宇宙学常数问题是什么？
What is the cosmological constant problem?
量子场论估算的真空能密度比观测到的暗能量密度大了约10的120次方倍，这一巨大差异称为宇宙学常数问题。它被视为理论物理最严重的失配之一。调和二者可能需要新的对称性或量子引力理论。
Quantum field theory estimates a vacuum energy density about 10^120 times larger than the observed dark energy density, a discrepancy known as the cosmological constant problem. It is considered one of the worst mismatches in theoretical physics. Reconciling them may require new symmetries or a quantum theory of gravity.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#宇宙学常数 #真空能 #精细调节
什么是弱引力透镜？欧几里得任务用它来测量什么？
What is weak gravitational lensing, and what does the Euclid mission measure with it?
与产生清晰弧像的强引力透镜不同，弱引力透镜使背景星系的形状产生微小而系统的拉伸。单个星系的变形几乎察觉不到，但统计数十亿个星系的平均形状，就能恢复出追踪前景暗物质分布的剪切场。欧几里得望远镜正是通过高精度测量星系形状的系统性变形，来绘制暗物质的大尺度分布图。由此可以检验宇宙学模型，并约束暗物质与暗能量的性质。
Unlike strong lensing, which produces dramatic arcs, weak lensing causes small, systematic distortions in the shapes of background galaxies. The effect is imperceptible for any single galaxy, but averaging billions of galaxies recovers the shear field that traces foreground dark matter. Euclid precisely measures these systematic shape distortions to map dark matter's large-scale distribution. The results test cosmological models and constrain the nature of dark matter and dark energy.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#弱引力透镜 #暗物质 #欧几里得
类星体为什么能发出比整个星系还亮的光芒？
Why can quasars outshine their entire host galaxies?
类星体是活动星系核中极端明亮的一类。中心超大质量黑洞把周围气体吸引过来，物质下落时释放的引力能转化为辐射，效率远超核聚变。因此，一个星系的核心就能发出相当于数百个星系的光。观测到的最远类星体红移超过 7，对应宇宙不足 10 亿岁的年代，说明超大质量黑洞在大爆炸后很快就已形成。
Quasars are the most luminous class of active galactic nucleus. The central supermassive black hole drags in surrounding gas, and the gravitational energy released as matter falls inward is converted into radiation far more efficiently than nuclear fusion. A single galactic core can therefore outshine hundreds of galaxies. The most distant quasars have redshifts beyond 7, from when the universe was less than a billion years old, showing that supermassive black holes formed very quickly after the Big Bang.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#类星体 #活动星系核 #超大质量黑洞
什么是宇宙的平坦性问题？
What is the flatness problem of the universe?
观测表明宇宙空间在大尺度上近乎几何平坦，但其密度需要在极早期被精确调校到极高精度才能保持平坦。暴胀理论通过极速膨胀将任何初始弯曲「拉平」，从而解释了这一巧合。
Observations show the universe is nearly geometrically flat on large scales, yet its density would have needed impossibly fine tuning early on to stay flat. Inflation solves this by stretching any initial curvature flat through rapid expansion.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#平坦性问题 #空间曲率 #暴胀 #宇宙学
星系旋转曲线如何揭示了暗物质的存在？
How did galaxy rotation curves reveal dark matter?
按照开普勒定律，旋涡星系外侧恒星绕银心旋转的速度应随距离增大而下降，就像太阳系行星那样。但 20 世纪 70 年代，鲁宾和福特观测发现，旋涡星系外围的旋转速度基本保持不变。这说明外围存在大量既不发光也不吸光、却参与引力作用的物质，其质量远超可见恒星。这就是暗物质最早的强证据之一。
Keplerian dynamics predict that rotation speeds in the outer parts of spiral galaxies should fall with distance, as planets do in the solar system. But in the 1970s Vera Rubin and Kent Ford observed that rotation curves in the outer regions stay essentially flat. The only explanation is a large amount of invisible matter that neither emits nor absorbs light yet participates gravitationally, outweighing the visible stars. This became one of the earliest strong pieces of evidence for dark matter.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#旋转曲线 #暗物质 #鲁宾
哈勃常数张力（Hubble tension）指的是哪两种测量方法之间的不一致？
Between which two measurement methods does the Hubble tension arise?
哈勃常数张力指早期宇宙方法（如普朗克卫星对宇宙微波背景的拟合，约 67 km/s/Mpc）与本地距离阶梯方法（如 SH0ES 团队用造父变星与 Ia 型超新星，约 73 km/s/Mpc）所得 H0 值存在超过 5σ 的偏差。这一差异可能暗示超出标准 ΛCDM 模型的新物理。
The Hubble tension refers to the discrepancy, exceeding 5σ, between early-universe methods (e.g., Planck CMB fitting, ~67 km/s/Mpc) and local distance-ladder methods (e.g., SH0ES using Cepheids and Type Ia supernovae, ~73 km/s/Mpc). The gap may hint at new physics beyond standard ΛCDM.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#哈勃常数 #哈勃张力 #宇宙学
暗物质既不发光又看不见，科学家凭什么说它存在？
Dark matter neither shines nor is seen, so on what grounds do scientists say it exists?
证据来自引力效应。星系旋转曲线显示，外缘恒星转得比可见物质引力能解释的快得多，说明星系四周裹着一层看不见的质量晕；引力透镜的弯曲程度也超过可见物质的预期。宇宙微波背景的温度起伏模式以及宇宙结构的演化，同样要求存在约占总能量27%的暗物质。它的粒子本质至今未知，正在被地下实验和加速器寻找。
The evidence is gravitational. Galaxy rotation curves show outer stars moving far faster than visible matter can explain, implying a halo of unseen mass; gravitational lensing is also stronger than expected from visible matter alone. The temperature-fluctuation pattern of the cosmic microwave background and the growth of cosmic structure likewise demand dark matter making up about 27 percent of the total energy. Its particle nature is still unknown and is being hunted in underground detectors and accelerators.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#暗物质 #旋转曲线 #引力透镜 #宇宙结构
暗物质有哪些候选粒子？科学家如何在实验室直接寻找它们？
What are the candidate particles for dark matter, and how do scientists search for them directly in laboratories?
主流候选粒子包括弱相互作用大质量粒子（WIMP）和轴子。WIMP 只通过弱力和引力与普通物质相互作用，轴子则是为解决强 CP 问题提出的极轻粒子，两者都可能构成冷暗物质。直接探测实验把探测器深埋地下以屏蔽宇宙射线，用高灵敏度探测器等待暗物质粒子偶尔与原子核碰撞产生的极微弱反冲信号。例如 LUX-ZEPLIN 使用数吨液态氙探测 WIMP，ADMX 等实验则用谐振腔寻找轴子，目前尚无确凿信号。
Leading candidate particles include weakly interacting massive particles (WIMPs) and axions. WIMPs interact with ordinary matter only through the weak force and gravity, while axions are extremely light particles originally proposed to solve the strong CP problem, and either could make up cold dark matter. Direct-detection experiments are placed deep underground to block cosmic rays, with ultra-sensitive detectors waiting for the faint recoil of a dark-matter particle striking a nucleus. LUX-ZEPLIN uses several tonnes of liquid xenon to hunt WIMPs and experiments such as ADMX use resonant cavities to look for axions, so far without a confirmed signal.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
LUX-ZEPLIN 合作组（暗物质直接探测）
LUX-ZEPLIN Collaboration (direct dark matter search)
#暗物质 #WIMP #轴子 #直接探测
宇宙射线是什么？它们从哪里来？
What are cosmic rays, and where do they come from?
宇宙射线是几乎以光速运动的高能带电粒子，主要是质子、原子核和少量电子。它们到达地球时还会与大气作用，产生次级粒子。能量较低的宇宙射线主要来自太阳和银河系内的超新星遗迹，后者通过激波加速机制把粒子推到极高能量。能量最高的极少数粒子可超过 10 的 20 次方电子伏特，被认为来自银河系外的活动星系核等极端天体。
Cosmic rays are high-energy charged particles, mostly protons, nuclei and a few electrons, moving at nearly the speed of light. On arrival they interact with Earth's atmosphere, producing secondary particles. Lower-energy cosmic rays come mainly from the Sun and from galactic supernova remnants, which accelerate particles through shock acceleration. The rarest ultra-high-energy particles exceed 10^20 electron volts and are thought to originate from extreme extragalactic sources such as active galactic nuclei.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#宇宙射线 #超新星遗迹 #高能粒子
宇宙的最终命运可能是什么？
What might be the ultimate fate of the universe?
