2026年1月托福机经套卷(第2套) - Read an Academic Passage Q5

Radio Astronomy: A New Perspective Radio astronomy is the study of celestial objects using radio waves rather than visible light. Unlike optical telescopes, radio telescopes can detect signals from sources obscured by dust or too faint to be seen with traditional instruments. This branch of astronomy has led to transformative discoveries, including the detection of cosmic microwave background radiation—a faint glow left over from the Big Bang—which has enabled scientists to reconstruct the universe's early conditions. One of the most famous radio astronomy discoveries was the identification of pulsars in 1967. These rapidly spinning neutron stars, the dense remnants of massive stars that have exploded, emit beams of radio waves at regular intervals. Observing pulsars helps scientists understand the end stages of stellar life and the behavior of matter under extreme conditions. However, radio astronomy faces growing challenges due to technological interference. Devices like mobile phones, wireless routers, and satellites emit radio frequencies that can overwhelm the faint cosmic signals astronomers seek to detect. This "radio frequency pollution" makes it increasingly difficult to isolate genuine astronomical data. To combat this, observatories are often located in remote areas and protected by radio quiet zones, but the global spread of wireless technology continues to pose a serious threat.