Attracting Lightning

[10fingers]

I was watching this show awhile back about lightning researchers using small model rockets to attract lightning bolts. I think it was on the discovery channel.
They would attach a small copper wire to a rocket, the wire was on a spool like fishing line on a reel. I suppose you would need a couple thousand feet.
When there was a thunderstorm overhead they would launch the rocket. If a lightning strike was on the verge of forming near the rocket it would use the copper wire as a path to ground. The wire could only carry a small current before vaporizing but it was enough to get the bolt started.
This system seemed to work pretty well, they had several strikes.
Anyway I thought this might be interesting for anyone into such things. Having lightning strike in your backyard would be a great conversation starter with your neighbors.
One drawback is that your rocket probably wouldn't be recoverable.

<small>[ May 31, 2002, 05:11 AM: Message edited by: 10fingers ]</small>

[A-BOMB]

10fingers I too saw that show awhile ago. And what to you mean probaly you mean deffiantly, didn't you see the part of the show when they went out and found the peices of the rockets. The only part of it I could tell was a rocket was the tail section, the nose cone and most of the body tube were melted away and there rockets were all made from stainless steel. (I think) But this would be away to get insurance money if you insurance covers lighting strikes or acts of God.

[xyz]

There was an article in the new scientist a while back about using a machine that fired a thin jet of salt water into the air as a mobile lightning attractor

They were developed to protect people at soccer matches and the like, they set them up about 200m away and all lightning goes for them and not the soccer pitch (or more importantly, the people on it :) )

[megalomania]

That show was about a team of grad students trying to create a new form of carbon using a massive jolt of electricity, which is cheaper to use lightning. I myself hope to recreate this experiment even though I have no support from friends and family on this one (I curse the gods and stand outside when it storms). I have my model rockets, and I acquired thousands of feet of copper wire from the recycle bin at work (electromagnet wire wrappings). I have my eyes on 2 old style TV antenna towers (the 50 foot kind) that are being scrapped. Combine these things together and I will have one hell of a hobby. The only thing I lack and have no idea where to get is the ionization meter the students used to determine the optimal condititions to launch the rocket. There is nothing like 1.21 Giga Watts to get the ol blood pumping.

[10fingers]

I want to try this too. I forgot to mention that they used an ionization meter to detect when there was a charge forming between cloud and ground. This would let them know when it was the best time to shoot the rocket.
Without the meter it might take a lot of rockets to get a strike.
I suppose you could just hold unto a tall grounded metal pole and when your hair started to stand on end, launch the rocket.

[kingspaz]

never heard of an ionisation meter but i have experimented with gold leaf electroscopes before. they are very sensitive to static charge so maybe one made with Al foil would be less sensitive due to the thicker foil but it should detect the chrage buildup in the clouds.

'The simple electroscope consists of a metal case within which, and near its center, is supported in a vertical position a well-insulated metal strip to the top of which is attached a narrow strip of thin foil, preferably of gold leaf. This strip of foil is usually spoken of as the leaf. The strip of metal and the leaf constitute the insulated system of the electroscope. When the insulated system is electrically charged by a suitable switch passing through the wall of the case, the leaf is repelled by the strip, and is deflected from its normal, vertical position. In opposite sides of the case are windows through which the position of the leaf can be observed. Such observation is usually made by means of a microscope having in its eyepiece a ruled scale. '

from here:

<a href="http://physics.nist.gov/GenInt/Curie/1927.html" target="_blank">http://physics.nist.gov/GenInt/Curie/1927.html</a>

[vulture]

I would stick a metal pole in the ground, put a few cm of isolating tube and then put another piece of metal pole on it. If you connect a voltmeter to the 2 parts you should be able to predict a lighting strike because the voltage get's higher. It's like the principle of a capacitator.

[xoo1246]

Seems like a good idea too me, or you could climb a tree and attach the second (isulated from the tree)metal pole.
Why not use a ballon?

<small>[ June 02, 2002, 02:55 PM: Message edited by: xoo1246 ]</small>

[megalomania]

Actually, using a balloon is a damn good idea. A few helium, or better yet hydrogen, filled balloons could carry the wire up and just sit there. That would prevent the problem of the wire snapping if not unspooled adequately during a rocket launch, and of course just looks more scientific like. The only downside I see so far, I don’t want to be unwinding the wire by hand if (when) it gets hit. No gloves are thick enough for that. High winds may also be a problem for thin wire.

