[(Title)] In a cosmic first, scientists detect 'ghost particles' from a distant galaxy.

When the sun was young and faint and the Earth was barely formed, a gigantic black hole in a distant, brilliant galaxy spat out a powerful jet of radiation.

当太阳年轻，微弱，地球几乎没形成，一个遥远的，灿烂的星系中的巨大的黑洞喷射出强大的辐射流。

That jet contained neutrinos - subatomic particles so tiny and difficult to detect they are nicknamed "ghost particles."

辐射流有中微子-亚原子粒子，如此微小和难以察觉，它们被称为“幽灵粒子”。

Four billion years later, at Earth's South Pole, 5,160 sensors buried more than a mile beneath the ice detected a single ghostly neutrino as it interacted with an atom. Scientists then traced the particle back to the galaxy that created it.

四十年后，在地球南极，5,160个传感器埋在冰下方一英里的地方，发现了一个幽灵的中微子，它与原子相互作用，科学家们随后追踪到了产生它的星系。

The cosmic achievement, reported Thursday by a team of more than 1,000 researchers in the journal Science, is the first time scientists have detected a high-energy neutrino and been able to pinpoint where it came from.

一个由一千多名研究人员组成的研究小组星期四在《科学》杂志上报道的宇宙成就，是科学家首次发现高能量的中微子，并且能够确定它来自何处。

It heralds the arrival of a new era of astronomy in which researchers can learn about the universe using neutrinos as well as ordinary light.

它预示着天文学的新时代的到来，在这个时代里，研究人员能够利用中微子以及普通光了解宇宙。

This is physics at its most mind-boggling and extreme.

这是物理学最难以置信和极端的物理学。

Researchers compared the breakthrough to the 2017 detection of ripples in space time caused by colliding dead stars, which added gravitational waves to scientists' toolbox for observing the cosmos.

研究人员将这一突破与2017年由于死星碰撞引起的时空涟漪检测进行了比较，后者为科学家观察宇宙的工具箱增加了引力波。

Neutrinos are so small that they seldom bump into atoms so humans can't feel them. They don't shed light, so our eyes can't see them. Yet these very qualities make them invaluable for conveying information across time and space, scientists say.

科学家们说，中微子非常小，很少碰到原子，因此人类无法感觉到它们，它们不会发光，因此我们的眼睛看不见它们，但是这些特性使它们非常宝贵地传递跨越时间和空间的信息。

Light can be blocked and gravitational waves can be bent, but neutrinos are unscathed as they travel from the most violent events in the universe into a detector at the bottom of the Earth.

光可以被阻挡，引力波可以被弯曲，但中微子从宇宙中最暴力的事件中穿透到地球底部的一个探测器时却毫发无损。

Scientists call the kinds of signals they can detect through space, like radio waves or gravitational waves or now neutrinos, "messengers."

科学家称将那些可以传递的空间信号称为“信使”，比如无线电波或引力波，以及现在的中微子。

If you're trying to understand complex and chaotic phenomena happening billions of light-years away, it's helpful to have a messenger like a neutrino: one that doesn't get lost.

如果你试图了解数十亿光年之外发生的复杂而混乱的现象，有像中微子这样的信使是有帮助的：一个没有丢失的信使。

"They're very clean, they have simple interactions, and that means every single neutrino interaction tells you something," said Heidi Schellman,

“它们非常干净，相互作用简单，这意味着每一个中微子相互作用都会告诉你一些事情，”海迪·谢尔曼说。

a particle physicist at Oregon State University and computing coordinator for a different neutrino detection project, the Deep Underground Neutrino Experiment, who was not involved with the new research.

他是俄勒冈州立大学的粒子物理学家兼不同中微子探测项目的计算协调员，深地下中子实验，没有参与新的研究。

Neutrinos arrive on Earth at varying energy levels, which are signatures of the processes that created them.

中微子以不同的能量水平到达地球，而这正是产生这些物质的过程的标志。

By pairing neutrino detections with light observations, Schellman said, scientists will be able to answer questions about distant cataclysms, test theories about the composition of the universe,

谢尔曼说，通过将中微子探测器与光观测结合起来，科学家将能够回答有关远方大灾难的问题，测试关于宇宙组成的理论，

and refine their understanding of the fundamental rules of physics.

并完善他们对物理基本规则的理解。

The high-energy neutrino reported Thursday was created in the fast-moving swirl of matter around a supermassive black hole at the center of the galaxy.

