星系、喷流与著名的黑洞

星系、喷流与著名的黑洞

2023年5月4日 The Galaxy, the Jet, and a Famous Black Hole Image Credit: NASA, JPL-Caltech, Event Horizon Telescope Collaboration Explanation: Bright elliptical galaxy Messier 87 (M87) is home to the supermassive black hole captured in 2017 by planet Earth’s Event Horizon Telescope in the first ever image of a black hole. Giant of the Virgo galaxy cluster about 55 million light-years away, M87 is the large galaxy rendered in blue hues in this infrared image from the Spitzer Space telescope. Though M87 appears mostly featureless and cloud-like, the Spitzer image does record details of relativistic jets blasting from the galaxy’s central region. Shown in the inset at top right, the jets themselves span thousands of light-years. The brighter jet seen on the right is approaching and…

银河系的黑洞

银河系的黑洞

2022年5月13日 The Milky Way’s Black Hole Image Credit: X-ray – NASA/CXC/SAO, IR – NASA/HST/STScI; Inset: Radio – Event Horizon Telescope Collaboration Explanation: There’s a black hole at the center of the Milky Way. Stars are observed to orbit a very massive and compact object there known as Sgr A* (say “sadge-ay-star”). But this just released radio image (inset) from planet Earth’s Event Horizon Telescope is the first direct evidence of the Milky Way’s central black hole. As predicted by Einstein’s Theory of General Relativity, the four million solar mass black hole’s strong gravity is bending light and creating a shadow-like dark central region surrounded by a bright ring-like structure. Supporting observations made by space-based telescopes and ground-based observatories provide a wider view of the galactic…

首张黑洞事件视界尺度的影像

首张黑洞事件视界尺度的影像

2022年5月1日 First Horizon-Scale Image of a Black Hole Image Credit: Event Horizon Telescope Collaboration Explanation: What does a black hole look like? To find out, radio telescopes from around the Earth coordinated observations of black holes with the largest known event horizons on the sky. Alone, black holes are just black, but these monster attractors are known to be surrounded by glowing gas. This first image resolves the area around the black hole at the center of galaxy M87 on a scale below that expected for its event horizon. Pictured, the dark central region is not the event horizon, but rather the black hole’s shadow — the central region of emitting gas darkened by the central black hole’s gravity. The size and shape of the…

全息原理和茶壶

全息原理和茶壶

2021年10月3日 The Holographic Principle and a Teapot Image Credit: Caltech Explanation: Sure, you can see the 2D rectangle of colors, but can you see deeper? Counting color patches in the featured image, you might estimate that the most information that this 2D digital image can hold is about 60 (horizontal) x 50(vertical) x 256 (possible colors) = 768,000 bits. However, the yet-unproven Holographic Principle states that, counter-intuitively, the information in a 2D panel can include all of the information in a 3D room that can be enclosed by the panel. The principle derives from the idea that the Planck length, the length scale where quantum mechanics begins to dominate classical gravity, is one side of an area that can hold only about one bit of…

黑洞世界的双重翘曲

黑洞世界的双重翘曲

2021年04月16日 The Doubly Warped World of Binary Black Holes Scientific Visualization Credit: NASA, Goddard Space Flight Center, Jeremy Schnittman and Brian P. Powell – Text: Francis Reddy Explanation: Light rays from accretion disks around a pair of orbiting supermassive black holes make their way through the warped space-time produced by extreme gravity in this stunning computer visualization. The simulated accretion disks have been given different false color schemes, red for the disk surrounding a 200-million-solar-mass black hole, and blue for the disk surrounding a 100-million-solar-mass black hole. That makes it easier to track the light sources, but the choice also reflects reality. Hotter gas gives off light closer to the blue end of the spectrum and material orbiting smaller black holes experiences stronger gravitational effects…

星系M87、喷流与著名黑洞

星系M87、喷流与著名黑洞

2021年04月15日 The Galaxy, the Jet, and a Famous Black Hole Image Credit: NASA, JPL-Caltech, Event Horizon Telescope Collaboration Explanation: Bright elliptical galaxy Messier 87 (M87) is home to the supermassive black hole captured by planet Earth’s Event Horizon Telescope in the first ever image of a black hole. Giant of the Virgo galaxy cluster about 55 million light-years away, M87 is the large galaxy rendered in blue hues in this infrared image from the Spitzer Space telescope. Though M87 appears mostly featureless and cloud-like, the Spitzer image does record details of relativistic jets blasting from the galaxy’s central region. Shown in the inset at top right, the jets themselves span thousands of light-years. The brighter jet seen on the right is approaching and close to…