在人类之前，地球上是否存在过文明？

早晨洗澡好还是晚上洗澡好？

What's best a morning shower or an evening shower?

魔术能教会我们关于大脑的什么？

What can magic teach us about the brain?

随着年龄增长如何结交朋友。

Making friends as you get older.

这些话题你都能在我们的新系列《阅读室》中发现，这是我们网站上杂志风格的文章系列。

These are all topics you'll discover in The Reading Room our new series of magazine style articles on our website.

每篇文章都附有重点词汇、理解题和音频下载。

They each come with highlighted vocabulary, comprehension questions and an audio download.

在bbclearningenglish.com的《阅读室》中了解世界并提升阅读技能。这里是六分钟英语

Learn about the world and improve your reading skills with The Reading Room at bbclearningenglish.com. Six Minute English

来自bbclearningenglish.com。

from bbclearningenglish.com.

你好，这里是BBC英语学习的《六分钟英语》节目，我是贝丝。

Hello. This is six Minute English from BBC Learning English. I'm Beth.

我是菲尔。

And I'm Phil.

菲尔，你相信其他星球上存在生命吗？

Phil, do you believe there's life on other planets?

嗯，宇宙中有那么多星球。所以是的，我认为肯定存在。

Well, there's a lot of other planets. So yeah, I think there must be.

我也这么认为。这个问题引起了美国天体物理学家亚当·弗兰克的兴趣，他与美国宇航局空间研究所所长加文·施密特就此进行了讨论。亚当在BBC国际频道的《大众科学》节目中回忆了他们的对话。

Yeah, I agree. Well, it's a question that interests American astrophysicist, Adam Frank, who discussed it with his colleague Gavin Schmidt, director of NASA's Institute for Space Studies. Here, Adam recalls their conversation for BBC World Service programme CrowdScience.

我们知道地球上从未存在过其他文明，他突然打断我问'你怎么能确定？'那一刻我震惊得下巴都要掉下来了。亚当的

We know that there's been no other civilisation on earth and he stopped at me and said how do you know that? And my jaw just dropped down to the floor. Adam's

'下巴掉下来'是形容人震惊时的习语。难道在我们之前，地球上真的存在过技术先进的文明吗？

jaw dropped an idiom for when someone looked shocked and surprised. Could there have been a technologically advanced civilisation before us here on Earth?

这听起来可能有些奇怪，但这个想法有个科学名称。下面请BBC《大众科学》节目主持人卡罗琳·斯蒂尔来解释。

It may sound weird, but this idea has a scientific name. Here is Caroline Steele, presenter of BBC's CrowdScience, to explain.

志留纪假说提出，如果数亿年前存在过技术先进的文明，我们将无法找到其踪迹。

The Silurian hypothesis proposes that if there was a technologically advanced civilization hundreds of millions of years ago, we wouldn't be able to find traces of it.

假说是一种解释事物如何发生的观点，可通过测试验证其正确性。本期节目我们将探讨志留纪假说——即认为地球上曾存在过比我们更早的技术先进文明，但未留下任何痕迹就消失了。和往常一样，我们会学习一些有用的新词汇和习语。请记住，你可以在我们的网站bbclearningenglish.com上找到所有词汇表。

A hypothesis is an idea which explains how something happens and can be tested to find out if it's correct. In this episode, we'll be discussing the Silurian hypothesis, the idea that a technologically advanced civilisation existed before us on Earth, but vanished without leaving a trace. As usual, we'll be learning some useful new words and idioms. And remember, you'll find all the vocabulary on our website bbclearningenglish.com.

但首先，菲尔，我有个问题要问你。人类文明已有数千年历史，但地球本身要古老得多。科学家认为地球有多少岁？是a)35亿年 b)45亿年 还是c)55亿年？

But first, I have a question for you, Phil. Human civilization is thousands of years old, but the planet itself is much older. So how old do scientists think the Earth is? Is it a) 3,500,000,000 years b) 4,500,000,000 years or c) 5,500,000,000 years?

我猜是c)55亿年。

I'm gonna guess c) 5,500,000,000 years.

好的，我们稍后会在节目中揭晓答案。要相信数亿年前地球上存在过技术先进的文明，大多数人可能都需要证据。我们通过化石（保存在岩石中非常久远的史前动植物遗骸）获得了关于恐龙等远古物种的证据。

Okay. Well, we will find the answer out later in the programme. To believe a technologically advanced civilization existed on Earth hundreds of millions of years ago, most people would probably want evidence. We have evidence about other species from the past, such as the dinosaurs from fossils, the remains of prehistoric plants or animals that have been preserved in rock for a very long time.