这取决于暗能量的性质。主流观点认为膨胀会持续加速，星系彼此远离，恒星燃尽、黑洞蒸发，宇宙最终走向寒冷空寂的“热寂”。
It depends on dark energy. The leading view is continued accelerating expansion: galaxies drift apart, stars burn out, black holes evaporate, and the universe ends in a cold, empty 'heat death.'
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#宇宙命运 #热寂
宇宙纤维结构之间是什么？
What lies between the cosmic filaments?
宇宙大尺度结构呈“宇宙网”：星系沿纤维和节点分布，纤维之间是近乎空旷的“宇宙空洞”。空洞内物质密度极低（约为宇宙平均的十分之一或更少），气体稀薄而温度低，却并非绝对真空——它们仍是暗物质和少量气体的稀疏分布区。空洞会随宇宙膨胀而不断变大。
On the largest scales the universe forms a cosmic web: galaxies lie along filaments and clusters, and between those filaments sit nearly empty regions called cosmic voids. Voids have very low density (a tenth of the cosmic mean or less) with thin, cool gas, but they are not true vacuums—they still contain sparse dark matter and gas. Voids grow larger as the universe expands.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#宇宙网 #空洞 #纤维
1998 年科学家如何发现宇宙在加速膨胀？
How did scientists discover in 1998 that the expansion of the universe is accelerating?
1998 年，两个团队用 Ia 型超新星作为标准烛光，测量极远超新星的红移和亮度。结果发现它们比预期的更暗，也就是距离比匀速膨胀模型预测的更远。结合红移数据推断，宇宙不仅在膨胀，而且膨胀正在加速。这说明存在一种具有负压、能量密度约占宇宙 70% 的成分，即暗能量；这一发现获得 2011 年诺贝尔物理学奖。
In 1998 two teams used Type Ia supernovae as standard candles, measuring the redshifts and brightnesses of extremely distant supernovae. They found the supernovae dimmer than expected and therefore farther away than a steadily expanding universe predicts. Combined with the redshift data, this showed that the expansion of the universe is not merely happening but accelerating. The result implies a component with negative pressure, making up about 70 percent of the cosmic energy budget, dark energy, and earned the 2011 Nobel Prize in Physics.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#暗能量 #Ia型超新星 #宇宙加速膨胀
重子声学振荡（BAO）是如何充当宇宙学中的标准尺的？
How do baryon acoustic oscillations act as a standard ruler in cosmology?
在宇宙再复合之前，光子与重子耦合的等离子体里传播着声波，到复合时刻（红移约 1100）声波冻结，留下约 150 Mpc（共动）的特征尺度。通过测量星系成团中这一尺度随红移表现的视角大小与红移展宽，天文学家可约束宇宙的膨胀历史和暗能量性质。
Before recombination the photon–baryon fluid carried sound waves that froze at the recombination epoch (redshift ≈ 1100), leaving a characteristic scale of about 150 comoving Mpc. Measuring how that scale appears in angle and in redshift broadening within galaxy clustering lets astronomers constrain the expansion history and the nature of dark energy.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
SDSS-III BOSS Collaboration 2013, MNRAS 433, 1202（重子声学振荡测量）
SDSS-III BOSS Collaboration 2013, MNRAS, 433, 1202 (baryon acoustic oscillation measurement)
#重子声学振荡 #标准尺 #宇宙膨胀史
1998年的超新星观测揭示了宇宙的什么重大事实？
What major fact did 1998 supernova observations reveal about the universe?
两个独立团队通过观测遥远 Ia 型超新星发现，宇宙不仅在膨胀，而且膨胀正在加速。这一发现意味着存在一种被称为“暗能量”的神秘成分约占宇宙总能量的68%，并因此获得2011年诺贝尔物理学奖。
Two independent teams found from distant Type Ia supernovae that the universe's expansion is accelerating, not slowing. This implied a mysterious “dark energy” makes up about 68% of the cosmic energy budget—work awarded the 2011 Nobel Prize in Physics.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
超新星宇宙学计划与高红移团队（Perlmutter、Riess、Schmidt，1998）
Supernova Cosmology Project & High-Z Team (Perlmutter, Riess, Schmidt, 1998)
#暗能量 #加速膨胀 #超新星 #诺贝尔物理学奖
什么是宇宙学原理？
What is the cosmological principle?
宇宙学原理认为，在大尺度上宇宙在空间上是均匀且各向同性的，即无论从哪个位置、朝哪个方向看，宇宙的整体面貌都大致相同。它是现代宇宙学模型的基本假设，得到了宇宙微波背景高度各向同性等观测的支持。但在小尺度上，星系和星系团的分布当然并不均匀。
The cosmological principle holds that on large scales the universe is homogeneous and isotropic in space, meaning from any location and in any direction its overall appearance is roughly the same. It is a basic assumption of modern cosmological models and is supported by the high isotropy of the cosmic microwave background. On small scales, of course, galaxies and clusters are far from uniform.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#宇宙学原理 #均匀性 #各向同性
科学家怎么知道宇宙在加速膨胀？
How do scientists know the universe's expansion is accelerating?
Ia型超新星被当作标准烛光：它们的峰值光度几乎一致，所以视亮度能可靠地换算距离。1998年，两个独立团队比较遥远Ia型超新星的亮度与红移，发现它们比预期的要暗，也就是比按减速膨胀算出的距离更远，说明膨胀在加快。这一结果后来得到微波背景与重子声波振荡的独立印证。
Type Ia supernovae serve as standard candles: their peak luminosities are nearly uniform, so apparent brightness converts reliably into distance. In 1998 two independent teams compared the brightness and redshift of distant Type Ia supernovae and found them dimmer than expected, hence farther than a decelerating expansion predicts, meaning the expansion is speeding up. The result was later corroborated independently by the cosmic microwave background and baryon acoustic oscillations.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录含书名，但缺版次 / 出版社 / 年份中的一部分，需编辑补全后才能做独立比对。
Perlmutter、Schmidt 与 Riess《超新星宇宙学计划》（1998/1999）；NASA 威尔金森微波各向异性探测器（WMAP）
Perlmutter, Schmidt & Riess, Supernova Cosmology Project (1998/1999); NASA Wilkinson Microwave Anisotropy Probe (WMAP)
#Ia型超新星 #标准烛光 #加速膨胀 #1998年发现
把红移换算成距离绘出的星系图上,星系团成员常沿视线被拉成长长的“手指”,这种失真从何而来?它为何反而成了有用工具?
On galaxy maps drawn by converting redshift into distance, cluster members often smear into long fingers along the line of sight - where does this distortion come from, and why has it turned into a useful tool?
失真源于本动速度:星系除哈勃退行外还有自身运动,星系团成员的速度可达每秒上千公里,被误折算成额外的距离差,于是指向观测者的成员在图上拖出长长的“手指”。更大尺度上,引力内聚让物质朝密集区涌动,沿视线方向的结构被压扁,即 Kaiser 效应。这类畸变并非噪声:压扁程度由结构增长率决定,配合功率谱分析可以称量暗物质、检验引力甚至约束中微子质量,已是大型巡天的标准产出。
The distortion comes from peculiar velocities: besides the Hubble recession, galaxies move on their own, cluster members reaching well over a thousand kilometres per second, which gets misread as extra distance offsets, so members pointing at the observer drag out long fingers on the map. On larger scales gravity pulls material toward overdensities, flattening structures along the line of sight - the Kaiser effect. Such distortions are not noise: their strength tracks the growth rate of structure, and combined with power-spectrum analysis they weigh dark matter, test gravity and even bound neutrino masses, becoming a standard science product of major surveys.
