Magnetic OU principle, You should really take a look at this !

[Sudonym]

Got bored so i thought I would really drive this one into the ground. Actually I realized why people may get confused after reading BEP's post again. Please see the following video....

http://www.youtube.com/watch?v=43AeuDvWc0k

Upon viewing this one might think........well that disproves everything sudonym said! they will implode!

Actually if you remember back to your physics basics you would apply the right hand rule. Thumb would point in the direction of current flow. This would mean that the magnetic "poles" on the wire will be perpendicular to the direction of the current flow. That means that in parallel they will be north to south in the two wires and attract. But within the wire, all domains will be in the same orientation causing repulsion within the wire.

All you need to solve this little dilema is the right hand rule and some common sense.

[TinselKoala]

Wowsers. Nice photos. But unfortunately they do not prove that wires don't implode under high currents, as BEP says. I have done many wire explosion experiments, where I discharged approximately 0.3 uF at 60 kV, through a triggered air gap, into lengths of various wires mounted between recording paper on a platen. (I've exploded a few capacitors doing this too--very exciting indeed!)
This technique leaves a record, often very beautiful, of traces of the products ejected from the wire when it "explodes".
It appears to me that wires do implode, but of course stuff is still ejected violently, just in the opposite direction from what you might think.
Two very interesting things I saw, over and over in these experiments: First, when using enameled copper magnet wire (#44 or #46, very thin, in 6 inch lengths) very often the implosion would completely vaporize and eject the copper, but would leave behind, nearly intact, the empty tube of enamel insulation. Second, I often curved the wire in s-curves, between the paper sheets in the platen. The ejecta always left the wire on the outside of the curvature, and the inflection points, where the curves reversed, were clearly noticed because the ejecta flipped instantly to the other side of the wire.
Only a few times was I able to reproduce the "segmenting" of the wire that others, like the Graneaus, have reported. I think the inductances have to be precisely tuned to achieve segmentation.
I know I'm not describing this very well; I'll try to find some photos of my recordings and post them.
Anyway, in my experience wires implode if the current is high enough; this implosion can look like an explosion from far away, but recordings taken by the platen method seem to indicate implosions.
An explosion mechanism, or tension segmentation, would presumably operate by the Graneau's postulated Ampere tension; while implosion or pinch segmentation would seem to be in line with more conventional predictions of the Biot-Savart force law.
Or did I get that backwards?

[BEP]

Like charges DO REPELL, Wires DO explode due to large currents, and coin crushers are NOT the same thing.

Only when they are not travelling together. Attraction increases with speed, close similarity between the charges and energy.

My statements are based upon experience with the use of bus bars in very high AIC switchgear systems. State what rules you wish. I can never claim to be correct 100% of the time but I'll change nothing in my previous post.

When a 250KAIC DC circuit breaker fails to open under a short circuit and the source of energy has over 200k instantaneous available the .25 x 4 inch 110 grade, silver plated copper bar shrunk so much it elongated the bolt holes upstream of the short circuit. The silver plating flaked off and the 4 inch portion distorted to less than 3 inches with no change in the thickness.
The distance increase between the positive and negative bars destroyed 4.5 inch Glastic isolators and 2 inch thick fiberglass sheeting.

The engineer was fired that same week and I've been designing these systems since - about 30 years.

Physics observations or not this is what happened.

Does anyone think CRTs explode because of the shrapnel they throw everywhere?

Great photos. I recognize them. Try placing two wires side by side with both ends shorted and bang them with a bit of current. Does the distance between them expand or contract? Yes, this isn't the same as a single conductor but any ideas of exactly how current flows through a wire are nothing but theory.

I was the one that had to replace the bus system. That was no theory.

BTW: The direction of elongation was the opposite of what would be expected if the bars simply stretched. Once removed the damaged bars measured the same length as originally installed.

[allcanadian]

I think the problem here may be you are trying to compare apples and oranges and assuming they must be the same. I have found you cannot compare a DC discharge to an AC discharge, you cannot compare a generated discharge to either a capacitive discharge or an inductive discharge. You cannot compare a low voltage/high current discharge to a high voltage/low current discharge. Each has specific qualities and properties and imparts these to it's surroundings. In which case all of you may be right in your examples but you are wrong in assuming all energy states must produce the same effects.

[Butch]

Here is a video of a test Mark did.
Thanks,
Butch LaFonte
See this link > http://www.youtube.com/user/LaFonteGroup
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