但据亚当·弗兰克所说，化石无助于证明志留纪假说，正如他在BBC国际频道节目《大众科学》中所解释的那样。

But according to Adam Frank, fossils won't help prove the Silurian hypothesis, as he explains here to BBC World Service program, CrowdScience.

大多数物质并不会形成化石。地球上只有极小部分生命最终化为了化石。试想一个延续万年的文明，对地质学而言不过弹指一瞬。这段时间实在太短，难以形成大量化石。

Most things are not fossilized. It's only a tiny fraction of Earth's life that has ever become fossilized. So imagine that you have a ten thousand year long civilization, which is a blink of the eye for geology. That's too short to really create a lot of fossils.

亚当认为只有极小部分——即地球上非常少量的生命转化为了化石。

Adam argues that only a tiny fraction, meaning a very small amount of life on Earth has turned into fossil.

在地质时间尺度上，即便是万年文明也不过是弹指一挥间（这个成语意指极短时间）。换言之，地球上可能存在过更古老的文明，但存续时间不足以留下化石证据。

In geological time, even a ten thousand year old civilization is the blink of an eye, an idiom meaning a very short period of time. In other words, older civilisations might have existed on Earth, but not for long enough to leave fossilised evidence.

然而并非所有人都认同亚当的观点。我们文明自身的证据——包括塑料和混凝土等人造材料——正在不断沉积到地壳中，这些物质将存续极长时间。因此史前先进文明理应留下类似痕迹。

However, not everyone is convinced by Adam's ideas. Evidence of our own civilization, including plastics and man made materials like concrete, is already being layered into the Earth's crust. And these are going to last a very long time. So surely a technologically advanced civilization from prehistory would have left similar marks.

对此，亚当·弗兰克在BBC国际频道《大众科学》节目中再次回应了这些质疑。

Well, here's Adam Frank again answering these objections on BBC World Service programme CrowdScience.

实际情况是会有其他学者跟进研究，要么证实并补充新证据，要么提出反对意见。当积累到二三十篇甚至四十篇论文时，就会形成共识。这时我们才能确定：这个问题已经被彻底研究过了。

What happens is somebody else will pick up on their work, either affirming it and showing new evidence for it or pushing back on it. And once you get to, like, twenty, thirty, 40 papers, then you have a consensus. You're like, okay. We've really, really looked at this, and now we don't.

亚当欢迎新证据，即便是反驳他观点的证据——因为这是验证假设对错所需的科学方法。科学家们正是通过这种方式形成共识（即对该问题的普遍认同）。

Adam welcomes new evidence, even evidence which contradicts his ideas as part of the scientific method needed to prove a hypothesis right or wrong. It's how scientists form a consensus, meaning a general agreement about the issue.

我个人认为，地球上存在史前文明这个想法非常神秘，保持开放心态是可以的。贝丝，现在是不是该揭晓你问题的答案了？

Personally, I think the idea of prehistoric civilizations on Earth is so mysterious, it's okay to keep an open mind. Now, isn't it time you revealed the answer to your question, Beth?

我也这么想。我问过你科学家认为地球有多少岁。你说55亿年，但恐怕你错了，菲尔。其实是45亿年。好吧。

I think it is. I asked you how old do scientists think the Earth is. You said five and a half billion years, and I'm afraid you were wrong, Phil. It's four and a half billion years. Okay.

让我们回顾一下学过的词汇，从成语'我下巴都惊掉了'开始，这个成语用来形容某人看起来非常震惊和惊讶的样子。

Let's recap the vocabulary we've learnt starting with the idiom my jaw dropped, which is used to say someone looks very shocked and surprised.

假说是为了解释某事物而提出的建议，之后可以通过测试来验证其真实性。

A hypothesis is a suggestion that's proposed to explain something which can then be tested to see if it's true.

化石是史前植物或动物的遗骸，它们在岩石中保存了非常长的时间。

Fossils are the remains of prehistoric plants or animals that have been preserved in rock for a very long time.

某物的极小部分指的是它的非常少量。

A tiny fraction of something is a very small amount of it.

成语'眨眼之间'意味着非常短的时间。

The idiom the blink of an eye means a very short period of time.

最后，共识指的是普遍达成的协议。我们的六分钟时间又到了，但如果你还想了解更多，请访问我们的网站bbclearningenglish.com，那里有本集配套的工作表和测验。我们下次再见。现在要说再见了。

And finally, a consensus is a general agreement. Once again, our six minutes are up, but if you're keen for more, then head over to our website bbclearningenglish.com, where you'll find a worksheet and a quiz for this episode. See you again soon. But for now, it's goodbye.

再见。六分钟英语。

Goodbye. Six Minute English.

来自bbclearningenglish.com。

From bbclearningenglish.com.