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Triggering Lightning

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LAN_403

_insertnamehere_

Wed Jun 09 2010, 08:14PM

Registered Member #2910 Joined: Wed Jun 09 2010, 07:50PM
Location:
Posts: 5

After seeing a video of University of Florida students triggering lightning with model rockets trailing copper wire, I've decided to do a lightning trigger project of my own.

Since I have no way to measure the charge in the thunderclouds, I've decided to use party balloons instead of a rocket, since they will stay airborne until struck by lightning.
I have made a rig to spool out about 100 yards of copper wire, with 70lb test fishing line as the main tether for the balloons. I have also made the whole spooling system remote controlled, so I can sit in my faraday cage (car) a safe distance away. I plan to set up the whole system in a remote field (with minimum fire hazards, and far away from any bystanders) far before the thunderstorm reaches the area.

I have a few questions though, and I feel this would be a good place to ask them.

1: If I were to place a bucket of sand underneath the copper wire, would it be possible to make fulgurites? (glass-like figures made from sand when lightning courses through it)

2: Is this an effective way to trigger lightning?

3: Any safety concerns that are blazingly obvious that I missed?

4: Has anyone else tried this? (and survived?)
Thanks! any criticism is welcomed!

Hon1nbo

Wed Jun 09 2010, 08:31PM

Registered Member #902 Joined: Sun Jul 15 2007, 08:17PM
Location: North Texas
Posts: 1040

first: balloons are an interesting idea, but can they carry the copper wire effectively, and couldn't wind also cause problems with them?

second: will the copper alone work at such a low altitude compared to the rocket? - the rocket also has the help of the smoke trail it leaves which adds conductivity in the air around the wire.

setting up before the storm and staying away is good thinking, nice thing about your plan is that everything is passive so no need for any wire trails going back to you.

but one safety concern is to make sure there are no objects within a radius a little larger than the height to which your copper wire can travel, as it could fall. And make sure you have a good anchor for all of this.

as for major safety concerns other than those, because you are not interacting with it you should be fine (let others fill in if I missed anything, as I might have).

The sand is an interesting idea. If you want to try that, I suggest that you sink a copper grounding rod for your copper wire and pile the sand around that? - maybe dig a small hole and fill that with sand so that more current travels through it via the rod rather than the rod strait to dirt.

be careful,

-Jimmy

Bjørn

Wed Jun 09 2010, 09:08PM

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

Your balloons are broadcasting that something is going on, making it likely that any people around are coming to have a look. Now your spool jams, what do you do? They can't hear you because of the thunder so shouting is no use.

Renesis

Wed Jun 09 2010, 11:18PM

Registered Member #2028 Joined: Mon Mar 16 2009, 08:13PM
Location: Norway
Posts: 319

I see what you are trying to do, but its of no use. For years The University of Florida has been trying to rig a telegraph line to heaven, but God always blasts it to pieces.

This is an interesting idea. But do take every safety measure imaginable. You are dealing with massive amounts of energy and incredible rise times.

I dont think the thickness of the copper wire really matters. The wire is bound to evaporate anyway, and the heat generated should be enough to ionize the air surrounding it. And a wire with a small cross-section should not be less likely to be struck than a wire with a large cross-section.

1: I dont know, you tell us. I think you are about to become a pioneer on the field.

2: You cant properly trigger lightning, only increase the likelyhood of a strike. Unless you have a really long line then there could be a few dissapointing thunderstorms before you score a hit.

3: As DaJJHman says, balloons and high winds dont match. If your balloon breaks free, dragging that cable behind it, you would effectively have a Red Alert-ish tesla bomber blimp waiting to desimate a nearby village

Joke aside, you should be aware that tall radio transmission towers and such can get electrostatically charged, to dangerous levels, by friction with particles in the wind. I dont know wether this could occur with your experiment, but be warned. I dont think you should approach the cable while it is in the air.

Also, it is possible that the lightning bolt can break free from your copper wire trail half way down, and decide to strike ground somewhere in the surrounding area. The same is seen when lightning strikes a tree, it may decide to break out of the trunk half way down and proceed the rest of the way through the air, or through the campers seeking shelter there from the rain. Those students you mention who experiment with rockets have also found that triggering such artificial lighrning bolts can sometimes trigger real lightning bolts at the same time, in the nearby area. So stay in your faraday cage.