On a related note, is it possible to induce an electric charge to attract the lightning? And if so how?

[PYRO500]

It is posible to charge an antenna to draw lightning but it would have to be a very powerful charge to have much of an effect on the lightning, the ground normally builds up a charge before the lightnig strikes ( remember lightning travels from - to +) so what you really want is to charge your antenna with millions of volts of electricity although that would have a small effect on lightning even if you could ever insulate your antenna.The balloon idea is good except that the baloons would get tugged from side to side rapidly and possibly snap your wire. You could possibly eliminate the need for a wire if you were to make a rocket that wpuld have a conductive exaust such as copper oxide vapor although it'd need to be very fast and would not direct the lightning to a specific spot.

[mrloud]

To release the balloon and wire, I would use a very long piece of cotton string. Just pull the end of the string to pull a pin out of a clip and let the balloon float away unwinding the wire off a drum as it goes. You could always use some sort of fancy radio controlled release mechanism but it's a safe bet it wont survive the first lightning strike.
In the documentry I saw, the scientists used their mouth to blow into a rubber tube which activated a switch to launch the rocket. A spa pool shop should be able to sell you this sort of equipment. On our spa, the buttons on the side of the spa are just little pistons which activate a switch back on the pump/heater box; thus keeping the people away from the voltage.

[10fingers]

I like the balloon idea much better than the rocket. The problem of course would be the wind. It may snap your wire and go catch itself on your neighbors house or something.
Occasionally there are slow moving thunderstorms with little wind where the balloon might work well.

[Snipie]

Maybe you could use a wire with a thin metal wire weaved through it. Farmers use it as electrical wire to keep the cows on there land.
It’s a bit heavier than the copper wire, but it can’t snap, or break (well it can, but not easy). And you can make as much H2 balloons as necessary to lift the heavier wire.

[J]

You could use a motor to unwind the reel. You'd need to test the system first, by adding enough balloons to lift the whole reel (since that's the final weight of the unwrapped wire).

Instead of using a bunch of balloons, you could use a bin bag filled with hydrogen/helium. I'd rather use helium, because of the problem of static.

This sounds fun, another project to eventually get round to :)

[mrloud]

A lightning detector is used in the mining industry when preparing explosives.

<a href="http://203.2.75.213/filetransfer3/thor.jpg" target="_blank">Here</a> is a picture of a lightning sentry known as 'Thor'. It detects snow dust and electrical storms with high levels of static electricity in the air. It measures the atmospheric voltage gradient and will flash lights and ring bells when the gradient approaches a level at which a lightning discharge could occcur.

[Bander]

I too have seen this Discovery channel show and become fascinated/obessed with the idea. I've been working to a rocket along the lines of the discussion here for some time now (first saw the episode 3 years ago). It will use a Richard Nakka style 'G' potassium nitrate/sucrose engine with a thousand or two feet of 28 gauge copper wire with a tungsten lead.

Personally, I'm going to stick with rockets, as much for the 'style' as anything else.

But regardless of the device used, rocket or balloon, the plans for a "<a href="http://www.amasci.com/emotor/chargdet.html" target="_blank">RIDICULOUSLY SENSITIVE CHARGE DETECTOR</a>" are sure to improve the odds. The above page also has links to more complex devices and general electrostatics information as well.

[PYRO500]

I built one of those a few years ago it wouldn't help you detect lightning unless you were charged and about to be struck. they are useful in the TV repair busnuess though.

[Zzzzeta]

I work for a company which makes power transformers, so I'll swipe a few thousand metres of fine copper wire and check out the balloon method. I'm guessing that if you unwind all your wire first, laying it out on a hard flat surface with no crossovers, you can let the balloon lift the wire without having to worry about operating a spool.

Zzzz

[kingspaz]

yer, a big field would make a good place to do that. your going to need a pretty big ballon also. it must lift the weight of the spool of wire. also, when you test make sure the clouds are right <img border="0" title="" alt="[Wink]" src="wink.gif" />

what about using hydrogen to fill the balloon. its more boyant that helium and will make a nice bang when struck....not that it would be very noticable against a lightning strike.