上周四报道的高能量中微子是在星系中心超大质量黑洞周围快速流动的物质旋流中产生的。

When this black hole generates a brilliant jet of radiation, and that jet is aimed directly at Earth, scientists call the galaxy a "blazar."

当这个黑洞产生了强大辐射流射流，直接瞄准地球喷射，科学家把该星系称为“布莱扎尔”。

Subsequent analysis revealed this blazar had also produced a flare of more than a dozen neutrino events several years earlier.

随后的分析表明，“布莱扎尔”在几年前还产生了一十多起中微子事件。

The new discovery, from the South Pole neutrino detector called IceCube, has also solved a mystery that stumped scientists for generations: What is the source of mysterious cosmic rays?

这个新的发现，来自南极的以微子为名的冰立方探测器，也解决了几代人以来困扰着科学家的奥秘：神秘宇宙射线的来源是什么？

These extremely energetic particles have been detected raining down from space since 1912, but researchers could not figure out what phenomenon could produce particles moving at such high speeds.

自1912年以来，这些极富活力的粒子被探测到从太空的降雨，但研究人员无法弄清楚是什么现象能产生以如此高的速度运动的粒子。

Astroparticle physicist and IceCube spokesman Darren Grant said it's as though scientists have spent 100 years listening to thunder with their eyes closed and never known what caused the booming sound.

阿斯特罗帕蒂斯物理学家和冰块发言人达伦·格兰特说，好像科学家花了一百年时间闭上眼睛，倾听着雷声，却从未知道是什么引起了轰鸣。

It wasn't until they looked up and saw lightning that the spectacle finally made sense. Both sound and light - or in this case, cosmic rays and neutrinos - are coming from the same event.

直到他们抬头一看，看到闪电最终才意识到这种景象，声音和亮光，或者宇宙射线和中微子都来自同一个事件。

"That's why this is exciting," Grant said of the neutrino detection. "It's a brand new vision on what's happening in the universe."

格兰特谈到中微子探测时说道：“这就是宇宙发生的全新视角。”

What is a neutrino?

什么是中微子？

Our universe is suffused with neutrinos, so named because they are uncharged (or "neutral") and infinitesimally puny (about a millionth of the mass of an electron).

我们的宇宙被中微子所淹没，因此被称为，因为它们是未知的（或“中性”的）和无穷小的（大约电子质量的百万分之一）。

They are created in nuclear reactions - at power plants, in the center of the sun, and amid even more extreme events - when protons accelerate, collide and then shatter in a shower of energetic particles.

它们是在核反应中产生的，即在发电厂、太阳中心以及在更为极端的事件中，当质子加速、碰撞和碎裂时，充满活力的粒子。

Neutrinos are the second most abundant type of particle in the universe, after photons (light particles). If you held your hand toward the sky, about a billion neutrinos from the sun would pass through it in a single second.

中微子是宇宙中第二大最丰富的粒子，仅次于光子粒子（光粒子），如果你把手伸向天空，那么太阳中的中微子将会在一秒钟内通过。

But you wouldn't feel their presence, because these ethereal particles rarely interact with normal matter. Unless a neutrino bumps right up against another particle, it passes through matter undisturbed and undetected.

但是你不会感觉到他们的存在，因为这些以太粒子很少与正常的物质相互作用。除非中微子撞击与另一种粒子，它通过物质不受干扰和不被察觉。

And the reality is, most of what we call "matter" is just empty space. If a hydrogen atom were the size of Earth, the proton at its center would fit inside the Ohio State football stadium.

而现实是，我们所谓的“物质”大部分只是空空，如果氢原子是地球大小的话，那么位于中心区的质子将会出现在俄亥俄州足球场里。

The electron orbiting it would be even smaller, and a neutrino could be compared to a lone ant.

绕着它转的电子会更小，而中微子可以被比作一只蚂蚁。

Neutrinos are said to come in "flavors" - called electron, muon and tau - and on the rare occasions that they collide with other matter they generate corresponding charged particles.

据说中微子具有“味道” - 称为电子，μ子和τ - 并且在极少数情况下它们与其他物质碰撞时会产生相应的带电粒子。

Many neutrino detectors work by looking for the flash of light emitted by these charged particles as they move through water or ice.

许多中微子探测器通过寻找这些带电粒子在水中或冰中移动时发出的闪光来工作。

Flavored specks that are found everywhere yet felt by no one; matter that seems solid but is actually mostly empty - this is the bizarre science of particle physics. It's difficult to wrap your mind around, and almost hard to believe.