难度 专业 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
N. Kaiser,1987年,Monthly Notices of the Royal Astronomical Society,227卷1页:Clustering in Real Space and in Redshift Space;M. A. Strauss 与 J. A. Willick,1995年,Physics Reports,261卷271页:The Density and Velocity Field of the Local Universe
N. Kaiser 1987, MNRAS, 227, 1 - Clustering in real space and in redshift space; M. A. Strauss & J. A. Willick 1995, Physics Reports, 261, 271 - The density and velocity field of the local universe
独立核验依据 · Independent verification: 核验依据 1 CROSSREF 标识 10.1093/mnras/227.1.1：Clustering in real spa
#红移巡天 #红移空间畸变 #Kaiser 效应
WIMP和轴子是暗物质的哪些候选者？
What are WIMPs and axions as dark matter candidates?
WIMP（弱相互作用大质量粒子）是质量约 GeV–TeV 量级、仅通过弱力和引力作用的假想粒子，源自超对称等理论。轴子则是极轻的假想标量粒子，最初为解决强CP问题而提出，也可在极早期大量产生。二者代表了“重冷”和“轻冷”两类不同的探测思路。
WIMPs (weakly interacting massive particles) are hypothetical particles of GeV–TeV mass interacting only via the weak force and gravity, motivated by supersymmetry. Axions are extremely light hypothetical scalar particles first proposed to solve the strong CP problem and could be produced abundantly in the early universe. They represent “heavy cold” and “light cold” detection strategies, respectively.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#WIMP #轴子 #冷暗物质
子弹星系团为什么被称为暗物质的“直接证据”？
Why is the Bullet Cluster called direct evidence for dark matter?
子弹星系团是两个星系团高速碰撞的产物。碰撞中，星系团内的稀薄热气体因摩擦减速而滞留在中心，星系本身和暗物质则几乎不受阻碍地继续飞行。钱德拉 X 射线观测显示热气体集中在中心，而引力透镜显示质量集中于两侧的星系。这说明大部分质量不与气体一起减速，符合暗物质基本不碰撞的特性，也令修改引力理论难以解释。
The Bullet Cluster is the product of two galaxy clusters colliding at high speed. During the collision, the diffuse hot gas decelerates through friction and lingers at the center, while the galaxies themselves and dark matter pass through nearly unimpeded. Chandra X-ray images show the hot gas concentrated centrally, whereas gravitational lensing places most of the mass with the galaxies on the sides. Because that mass does not slow down with the gas, the system matches weakly-interacting dark matter and is hard to explain with modified gravity.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#子弹星系团 #暗物质 #引力透镜
ΛCDM标准宇宙学模型包含哪些关键成分？
What key components does the Lambda-CDM standard cosmological model include?
ΛCDM模型以冷暗物质和宇宙学常数Λ为核心，配合普通重子物质、中微子和辐射，描述从初期暴涨到今天的结构形成。冷暗物质率先成团提供引力骨架，宇宙学常数则驱动近期加速膨胀。普朗克卫星的精确参数测量使该模型成为当代宇宙学的基准框架。
The Lambda-CDM model centers on cold dark matter and a cosmological constant Lambda, joined by ordinary baryonic matter, neutrinos, and radiation, describing structure formation from early inflation to today. Cold dark matter clumps first to provide gravitational scaffolding, while the cosmological constant drives recent accelerated expansion. Precise parameter measurements from Planck have made it the benchmark framework of modern cosmology.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Planck Collaboration《Planck 2018 宇宙学结果》；Peebles《Cosmology's Century》（2020，Princeton University Press）
Planck Collaboration, Planck 2018 cosmological results; Peebles, Cosmology's Century (2020, Princeton University Press)
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL21670954W：Cosmology's Century（首版
#ΛCDM模型 #冷暗物质 #宇宙学常数
宇宙真的从一个奇点开始吗？
Did the universe really begin from a singularity?
标准宇宙学表明，可观测宇宙在约138亿年前从一个极热、极密的状态膨胀而来，把时间往回推会得到一个密度和曲率发散的“奇点”。但奇点更可能是现有广义相对论在极端条件下失效的标志，而非真实物理状态；要描述那一刻需要尚未完成的量子引力理论。因此宇宙“从奇点开始”是一种基于外推的说法，而非已被证实的论断。
Standard cosmology shows the observable universe expanding from an extremely hot, dense state about 13.8 billion years ago, and extrapolating backward leads to a singularity of diverging density and curvature. But the singularity is more likely a sign that general relativity breaks down under extreme conditions than a real physical state; describing that moment requires a still-incomplete theory of quantum gravity. So saying the universe began from a singularity is an extrapolation, not an established fact.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#起源 #奇点 #量子引力
宇宙学常数问题（真空能的灾难性失配）指的是什么？
What is the cosmological constant problem — the vast mismatch between predicted vacuum energy and the observed value of Λ?
量子场论估算的真空能密度比宇宙学观测得到的暗能量密度大约高出 10^120 倍，是物理学中已知最极端的精细调节难题之一。观测到的 Λ 对应的特征能量尺度仅约 10^-3 电子伏（毫电子伏）量级，而理论预期却在普朗克尺度附近。
Quantum field theory estimates a vacuum-energy density roughly 10^120 times larger than the dark-energy density inferred from cosmological observations, making this one of the worst fine-tuning problems in physics. The observed Λ corresponds to a characteristic energy scale of only about 10^-3 eV (milli-electron-volts), whereas theory expects a value near the Planck scale.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
Weinberg,《The cosmological constant problem》,Reviews of Modern Physics,1989 (DOI: 10.1103/revmodphys.61.1)
Weinberg, 'The cosmological constant problem', Reviews of Modern Physics, 1989, DOI: 10.1103/revmodphys.61.1
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1103/revmodphys.61.1
#宇宙学常数问题 #真空能 #暗能量
为什么红移能证明宇宙在膨胀？
Why does redshift prove the universe is expanding?
光在膨胀的空间里传播时，波长会随着空间本身的拉伸一起变长，向红端移动，这个现象叫宇宙学红移。它的大小满足1加红移等于现在与发射时刻的宇宙尺度之比，所以红移直接刻画了宇宙的膨胀倍数。更关键的证据是，遥远超新星的视亮度与其红移的关系符合加速膨胀的预期，说明红移确实来自空间扩张而不是简单的运动效应。
As light travels through expanding space, its wavelength is stretched along with space itself, shifting toward the red — the cosmological redshift. It satisfies the relation 1 + z equals the ratio of the current scale factor to the scale when the light was emitted, so redshift directly encodes how much the universe has grown. Crucially, the brightness-versus-redshift relation of distant supernovae matches an accelerating expansion, confirming that the shift comes from the stretching of space rather than a simple velocity effect.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#宇宙学红移 #尺度因子 #加速膨胀
宇宙暴胀理论是什么？
What is cosmic inflation theory?
暴胀理论提出，在大爆炸后极短的一瞬间（约10的负32次方秒量级），宇宙经历了指数级的急剧膨胀，把原本极小区域放大到整个可见宇宙。它能解释宇宙为何如此均匀平坦，以及物质密度微小涨落的来源。这些涨落后来成长为星系和星系团。
Inflation theory proposes that around 10^-32 second after the Big Bang, the universe underwent exponential expansion, blowing up a minuscule region into the entire visible universe. It explains why the universe is so uniform and flat, and where the tiny density fluctuations came from. Those fluctuations later grew into galaxies and clusters.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#暴胀 #早期宇宙 #均匀性
宇宙再电离时期指的是什么事件，现代观测如何约束它发生的时刻？
What event does the epoch of reionization describe, and how do modern observations constrain when it occurred?