[10fingers]

A couple thousand feet of copper wire would weigh a few pounds, depending on what gauge it was. So I would guess you would need a balloon a couple feet in diameter to lift it.
The balloon definitely has advantages over the rocket in low wind conditions since it would stay up there indefinitely.
With a rocket you would have to use some type of ionization meter to know the optimum time to launch the rocket.

[Mick]

you also have the problem of will the wire support itself?

what i mean is..
</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">O ] - ballon
| ] - part A
| }
| }
| } - part B
| }
| }</pre><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">will part A of the wire be strong enough to support the rest of the wire(part B) all the way to the ground, and will the wire be able to withstand the drag created from the wind blowing the ballon around.

[kingspaz]

maybe some sort of hollow woven wire, like a showlace made of copper strands, may be more effective. plenty of copper to carry electricity but very flexible and strong (similar to rope). it would also be a hell of alot lighter than traditional wire. although where to get somthing like this i have no idea about.

[megalomania]

I almost got to test it this weekend because of a big storm, but I was not ready. My hydrogen generator refused to generate, my wire wasn’t ready to be unwound, and the storm was already upon me. The storm proved to be a dud in the end.

Upon reflection I realized you do not need a giant balloon when several will do the trick. I have devised this to make the works more stable in windy conditions or otherwise:

O – 1st balloon
|
| - first wire segment
|
|
O - 2nd balloon
|
| - second wire segment
|
|
O – 3rd balloon
|
| - third wire segment
|
|

You can add as much wire to a balloon as it can lift to make it as high as you want. I also hypothesize that this system would be less affected by winds because each piece can stabilize itself. If you had 10 balloons on top, that is a lot of surface area being hit by wind. If the wind pushes that down, the total length will be reduced. If you have individual balloons, the wind conditions will be different for each. The balloons will be pushed and pulled in all different directions, and this should average out to less moving overall.
I recommend hydrogen only because it is cheaper, and it would produce a nice fireball. Of course that would probably pale in comparison to the lightning strike. Producing hydrogen yourself does complicate things as the pressure on a homemade system leaves much to be desired, whereas a commercial tank can fill a balloon much faster.

[Tyler_Durden]

i was going to suggest that very balloon placement setup, mega.

anyway,

what's to keep you from setting it up (putting the baloons/wire in position) a 12-48 hours in advance? i mean, why worry about a method of getting it in place during or close to storm time? just set it up and leave it once you hear a storm is on its way.

[Zzzzeta]

I'm thinking of using a very fine gauge PEI (varnish insulated) winding wire, maybe .355mm or so, with the top few metres stripped bare and the bottom stripped and soldered to a 25mmx150mm copper ground peg. Something this fine will vaporise instantly when struck, but it should be enough to initiate a strike.

With hydrogen being so easy and cheap to manufacture, I'll use a bunch of party balloons to provide the lift - although since hydrogen is such a small molecule and leaks out through balloon membranes, there won't be a long flight time.

IAN

[10fingers]

The multiple balloons looks like a good idea. You could also use fishing line to hold the balloon and then you could use an even finer wire. Fishing line can be purchased in large spools and is fairly cheap.
It would be nice if there was an easy way to recover the balloons and wire if there was no strike. A large fishing reel would work nice but if you do get a strike, you'll need another reel. Something similar could be rigged up that was easily replaceable.
It's too bad I haven't had time to try this because we've been having some good thunderstorms. If I do get around to doing it I'm going to try to capture the strike on my camcorder.

[BoB-]

Dare I say it? You could always go Ben Franklin style, using magnet wire, you could even glue foil to the entire back of the kite, providing more surface area for a strike to occur. This would solve the problem of thin wire snapping as larger kites can lift several hundreds pounds, so using thicker gauged, or even insulated wire would not be a problem.

Of course, I sure as hell wouldnt wanna be the one who got the kite in air.

On megas idea; Wouldnt using those foil, semi-expensive balloons be more reliable? the entire balloon could then attract lightning.