任何地方都能找到的味道斑点，但没有人感觉到; 看起来很稳固但实际上大部分都是空的物质 - 这是粒子物理学的奇异科学。 很难将你的思想包裹起来，几乎很难相信。

Yet scientists assure us they are not just making things up.

然而科学家向我们保证，他们不是胡编乱造。

Since the 1950s, when neutrinos were detected for the first time, researchers have observed low-energy versions of these ghostly particles coming from the sun and a 1987 supernova in a nearby galaxy.

自20世纪50年代首次探测到中微子以来，研究人员观察到这些幽灵的粒子的低能级，这些粒子来自于太阳和1987年近星系的超新星。

Maps of neutrinos emanating from the surface of the Earth have even been used to identify the sites of nuclear reactors.

来自地球表面的中微子绘图甚至被用来识别核反应堆的场地。

But high-energy neutrinos, generated only in extreme environments where protons are accelerated to astonishing speeds, have been challenging to pin down.

但是只有在质子加速到惊人的极端环境中才能产生高能量的中微子，很难控制。

To be detected, a neutrino had to form long ago in a far away cataclysm, travel across intergalactic space, fly through our galaxy, enter our solar system, sail on to Earth,

要探测，中微子远古之前必须在遥远的大灾难中形成，穿越星系际空间，飞经我们的星系，进入太阳系，驶往地球，

and then happen to interact with a particle minding its own business in the ice below the South Pole.

然后恰好与关注自己在南极冰层下的一个粒子相互作用。

And, in a process that seems just as improbable, in the time since the neutrino left its source 4 billion years ago, life on Earth had to arise, expand, and evolve to the point that a few enterprising Homo sapiens were willing to go to the extreme effort of detecting it.

并且，在一个看起来同样不可能的过程中，自中微子在40亿年前离开其源头以来，地球上的生命诞生，演化并发展到一些有进取心的智人，愿意付出极端的努力去探测它的存在。

"It's crazy," said Chad Finley, an astroparticle physicist at Stockholm University who spent 10 years coordinating the effort to pinpoint neutrinos' origins for the IceCube team. "These are particles that seldom interact with anything.

“这太疯狂了，”斯德哥尔摩大学的天体物理学家查德芬利说，他花了10年的时间协调确定IceCube团队的中微子起源。 “这些粒子很少与任何东西相互作用。

That has to be the unluckiest neutrino ever."

“那必定是有史以来最不幸的中微子。”

On the other hand, he mused, he and his colleagues are some pretty lucky humans.

另一方面，他沉思着，他和他的同事都是相当幸运的人。

'Ghost' hunting on ice

“在冰上狩猎幽灵”

This was the detection scientists were dreaming of when the National Science Foundation began building the $279 million IceCube Neutrino Observatory in 2005.

这是国家科学基金会于2005年开始建造价值2.79亿美元的IceCube Neutrino天文台的科学家梦寐以求的探测器。

Working during the South Pole summer, when the sun never sets and temperatures hover at a balmy negative 18 degrees Fahrenheit, scientists and engineers melted dozens of mile-deep holes in the ice and dropped strings of spherical sensors into them. (Neutrino detectors are typically buried or submerged to filter out other cosmic signals that would obscure the tiny particles.)

在南极夏季工作期间，当太阳从未停止并且气温在华氏18度华氏度时徘徊时，科学家和工程师在冰上融化了几十英里深的洞，并将一串球形传感器放入其中。 （中微子探测器通常被掩埋或浸没，以滤除其他会掩盖微小粒子的宇宙信号。）

The result was a grid array of sensors spread across a cubic kilometer of glacier and capable of catching a ghost.

其结果是散布在一立方公里的冰川上的网格传感器阵列，能够捕捉到幽灵粒子。

The sensors record the energy level and direction of the flash of light emitted by the charged particle created when a neutrino crashes into other matter.

该传感器记录了微子碰撞到其他物质时带电粒子发出的闪光能量水平和方向。

From that information, scientists can extrapolate the energy level of the neutrino and where it came from.

根据这些信息，科学家可以推断中微子的能量级别和它从何处产生。

Since the observatory was completed in 2010, IceCube scientists have detected dozens of high-energy neutrinos coming from outside the solar system.

