Talk:Lightning strike: Difference between revisions
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As I am not an "expert" on the subject, I don't feel I am in a position to rewrite the many sentences needing rewritten in this article, lest I misconstrue meaning. (And given how poorly some of this article is written, it's a possibility.) But I would encourage someone who knows and understands the subject better than I do to give this article a good editing for meaning, grammar, structure, and punctuation, as much of it is a mess. [[User:Fiddlecub|Fiddlecub]] ([[User talk:Fiddlecub|talk]]) 05:43, 4 April 2013 (UTC) |
As I am not an "expert" on the subject, I don't feel I am in a position to rewrite the many sentences needing rewritten in this article, lest I misconstrue meaning. (And given how poorly some of this article is written, it's a possibility.) But I would encourage someone who knows and understands the subject better than I do to give this article a good editing for meaning, grammar, structure, and punctuation, as much of it is a mess. [[User:Fiddlecub|Fiddlecub]] ([[User talk:Fiddlecub|talk]]) 05:43, 4 April 2013 (UTC) |
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== Apollo 12 |
== Apollo 12 == |
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"Thirty-six-and-a-half seconds after lift-off, the Apollo 12 Mission's Saturn V rocket and its ionized exhaust plume became part of a lightning flash channel as it terminated on earth. Discharge occurred "through" vehicle, however it did not affect instrumentation or ignite the rocket's highly combustible fuel. Due to the rocket not being "grounded" as it was in the middle of the atmosphere, electrical potential does not exist, passing relatively benignly "around" the unit, just as "birds on a wire" are similarly unaffected." Yes, exactly like airplanes, which totally aren't certified to withstand the 200,000 odd amps a lightning strike puts through the airframe. (spoiler: lightning protection is the whole point of a number of FARs) We need an actual source for this one. [[Special:Contributions/68.103.185.180|68.103.185.180]] ([[User talk:68.103.185.180|talk]]) 23:56, 22 May 2013 (UTC) |
"Thirty-six-and-a-half seconds after lift-off, the Apollo 12 Mission's Saturn V rocket and its ionized exhaust plume became part of a lightning flash channel as it terminated on earth. Discharge occurred "through" vehicle, however it did not affect instrumentation or ignite the rocket's highly combustible fuel. Due to the rocket not being "grounded" as it was in the middle of the atmosphere, electrical potential does not exist, passing relatively benignly "around" the unit, just as "birds on a wire" are similarly unaffected." Yes, exactly like airplanes, which totally aren't certified to withstand the 200,000 odd amps a lightning strike puts through the airframe. (spoiler: lightning protection is the whole point of a number of FARs) We need an actual source for this one. [[Special:Contributions/68.103.185.180|68.103.185.180]] ([[User talk:68.103.185.180|talk]]) 23:56, 22 May 2013 (UTC) |
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![]() | This article was nominated for deletion on 12 June 2006. The result of the discussion was keep. |
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Lightning rod merge
I removed the bulk of the lightning rod article here. Too lengthy for this article. A breif synopsis should be made with a "main" wlnk. JDR 17:30, 15 August 2005 (UTC)
Fatality Rate?
Is it 25 to 33% or 10%? The second sentence implies 10%. "between 25 to 33% of those struck die.[1][verification needed] In the United States, it is the #2 weather killer (second only to floods), killing 100 annually and injuring ten times that number."
- Probably the latter stat is all lightning-related injuries (i.e., a tree fals on you), while the former is direct strike victims. --Xiaphias 03:58, 20 June 2007 (UTC)
- One of the cited links (the guide for kids) says "80% of strike victims survive the initial shock", which is also incompatible with the 9-10% number. But the first one (the Disability paper) says official reports of strikes only include those hospitalized or covered in the paper, which underreports significantly. I think her number (9-10%) sounds the most trustworthy.
- A more glaring problem is the paragraph cites two different numbers (100 and 75) for yearly fatalities in the US, each with a citation, in successive sentences. The 75 number is from a MythBusters episode, while the other is from a scholarly paper. NOAA found an average of 90 late last century. Of course, it's all averages, so it could differ based on what period you're averaging over. --Xkcd ([[User ta
lk:Xkcd|talk]]) 19:54, 20 July 2008 (UTC)
Field or Tree?