[McGuyver]

Not to put you down Zeta, but it's not necessary to strip the top few feet of your wire, or do the ground rod thing. There is so much power in lightning it doesn't give a crap how much insulation is there, if the wire provides an easier path than the air it will take it. Also, the thickness of the wire doesn't really matter, but thin wire is easier to lift. As long as the wire is touching the ground (or close) and the top near the clouds it will strike- if the charge is there, of course. You don't have to worry about the wire not being vaporized either, did you ever see a tree that was stuck by lightning?

[Zzzzeta]

Yeah, I know the wire will be vaporised - you should see the fun I have with our 132KV impulse tester at the back of the workshop ;-)

I'm planning on the lightweight wire specifically because it'll be easier to lift. I'm after something I can let go on its own, without having to hold a wet string or fishing line in my hands during a violent electrical storm, and PEI winding wire is quite strong for its size.

You're right about the insulation, of course - the lightning's not going to be bothered at all by a 240v coating. I'll still do the ground peg though, just as an anchor if nothing else.

All this is academic at the moment, anyway. Sydney's autumn storm season is over, and we're unlikely to see any electrical storms until October or November. At least I've got plenty of time to assemble the rig.......

IAN

[xoo1246]

We have had something like 10 thunderstorms in three weeks, it really weird. I can remember anything like it. I woke up 02:00 tonight and it sounded like artillery fire. And the sound duration of those strikes was several seconds. I tried to catch an image with my camera but it was futile.

[Harry]

Speaking of Dr. Franklin, if you want a REALLY simple detector, make a set of "Franklin's Bells". One object connected to ungrounded lightning rod, another object connected to ground. Let's say they're bells. A small conductor (ball bearing, fishing weight) on an insulating string, hangs between. If distances are right, the bells will ring to indicate a charge buildup.

[frostfire]

lightning strike going through small resistance (eg. you body) in its way to the ground or conductor proved to be fatal. Apart from the electric shock, it's known to generate a tremendous amount of heat (like passing a high voltage through small resistor), could this actually create a blast to set HE? even if it's not the case, can the heat itself detonate a HE (ones that detonate with heat...or decompose :()

[Fl4PP4W0k]

Yeah.... Im sure the huge electrical energy of a lighting strike would be enough to detonate many somewhat sensitive HE's.
Just think of the amount of raw power lighting has!!

Something like AP or HMTD for sure, as they would be set off by the huge heat wave. Something like PETN... im not sure. Im guessing that the amount of power would cause the explosive to decompose...rapidly (detonate).

Not sure tho.

Someones gonna have to put some RDX and PETN on the balloons...

[pyromaniac_guy]

since a joule or two is all that is required to set off an EBW with pressed PETN it is safe to assume that a lightning stirke would have sufficent energy to set it off.... Hell it would probably set off AN

[Fl4PP4W0k]

Hmm...
If it detonated CaCO3 (chalk) - THEN id be impressed.

Ahahaha... tee hee... ho ho

[AmonDin]

I'm a bit skeptical about the baloon thing, the setup with the multiple segments. What are you going to do, sit there... at the base of the wire.... where the lighning will be drawn... tying the baloons on? Even if you had a way to do this remotely, chances are it wouldn't survive the strike. The wind would probably snap the wire if you used one large baloon, but you might get lucky. Rockets are the way to go, and even then, you need a good remote setup, preferably with very few conductive wires leading back to you, the rocket would have to be launched at the right moment, but several random rockets would probably do the job. The rocket exhaust would melt the copper wire, but this problem is solved by attaching tungsten leads to the rocket, then that to the copper wire. My friend and I have been thinking of an experiment of this nature, but we don't have the right equipment at this time, by the time we do have the equipment, thunderstorm season may have passed. (oh well, there's always next year)

[frostfire]

<a href="http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=1743942615" target="_blank">http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=1743942615</a>

you should be able to modify its helium use for altitude & outdoor use....requires a thick wallet for a better one though, but you can even put camera on it and record the whole show :) :) :) :)

wait, these things got more potential, the 6 channel model can even drop things, take pictire, vidcam etc etc...hmm, any weapon/intelligence use?