4: Yes, Benjamin Franklin did.

Nik

Wed Jun 09 2010, 11:57PM

Registered Member #53 Joined: Thu Feb 09 2006, 04:31AM
Location: Ontario, Canada
Posts: 638

I have done the ben franklin experiment (if you look it up he did it on a clear day not a stormy one) and measured 800v on my copper wire hanging from a kite.

You are going to need one hell of a balloon to get high enough to trigger lightning reliably. Even very thin wire (I was using 30awg) is heavy in long lengths and if you go too thin it will break in the wind. Also your tether rope will have to be very strong to deal with the pull of the balloon + the pull of the wind. I think you are going to be looking a something in the weather balloon size ;)

Dave Marshall

Thu Jun 10 2010, 01:11AM

Registered Member #16 Joined: Thu Feb 02 2006, 02:22PM
Location: New Wilmington, PA
Posts: 554

A balloon carrying a wire aloft would be no more effective at triggering a lightning strike than a radio tower of the same height. A particularly prominent radio tower in the southeastern US (prime lightning real estate) can expect to see between 10 and 30 strikes a year. The reason UF's rockets work is they carefully monitor the local electric field before they're launched, firing them at peak gradient density. The sudden introduction of a conduction path through the field gradient is what triggers the lightning. I suppose if the balloon were launched at just the right moment, it could rise fast enough to trigger a strike now and then, but it wouldn't be particularly reliable. Also, UF's rockets hit 300m give or take.

There are relatively simple devices that can give you at least some idea of the local electric field. There are plans out there for Field Mills, as well as the old ionizing razorblade trick.

-Dave

_insertnamehere_

Thu Jun 10 2010, 03:01AM

Registered Member #2910 Joined: Wed Jun 09 2010, 07:50PM
Location:
Posts: 5

Thanks for all the feedback!

As far as the tether goes, it is deep sea fishing line, so I'm not too worried about it snapping. I do have a few weather balloons, although they were going to be used for a different project. I've calculated the lift of a party balloon, and found that I need about 25 to lift the weight of the tether and the line. Making it rise quickly is a whole other problem, but it looks like I might have to add more to get the lift speed needed for a reliable strike. I've found a rather large concrete launching pad out in the Colorado grasslands (which are green right now, so minimum fire hazard) that the local high power rocketry club uses. I think that would be far enough away from any real population that might come running at the sight of balloons. I'll just have to ask they're permission first.
While I'm out there, maybe I should just launch a rocket.

It looks from the feedback that I need a longer line to be more reliable. I Guess I'll have to stop by the jewelry store again. They're really going to wonder why I'm making so many necklaces with copper wire...

radiotech

Thu Jun 10 2010, 06:09AM

Registered Member #2463 Joined: Wed Nov 11 2009, 03:49AM
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Posts: 1546

"3: Any safety concerns that are blazingly obvious that I missed?
"

I think that if your "kite string" (Franklin) worked you might wonder about the next one who tried it and was killed. I believe it was a German physicist.

Film :document what you do.

Globe or ball lightning, 'not well understood' seems to pass through
anything. Faraday cage wont help. Solid steel cant stop oscillatory discharge driven by strong >~ 50 kW sources.

Here is a testimonial from a survey on ball lightning 46 years ago.
(typical of many that came in)

IntraWinding

Thu Jun 10 2010, 06:44AM

Registered Member #2261 Joined: Mon Aug 03 2009, 01:19AM
Location: London, UK
Posts: 581

I think the biggest problem with a balloon will be it floating off down wind. Why not stick with rockets? You could fire them remotely by fibre optic link.

Would a single carbon fibre filament be strong enough to replace heavy copper?

I'm pretty sure I saw a circuit for measuring the charge on overhead clouds in a hobby magazine years ago. I think it was just a very high impedance op-amp low pass filter, using a metal plate as a sensor.

_insertnamehere_

Thu Jun 10 2010, 06:45AM

Registered Member #2910 Joined: Wed Jun 09 2010, 07:50PM
Location:
Posts: 5

Do you think "ball Lightning" is a serious concern? All the stories I've heard of people getting killed by lightning is being directly or indirectly struck.

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