担更高的风险。如果你回顾航天飞机，它发射了135次，失败了两次，导致了灾难性的坠毁。
在美国，每一个都是巨大的创伤。但是对于试飞员和寻求刺激的人来说，低于2%的失败率是可以接受的。如果贝佐斯和马斯克想要为准备冒险的寻求刺激的人制定一个载人太空飞行计划，那就太好了。但他们不应该将其作为旅游业。
我祝他们好运的一个原因是人类增强实验在地球上受到严格监管。但是，如果这些人在火星上的恶劣环境中，他们将有充分的动力使自己适应这种环境，并且他们将远离监管机构。因此，如果要存在一个后人类物种，那么它可能会从这些大胆的先驱者的后代中出现并以最快的速度进化。

Which achievements are you most proud of when you look back on your life as a scientist?
I wouldn’t claim any great individual achievements, but I think I’ve been very lucky to have contributed to exciting debates that have led to a growth in the understanding of the cosmos, galaxies and stars.
I think when the history of science in this half-century is written, then the expansion in our understanding of the cosmos will be one of the exciting chapters.

【17】当你回顾你作为科学家的生活时，你最自豪的成就是什么？
我不会声称任何伟大的个人成就，但我认为我很幸运能够为激动人心的辩论做出贡献，这些辩论导致了对宇宙、星系和恒星的理解的增长。
我想当这半个世纪的科学史写完，我们对宇宙理解的扩展，将是激动人心的篇章之一。