On the one-month anniversary of this year's April Fool's Day, I'm finally getting around to posting something I ran across at the Museum of Hoaxes Web site:
In 1976 the British astronomer Patrick Moore announced on BBC Radio 2 that at 9:47 AM a once-in-a-lifetime astronomical event was going to occur that listeners could experience in their very own homes. The planet Pluto would pass behind Jupiter, temporarily causing a gravitational alignment that would counteract and lessen the Earth's own gravity. Moore told his listeners that if they jumped in the air at the exact moment that this planetary alignment occurred, they would experience a strange floating sensation.
When 9:47 AM arrived, BBC2 began to receive hundreds of phone calls from listeners claiming to have felt the sensation. One woman even reported that she and her eleven friends had risen from their chairs and floated around the room.
(Emphasis and extra paragraphing added.) One commenter remarked that this was simply an example of the placebo effect; another wondered whether the room-floating woman was simply going along with the gag.