评论
打印
In Arizona, at Kitt Peak National Observatory, a telescope has spent three years building a three-dimensional map of the heavens.
在亚利桑那州的基特峰国家天文台，一台望远镜花了三年时间绘制了一幅三维天空地图。
In examining the light from tens of millions of galaxies, the Dark Energy Spectroscopic Instrument (DESI) may have found something astounding.
在检查数千万个星系发出的光时，暗能量光谱仪(DESI)可能发现了一些令人震惊的东西。
DESI, as its name suggests, is a tool to investigate the nature of dark energy, a mysterious entity that accounts for 68% of everything in the universe and which pushes space apart in a repulsive version of gravity.
DESI，顾名思义，是一种研究暗能量性质的工具，暗能量是一种神秘的实体，占宇宙中所有物质的68%，它以排斥力的形式将空间推开。
Though they do not know what it is, scientists have hitherto assumed that the density of dark energy has been the same since the start of the universe, 13.7bn years ago.
虽然科学家们不知道它是什么，但他们迄今为止一直认为，暗能量的密度自137亿年前宇宙诞生以来一直保持不变。
But DESI's initial results suggest that this assumption may have been wrong. Perhaps, say DESI's scientists, the density has been changing over time.
但DESI的初步结果表明，这一假设可能是错误的。DESI的科学家说，也许暗能量的密度一直在随着时间而变化。
"It's so bizarre," says Dragan Huterer from the University of Michigan, who was involved with the work.
“这太奇怪了，”参与这项工作的密歇根大学的德拉甘·胡特尔（Dragan Huterer）说道。
If the findings prove true, it would catapult cosmology into a crisis. The study of dark energy is surprisingly new.
如果这一发现被证实，那么宇宙学将陷入危机。暗能量的研究出奇新颖。
Direct evidence for its existence was not detected until 1998, when scientists discovered that extremely bright exploding stars called supernovas were moving away from Earth much more quickly than they ought to.
直到1998年，科学家才发现暗能量存在的直接证据，当时科学家发现，被称为超新星的极其明亮的爆炸恒星正在以比应有的速度快得多的速度远离地球。
Their conclusion: not only was the universe expanding, but that expansion was accelerating.
他们得出的结论是：宇宙不仅在膨胀，而且膨胀速度还在加快。
"People did not expect that," says Adam Riess of Johns Hopkins University, who shared a Nobel prize in physics for the discovery in 2011.
“人们没有想到这一点，”约翰霍普金斯大学的亚当·利斯说道，他因这一发现于2011年获得诺贝尔物理学奖。
Because it is hard to study directly, the true nature of dark energy remains poorly understood. The leading hypothesis is that it is energy intrinsic to the vacuum of empty space.
由于很难直接研究，暗能量的真正本质仍不太清楚。主流假设是，它是真空中固有的能量。
Per quantum theory, a vacuum is not really empty, it fizzes with countless pairs of particles and antiparticles that emerge from nothing, only to annihilate each other.
根据量子理论，真空并不是真正空的，它充满了无数对从虚无中出现的粒子和反粒子，最终相互湮灭。
These interactions produce a "vacuum energy" that, over the scales of the cosmos, could push space apart.
这些相互作用产生了一种“真空能量”，在宇宙尺度上，它可以将空间推开。
This idea is not without its problems—when physicists try to calculate what this vacuum energy density would amount to, they get a value between 60 and 120 orders of magnitude larger than what observational evidence currently supports—a fiasco known as the vacuum catastrophe.
这一观点并非没有问题。当物理学家试图计算真空能量密度时，他们得到的值比目前观测证据支持的值高出60到120个数量级，这一惨败被称为真空剧变。
"The general consensus is that resolving the [catastrophe] will require fundamental new insight," says Dr Huterer.
“普遍的共识是，解决[灾难]需要根本的新见解，”胡特尔博士说道。
Vacuum catastrophe aside, dark energy now forms one of two central pillars of the standard model of cosmology, the best scientific description of the universe's evolution.
除了真空剧变之外，暗能量现在是宇宙学标准模型的两个核心支柱之一，这是对宇宙演化的最佳科学描述。
The other pillar is dark matter, an invisible form of matter that makes up 27% of the universe. Regular matter, which constitutes stars and galaxies, accounts for a measly 5%.
另一个支柱是暗物质，一种不可见的物质形式，占宇宙的27%。构成恒星和星系的常规物质仅占5%。
The standard model says that, after the Big Bang set the universe's expansion in motion, the gravitational attraction between atoms first led to the formation of stars and galaxies, while also acting as a brake on the universe's overall growth.
标准模型认为，在大爆炸引发宇宙膨胀后，原子之间的引力首先导致恒星和星系的形成，同时也阻碍了宇宙的整体增长。
As the amount of empty space increased, however, so did the amount of dark energy and, eventually, it took over as the primary influence on the evolution of the cosmos, driving the accelerated expansion that Dr Riess observed a quarter of a century ago.
然而，随着真空区的增加，暗能量的数量也随之增加，最终成为影响宇宙演化的主要因素，推动了利斯博士在25年前观察到的加速膨胀。
This expansion of the universe is expected to go on for ever, with galaxies eventually drifting out of each other's sight, a fate known as the Big Freeze.
宇宙的这种膨胀预计将永远持续下去，星系最终会漂移出彼此的视线，这一现象被称为大冻结。
But if, as DESI suggests, the density of dark energy can change, other scenarios come into play:
但是，如果像DESI所说，暗能量的密度可以改变，那么其他情况就会出现：
ever-denser dark energy could one day cause atoms and even the fabric of spacetime itself to burst apart, a scenario known as the Big Rip.
密度越来越大的暗能量有朝一日可能会导致原子甚至时空结构本身破裂，这种情况被称为大撕裂。
Conversely, a dark energy of decreasing density could cause matter and gravity to take over the universe once again, recollapsing the cosmos into an inverse Big Bang, known as the Big Crunch.
相反，密度降低的暗能量可能导致物质和引力再次掌控宇宙，使宇宙重新陷入逆向大爆炸，即大收缩。
(Earthlings need not worry overmuch—the Sun will swallow up the innermost planets of the solar system long before either fate occurs.)
（地球人不必过于担心——太阳会在这两种命运发生之前很久就吞噬太阳系最内层的行星。）
DESI's preliminary findings were announced at the American Physical Society's annual meeting in California in April, swiftly after a series of papers were published on arXiv, a preprint server.
DESI的初步发现于4月在加利福尼亚举行的美国物理学会年会上公布，此前不久，一系列论文在预印本服务器arXiv上发表。
The papers contained the data from the first year of DESI's five-year survey.
这些论文包含了DESI五年调查第一年的数据。
Tasked with capturing an invisible target, DESI has had to find creative, indirect methods to hunt for the signs of dark energy.
DESI的任务是捕捉一个看不见的目标，它必须找到创造性的间接方法来寻找暗能量的迹象。
The instrument's main task is to map the distribution of galaxies in space. Buried in this map are imprints of sound waves that travelled through the early universe.
该仪器的主要任务是绘制太空中星系的分布图。这张地图上隐藏着穿越早期宇宙的声波的印记。
