|MadSci Network: Medicine|
Yes you were extremely lucky. What likely happened is this: when you grabbed that wire, you created short circuit between the 2 bared wires; allowing huge amount of electricity to flow for the fraction of second it took for circuit breaker to trip. Most household wires carry no more than 15 to 20 amps. During short circuit, thousands of amps may flow, enough to explosively vaporize the copper wire into blinding fireball at 10,000 degrees F. The flash was too brief to cause serious injury - the black is merely copper residue that had been vaporized. You got no shock because current took path of least resistance which happened to be not your body. Had you been in contact with a grounded object you would have been shocked. It only takes .06 amps of mains current through your heart to cause cardiac arrest. The fireball is called arc flash. In situations where much bigger currents are involved, like power substations, arc flash can yield explosion equal to many sticks of dynamite. Equipment can be destroyed, people close may be hurt or killed by blast even if not shocked. The ultimate arc flashes are lightning bolts.
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