In the latest theatrical version of *Detective Conan*, the scene where Dr. Agasa's car weaves through a radio telescope array has sparked lively discussions among astronomy enthusiasts. Those neatly arranged metal dish-shaped antennas, which are actually humanity's precision "ears" for listening to the universe's whispers, have been imagined as sci-fi weapons in the film. This collision between artistic creation and scientific reality just happens to lift the veil of mystery surrounding radio telescopes: from Karl Jansky's "merry-go-round" device detecting radio emissions from the Milky Way in the 1930s, to China's FAST capturing pulsar signals from billions of light-years away with its 500-meter aperture, this equipment, dubbed a "cosmic radio," is opening new dimensions in humanity's understanding of the universe with unique advantages that surpass optical telescopes. 01. Sci-Fi Narratives vs. Scientific Reality When the 45-meter radio telescope at the Nobeyama Radio Observatory served as a backdrop in the movie, few likely realized that these "silent steel dishes" are actually the universe's most sensitive "ears." While Conan uses a mobile phone to make calls in the radio wave protection zone in the film, in reality, observers would already be on high alert due to electromagnetic interference. Radio telescopes have far stricter requirements for the electromagnetic environment than one might imagine: the radio signals they detect have an intensity of only 0.1 millijansky, equivalent to capturing the faint sound of a coin dropping on the moon's surface from Earth. Using a mobile phone with a 2-watt transmission power in the observation area is no different from holding a heavy metal concert in the middle of a library. The 32-kilometer radio quiet zone around the U.S. Green Bank Telescope and the ban on all radio transmitting devices within 5 kilometers of FAST's core area in China—these seemingly harsh regulations exist precisely to protect cosmic signals from being drowned out by the electromagnetic noise of human civilization. The appearance of a laser guide star system in the film reveals another cognitive blind spot: adaptive optics, a technology used by optical telescopes to correct atmospheric disturbances, was incorrectly attributed to radio telescopes. In fact, the millimeter-to-meter wavelengths observed by radio telescopes are barely affected by atmospheric turbulence, and their metal mesh reflectors (such as FAST's aluminum panels, which have gaps wide enough for a finger to pass through) cannot achieve mirror-like reflection of visible light at all. Even more dramatic is the scene where the villain races an antenna transport truck— in reality, the speed limit for ALMA antenna transporters is 12 km/h, with every piece of gravel requiring manual removal. The metal frame structure of radio antennas would lose alignment precision entirely under violent vibrations. These discrepancies between film creation and scientific fact highlight the true nature of radio telescopes as precision scientific instruments: they are not weapon platforms for Transformers, but "sensitive beings" that need to listen quietly to the universe in an electromagnetic vacuum. 02. The Technological Evolution of Radio Telescopes When Karl Jansky discovered radio emissions from the center of the Milky Way in 1932 using a homemade rotating antenna device, he could hardly have imagined that this invention would spawn a new discipline. This American radio engineer's "merry-go-round" device, by recording interference signals in transatlantic radio communications, confirmed the existence of cosmic radio sources for the first time. In the 1960s, Martin Ryle's invention of aperture synthesis technology allowed radio telescopes to break through the resolution limits of single antennas—by interfering with signals from multiple antennas, the effective aperture could match the distance between two locations. This achievement earned him the 1974 Nobel Prize in Physics. From Jansky's simple device to Ryle's interference principle, the core pursuit of radio telescopes has remained unchanged: how to capture cosmic signals more敏锐ly and解析 deep-space images more clearly. Modern radio telescopes operate like a precision "cosmic signal translation system": a huge parabolic antenna converges radio waves like a funnel; a feed receiver converts them into weak electrical signals and amplifies them by billions of times; backend equipment processes them through filtering, frequency conversion, and digitization; and finally, a computer reconstructs the data into scientific images. Take China's FAST, for example: its 500-meter spherical reflector is composed of 4,450 triangular aluminum panels, with 100,000 optical fibers and over 2,000 motors beneath enabling millimeter-level control. Its sensitivity is 2.25 times that of the Arecibo Telescope. This spherical design, which surpasses traditional rotating parabolic surfaces, corrects spherical aberration in real time through an active deformation cable net system, giving humanity the ability to detect nanohertz gravitational waves for the first time. When FAST's receiving equipment converts signals from pulsars into pulse curves on a screen, those periodic radio pulses are actually the cosmic rhythm of neutron star rotation. 