<small>[ June 28, 2002, 03:55 PM: Message edited by: frostfire ]</small>

[pyromaniac_guy]

if your worried about a thin wire snapping, why not just buy a very long spool of monofiliment and braid a very thing magnet wire onto the first 1000 feet of the spool or so.... you can then wrap the filament / mag wire combintation onto a large down rod with bearings on the ends... this way you trail another 1000 feet of filament to your lightning bunker, and as you slowly release your end of the filament, the spool turns via the up force ebing exerted by the kite or ballon.... your conductor is then played out... since very fine wire and monofilament is evry light you could get away with useing very little up force to try this out... even a few small mylay ballons they sell at grocery stores ect should be sufficent.... (before trying this i would verify the monofilament you use had little or no conductivity with a tesla coil, ect... just to be sure...)

[megalomania]

I like the idea of using fishing line to support the balloons. One could use those as the main supports and just dangle the metal wire from the top. Using two or 3 lines in a triangular fashon may provide considerable stability even in high winds. You will just need more balloons.

[BobsRAC]

Just a few weeks ago, I had the opportunity to visit the facility at which UF's Electrical Engineering chair conducts lightning research. This is the only facility inthe US, and the only electronic facility in the world. It is located on Camp Blanding, Half-way between Gainesville and Jacksonville, FL.
The rockets are sent up 2000' trailing a #32 copper wire covered in kevlar. As the rocket approaches 1000', the streamers from the storm cloud branch towards the rocket. When the streamers make contact with the rocket, the return stroke (that which produces the fantastic flash) flows back up the streamer and into the cloud. This process can occur up to 20 times durring the next couple of seconds once the air has been ionized by the streamer.
The first return stroke carries currents to about 350kA as I recall (this may be inaccurate), while successive strokes carry up to half of that. Each return stroke lasts apporxamitely 1us.
The facility measures electric and magnetic fields created by the strikes, as well as guiding the current to test fixtures.
The cost of each rocket is $800

[Zero]

Here's one for you: What if you just threaded some wire through a regular rope? You can easily get your hands on a balloon large enough to provide the lift for a rope, as illustrated by those silly things that used car dealerships like to fly over their buildings. The rope would be a lot harder to snap or mangle than a single stand of wire.

Had I 2000' of wire sitting around I'd try this in a heartbeat...

Away from my house.

~Zero the Inestimable

[pyromaniac_guy]

zero...
thats what i had suggested with fishingline... that way instead of useing a 100$ ballon and a full tank of helium, one could get away with useing a few latex ballons costing maybe 1$ and a much smaller quantity of helium.... i have miles of higer guager wire, if i had acess to a large enough area to not have to worry about a streamer hitting my house i'd try it myself...

[BobsRAC]

The research team at Blanding uses the rockets and kevlar coated spool configuration because it is appearently critical to get the timing just right. They use filed mills to determine that the electrical fields in the strike area are high enough to be conducive of a trike. They are connected to the National Weather Service to determine that a storm has produced multiple return strokes per minute. They also monitor natural return strokes so that they don't fire a rocket just after a natural return stroke, so that the cloud has time to regenerate the lost charge. Even while they monitor all of this information, and only fire a rocket when all the conditions are correct, only about 60% of the rockets trigger a return stroke. At $800 per rocket and 100 rockets per season, that's a great deal of money burnt on non-triggering rockets.

I'm not sure that 2000' of rope would be very cost-effective ( nor would be the time required to braid it <img border="0" title="" alt="[Wink]" src="wink.gif" /> lol ). Another reason for the use of thin #30 wire coated with kevlar is the assurance that all material will be vaporized. The kevlar (if you're not familiar with the material) is several timer stronger than steel, and rarely snapped. I believe they indicated that damage to the wire occured mostly in the case of the spool jamming or becomming otherwise unable to dispense wire.

Various schemes were brought up by guests at the presentation, including dispersion of brass shavings to form a conductive path, although this idea was dismised as it does not bring ground potential any closer to the storm cloud.

As a side onte on safety, the group had set up (albeit spaced with holes up to 3 or 4 meters) well-grounded Faraday cages above and around all structures containing people or test equipment. Another necessary precaution was the use of generator power ( so as to disconnect themselves from the power grid) while performing lighning testing. All test data was brought into the measurement center via fibre-optics.

[BobsRAC]

And b.t.w.

The rockets are now recoverable and hence are reused many times. Only the spool (much of the cost) and the motor have to be replaced each time.

