Has Anyone Ever Observed This?

[Eighthman]

Has anyone ever observed a circuit breaker get popped because of an arc within an existing circuit?  I'm not talking about an arc to ground but an arc that develops because there's a sudden break in an existing conductive path but the arc completes the circuit anyway.
I vaguely recall this happening sometimes but I can't remember an exact incident.  Such a thing might suggest overunity in an arc.....

[lzbin80]

Yes. I firmly believe the spark gap is a mean factor for collection energy from environment. 

I did observe static attraction on a circuit breaker caused by high voltage before spark gap formed on that breaker's gap.

[TinselKoala]

A supply CB or fuse will trip/blow when the circuit it is protecting exceeds the current draw rating of the CB or fuse! This of course does not require an "arc to ground" except in very simple circuits. Plug in your electrical heater, your air conditioner and your table saw into the same circuit and turn them all on. No arcs, but your breaker had better trip, because you are asking for too much current from your mains supply for your house wiring to handle safely. Construct some complex device, like my flyback jacob's ladder power-arc demonstration system, where neither side of the arc is connected to any grounds or even directly to any input wiring, and when the current draw exceeds the inline fuse or CB rating, the CB will trip or the fuse will blow.

Yes, high voltages can draw loose conductors or contacts together and when they get close enough an arc can happen. Even a relatively low "high voltage" like 500 volts is enough to produce significant attractive force and I have even (accidentally!) constructed a motor that operated on this principle at that low level of "HV".

For a spark or arc to entrain any energy from the arc environment, the energy has to be put into the environment somehow, and has to be prevented from "leaking" back out of the receiver system into the tuned antenna circuit. I can imagine systems that might use a small arc to enable the collection of larger amounts of energy from the environment; this is essentially what "detector" or "coherer" systems do in ancient radio receiver designs. A tiny bit of the RF energy in the environment, put there by the system's transmitter, is collected by the tuned antenna circuit and rectified by the coherer, to be amplified by the receiver's output electronics. But you have to put in more energy than you are collecting, usually. In the case of the Crystal Radio, the design is efficient enough so that the germanium diode, or the diode junction found by tickling a galena crystal with a stiff wire, produces the "spark gap coherer" action and if the transmitter is strong enough you can hear the result in a sensitive high-impedance earphone.

[Low-Q]

Has anyone ever observed a circuit breaker get popped because of an arc within an existing circuit?  I'm not talking about an arc to ground but an arc that develops because there's a sudden break in an existing conductive path but the arc completes the circuit anyway.
I vaguely recall this happening sometimes but I can't remember an exact incident.  Such a thing might suggest overunity in an arc.....

It is called a welding machine. They pop fuses all the time.