03. China's FAST: A Cosmic Journey At an international conference in Kyoto, Japan, in 1993, when Chinese astronomers heard the proposal to build a new generation of radio telescopes, China's largest radio telescope had an aperture of less than 30 meters, while the U.S. Arecibo Telescope already stood at 305 meters. The 11 years during which Nan Rendong led his team to survey over a hundred karst depressions in Guizhou epitomize China's leap from following to leading in radio astronomy. The unique karst depression of Dawodang not only provided a natural site but also its geological stability met FAST's construction needs. Completed in 2016, "China's FAST" not only became the world's largest with a 500-meter aperture but also achieved multiple technological breakthroughs: a flexible cable net supporting the reflector system, lightweight aluminum alloy panels, and high-precision dynamic control. These innovations allowed FAST to discover its first pulsar in the same year it was completed. FAST's scientific output is刷新 human understanding at an astonishing rate: by the end of 2024, it had discovered over 1,000 pulsars, exceeding the total number found by foreign telescopes in the same period. It has observed black hole "pulses" in the radio band for the first time, detected key evidence of nanohertz gravitational waves, and built the world's largest sample of neutral hydrogen galaxies. A more landmark event was its opening to the global scientific community in 2021: teams from 15 countries, including the United States, the Netherlands, and Australia, have used FAST for over 900 hours of observations, from drift-scan surveys to fast radio burst research. This "Made in China" instrument has become a core platform for global astronomical cooperation. When FAST's receiving cabin captures signals from 1.3 billion light-years away at the focus of its reflector, those radio waves traveling through the universe not only tell stories of galactic evolution but also witness China's technological leap from catching up to leading. 04. New Dimensions in Cosmic Observation While optical telescopes are limited by interstellar dust, radio telescopes are leveraging their long-wavelength advantage to penetrate cosmic fog—from molecular clouds at the center of the Milky Way to the distribution of neutral hydrogen in the early universe, cosmic landscapes invisible to optics are clearly visible in the radio band. The future development of radio telescopes shows two major trends: first, expanding to higher frequency bands, such as ALMA's observations of submillimeter waves, which can reveal details of star-forming regions; second, developing larger arrays. The Square Kilometre Array (SKA) plans to build thousands of antennas in Australia and South Africa, with comprehensive capabilities 50 times that of FAST, promising to unravel the mysteries of the cosmic dawn. China's layout in radio astronomy is equally forward-looking: in addition to FAST, the 110-meter radio telescope in Qitai, Xinjiang, is under construction, which will form a north-south observation network with FAST. Although the space station survey telescope is primarily optical, its radio auxiliary equipment will enable multi-band collaborative observations. As technological innovation and scientific goals merge deeply, radio telescopes will not only be observation tools but also information bridges connecting humanity to the universe—stable signals from pulsars may become beacons for interstellar navigation; the origin of fast radio bursts may reveal extreme physical processes in the universe; and the detection of nanohertz gravitational waves will ultimately open a new window to understanding black hole mergers. When we look up at the starry river in the night sky, those silent metal dish-shaped antennas,结晶 of human wisdom, are transforming the universe's electromagnetic whispers into a ladder for civilizational understanding. On FAST's reflector, every ripple of radio waves is a letter the universe writes to humanity, and China's FAST gives humanity the powerful tool to decode these cosmic messages for the first time. This exploration of the unknown is perhaps the most touching aspect of technology: not the exaggerated depictions in films, but rigorous verification in laboratories, perseverance in wilderness construction, and the shared仰望 and listening of all humanity in the face of the universe.