再电离时期指第一批恒星和星系的紫外辐射把中性氢重新电离成等离子体的过程，标志宇宙从黑暗走向被点亮。它大致发生在红移6到10之间，即大爆炸后约4亿到10亿年。普朗克卫星通过宇宙微波背景的偏振光学深度，以及詹姆斯·韦伯望远镜对早期星系的直接成像，共同约束了这一时期的起止时间。
The epoch of reionization is the era when the first stars and galaxies emitted ultraviolet radiation that reionized the neutral hydrogen, ending the cosmic dark ages. It took place roughly between redshift 6 and 10, or about 400 million to 1 billion years after the Big Bang. The Planck satellite constrains its timing through the optical depth of CMB polarization, while the James Webb Space Telescope maps the earliest galaxies directly.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
Planck Collaboration《Planck 2018 结果》X 章（再电离）；Barkana 与 Loeb《In the Beginning》（2001，Physics Reports）
Planck Collaboration, Planck 2018 results X (reionization); Barkana & Loeb, In the Beginning (2001, Physics Reports)
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1016/s0370-1573(01)00019-9（复合著录按段核验：本标识只
#再电离 #第一代恒星 #宇宙学红移
宇宙的“再电离时期”是什么？
What was the universe's “reionization epoch”?
再电离时期发生在宇宙诞生约数亿年后，第一批恒星和星系发出的紫外辐射逐渐把中性氢气体重新电离成等离子体。普朗克卫星与韦伯望远镜的观测帮助确定了这一过程大致在红移约6至10、即大爆炸后约10亿年内完成。
The reionization epoch occurred a few hundred million years after the Big Bang, when ultraviolet light from the first stars and galaxies gradually reionized neutral hydrogen into plasma. Data from Planck and the James Webb Telescope place this process roughly at redshift 6–10, completing within about a billion years of the Big Bang.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#再电离 #中性氢 #早期宇宙 #韦伯望远镜
为什么中微子质量对宇宙学参数拟合有不可忽略的影响？
Why do neutrino masses have a non-negligible impact on cosmological parameter fitting?
中微子作为从相对论到非相对论过渡的轻子，其总质量会抑制小尺度物质功率谱并改变复合后的宇宙学距离。普朗克 CMB 数据与星系巡天联合拟合给出的中微子总质量上限约 0.12–0.26 eV，已成为连接粒子物理与宇宙学的关键桥梁。
Neutrinos—leptons transitioning from relativistic to non-relativistic—suppress the small-scale matter power spectrum and alter post-recombination cosmological distances. Joint CMB and galaxy-survey fits place the summed neutrino mass upper limit around 0.12–0.26 eV, linking particle physics and cosmology.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#中微子质量 #功率谱 #宇宙学拟合
宇宙再电离纪元大约在红移多少结束，主要证据来自哪些观测？
At about what redshift did cosmic reionization end, and what observations primarily constrain it?
宇宙再电离主要由首批恒星和星系的紫外光子完成，整体在红移 z ≈ 6（约大爆炸后 10 亿年）基本结束，但过程从 z ~ 15 起持续了数亿年。主要约束来自类星体光谱的 Gunn–Peterson 吸收槽、WMAP/Planck 给出的 Thomson 光学深度，以及高红移星系的发射线。
Cosmic reionization, driven mainly by ultraviolet photons from the first stars and galaxies, was essentially complete by redshift z ≈ 6 (about 1 billion years after the Big Bang), though the process began around z ~ 15 and lasted hundreds of millions of years. Key constraints come from the Gunn–Peterson troughs in quasar spectra, the Thomson optical depth measured by WMAP and Planck, and emission lines in high-redshift galaxies.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Planck Collaboration 2018, A&A 641, A6；Fan 等 2006, ARA&A 44, 415
Planck Collaboration 2018, A&A, 641, A6; Fan et al. 2006, ARA&A, 44, 415
#再电离 #Gunn-Peterson吸收槽 #红移
宇宙暴胀理论试图解决标准大爆炸模型的哪些难题？
What problems of the standard Big Bang model does cosmic inflation aim to solve?
暴胀理论假设宇宙在极早期经历了指数级的急速膨胀，能在极短时间内把一小块均匀区域拉伸成可观测宇宙。它自然解释了宇宙为何在大尺度上如此均匀且平坦，并把原初量子涨落放大为后来的密度扰动。古斯在1981年提出这一设想，此后被宇宙微波背景的涨落谱所支持。
Inflation posits that the early universe underwent a brief phase of exponential expansion, stretching a tiny homogeneous patch into the observable cosmos. It naturally explains why the universe is so uniform and flat on large scales and amplifies quantum fluctuations into the seeds of later structure. Guth proposed it in 1981, and it has since been supported by the fluctuation spectrum of the CMB.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-05 · 3 条独立证据
来源 · Source
Guth《The Inflationary Universe》（1981，Physical Review D）；Planck Collaboration《Planck 2018 结果》
Guth, The Inflationary Universe (1981, Physical Review D); Planck Collaboration, Planck 2018 results
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL3347725W：The inflationary univer · 核验依据 3 CROSSREF DOI 标识 10.1103/physrevd.23.347（按标识回读: Inflation
#宇宙暴胀 #平坦性 #视界问题
宇宙会一直变大下去吗？
Will the universe keep getting bigger?
是的，科学家发现宇宙现在不仅在变大，而且变大的速度还在加快。这可能是因为一种叫做暗能量的神秘力量在把空间往外推。如果暗能量不变，宇宙会一直膨胀下去，星系会越来越分散。
Yes, scientists have found that the universe is not only expanding but speeding up as it does. This may be due to a mysterious force called dark energy pushing space outward. If dark energy stays the same, the universe will keep expanding and galaxies will drift ever farther apart.
难度 专业 · 适合 幼儿(3-6)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#宇宙膨胀 #暗能量 #加速
重子声学振荡（BAO）是什么，为何重要？
What are baryon acoustic oscillations, and why do they matter?
重子声学振荡是早期宇宙中声波在等离子体里留下的密度波纹，在星系分布中表现为约5亿光年的特征尺度。它被用作「标准尺」，帮助测量宇宙的膨胀历史与暗能量性质。
Baryon acoustic oscillations are density ripples left by sound waves in the early universe's plasma, showing up as a characteristic scale of about 500 million light-years in galaxy distributions. Used as a "standard ruler," they help measure cosmic expansion and dark energy.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
斯隆数字巡天（SDSS）
Sloan Digital Sky Survey (SDSS)
#重子声学振荡 #标准尺 #宇宙膨胀 #暗能量
什么是暗物质？
What is dark matter?
暗物质是一种不发光、不与电磁波直接作用、却通过引力影响星系和星系团运动与成团的物质，约占宇宙总物质的85%。
Dark matter neither emits nor absorbs light and barely interacts with normal matter, but its gravity shapes galaxies and clusters; it makes up about 85% of all matter.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#暗物质 #引力
什么是暴胀理论？
What is cosmic inflation?
暴胀认为宇宙在大爆炸后极早期（10^-36到10^-32秒）经历了指数级暴涨，解释了宇宙的大尺度均匀性和平坦性。
Inflation proposes the early Universe underwent exponential expansion (around 10^-36 to 10^-32 s after the Big Bang), explaining its large-scale uniformity and flatness.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#暴胀 #早期宇宙
大爆炸核合成产生了哪些轻元素？
Which light elements did Big Bang nucleosynthesis produce?
大爆炸核合成发生在宇宙诞生后约三分钟到二十分钟内，由高温高密度下的质子中子融合生成大部分宇宙中的氦-4、氘、氦-3和锂-7。其丰度强烈依赖于重子密度和膨胀速率。观测到的轻元素丰度与理论预言高度吻合，是标准模型的重要支柱。
Big Bang nucleosynthesis occurred in the first few minutes of the universe as protons and neutrons fused under high temperature and density, producing most of the cosmic helium-4, deuterium, helium-3, and lithium-7. Their abundances depend strongly on the baryon density and expansion rate. Observed light-element abundances match predictions closely, a key pillar of the standard model.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#大爆炸核合成 #轻元素 #氦丰度
宇宙加速膨胀有哪些证据？
What evidence supports the accelerated expansion of the universe?