自该观测站于2010年完成以来，冰岛立方体科学家已检测到来自太阳系之外的数十种高能量中微子。

But they were never able to connect those particles with a source that could be observed by conventional telescopes.

但是，它们从来不能将这些粒子与常规望远镜能够观测到的源联系起来。

Establishing such a connection was a "holy grail of the field," Finley said, in large part because of the link between neutrinos and the enigma of cosmic rays.

建立这样的联系是“该领域的圣杯”，芬利说，这在很大程度上是因为中微子与宇宙射线的谜团之间的联系。

These are extremely energetic protons and atomic nuclei moving through space at almost the speed of light.

它们是极有活力的质子，原子核几乎以光速穿过空间。

They're considered one of the threats to humans on a potential mission to Mars: During the months-long journey through space, cosmic rays would damage the cells of astronauts and could cause radiation sickness.

它们被认为是人类在火星的潜在飞行任务中面临的威胁之一：在穿越太空的长达数月中，宇宙射线会损害宇航员的细胞，并可能导致辐射疾病。

But unlike neutrinos, cosmic rays have a charge, which means their path can be deflected by magnetic fields.

但是与中微子不同的是，宇宙射线有电荷，这意味着它们的路径可以被磁场偏移。

This allows Earth's magnetic field to protect us from these powerful particles, but it also makes it impossible for scientists to figure out where the particles come from.

这使得地球的磁场能够保护我们不受这些强大粒子的影响，但也使得科学家无法找出这些粒子的来源。

Extensive research suggests that whatever process accelerates protons to such speeds also generates high-energy neutrinos.

大量研究表明，无论何种过程将质子加速到这样的速度，都会产生高能中微子。

So if IceCube could figure out where neutrinos were coming from - a task made simpler by the fact that neutrinos are such dependable "messengers" - they'd know the source of cosmic rays as well.

因此，如果IceCube能够指出中微子来自何处，这就简单化了，因为中微子是如此可信的“信使”，那么他们也会知道宇宙射线的来源。

"Neutrinos are the smoking gun," Finley said.

“中微子是冒烟的枪，”芬利说。

On Sept. 22, an alert went out to the international astronomy community: IceCube had seen the signature of a muon neutrino coming from just above the right shoulder of the constellation Orion in the night sky.

9月22日，国际天文界发出警报：IceCube看到了一个μ子中微子的标志，它来自夜空中猎户星座右肩的正上方。

Swiftly, scores of scientists began pointing their telescopes in that direction, staring at the right region of the universe in every wavelength of the electromagnetic spectrum.

与此同时，数十名科学家开始将望远镜指向这一方向，在电磁波谱的每个波长中直视着宇宙的右侧。

Researchers using NASA's Fermi space telescope saw a burst of gamma rays coming from the presumed source. Gamma rays are associated with the particle acceleration that produces both neutrinos and cosmic rays.

研究人员使用美国宇航局的费米太空望远镜观测到来自推定来源的伽马射线爆发。 伽玛射线与产生中微子和宇宙射线的粒子加速度有关。

Other observatories saw flares of X-rays, radio waves and visible light. Taken together, these observations revealed a blazar - a giant elliptical galaxy with a spinning supermassive black hole at its core.

其他观测站看到了X光、无线电波和可见光的耀斑，这些观测同时揭示了一颗斑叶，这是一个巨大的椭圆星系，其核心是旋转超大质量黑洞。

As a blazar spins, twin jets of light and charged particles - one of which is aimed toward Earth - spurt from its poles.

当喷射光和带电粒子的两股喷射时（其中一种是针对地球的）喷射出它的极点。

The blazar was given the catchy name "TXS 0506+056" - the first known source of a high-energy neutrino, and a possible answer to the century-old cosmic ray mystery.

布拉扎尔被授予了可捕名称"TXS0506+056"，这是高能量中微子的第一个已知来源，是对百年宇宙射线神秘性的可能答案。

As a matter of due diligence, Finley suggested that the IceCube team go back through their old data to examine whether any other neutrinos had come from the same direction.

作为尽职调查问题，芬利建议IceCube小组回过以前的数据，检查是否有其他中微子来自同一方向。

He didn't expect to find anything - neutrinos react so rarely that finding more from a single source would be like lightning striking twice in the same spot.

他并不期望能找到任何中微子反应——很少反应，从单一来源获得更多就像闪电在同一地点两次击中。

So he was shocked to discover that IceCube had recorded more than a dozen neutrino events from what they now knew was the same blazar between late 2014 and early 2015.

