As a lightning bolt hit near a lab, a blue spark jumped from a radio in the lab room to a student. Was the spark lightning? Mysteries of Science
Transcript
A chemistry lab was typically occupied into the late hours by graduate students working on experiments.
One student brought in a short wave radio receiver and strung a 200 foot long copper wire antennae up on the building's flat roof. A coaxial cable ran down the fume hood vent and into the lab.
Two graduate students were working in the lab at 2 am when the radio picked up static.
The students assumed that a thunderstorm was on the way, the storm arrived with fierce lightning.
A big bolt hit about 1000 feet away from the lab. A blue spark jumped from the radio to one of the student's hands knocking him to the floor.
The student was fine and not struck by lightning. What caused the jolt through the radio?
Here's the rest of the story.
The air slowly built up a static charge, as did the antenna. The lightening strike instantly removed the charge by sending it to ground. Then the air was neutral but the antenna was still charged. The student provided a convenient pathway to ground when he put his hand near the radio.