1998年对遥远 Ia 型超新星的观测发现它们比预期暗，说明宇宙在加速膨胀，这一发现获诺贝尔奖。此后宇宙微波背景、重子声学振荡和星系团计数等多种独立证据都指向同一结论。加速被认为由暗能量驱动。
In 1998, observations of distant Type Ia supernovae found them dimmer than expected, implying accelerated expansion—work awarded the Nobel Prize. Since then, independent evidence from the cosmic microwave background, baryon acoustic oscillations, and cluster counts all point the same way. The acceleration is attributed to dark energy.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#加速膨胀 #超新星 #暗能量证据
为什么 CMB 的黑体谱是支持大爆炸而非稳恒态宇宙的关键证据？
Why is the blackbody spectrum of the CMB key evidence for the Big Bang rather than a steady-state universe?
COBE 卫星在 1990 年测得的 CMB 谱与 2.725 K 黑体辐射吻合到万分之几的精度，这种普适热平衡谱只能由早期高温致密宇宙冷却形成。稳恒态模型用星系际尘埃散射星光来解释 CMB，却无法自然产生如此精确的黑体形状。
The COBE satellite measured the CMB spectrum in 1990 to match a 2.725 K blackbody to better than a few parts in 10,000, a universal thermal-equilibrium shape that only arises from the cooling of an early hot, dense universe. Steady-state models invoked interstellar dust scattering starlight, but they cannot naturally produce such a precise blackbody form.
难度 进阶 · 适合 小学高段(9-12)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Mather 等 1990, ApJ 354, L37（COBE/FIRAS 黑体谱测量）
Mather et al. 1990, ApJ, 354, L37 (COBE/FIRAS blackbody spectrum)
#宇宙微波背景 #黑体谱 #稳恒态模型
宇宙主要由什么构成？
What is the universe mostly made of?
根据普朗克卫星的观测，宇宙约68%是暗能量、27%是暗物质，仅约5%是我们熟悉的普通物质。肉眼可见的恒星和星系其实只占极小一部分。
According to the Planck satellite, the universe is about 68 percent dark energy, 27 percent dark matter, and only about 5 percent ordinary matter. The stars and galaxies we see are just a tiny fraction.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#暗能量 #暗物质 #普通物质 #宇宙组成
宇宙年龄只有138亿年，可观测宇宙的直径为什么却有930亿光年？
The universe is only 13.8 billion years old, so why is the observable universe 93 billion light-years across?
因为空间本身在膨胀。远处天体发出的光虽然只传播了138亿年，但光经过的空间一直在被拉伸，等光到达我们时，发出光的天体早已被推到更远的地方。把这些最远天体现今的坐标加起来，可观测宇宙的半径约有465亿光年，直径自然超过900亿光年。
Because space itself expands. Light from distant objects has travelled for only 13.8 billion years, but the space it crossed has kept stretching, so by the time it reaches us the source has been carried much farther away. Adding up the present-day coordinates of the farthest visible objects gives an observable radius of about 46.5 billion light-years, hence a diameter well over 90 billion.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#可观测宇宙 #空间膨胀 #光年
银河系在结构上由哪几部分组成？
What are the main structural components of the Milky Way?
银河系由银盘、银心（中央核球）、银晕和银冕组成。银盘是薄薄的恒星和气体盘，太阳就位于盘面内离银心约 2.6 万光年的一条旋臂上；中央核球呈棒状结构；银晕是包围银盘、分布着球状星团的稀疏恒星区，其外还有更大范围看不见的暗物质晕。
The Milky Way consists of a disk, a central bulge, a halo and a corona. The disk is a thin disk of stars and gas in which the Sun sits on a spiral arm about 26,000 light-years from the center; the bulge is bar-shaped; the halo is a sparse region of stars and globular clusters enveloping the disk, and beyond it lies a far larger invisible dark matter halo.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#银河系 #银盘 #银晕
宇宙未来的命运可能是什么？
What might be the ultimate fate of the universe?
如果暗能量保持恒定（宇宙学常数），宇宙将永远加速膨胀，星系彼此远离，最终进入寒冷稀薄的热寂状态。若暗能量增强，可能发生大撕裂把星系甚至原子撕碎；若减弱，引力或使宇宙重新收缩为大坍缩。目前的观测更支持持续加速膨胀的图景。
If dark energy stays constant (a cosmological constant), the universe will expand forever, galaxies drift apart, and it ends in a cold, dilute heat death. If dark energy strengthens, a big rip could tear apart galaxies and even atoms; if it weakens, gravity might reverse expansion into a big crunch. Current observations favor continued accelerating expansion.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#宇宙命运 #热寂 #大撕裂
弱引力透镜如何被用来探测暗物质分布？
How is weak gravitational lensing used to probe dark matter distribution?
大质量天体（含不可见暗物质晕）的引力会轻微扭曲背景星系的像。通过统计大量星系形状的系统畸变（剪切场），可重建全天暗物质的质量图，而不依赖任何发光物质。暗能量巡天（DES）与 Euclid 卫星均以此绘制宇宙大尺度结构。
Massive objects, including invisible dark-matter halos, gravitationally distort the images of background galaxies. By statistically measuring systematic shape distortions (shear) across many galaxies, one reconstructs all-sky dark-matter mass maps independent of luminous matter. DES and the Euclid satellite map large-scale structure this way.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#弱引力透镜 #暗物质 #大尺度结构
大爆炸之后，宇宙经历了怎样的时间线？
What is the timeline of the universe after the Big Bang?
大爆炸后的极早期宇宙经历了快速膨胀的暴涨时期；最初几分钟内，质子和中子合成出氢、氦和微量锂。约38万年后宇宙冷却到可以形成原子，光得以释放，留下微波背景。随后物质在暗物质的引力下聚集，约一两亿年后诞生了第一批恒星，138亿年后的今天，星系早已连成庞大的宇宙网。
The very early universe went through inflation, a burst of rapid expansion; in the first few minutes protons and neutrons fused into hydrogen, helium, and a trace of lithium. About 380,000 years later the universe cooled enough for atoms to form and light was set free, leaving the microwave background. Matter then clumped under the gravity of dark matter, the first stars lit up around 100 to 200 million years in, and 13.8 billion years later galaxies are strung into a vast cosmic web.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#大爆炸时间线 #暴涨 #原初核合成 #第一批恒星
宇宙大爆炸理论说的是什么？
What does the Big Bang theory describe?
大爆炸理论认为宇宙约138亿年前从一个极热极密的状态膨胀而来。它能解释星系退行、宇宙微波背景辐射和轻元素丰度等观测事实。
The Big Bang theory holds that the universe expanded from an extremely hot, dense state about 13.8 billion years ago. It explains the recession of galaxies, the cosmic microwave background, and the abundances of light elements.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#大爆炸 #宇宙膨胀 #宇宙学 #起源
宇宙现在还在膨胀吗？
Is the universe still expanding?
是的。观测显示星系彼此远离，且距离越远的星系退行越快，说明宇宙至今仍在膨胀，并且膨胀还在加速。
Yes. Galaxies recede from each other, faster the farther away they are, showing the universe is still expanding—and the expansion is accelerating.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#宇宙膨胀 #哈勃
仙女座星系和我们有什么关系？几十亿年后会怎样？
What is the Andromeda galaxy's relationship to us, and what will happen billions of years from now?
仙女座星系（M31）是距离银河系最近的大型旋涡星系，约 250 万光年，两者同属本星系群，并在相互吸引。计算表明约 40 亿年后仙女座星系将与银河系发生碰撞并合，最终形成一个更大的椭圆星系，届时太阳系可能被抛向星系外围，但恒星相撞的概率很低。
Andromeda (M31) is the nearest large spiral galaxy, about 2.5 million light-years away; both belong to the Local Group and are gravitationally approaching each other. Simulations show the two will merge in about 4 billion years, forming a larger elliptical galaxy; the solar system may be flung to the outer regions, but direct stellar collisions are very unlikely.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#仙女座星系 #本星系群 #星系并合
哈勃如何给星系分类？为什么叫“哈勃音叉图”？
How did Hubble classify galaxies, and why is it called the Hubble tuning-fork diagram?
