銀河系直徑20萬光年，光都要走20萬年，人類是怎樣測量出來的？
98 影片觀看·2024年3月18日
"How did humans measure the diameter of the Milky Way, which is 200,000 light-years across and takes light 200,000 years to travel?"@科學解說員小鶴
"How did humans measure the diameter of the Milky Way, which is 200,000 light-years across and takes light 200,000 years to travel?"@科學解說員小鶴