They said, "It's all right, you can detect radio waves from the Sun, but the Sun is the only object in the universe that's close enough and bright enough actually to be detectable. You can easily calculate that radio waves from the Sun are fairly faint, and everything else in the universe is millions of times further away, so it certainly will not be detectable.
「太陽から来る電波なら検出できる 現実的には検出できるほど十分に近くて明るい天体なんて この宇宙で 太陽だけだ 簡単な計算で分かるけど 太陽の電波でさえとても弱い ほかの天体は太陽よりも何百万倍も遠いのだから 検出なんて無理だ