埃德温·哈勃根据形状把星系分为椭圆星系、旋涡星系（包括棒旋星系）和不规则星系三大类。按形态从椭圆到旋涡的排列图状如音叉，故称“哈勃音叉图”；哈勃曾以为这是一种从椭圆到旋涡的演化序列，现在知道它主要反映的是星系结构和形成历史的差异。
Edwin Hubble classified galaxies by shape into ellipticals, spirals (including barred spirals) and irregulars. Arranged by morphology, the diagram looks like a tuning fork, hence its name; Hubble once thought it was an evolutionary sequence from ellipticals to spirals, but it is now known to reflect differences in structure and formation history.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#星系分类 #哈勃音叉图 #椭圆星系
宇宙中的巨洞会对星系运动产生什么影响？
How do cosmic voids affect galaxy motion?
空洞内物质稀少、引力很弱，周围纤维和星系团较强的引力会把星系从空洞边缘拉走，使空洞随时间膨胀、星系向高密度区汇聚。
Voids have little mass and weak gravity, while surrounding filaments and clusters pull galaxies away from void edges, so voids expand over time as galaxies flow toward denser regions.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#空洞 #宇宙网 #引力
宇宙大爆炸是什么？
What is the Big Bang?
大爆炸是约138亿年前宇宙从一个极热极密状态开始膨胀冷却的起源事件，并非发生在某一点，而是空间本身的膨胀。
The Big Bang is the origin about 13.8 billion years ago when the Universe began expanding and cooling from an extremely hot, dense state—not an explosion in space but of space itself.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#大爆炸 #宇宙起源
什么是可观测宇宙？
What is the observable universe?
可观测宇宙是以我们为中心、光自大爆炸以来所能到达的球形区域，半径约465亿光年；超出此范围的区域其光还没来得及到达我们这里。
The observable universe is the spherical region around us from which light has had time to reach us since the Big Bang, about 46.5 billion light-years in radius; beyond it, light hasn't arrived yet.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#可观测宇宙 #视界
为什么把 Ia 型超新星当作标准烛光，能让我们发现宇宙在加速膨胀？
Why can Type Ia supernovae, used as standard candles, reveal that the universe's expansion is accelerating?
Ia 型超新星来自白矮星达到钱德拉塞卡极限后的热核爆发，其峰值光度高度一致，可校准为绝对星等约 −19.3。比对它们的红移与视亮度后，观测发现遥远的超新星比匀速膨胀模型预期的更暗，说明自约 50 亿年前起膨胀在加速，通常归因为暗能量。
A Type Ia supernova comes from the thermonuclear disruption of a white dwarf near the Chandrasekhar limit, giving a remarkably uniform peak luminosity calibrated to an absolute magnitude near −19.3. Comparing their redshifts with apparent brightness showed distant supernovae fainter than a constant-expansion model predicts, implying acceleration that began roughly 5 billion years ago and is attributed to dark energy.
难度 进阶 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Riess 等 1998, AJ 116, 1009；Perlmutter 等 1999, ApJ 517, 565
Riess et al. 1998, AJ, 116, 1009; Perlmutter et al. 1999, ApJ, 517, 565
#Ia型超新星 #标准烛光 #加速膨胀
宇宙微波背景是什么？
What is the cosmic microwave background?
宇宙微波背景是充满全天的微弱微波辐射，源自大爆炸后约38万年宇宙冷却到足以让光子自由穿行时释放的“余晖”。它温度约2.7开尔文，是大爆炸最直接的化石证据。其均匀性中的微小涨落孕育了后来的星系。
The cosmic microwave background is a faint microwave glow filling the sky, the “afterglow” released about 380,000 years after the Big Bang when the universe cooled enough for photons to travel freely. At about 2.7 kelvin, it is the most direct fossil evidence of the Big Bang. Tiny fluctuations in its uniformity seeded later galaxies.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#宇宙微波背景 #余晖 #大爆炸证据
哈勃定律说的是什么？
What does Hubble's law state?
哈勃定律说，星系离我们越远，退行速度越快，两者成正比，即速度等于哈勃常数乘以距离。这意味着几乎所有星系都在相互远离，是宇宙在整体膨胀的强有力证据，而不是地球处在宇宙中心。普朗克卫星测得的哈勃常数约为每百万秒差距每秒67到68公里。
Hubble's law states that the farther a galaxy is from us, the faster it recedes, the two being proportional: recession speed equals the Hubble constant times distance. Since nearly every galaxy is moving away from every other, this is powerful evidence that the whole universe is expanding, not that Earth sits at its centre. The Planck satellite measured the Hubble constant at about 67 to 68 kilometres per second per megaparsec.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#哈勃定律 #宇宙膨胀 #哈勃常数
暗能量是什么？
What is dark energy?
暗能量是一种充满空间、产生排斥性引力并驱动宇宙加速膨胀的神秘成分，约占宇宙总能量的七成。它最简单的模型是爱因斯坦引入又放弃的“宇宙学常数”。其本质仍是当代物理学最大的未解之谜之一。
Dark energy is a mysterious component pervading space that produces repulsive gravity and drives the accelerated expansion, making up about 70 percent of the universe's energy. Its simplest model is the cosmological constant that Einstein introduced and later retracted. Its nature remains among the biggest unsolved problems in physics.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#暗能量 #加速膨胀 #宇宙学常数
暗物质到底是什么？
What exactly is dark matter?
暗物质是一种不发光、不与电磁波直接作用，却通过引力影响星系和宇宙大尺度结构的未知物质。它约占宇宙总质能的四分之一，远多于普通物质。其本质可能是尚未发现的基本粒子，如WIMP或轴子。
Dark matter is unknown matter that emits no light and does not interact directly with electromagnetic waves, yet exerts gravity shaping galaxies and large-scale structure. It makes up about a quarter of the universe's total mass-energy, far more than ordinary matter. Its nature may be undiscovered particles such as WIMPs or axions.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据结论有争议 · Contested
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#暗物质 #引力 #未知粒子
哈勃-勒梅特定律描述了宇宙的什么现象？
What phenomenon does the Hubble–Lemaître law describe?
该定律指出，遥远星系的退行速度与其距离成正比（v = H₀·d），比例常数 H₀ 即哈勃常数。它直接表明宇宙正在膨胀，是现代观测宇宙学的基石，由勒梅特与哈勃分别在1927和1929年提出。
The law states that a galaxy's recession speed is proportional to its distance (v = H₀·d), with H₀ the Hubble constant. It shows directly that the universe is expanding and is a foundation of observational cosmology, formulated by Lemaître (1927) and Hubble (1929).
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
乔治·勒梅特（1927）；埃德温·哈勃（1929，星系退行观测）
Georges Lemaître (1927); Edwin Hubble (1929)
#哈勃定律 #宇宙膨胀 #红移 #哈勃常数
所谓哈勃张力指的是哪两条测量路径得到的哈勃常数互不相容?差异有多大,又可能意味着什么?
Which two measurement routes yield mutually incompatible values of the Hubble constant in the so-called Hubble tension, how large is the discrepancy, and what might it imply?
一条路径利用普朗克卫星的微波背景辐射数据,在 ΛCDM 框架下从早期宇宙外推,得到 H0 约 67.4 千米每秒每百万秒差距;另一条路径由 SH0ES 团队用造父变星定标 Ia 型超新星,在近邻宇宙直接测得约 73.0,两者相差约五个标准差。超新星光度演化、造父零点校准等已知系统误差都不足以弥合分歧,所以被称为张力而非统计涨落。如果最终确认存在,可能的解释包括早期暗能量、额外的相对论性粒子等超出标准宇宙学的物理。
One route uses Planck cosmic microwave background data extrapolated from the early universe within the Lambda-CDM framework, giving H0 near 67.4 km/s/Mpc; the other route, pursued by the SH0ES team, calibrates Type Ia supernovae with Cepheid variables and measures about 73.0 directly in the local universe, a gap of roughly five sigma. Known systematics such as supernova luminosity evolution or Cepheid zero-point calibration cannot close the disagreement, hence the label tension rather than statistical fluctuation. If confirmed, candidate explanations include early dark energy or additional relativistic particle species beyond standard cosmology.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
Planck 合作组,Astronomy and Astrophysics 641:A6 (2020);Riess 等,Astrophysical Journal 908:L6 (2021)
Planck Collaboration, Astronomy and Astrophysics 641, A6 (2020); Riess et al., Astrophysical Journal 908, L6 (2021)
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.3847/2041-8213/abdbaf（复合著录按段核验：本标识只担保第二段
#哈勃常数 #ΛCDM 模型
夜空里的星系为什么不是均匀撒开的,而是连成一张带空洞的大网?
