Dark energy is even stranger than we thought, new 3D map of the universe suggests. 'What a time to be alive!' (video)

新的宇宙三维地图显示，暗能量比我们想象的还要神秘。‘真是个令人兴奋的时代！’（视频）

New results from the Dark Energy Spectroscopic Instrument (DESI) suggest that the unknown force accelerating the expansion of the universe isn't what we believed it to be. This hints that our best theory of the universe's evolution, the standard model of cosmology, could be wrong.

暗能量光谱仪（DESI）的最新成果显示，推动宇宙加速膨胀的未知力量并非我们之前所认为的那样，这暗示我们关于宇宙演化的最佳理论——宇宙学标准模型可能有误。

The newly released DESI data comes from its first three years of observations collected as the instrument, mounted on the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory, continues to build the largest 3D map of the universe ever created. By the time DESI completes its five-year mission next year, the instrument will have measured the light from an estimated 50 million galaxies and black hole-powered quasars, in addition to the starlight of over 10 million stars.

暗能量光谱仪（DESI）最新发布的数据来自其在基特峰国家天文台的尼古拉斯·u·梅耶尔4米望远镜上安装的仪器，过去三年间收集的数据。这些数据正在构建有史以来最大的宇宙三维地图。明年DESI完成为期五年的任务时，该仪器将测量估计5000万个星系和由黑洞驱动的类星体发出的光，以及超过1000万颗恒星的星光。

It is the capability of DESI to capture light from 5,000 galaxies simultaneously that makes it the ideal instrument to conduct a survey large enough to investigate the properties of dark energy. This new analysis focuses on data from the first three years of DESI observations, encompassing nearly 15 million of the best-measured galaxies and quasars.

暗能量光谱仪（DESI）能够同时捕捉5000个星系的光，这使其成为进行大规模调查以研究暗能量特性的理想仪器。这项新的分析聚焦于DESI观测的前三年数据，涵盖了近1500万测量最为精确的星系和类星体。

"The universe never ceases to amaze and surprise us," DESI Project Scientist Arjun Dey said in a statement. "By revealing the evolving textures of the fabric of our universe as never before, DESI and the Mayall telescope are changing our very understanding of the future of our universe and nature itself."

“宇宙总是以无尽的惊奇让我们叹为观止。”暗能量光谱仪项目科学家阿尔琼·戴在一份声明中表示，“通过以前所未有的方式揭示宇宙结构的演变纹理，暗能量光谱仪和梅耶尔望远镜正在改变我们对宇宙未来以及自然本质的理解。”

Dark energy is the placeholder name given to whatever aspect of the universe is causing the fabric of spacetime to inflate faster and faster, constantly pushing galaxies apart more rapidly.

暗能量是宇宙中某种导致时空结构加速膨胀、不断将星系彼此越推越远的未知力量的代名词。

It is thought to account for around 70% of the universe's matter and energy. The mysterious "stuff" called dark matter makes up another 25%, and ordinary matter comprising stars, planets, moons, our bodies and the cat next door accounts for just 5%. Essentially, everything we understand about the universe, including all of chemistry and biology is wrapped up in that 5%!

暗能量被认为占宇宙物质和能量总量的约70%。被称为暗物质的神秘物质占另外25%，而构成恒星、行星、月亮、我们的身体以及隔壁的猫的普通物质仅占5%。实际上，我们对宇宙的理解，包括所有化学和生物学的知识，都包含在那5%里！

The current "best guess" at the identity of dark energy is the cosmological constant, the vacuum energy of energy space, which is baked into the pie we call the standard model of cosmology or the Lambda Cold Dark Matter (LCDM) model. However, this model is built on the presumption that dark energy, represented by the Greek letter lambda (Λ), is constant over time.

目前对暗能量身份的“最佳猜测”是宇宙学常数，即空间的真空能量，它被嵌入到我们所称的宇宙学标准模型或Λ冷暗物质（ΛCDM）模型中。然而，该模型建立在暗能量（用希腊字母λ表示）随时间恒定不变的假设之上。

Vacuum energy describes the density of particles popping in and out of existence. While "something" appearing from "nothing" sounds crazy, you can think of it as the universe having an overdraft facility. Pairs of virtual particles are allow to "borrow" some energy from the cosmos to come into existence as long as they pay it back by meeting and annihilating each other.

真空能量描述了粒子不断产生和湮灭的密度。虽然“从无到有”听起来不可思议，但可以想象成宇宙有一个透支机制。虚拟粒子对被允许“借用”宇宙的能量来存在，只要它们通过相遇和湮灭来“归还”能量。

When taken in isolation, the DESI findings don't actually challenge the picture of dark energy developed in the LCDM model. It is when the DESI data is compared with other measurements of the cosmos that problems with the cosmological constant start to manifest.

