Antennas

Look at any ham tower and you will know it instantly: the long boom, the row of elements getting shorter toward the front. The Yagi-Uda antenna turns 100 in 2026, and it remains the most recognizable antenna on Earth — the rooftop TV antenna of the 1960s, the contest station's beam, the direction-finder's pointer. A century after its invention, we still have not found a better way to aim radio waves.

The moon is a terrible reflector of radio waves. It absorbs most of what hits it, returns only a whisper, and keeps moving the whole time. Amateurs have been bouncing signals off it for more than 70 years anyway.