Why are galaxies strung into filaments with huge voids instead of spread evenly across the sky?
宇宙始于近乎均匀但带有微小密度涨落的气体。引力是「嫌贫爱富」的不稳定放大器:密度略高的区域吸引更多物质,越富越吸;略稀疏的区域则被抽空。暗物质占总物质的八成以上且不发光不碰撞,先在自身引力下坍缩成巨大的暗物质晕并连成纤维状骨架,普通气体顺骨架流入晕中点亮为星系。数值模拟重现出的宇宙网与红移巡天绘制的三维地图高度一致——纤维、壁、节点与空洞,正是初始涟漪历经百亿年引力放大的模样。
The universe began nearly homogeneous but with tiny density ripples. Gravity is an unstable amplifier that favors the rich: slightly denser patches attract more matter while underdense ones get drained. Dark matter, over eighty percent of the cosmic mass and both invisible and collisionless, collapsed first into vast halos threaded by filamentary scaffolds; gas flowed along the filaments into halos and lit up as galaxies. Simulations reproduce this cosmic web, and redshift surveys map exactly the filaments, walls, nodes and voids that those primordial ripples grew into over ten billion years.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-02
来源 · Source
Bond、Kofman 与 Pogosyan,《How filaments of galaxies are woven into the cosmic web》,Nature 第380卷,1996
J. R. Bond, L. Kofman and D. Pogosyan, How filaments of galaxies are woven into the cosmic web, Nature 380, 1996
独立核验依据 · Independent verification: 核验依据 1 CROSSREF 标识 10.1038/380603a0：How filaments of galaxies a
#宇宙大尺度结构 #暗物质晕 #宇宙网
只测每个星系的一条红移,天文学家为什么就能拼出宇宙的三维地图?低红移端又会遇到什么麻烦?
How does measuring just one redshift per galaxy let astronomers assemble a three-dimensional map of the universe, and what complicates matters at the lowest redshifts?
因为哈勃定律让红移直接对应距离:宇宙膨胀把星光整体拉长,在低红移下距离近似等于光速乘以红移再除以哈勃常数,一条光谱便是一把量尺。巡天批量采集星系光谱后,天球上的二维投影沿视线方向展开,显露出星系墙、巨洞与纤维交织的宇宙网,CfA 巡天的窄片图首次绘出该结构,斯隆数字巡天更将其扩展至上百万个星系。只是在小红移处,星系自身数百公里每秒的本动速度会混入退行速度,需按速度场模型加以改正。
Because Hubble's law ties redshift directly to distance: cosmic expansion stretches starlight, and at low redshift the distance is approximately cz divided by the Hubble constant, so a single spectrum doubles as a rangefinder. Once surveys collect spectra in bulk, the sky's two-dimensional projection unfolds along the line of sight, exposing walls, voids and filaments of the cosmic web; the CfA survey's narrow slice charts drew them first, and the Sloan Digital Sky Survey extended the census past a million galaxies. At small distances, however, peculiar velocities of hundreds of km/s contaminate the recession speed and must be corrected with flow models.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
V. de Lapparent、M. Geller 与 J. Huchra,1986年,The Astrophysical Journal,302卷L1页:CfA 切片揭示星系巨墙;D. York 等人,2000年,The Astronomical Journal,120卷1579页:斯隆数字巡天技术概要
V. de Lapparent, M. Geller & J. Huchra 1986, ApJ, 302, L1 - A slice of the universe revealing the Great Wall; D. York et al. 2000, AJ, 120, 1579 - The Sloan Digital Sky Survey technical overview
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1086/184625
#红移巡天 #哈勃定律 #宇宙网
宇宙的年龄是如何被测定为约 138 亿年的？
How is the age of the universe determined to be about 13.8 billion years?
宇宙年龄由哈勃常数 H0、物质密度与暗能量密度共同决定，可表述为这些参数积分得到的宇宙时。普朗克卫星结合 CMB 温度与偏振涨落拟合 ΛCDM 模型，得出宇宙年龄 13.80 ± 0.02 Ga。该结果与最老球状星团年龄相互印证。
The cosmic age follows from integrating cosmic time in terms of H0, matter density, and dark-energy density. Planck's CMB temperature and polarization fluctuation fit to ΛCDM yields 13.80 ± 0.02 Gyr, consistent with the ages of the oldest globular clusters.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#宇宙年龄 #哈勃常数 #球状星团
暗能量是如何被发现的，它导致宇宙膨胀发生什么变化？
How was dark energy discovered, and what change in cosmic expansion does it cause?
1998年两个超新星巡天小组通过测量遥远Ia型超新星的亮度，发现它们比无加速度的宇宙模型预期的更暗。这说明宇宙膨胀不但在继续，而且在加速，需要一种具有负压强的能量成分来解释。这一发现后来获得诺贝尔物理学奖，并确立了暗能量约占宇宙能量密度七成的图景。
In 1998 two supernova survey teams found that distant Type Ia supernovae appeared dimmer than expected in a universe expanding without acceleration. This implied that cosmic expansion is not merely continuing but accelerating, requiring an energy component with negative pressure. The result earned a Nobel Prize and established the picture in which dark energy makes up roughly 70 percent of the cosmic energy density.
难度 进阶 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录含书名，但缺版次 / 出版社 / 年份中的一部分，需编辑补全后才能做独立比对。
Perlmutter、Schmidt 与 Riess《超新星宇宙学计划》（1998/1999）；NASA 威尔金森微波各向异性探测器（WMAP）
Perlmutter, Schmidt & Riess, Supernova Cosmology Project (1998/1999); NASA Wilkinson Microwave Anisotropy Probe (WMAP)
#暗能量 #超新星 #宇宙加速膨胀
宇宙微波背景辐射是什么，它为什么能告诉我们宇宙诞生初期的信息？
What is the cosmic microwave background, and why does it reveal conditions in the very early universe?
宇宙微波背景是宇宙诞生约38万年后、物质与辐射退耦时释放的光子，今天冷却成约2.7开尔文的微波。它的温度涨落只有十万分之一的量级，却记录了原初密度扰动，是宇宙大尺度结构形成的种子。这些各向异性被精确测量后，成为检验宇宙学模型最有力的观测证据之一。
The cosmic microwave background is the relic radiation released about 380,000 years after the Big Bang, when matter and radiation decoupled, now cooled to a nearly uniform 2.7 kelvin microwave glow. Its tiny temperature fluctuations, at the level of one part in 100,000, encode the primordial density variations that seeded all later cosmic structure. The precise mapping of these anisotropies provides one of the strongest observational tests of cosmological models.
难度 进阶 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#宇宙微波背景 #大爆炸 #宇宙学
暗能量到底是什么？
What exactly is dark energy?
暗能量是推动宇宙加速膨胀的神秘力量，约占宇宙总能量的68%。它在空间里表现为一种近乎均匀的排斥性压力，与暗物质正好相反。1998年科学家通过观测遥远超新星发现宇宙在加速膨胀后，暗能量才进入主流视野，它最像爱因斯坦提出的宇宙学常数，但本质仍然是个谜。
Dark energy is the mysterious force driving the universe's expansion to accelerate, making up about 68 percent of the total energy budget. It acts as a nearly uniform repulsive pressure filling space, the opposite of dark matter's clustering effect. It entered the mainstream after the 1998 discovery, from distant supernovae, that expansion is speeding up; it resembles Einstein's cosmological constant, though its true nature remains a mystery.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#暗能量 #加速膨胀 #宇宙学常数
什么是 ΛCDM 模型所描述的宇宙组分比例？
What are the cosmic component fractions described by the ΛCDM model?