And another note:

The research team at Blanding used fiber-optics to control a pneumatic actuatoc. This actuator is mounted at the launch site, but is isolated from the ground point. This actuator presurizes a line. On the other end is a pneumatic relay that shorts a 9-v battery to the rocket igniter. This only leaves the battery ( a relatively robust device ) to be destroyed by the strike. In the case of a strike arcing to the fibre-optic reception circuitry, no electrical spikes weould be fed back to the control area. They somewhat jovially noted that the biggest problem they had with the system was animals knawing through the fibre-optics. They had recently invested in armored fibre and no longer had the animal issues.

<small>[ July 12, 2002, 05:08 AM: Message edited by: BobsRAC ]</small>

[auzquad]

learn to spell

<small>[ July 22, 2002, 07:19 AM: Message edited by: Machiavelli ]</small>

[McGuyver]

I'm not so sure that your rocket will last that long. If the lightning does just vaporize the copper it will still mess up your rocket. Think about metal being vaporized- it takes a lot of power to do something like that. If you mess up the rocket even a little it could drastically effect the flight path and aerodynamics.

I'm not to sure about this but I think the sonic boom you hear is because air molecules or ions or something along that line are actually splitting. Someone correct me if I'm wrong. Also, if someone knows about what kind of rockets the Blanding research team uses let us know.

[PYRO500]

No, sonic booms are not caused by air molecules spliting, rather it is caused by the sound waves the object creates getting all bunched up and hitting you at the same time.

[rikkitikkitavi]

the sonic boom comes from the air(plasma) in the conduction channel of the lightning bolt beeing heated to 4000+ K in about millisecond, thus expanding extremely fast. Not very different from a high explosive..

some molecules are split, that is why you can(are supposed to) smell
NOx and O3 during a thunderstorm. Never smelt it myself though , since I usually keep me indoors because of the rain.

/rickard

[xoo1246]

I always smell something in the air, when there is about thunder. I can feel it even before the thunderstorm has fully started, the weird thing is I'm the only one I know who smell it. It is extra strong if there is some light rain.

[PYRO500]

I see what you were talking about. Lightning does cause ionization of atoms in the air but it's really the heat that heats the air in the lightning bolt that causes the air to rapidly expand so fast that it can break the sound barrier and create a thunderclap. The smell that thunderstorms create is from O3 or ozone. The air strips electrons off of oxyagen and causes them to bond into the unstable O3 compound. Same goes for the nitrogen creating NOx gasses.

If the smell you are smelling smells sort of sweet then it's probobly ozone. If not it's probobly humidity in the air.

<small>[ July 22, 2002, 04:38 AM: Message edited by: PYRO500 ]</small>

[Harry]

The wire-trailing rocket is readily available to certain people on the government payrolls of the world. It's called a TOW missile, and the wire is used for guidance. Any soldier-types care to try rigging a vertical stand and remote actuator? Anyway, a body could copy some of the concepts into his own device.

BTW, traditionally (latter half of 20th century, pre-Kevlar), when the really big kites flew, music wire was used instead of string, being stronger by weight.

Harry

[McGuyver]

My Tesla coil generates tons of ozone so I know exactly what it smells like, and yes, you can smell it after a good lightning storm.

I didn't relize that splitting atoms makes ozone though.... interesting.

[pyromaniac_guy]

you splitting moluecues, molecules of o2 to be specific.... not splitting ataoms... dont mean to be overly picky here, but there is a BIG diffrence!!!!

[McGuyver]

Yeah, Yeah, that's what I meant. Wouldn't it be interesting if it was atoms :D .

[Mick]

what you want for wire is fencing tape
<img src="http://www.farmstoreonline.co.uk/media/125154.gif" alt=" - " />

20mm wide and contains 15 strands of stainless steel wire, its 200m long and has a breaking strain of 250kg.

providing you had balloons at intervals down the tape you could quite easily join 20 of these spools together.

but, what are you going to do with the lightning once you attract it? it seems like an awful waste to have it go into the ground.

