Long Delayed Echoes (LDEs) were mysterious radio signals reported by operators worldwide in the 1920s that returned seconds to minutes after transmission, defying normal physics since radio waves travel at light speed; while scientists proposed explanations like ionosphere bouncing and magnetic disturbances, none fully account for the phenomenon, and the extraterrestrial theory suggested by astronomer Duncan Lunan remains heavily disputed despite the echoes being real and documented.
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Who Sent the Echo BackAdded:
In the 1920s, [music] radio operators began reporting something impossible. They would transmit a signal across the world, then hear it return seconds later. Not milliseconds, seconds. An ordinary radio echo should bounce back almost instantly.
>> [music] >> Radio waves travel at the speed of light. A delay of several seconds meant the signal had traveled an impossible distance. The phenomenon became known as long delayed echoes, LDEs. Some echoes returned after 3 seconds, others after 15, some after nearly a minute, [music] which raised a terrifying question.
Where exactly were the signals going?
Scientists [music] proposed explanations. Signals bouncing off the ionosphere, charged [music] plasma clouds, magnetic disturbances around Earth, but none fully explained the longest delays.
Then, >> [music] >> the mystery deepened.
In 1928, Norwegian engineer Jørgen Hals carefully documented strange delayed echoes while operating radio equipment across Europe.
Decades later, astronomer Duncan Lunan controversially suggested some echo patterns resembled an artificial message mapped [music] through star positions, specifically the Epsilon Boötis system.
The theory remains heavily disputed.
Most scientists [music] reject extraterrestrial explanations entirely.
But the echoes themselves [music] were real, recorded, measured, observed by multiple operators across decades.
Even today, no single explanation fully accounts for every case, which means somewhere in the history of radio, humanity [music] transmitted signals into the darkness, and something answered later than physics said it should.
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