ΛCDM（冷暗物质加宇宙学常数）模型描述当前宇宙约由 5% 普通重子物质、27% 冷暗物质和 68% 暗能量组成。普朗克卫星对宇宙微波背景的观测给出了这一标准宇宙学模型的关键参数。
The ΛCDM (cold dark matter plus cosmological constant) model describes the present universe as roughly 5% ordinary baryonic matter, 27% cold dark matter, and 68% dark energy. Planck satellite observations of the cosmic microwave background provide the key parameters of this standard cosmological model.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#暗能量 #暗物质 #ΛCDM
暗能量与暗物质在宇宙学作用上的根本区别是什么？
What is the fundamental difference between dark energy and dark matter in cosmology?
暗物质通过引力把物质拉到一起，促进星系和星系团的形成，是聚集性的成分；暗能量则表现为产生负压的宇宙学常数，驱动宇宙加速膨胀，是弥散性的排斥成分。两者都不与电磁波直接作用，故无法直接观测。
Dark matter pulls matter together through gravity and fosters the formation of galaxies and clusters—it is a clustering component. Dark energy behaves as a cosmological constant with negative pressure, driving accelerated expansion—a diffuse, repulsive component. Neither interacts directly with electromagnetic waves, so both evade direct detection.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#暗能量 #暗物质 #加速膨胀
宇宙微波背景辐射的温度起伏大约是什么量级，它又能告诉我们什么？
What is the typical amplitude of temperature fluctuations in the cosmic microwave background, and what do they reveal?
宇宙微波背景辐射全天空平均温度约为 2.725 开尔文，其温度起伏幅度仅约十万分之五（约 ±0.00014 开尔文）。这些微小密度涨落被认为是日后星系与大尺度结构形成的种子，也是宇宙学标准模型最直接的观测支柱之一。
The cosmic microwave background has a mean temperature of about 2.725 kelvin, with temperature fluctuations of only about five parts in 100,000 (roughly ±0.00014 K). These tiny density ripples are regarded as the seeds from which galaxies and large-scale cosmic structure later grew, and are among the strongest observational pillars of the standard cosmological model.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Planck Collaboration 2018, A&A 641, A6（普朗克卫星最终宇宙学参数）
Planck Collaboration 2018, A&A, 641, A6 (Planck final cosmological parameters)
#宇宙微波背景 #温度起伏 #原初涨落
什么是红移，它如何帮助测量宇宙？
What is redshift, and how does it help measure the universe?
红移指天体光谱线向长波（红端）移动，通常由宇宙膨胀造成的星系退行引起。红移越大意味着天体越远、时代越早，它是宇宙学距离测量的基础。
Redshift is the shift of a celestial object's spectral lines toward longer (redder) wavelengths, usually from the recession of galaxies due to cosmic expansion. Larger redshift means greater distance and earlier epoch, forming the basis of cosmological distance measurement.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#红移 #光谱 #宇宙膨胀 #距离测量
什么是引力透镜？它为什么能帮助天文学家测量质量？
What is gravitational lensing, and why does it help astronomers measure mass?
根据广义相对论，大质量天体或星系团会弯曲它周围的时空，使经过的光线偏折，就像一面透镜。背景星系的光因此被扭曲、放大，甚至形成环状或弧状影像，透镜的强度和变形程度取决于前景天体的质量，因此可以测量出包括暗物质在内的总质量。
According to general relativity, a massive object or galaxy cluster warps surrounding spacetime and deflects passing light like a lens. Background galaxies appear distorted, magnified, or arranged into rings and arcs; the strength of this lensing depends on the foreground mass, so it measures total mass including dark matter.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#引力透镜 #广义相对论 #星系团
宇宙的几何形状是怎样的？
What is the geometry of the universe?
根据宇宙微波背景和星系巡测的观测，我们所处的宇宙空间在大尺度上几乎是平坦的，即三角形的内角和约为180度。这与暴胀理论和密度参数接近临界值相符。如果空间正曲率为闭、负曲率为开，宇宙的整体命运也会不同。
Observations of the cosmic microwave background and galaxy surveys show that on large scales our universe is nearly flat, meaning the angles of a triangle sum to about 180 degrees. This matches inflation theory and a density parameter close to the critical value. Positive or negative curvature would imply closed or open cosmic fates, respectively.
难度 入门 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#宇宙几何 #平坦 #曲率
宇宙有多大年纪？
How old is the Universe?
科学家通过宇宙微波背景和星系运动测算，宇宙年龄约为138亿年。
From the cosmic microwave background and galaxy motions, scientists estimate the Universe is about 13.8 billion years old.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#宇宙年龄 #138亿年
我们能看到宇宙的“边界”吗？
Can we see the “edge” of the universe?
没有传统意义上的边界。我们能观测到的极限是“可观测宇宙”，由光自大爆炸以来走过的距离决定，半径约465亿光年。超出这一范围的区域之光尚未到达我们，并非宇宙的真正尽头。宇宙整体可能远比可观测部分大得多。
There is no edge in the usual sense. The limit we can observe is the “observable universe,” set by the distance light has traveled since the Big Bang, about 46.5 billion light-years in radius. Regions beyond simply have light that has not reached us yet, not a true end. The whole universe may be far larger than the observable part.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#可观测宇宙 #视界 #宇宙边界
宇宙中有多少是暗物质？
How much of the universe is dark matter?
如果把宇宙的总质能看作100%，普通物质（恒星、气体、我们）只占约5%，暗物质约占27%，其余约68%是暗能量。也就是说我们熟悉的物质只是宇宙的“少数派”。这一配比来自对微波背景和星系运动的综合测量。
Treating the universe's total mass-energy as 100 percent, ordinary matter—stars, gas, us—is only about 5 percent, dark matter about 27 percent, and dark energy the remaining 68 percent. The matter we know is thus the minority. This budget comes from combined microwave-background and galaxy-motion measurements.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#暗物质比例 #质能组成 #暗能量
暗能量是什么？它和暗物质是一回事吗？
What is dark energy, and is it the same as dark matter?
暗能量不是物质，而是一种驱动宇宙加速膨胀的未知能量，约占宇宙总能量的七成；它与只提供引力的暗物质完全不同。
Dark energy is not matter but an unknown energy driving the universe's accelerated expansion, making up about 70% of its energy budget—quite different from gravity-providing dark matter.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#暗能量 #膨胀 #宇宙学
大爆炸理论认为宇宙是从哪里来的？
What does the Big Bang theory say the universe came from?
大爆炸理论说，宇宙在约 138 亿年前从一个极热、极密的状态开始膨胀并冷却，并不是从一个小点炸进早已存在的空间里。随着膨胀，物质、恒星和星系才一点点成形。
The Big Bang theory holds that the universe began expanding and cooling from an extremely hot, dense state about 13.8 billion years ago, rather than exploding from a point into pre-existing space. Matter, stars and galaxies took shape gradually as that expansion proceeded.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#大爆炸 #宇宙起源 #膨胀
宇宙的年龄大约是多少？
About how old is the universe?
根据宇宙学标准模型和普朗克卫星的观测，宇宙年龄约为138亿年。这一数字来自对膨胀速率和物质组成的反推。不同独立方法（如最年老恒星年龄）也都与此相符。
From the standard cosmological model and Planck satellite observations, the universe is about 13.8 billion years old. The figure comes from extrapolating backward using expansion rates and composition. Independent methods, such as the ages of the oldest stars, agree with it.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#宇宙年龄 #普朗克 #标准模型
什么是大爆炸？
What was the Big Bang?
大爆炸是指约138亿年前宇宙从一个极热极密的状态开始膨胀与冷却的起源事件。它并非空间中某个点的爆炸，而是空间本身的膨胀。此后物质、星系和生命才逐步在冷却中形成。
The Big Bang refers to the origin event about 13.8 billion years ago when the universe began expanding and cooling from an extremely hot, dense state. It was not an explosion at a point in space but the expansion of space itself. Matter, galaxies, and life subsequently formed as it cooled.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Carroll & Ostlie,《An Introduction to Modern Astrophysics》第2版,Cambridge University Press,2017
B. W. Carroll and D. A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed., Cambridge University Press, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-1-108-42216-1 (2nd ed., Cambridge Univ. Press)
#大爆炸 #宇宙起源 #膨胀