因此，他震惊地发现，IceCube记录了十几个中微子事件。

It was so improbable that Finley found himself repeating the words uttered by Isidor Isaac Rabi, a Nobel prize-winning U.S. physicist, when he discovered the muon: "Who ordered that?"

这是不可能的，芬利发现自己重复了诺贝尔奖得主美国物理学家伊西多尔·艾萨克·拉比所说的话，当时他发现了一个μ子：“谁下的令？”

'An absolutley beautiful messenger'

“一个极其美丽的信使”

Combined with gravitational wave detection and traditional light astronomy, the observation of a neutrino from a known source gives researchers three ways to observe the cosmos,

结合引力波探测和传统的光天文学，从已知源观测中微子为研究人员观测宇宙提供了三种方法，

and they say we're now in the era of "multi-messenger astrophysics." (Since gravitational waves are often described as the way we "hear" the universe and light is how we "see" it, some scientists wondered whether neutrinos would be how we "smell" it.)

他们表示，我们现在处在一个“多引力信使天体物理学时代”（因为人们常把波描述为我们“听到”宇宙和光的方式，也就是我们如何看待它，一些科学家想知道，中微子到底是如何闻到它的）。

Of all these "senses," neutrinos are in some ways the most reliable. High-energy light from distant sources rarely makes it to Earth, because photons are so reactive they get lost along the way.

在所有这些“感官”中，中微子在某种程度上是最可靠的。来自远方的高能量光很少能到达地球，因为光子如此被动，在途中会丢失。

Neutrinos, on the other hand, will travel in a straight line right from their origin point to a detector.

另一方面，中微子将从源点直行到探测器。

"It's an absolutely beautiful messenger," Grant said.

格兰特说：“这是个非常漂亮的信使。

Neutrinos' ghostly quality also means they can be used to probe celestial objects light can't penetrate.

中微子的幽灵品质也意味着可以用来探测天体光无法穿透。

Schellman pointed out that astronomers using regular telescopes can't see beneath the surface of the sun, but 30 years of observations of the low-energy neutrinos that emanate from our star's center have allowed scientists to peer into its core.

谢尔曼指出，天文学家使用常规望远镜不能在太阳表面下看到，但是从恒星中心产生的低能量中微子经过30年的观察使科学家得以同心同感。

By looking at their energy levels, researchers could understand the fusion process that creates the neutrinos and generates the sun's energy.

通过观察他们的能量水平，研究人员可以理解产生中微子的融合过程，并生成太阳的能量。

This research also revealed that it takes 100,000 years for energy at the center of the sun to make it to the surface, "which means the sun is going to keep working for at least 100,000 years," Schellman said.

这项研究还表明，太阳中心的能量需要10万年，才能到达地面，"这意味着太阳将持续至少10万年，"谢尔曼说。

So that's one disaster Earthlings don't have to worry about.

所以这是地球人不必担心的一场灾难。

The neutrinos detected by IceCube are millions of times more energetic than those coming from the sun, but they offer the same kinds of insights into the intense environments from which the particles emanate.

IceCube探测到的中微子要比来自太阳的中微子多出几百万倍，但是它们提供了同样的洞察力，了解粒子产生出的强烈环境。

The telescopes looking at TXS 0506+056 could only capture what happened on the surface of the blazar; the neutrinos carry signatures of the processes at its very center.

观察TXS0506+056的望远镜只能记录在布拉扎尔表面发生的事情；中微子把过程签名放在它的中心。

It's in these extreme settings that the laws of nature are stretched to their limits.

正是在这些极端环境中，自然法则被延伸到了极限。

What neutrinos reveal about the acceleration of charged particles and the voracious behavior of black holes could help scientists refine the rules of physics - or rethink them.

中微子揭示了带电粒子的加速以及黑洞的贪婪行为，这有助于科学家完善物理的规则或者重新思考。

And there are even more energetic neutrinos out there - ones that make the powerful IceCube particles look practically wimpy.

还有更精力充沛的中子体——它们使得强大的冰立方粒子几乎看起来无足轻重。

To Schellman, this suggests that other, even more chaotic and cataclysmic, sources of neutrinos are still waiting to be found.

对于谢尔曼来说，这表明，其他更为混乱和灾难性的中微子源仍在等待被发现。

"There are things we don't even know about yet," she said. "This is just the start."

“有些事情我们还不知道，”她说，“这只是个起点。”