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LAN_403

Tesladownunder

Fri Jun 09 2006, 01:39PM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

I'll have a think about this on the weekend. My guess is that you need kilojoules rather than joules. Dont forget two elecrtric kettles for 1 second is 5kJ.

They were frighteningly casual if this was the power though.

In the meantime how about a hot dog ball lightning. This is the only frame in the video with a flash on it. It was so visually disappointing you can hear my son's Ohhhh... on the video.

Peter

1149860361 10 FT11122 Pulsecapshotdogfire

My take on the experiment described is that the water vaporises in an area between the conductive wet ceramic and the central electrode, reducing the contact area progressively such that when the entire space is emptied the arc follows the water out, still attached to the electrode and propelled by the exploding steam. You are seeing the end of an arc in steam and salt spray. I would have expected a yellow colour but wonder about a contribution from some electrode material or the ceramic.
The difference between the ceramic and a metal tube is the high conductivity of the metal will form a localised arc. The dead space between the electrode and and the ceramic may be critical since 5kJ doesn't vaporize much really.

Peter

Dr. Shark

Fri Jun 09 2006, 02:37PM

Registered Member #75 Joined: Thu Feb 09 2006, 09:30AM
Location: Montana, USA
Posts: 711

Your theory on the experiment makes sense, but I really wonder how they came up with the idea to try this in the first place?

I expect the current to be delivered fairly slowly, e.g. maybe with the 50A they are talking about. The resistance would then have to be ~100Ohm, I don't know whether this is plausible for a piece of wet ceramic. The arc would then be more like what you get from welding than from exploding wires, which explains there is no water splashing all over the room, and the guys casually standing by.

Terry Fritz

Fri Jun 09 2006, 10:41PM

Registered Member #393 Joined: Tue Apr 18 2006, 12:30AM
Location:
Posts: 297

Hi,

I attempted this at about 6 joules. But for "sure" it really is 6000 joules so you need 500uF of capacitance at 5000V. The water is able to absorb a whole lot of that energy. But be real careful!! I was hoping they meant "0.5MFD" for those that remember when no one who marked capacitor values new the metric system :o))) But it really is 0.5 milli-joules in whatever notation system that is supposed to be...

Here is info on my test:

The electrode I used is described here.

I think I can get on a 350Uf 10kV cap this weekend >:-))) So stay tuned!!

Forget the currents they mention. It takes a "good" current monitor and a scope. They were "way off" unless there is a significant problem with the setup description.

Cheers,

Terry

Bjørn

Sat Jun 10 2006, 12:21AM

Registered Member #27 Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058

The picture looks like a composite.

Here is the original press release: http://www.ipp.mpg.de/ippcms/eng/presse/pi/05_06_pi.html
Here is the video: http://www.ipp.mpg.de/ippcms/de/presse/pi/05_06_kugelblitz.mpg
More information in German: http://plasma.physik.hu-berlin.de/sonstiges/Kugelblitz.htm

Carbon_Rod

Sat Jun 10 2006, 04:05AM

Registered Member #65 Joined: Thu Feb 09 2006, 06:43AM
Location:
Posts: 1155

Itâ€™s interesting â€“ but I get annoyed when these press releases basically say, â€œthey have recreatedâ€ an atmospheric phenomena not previously documented by science. =-/ IIRC there have been over a hundred sightings with not one real measurement ever done.

Although the voltage levels are too high to be simply modeled as normal electrolysis â€“ does anyone know if they have removed the possibility of a rising cloud of burning H2?
The yellow colour could simply be from minute quantities of sodium and a large enough volt meter potential to temporarily split the H2 and O to create a rising heated cloud.

If someone does get this to work â€“ a simple spectroscope and a camera could help figure out whatâ€™s going on.

Still very neat,
Cheers,

Tesladownunder

Sat Jun 10 2006, 05:04AM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

Terry Fritz wrote ...

..Forget the currents they mention. It takes a "good" current monitor and a scope. They were "way off" unless there is a significant problem with the setup description.

Why, Terry? 50A 5000V for 20 ms is 5kJ. Quite realistic I would have thought for a water arc which is resistive limited. Unlike a can crusher where the first half discharge cycle is in 30 us and the current is inductance limited and is typically 50kA peak.

Peter

cbfull

Sat Jun 10 2006, 09:36AM

Registered Member #187 Joined: Thu Feb 16 2006, 02:54PM
Location: Central Ohio
Posts: 140

Carbon_Rod wrote ...

Itâ€™s interesting â€“ but I get annoyed when these press releases basically say, â€œthey have recreatedâ€ an atmospheric phenomena not previously documented by science. =-/ IIRC there have been over a hundred sightings with not one real measurement ever done.

I thought the same thing initially, but I think the term ball lightning is being used in a very general sense here. Since lightning is basically a plasma channel, and the plasmoid they have created is round-ish, they are calling it ball lightning.

It would be a mistake to claim that they have duplicated the phenomenon that has become historically known as ball lightning. Since no one really knows the exact nature of the ball lightning described by "eyewitnesses", it's a bit difficult to develop a list of criteria and officially pin down the phenomenon and it's properties.

Terry Fritz

Sat Jun 10 2006, 06:56PM

Registered Member #393 Joined: Tue Apr 18 2006, 12:30AM
Location:
Posts: 297

Why, Terry? 50A 5000V for 20 ms is 5kJ. Quite realistic I would have thought for a water arc which is resistive limited.

Apparently, the small tube is a small porus cermic. If is soaks with salt water and makes sort of a HV water resistor of say 100 ohms, then it would all make sense. Most of the power would go into heating the tube until the steam blasted out and the inside became an arc cavity. The current limiting then would also explain why it just does not "explode". I will go searching for ceramic tubes now. >:))

Cheers,

Terry

Marko

Sat Jun 10 2006, 06:58PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

It looks tricky to insulate everything and don't directly let the water into the tube.

PS. I think I had some ceramic tubes, out of old ignition electrodes, but they are definitely not porrous and hole inside is pretty narrow.

It seems that this needs to be real baked clay hat will get wet under water, but won't dissolve or crumble apart.

Conundrum

Sat Jun 10 2006, 08:56PM

Registered Member #96 Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4061

Hi.

A few ideas:-

1) try replacing the toroidal electrode with a circular NIB magnet, with a glass disk over the centre.

2) replace the ceramic electrode with a thin glass tube.

-A Device

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