宇宙微波背景辐射
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宇宙可能不是想象的那么“匀称”
Huan Qiu Wang Zi Xun· 2025-12-29 01:27
这个发现可不是小事。我们现代所有关于宇宙的理论大厦,也就是如今被广泛采用的"标准宇宙学模型",都建立在一个基础信念上:宇宙从大的、平均的角 度看,在每个方向、每个地方都应该差不多。这就像默认蛋糕液在模具里是完美均匀的一样。但现在,这个"完美蛋糕"的假设遇到了大麻烦。科学家们发现 了一个叫作"宇宙偶极异常"的矛盾。 这异常是什么?要理解它,还需从宇宙微波背景辐射说起。这是大爆炸留下的"余温",如今均匀地充满整个宇宙。科学家早就发现,这"余温"在天空中的温 度其实有极其微小的差别:一边稍微热一点点,另一边稍微冷一点点。这个差别非常非常小。以前,大家觉得这很正常,如果我们的银河系在宇宙中快 速"飞奔",那这种差别产生的感觉,就像开车时感觉前方的雨点更密一样。这在宇宙学中,叫偶极各向异性。 按道理说,如果宇宙真是均匀的,那么我们在"余温"里感受到的这种"一边热一边冷"的偶极结构,也应该在遥远星系的实际分布里看到:朝着我们运动的方 向,看到的星系应该也稍微多一点。 于是,科学家们去数了宇宙中无数个极其遥远的星系。结果出来了:和预想的完全对不上!星系分布所显示的"歪斜"模式,和"余温"显示的"歪斜"模式,方 向对不上,程 ...
观时空涟漪 听宇宙初啼探访阿里原初引力波探测实验一期
Zhong Yang Ji Wei Guo Jia Jian Wei Wang Zhan· 2025-09-01 00:34
Core Viewpoint - The successful completion of the AliCPT-1 experiment marks a significant advancement in China's efforts to detect primordial gravitational waves, which are crucial for understanding the origins of the universe [8][15]. Group 1: Overview of the AliCPT Experiment - The AliCPT experiment, led by the Chinese Academy of Sciences, aims to detect primordial gravitational waves, which are considered key to testing theories of the universe's origin [8][10]. - The first phase of the AliCPT experiment has been completed, achieving its first light observation and capturing clear images of radiation from the Moon and Jupiter at a frequency of 150 GHz [15][16]. - The observatory is located at an altitude of 5,250 meters in Tibet, making it the first high-altitude gravitational wave detection facility in the Northern Hemisphere [12][15]. Group 2: Technical Achievements - The AliCPT-1 telescope is noted for having the largest effective aperture and light-gathering capacity among similar telescopes, with multiple leading international performance metrics [16]. - Key technological breakthroughs have been achieved in areas such as low-temperature superconducting detectors and CMB data analysis, significantly advancing China's capabilities in gravitational wave research [16][17]. Group 3: Future Plans and International Collaboration - The second phase of the AliCPT experiment is planned, which will involve upgrading the existing telescope and adding more detectors [17]. - The project is positioned as an international collaboration, involving 16 research institutions, including Stanford University, to enhance China's research capabilities and global influence in this field [17][18].
【人民日报】聆听138亿年前的“第一声婴啼”
Ren Min Ri Bao· 2025-08-25 02:18
Group 1 - The core theory of modern cosmology suggests that the universe underwent a rapid inflation phase shortly after its birth, leading to the formation of cosmic structures and the generation of primordial gravitational waves [1][2] - Primordial gravitational waves carry essential secrets about the universe's birth, with various cosmological models predicting different mechanisms and strengths for their generation [2][3] - Detecting primordial gravitational waves is crucial for understanding the quantum effects of gravity and the nature of spacetime, as they provide direct evidence of quantum fluctuations amplified by inflation [2][3] Group 2 - The search for primordial gravitational waves requires specific environmental conditions, with ideal observation sites having low median water vapor content, such as Antarctica, the Atacama Desert in Chile, Greenland, and the Ali region in Tibet, China [3] - The Ali Primordial Gravitational Wave Detection Experiment (AliCPT) successfully achieved its first light observation in April 2025 at an altitude of 5,250 meters, making it one of the most effective telescopes for this purpose [3] - AliCPT-1 has transitioned to the scientific observation phase, aiming to identify unique signatures of primordial B-mode polarization in the cosmic microwave background (CMB) over the coming years [3]
聆听138亿年前的“第一声婴啼”(唠“科”)
Ren Min Ri Bao· 2025-08-22 22:11
Group 1 - The mainstream theory of modern cosmology posits that the universe underwent a rapid inflationary phase shortly after its birth, leading to the formation of cosmic structures and the generation of primordial gravitational waves [1] - Primordial gravitational waves carry the core secrets of the universe's birth, with various theoretical models predicting different mechanisms and strengths for their generation [2] - Detecting primordial gravitational waves would provide direct evidence of quantum fluctuations in spacetime and could confirm the existence of gravitons, which is crucial for understanding the nature of spacetime [2] Group 2 - The detection of primordial gravitational waves requires specific environmental conditions, with ideal observation sites having median precipitation levels below 2 millimeters [3] - The AliCPT experiment in Tibet, which began scientific observations in April 2025, is currently the largest in terms of effective aperture and number of detectors among similar international telescopes [3] - The exploration of primordial gravitational waves aims to reveal the universe's earliest characteristics, allowing for the "listening" of echoes from 13.8 billion years ago [3]