单独来看，暗能量光谱仪（DESI）的发现实际上并不挑战在Λ冷暗物质（ΛCDM）模型中发展的暗能量图景。只有当DESI的数据与其他宇宙测量结果进行对比时，宇宙学常数的问题才开始显现。

DESI is hinting, and not for the first time, that dark energy isn't constant but is changing over time. Specifically, this accelerating "push" seems to be weakening.

暗能量光谱仪（DESI）再次暗示，暗能量并非恒定，而是随时间变化。具体而言，这种加速膨胀的“推力”似乎在逐渐减弱。

These measurements include our observations of a "fossil" light left over from an event that happened shortly after the Big Bang called the "last scattering," when the universe had expanded and cooled enough to allow electrons to bond with protons and form the first neutral atoms.

这些测量数据包含了我们对一种“化石”光线的观测，这种光线源自大爆炸后不久发生的“最后散射”事件。当时，宇宙已经膨胀并冷却到足以让电子与质子结合，形成首批中性原子。

The disappearance of free electrons suddenly allowed photons, the particles that make up light, to travel freely. In other words, it was as if a universal fog had lifted, and the cosmos became transparent. This first light is referred to as the "cosmic microwave background" or "CMB," and it can still be observed today.

自由电子的消失使得构成光的光子能够自由传播。换言之，仿佛宇宙间的雾霭消散，宇宙变得澄澈透明。这最初的光芒被称为“宇宙微波背景辐射”（CMB），直至今日，我们依然能够观测到它。

Tiny variations or "wrinkles" were "frozen into" the CMB by fluctuations in the density of matter in the early universe called baryon acoustic oscillations (BAO). As the cosmos continued to expand, so too did these wrinkles. Thus, BAO wrinkles can act as a standard measuring stick of the expansion of the universe, with their size varying at different cosmic times. This variation arises as a result of how fast the universe was expanding at those times.

早期宇宙中的重子声波振荡（BAO）导致物质密度波动，这些波动使宇宙微波背景（CMB）中产生了微小变化或“皱纹”，并且随着宇宙的持续膨胀，这些皱纹也随之扩大。因此，BAO皱纹可以作为衡量宇宙膨胀的标准尺度，其大小随宇宙不同时期而变化，这种变化源于宇宙在不同时期的膨胀速度。

Thus, measuring the BAO reveals the strength of dark energy throughout the history of the cosmos, and DESI can do this more precisely than any other instrument.

因此，测量重子声波振荡（BAO）可以揭示暗能量在宇宙历史中的强度变化，而DESI仪器在这方面比任何其他仪器都更为精确。

Changes in dark energy itself were also hinted at when DESI data was compared with observations of type Ia supernovas, cosmic explosions that occur when white dwarf stars "overfeed" on a companion star. This stolen material piles up on the surface of the stellar remnant until a thermonuclear runaway is triggered.

当DESI的数据与Ia型超新星的观测结果进行对比时，也暗示了暗能量本身的变化。Ia型超新星是宇宙中的一种爆炸现象，发生在白矮星从其伴星“过度摄取”物质时。被窃取的物质堆积在恒星残余物的表面，直至引发热核失控反应。

Type Ia supernovae are so uniform in terms of their light output that astronomers can use them as "standard candles" for measuring cosmic distances. In fact, type Ia supernovas were integral to the discovery that the expansion of the universe is accelerating, the genesis of dark energy, back in 1998.

Ia型超新星的光度极为一致，天文学家可以将它们用作“标准烛光”来测量宇宙距离。事实上，Ia型超新星在1998年发现宇宙膨胀加速以及暗能量起源的过程中起到了关键作用。

These distance measurements are possible because of a phenomenon called "redshift," which occurs when the wavelength of traveling light is stretched as it crosses the expanding universe. The longer the light has traveled, the more extreme the shift toward the long wavelength "red end" of the electromagnetic spectrum. That means measuring the redshift of a very well-known and consistent source of light, a standard candle, can give distance measurements.

这些距离的测量要归功于一种名为“红移”的现象。当光线穿越不断膨胀的宇宙时，其波长会被拉长。光线传播的距离越长，波长被拉长的程度就越显著，越趋向于电磁波谱中波长较长的“红端”。这意味着，只要测量一个已知且稳定光源（即标准烛光）的红移程度，就能推算出相应的距离。

DESI data can also be combined with observations of an effect called "gravitational lensing," the distortion of light from distant galaxies by foreground objects of great mass to show the signature of evolving dark energy.