<small>[ July 23, 2002, 01:49 PM: Message edited by: Mick ]</small>

[pyromaniac_guy]

another thought on how to attract lighning....
a spud cannon...
a buddy of mine built a spud cannon that worked on compressed air, instead of combustion. it was more than enought to propel a spud to distances where it could no longer be seen by the naked eye. if a suitable spud like projectile was coupled to a coil of wire, you would have a cheap, resusable platform that only cost a few cents per shot (except when the wire got vaporized) obviously it would require some work as far as remote operation goes, and since this is the EW forum, maybe a small bag of black powder would be a better propellant, but still, a 20$ jug of black powder would get one many many, MANY launches....

[Energy84]

The most interesting thing that I can think of to do with the strike once it's attracted, is to ground it into a sandbox or something like that. I've seen it on TV and in a few books too that when lightning strikes sand, it cooks it and turns it into glass. Coolest part is, the glass is in the shape of the lightning bolt that hit it. So you could easily record how "thick" of a bolt you got.
Wouldn't that be interesting, if people started doing this to see who could attract the biggest bolt :p

[nbk2000]

I could see a good use for attracting lightning.

Banks.

As in attracting lightning to a bank, and routing the pulse through the alarm system to vaporize it. At that same moment, The charge that gets you into the vault goes off. Anyone near enough to hear the explosion will see the lightning strike and think it's the thunder.

:)

Two birds with one stone.

Hell, even without attracting the lightning, you can still use it to cover the sound of an explosion. Some bank thieves back in the 60's used a lightning storm to cover the sound of a 20mm cannon blasting into a vault. They fired in time with the thunder. Nobody knew about the robbery till monday. :p

[pyromaniac_guy]

How do you use a 20mm cannon to blast a hole into a vault??? even if it pernatrates, you sure aint gunna squeeze yourself through a hole that big!!!!

[Energy84]

First you make sure that it's gonna be a very violent thunderstorm, then make sure you have plenty of ammo. I think you know the rest :D

[zaibatsu]

The 20mm cannon won't just punch a 20mm hole through the wall, if you were firing HE shells then the blast will knock a large portion of the wall out, and weaken the surrounding area, allowing you to either fit in or finish the hole with a sledgehammer

[Anthony]

You could make an exploding bridgewire detonator :)

[pyromaniac_guy]

zaibatsu,
have you ever seen a bank vault during construction? they have probably as much re bar in um as concrete... you certainly are NOT gunna be able to go after that with just a sledge, no matter how much the wall is weakened...

[xoo1246]

Wait a second, the whole cable becomes an exploding bridgewire. <img border="0" title="" alt="[Wink]" src="wink.gif" />
Sorry, this topic has really drifted away.
Is the story about the 20mm cannon true? I belive I saw a film with the same theme(based on a true story, or was it the other way around, crime based on a movie, sorry I should really go to sleep).
Why not use the thunder to energise a FCG, now that's a good idea. <img border="0" title="" alt="[Wink]" src="wink.gif" />

<small>[ July 26, 2002, 04:12 PM: Message edited by: xoo1246 ]</small>

[nbk2000]

Yes, the 20mm is true. Happened back in the early-mid 60's. Sounds like the kind of thing you'd see in one of those 70's action thrillers with Charles Bronson, don't it? :)

[pyromaniac_guy]

From what I understand, most of the standards for modern vault construction come from the governments tests of hardened structures against nuclear explosions, so possibly the vault in question was built before such information was avalible... I doubt even high explosive 20mm rounds are going to have much of an effect on a modern vault, not unless you have a virtually limitless supply of ammo :)

[zaibatsu]

The point of the sledgehammer (in my eyes anyway) was to remove the chunks of concrete hanging off after the shell has struck. But if thats too much trouble, go for a couple of Brunswick RAWs, one shot with one puts a 30cm hole in 20cm thick reinforced concrete :cool:

[DarkAngel]

Xoo: that reminds me of <a href="http://us.imdb.com/Title?0072288" target="_blank">"Thunderbolt and Lightfoot"</a> ,whas this the one you also saw?

[PYRO500]

I'm not sure if this would work but what about one or several manhole cover sized shaped charges that hammer into the wall? I'd imagine the jet on one of those things would be like the energiser bunny, it keeps on going (through the wall) and going (through the other side of the vault) and going (through the wall and into the building next door. :)

[nbk2000]

There's a book that was published back in the '70's called "Barrier Penetration Database". It described how to penetrate every barrier known to that time and how long it would take to do so based on various factors. I used to have it till my parole officer stole it. :mad:

Anyways, they (the government) did tests against vaults using EFPs. An EFP made from the fish plate of a railroad car (the big round bumper plate on the ends) backed by 400 pounds of TNT <img border="0" title="" alt="[Eek!]" src="eek.gif" /> blasted a man sized hole through 6 feet of reinforced concrete, cutting the rebar in the process.

The problem then becomes one of how to avoid drawing attention to the fact of 400 pounds of explosive going off. That, and getting through the blasted rubble that used to be the bank building to get into the vault.

Much better would be to make a small hole into the vault (~3"), then slid radial shaped charges into the hole. When these are detonated, they'll fracture the concrete and cut the rebar enough to make a hole for a person to crawl through. This would require only a few pounds of explosives to accomplish.

Assuming you've managed to channel a lightning strike through the security system, and time the explosions to the thunder, then nobody should be the wiser. :)

If only room-temperature superconductors were available. Then, if you could capture and store the strike, you'd have an awesome weapon. Probably kill you to use it, but hey... :)

I've seen in Scientific American an article about using ionizing UV lasers to channel lightning in any desired direction. Catch a strike and "beam" it onto a target with surgical precision.

[pyromaniac_guy]

you would have to be carefull with the uv laser idea... the lightning propigates along an ionization path caused by the laser.. you would either have to have your laser on the building about to get zapped, or would have to use optics to route it there, and HOPE the lighining grounds out at the building and doesnt cause a streamer to come back to your laser :)

they normally do this by greatly increasing the diameter of the laser beam at the source, and down collimating it to a tiny beam in the target area.. but if you can afford such large aperture uv grade optics, you dont need to be robbing a bank!!!! :)

[kingspaz]

what about fibre otpic cables to carry the laser? not sure how well UV travels through fibre optic stuff but if it does then you could have the laser 200m away from where the end of the fibre optic cable pointed to the sky.

[pyromaniac_guy]

fiber doesnt like to transmit uv well, and even in the visable or near ir, bands of light where most fibers transmit mosy effectivly, it's hard, if not down right impossible to carry the kind of peak power required to do the kind of work were talking about here... you end up literally blowing the ends of your fiber off...

[AmonDin]

Even if it was capable of carrying a UV beam, after the lightning hit, BAM! No more cable. Fiber optic cable is expensive, and nobody but the fabulously wealthy or the stupendously stupid would use it for that purpose, even if it were possible.

[pyromaniac_guy]

multimode fiber suitable for MODERATE power / energy transmission in the near ir can often be had for .01's$/foot on ebay...

[rjche]

For detecting when lightning is about to strike, I recall some scientists studying strikes on a mountain top, viewing it from another top that had an observatory on it.

They used a 6 ft whip antenna on top of a wood box, with a tuned circuit inside. The ant was connected to the tuned circuit top, and the bottom was grounded via a spark plug for a gap.

When a cloud passed over with charge the whip would charge up and spark over the gap, causing a humongous signal at the frequency of the tuned circuit. They worried the FCC might come looking for them, but that didn't happen. Their coil and capacitor ended up tuned around 8 mhz, which is populated by freaky signals anyway.

Such a device in the direction from which a storm front was coming would alert you that a charged cloud was coming.

One near you could then alert you that it had arrived, time to jump into the faraday cage if still outside, and install ear plugs.

Having been 20 feet from a small stroke once, I can state that it is quite loud, like a deer rifle firing, except a much sharper brissant single crack, much like a silver fulminate toy firing. The lack of thunder was surprising. It also was not as loud as expected considering its energy, but then I realized most of that was released far above, and that shock wave propagates mostly horizontal from a vertical column source.

If you experiment, take my word, the experience is very un-nerving.

I was facing it with my feet perpendicular to the radially radiating current from the strike spot. It is dangerous if you have feet apart, and lined up with the radial, for large voltages appear over even a foot of distance of dirt, and a spark can jump up one foot, scorch the hinge at the crotch, and go down the other foot, a common event with cattle.

Most dogs experience this also which is why they fear thunderstorms so much. Even a quite distant stroke lights them up as they are barefoot, and some feet are always in the wrong alignment.

I mention all that because if one is going to fool with lightning most of those things do not occur to them until after an "event". So consider it safety related.