DESI的数据还能与一种名为“引力透镜效应”的现象观测相结合。这种效应是由于前景天体的巨大质量使来自遥远星系的光线发生扭曲，从而展现出暗能量演化的迹象。

The evolution of dark energy isn't robust enough to be considered a "discovery" just yet, but different combinations of the data with other observations are pushing this concept toward what is considered the "gold standard" in physics for such a determination.

暗能量的演化还不足以被视为一项“发现，”但将不同数据与其他观测相结合，正推动这一概念朝着物理学中此类判断的“黄金标准”迈进。

In addition to unveiling these latest dark energy results on Wednesday (March 19), the DESI collaboration also announced that its Data Release 1 (DR1) is now available for anyone to explore through the National Energy Research Scientific Computing Center (NERSC).

除了在周三（3月19日）公布这些最新的暗能量研究结果之外，DESI合作组还宣布，他们的数据发布第一版（DR1）现已通过美国国家能源研究科学计算中心（NERSC）向所有人开放探索。

DR1 contains information regarding 18.7 million cosmic objects, including roughly 4 million stars, 13.1 million galaxies, and 1.6 million quasars.

DR1包含了1870万个宇宙天体的信息，其中包括大约400万颗恒星、1310万个星系以及160万个类星体。

Luz Ángela García Peñaloza, a former DESI team member and a cosmologist at the Universidad ECCI in Colombia, is just one scientist who is thrilled with the new DESI results and the fact that DR1 is now available to the general astronomical community. told Space.com.

哥伦比亚宇宙学家、前DESI团队成员Luz Ángela García Peñaloza对新的DESI成果以及DR1向天文学界开放表示兴奋。她告诉Space.com。

"I am also really excited to find out DESI has released redshift information of about 19 million galaxies and quasars. We've increased the number of identified galaxies by an order of magnitude in less than 10 years!" García Peñaloza said. "The most fascinating result of all is that different sets of observations, a combination of BAO from DESI with CMB data from Planck, and the three main sets of luminosity distances of type Ia supernovas are making a stronger case for an evolving dark energy model, disfavoring the cosmological constant.

“我同样为DESI发布了约1900万个星系与类星体的红移信息而感到兴奋不已。在不到十年的时间里，我们已将已识别星系的数量提升了十倍之多！”加西亚·佩尼亚洛萨说道，“然而，最为引人入胜的成果在于，不同的观测数据集——DESI的重子声波振荡（BAO）与普朗克卫星的宇宙微波背景（CMB）数据相结合，以及Ia型超新星的三大主要光度距离数据集——正愈发有力地支持暗能量演化模型，使宇宙常数模型逐渐失去优势。”

"This is getting more and more consistent with other independent cosmological tests that seem to be opening a window of opportunity for new ways to explore and study dark energy and the accelerated expansion of the universe."

“这一发现与其它独立的宇宙学测试越来越一致，似乎正为探索和研究暗能量以及宇宙加速膨胀开辟新的途径。”

The availability of the DR1 data means astronomers outside the DESI collaboration can now dive into this vast dataset collected between May 2021 and June 2022.

DR1数据的开放，意味着DESI团队之外的天文学家如今能够深入研究这批海量数据集，这些数据采集于2021年5月至2022年6月期间。

"Our results are fertile ground for our theory colleagues as they look at new and existing models, and we're excited to see what they come up with," DESI director Michael Levi, a scientist at Berkeley Lab, said. "Whatever the nature of dark energy is, it will shape the future of our universe.

“我们的研究成果为理论界的同行们提供了肥沃的土壤，他们在审视新的和现有的模型时，我们迫不及待地想看看他们会得出什么成果，”DESI项目负责人、伯克利实验室科学家迈克尔·莱维表示，“无论暗能量的本质是什么，它都将塑造我们宇宙的未来。”

"It's pretty remarkable that we can look up at the sky with our telescopes and try to answer one of the biggest questions that humanity has ever asked.”

“能够用望远镜仰望天空，试图解答人类有史以来提出的最大问题之一，这实在令人惊叹。”

Meanwhile, the DESI collaboration is preparing to begin additional analyses of the new dataset to extract even more findings as DESI itself continues collecting data during its fourth year of operations.

与此同时，DESI团队正着手准备对新数据集展开进一步分析，力求从中提炼出更多科研成果，而DESI本身在第四年的运行中仍在持续收集数据。

"Just amazing," García Peñaloza concluded. "What a time to be alive and to be a cosmologist!"

“真是令人惊叹，”加西亚·佩尼亚洛萨总结道，“能活在这个时代并成为一名宇宙学家，实在是太幸运了！”

The DESI data is discussed in a series of papers available here.

有关DESI数据的讨论，请参阅此处的一系列论文。