If you are in a field during a storm, should you stay in the open or hide under a tree? Either one seems fatal. Catch-22? smurrayinchester(User), (Talk) 09:40, 22 October 2005 (UTC)
The odds that lightning will strike the tree are MUCH higher than the odds that it will strike any given section of an open plane, so by being near the tree you greatly raise your odds of being in a strike. The ideal thing to do is to be far from the tree, and then become "a basketball with feet" - crouch down on the ground, with only your feet on the ground, and your body curled up in a ball. That way, you are minimally higher than the ground and thus not significantly more attractive to the lightning. DO NOT LIE DOWN - if lightning strikes near you, the voltage potential across the ground will cause a current flow through your whole body, including the thoracic cavity and heart. By only having two small points of contact (your feet) that are very near each other, the voltage across them will be smaller than they would be across your whole supine body, and any current flow they experience will only be through your legs and pelvis - avoiding the the heart. N0YKG 14:33, 22 October 2005 (UTC)
Guy gets hit by lightning
Im not sure if this is a urban legend, but if it is not so, what is the name of the guy who was struck by lightning a phenomal number of times? Anouymous 02:18, 2 November 2005 (UTC)
- It was a guy called Roy Sullivan, he was struck seven times. This occured over a number of years. Bobman999 08:30, 10 September 2007 (UTC)
Forests
If you're in the middle of a forest during a thunderstorm, what should you do? --Carnildo 08:24, 1 April 2006 (UTC)
- Leave.--Xiaphias 10:01, 7 May 2007 (UTC)
- (only guessing here so dont quote me) the risk inside a forest would be lower than standing under an isolated tree because as it were the lightning has thousands of trees to "choose" from. Having said that if there is a particularly tall tree in among smaller ones it is more likely to be hit. 213.40.117.122 (talk) 14:11, 25 September 2009 (UTC)
Myths
Would someone care to add a section on lightning protection myths? You could include an illustration similar to the one here[1], showing how insignificant the height of the Sears Tower is (much less an umbrella or person) when compared to the height of a thunderstorm. Other important points to cover are that metal (other than skyscrapers or tall antennae) has practically no influence over whether or where lightning will strike, and that lightning might strike a poor conductor rather than a better conductor nearby.
I can't recall the source, but I also remember reading an humorous tale by Mark Twain or a contemporary about an ignorant couple trying numerous crazy things in attempt to reduce the risk of being electrocuted by a thunderstorm. This story might be relevant as well.
A good closing would be something to the effect that while measures might be taken to decrease the damage caused by lightning, the only way to significantly reduce the risk of electrocution is to avoid being outdoors in a thunderstorm.
-JP
Moved to Keraunomedicine
FYI, I moved a lot of the info to the Keraunomedicine article, as it seemed more appropriate there. --Xiaphias 14:44, 19 May 2007 (UTC)
Misc Stat
2% of lightening fatalities in the US are people who were talking on the phone at the time, according to the 'Mythbusters' ref I posted for another statistic. This seems pertinent, but I'm not sure where to add it. --151.196.133.61 20:34, 17 September 2007 (UTC)
- Landline telephones (other than the cordless variety) do carry some risk during thunderstorms by virtue of being connected to miles of (often oveground) copper wire. Dunno how accurate the percentages quoted are though.213.40.117.122 (talk) 14:18, 25 September 2009 (UTC)
Car safety?
If you are in a car during a storm aren't you safe? should this be added? —Preceding unsigned comment added by 68.250.188.227 (talk) 22:42, 22 April 2008 (UTC)
- What if the car has a non-conductive body such as fibreglass or even plastic ? 213.40.117.122 (talk) 14:15, 25 September 2009 (UTC)
Practical?
Can you add a short advice how to avoid being struck by lighting eg. in the field or in the forest? Would be useful, especialy as there is lot of nonsense trivia in Wikipedia. —Preceding unsigned comment added by 84.83.241.4 (talk) 15:58, 15 July 2009 (UTC)
I had turned and was walking away from a building when lightning struck the eave of the building and I felt something sort of snatch at the hair on the back of my head and I hit the ground without damage. So there must be a localized electrostatic field generated in the volume of space around a lightning strike that is capable of attracting matter. Is that a reasonable supposition?WFPM (talk) 20:22, 10 August 2009 (UTC)
Statistics / Underreported
It is claimed in Germany around 100 ppl are injured by lightning /a. It seems to me that only the industrial nations with proper infrastructure actually report correctly and that the real world figure is probably far higher.Slicky (talk) 09:27, 15 August 2009 (UTC)
Article does not say if this is direct or alternating current
It needs to say which it is. Are you ready for IPv6? (talk) 10:55, 26 May 2010 (UTC)
- I wonder if initial lightning strikes can be called "unipolar." I think somewhere on wiki there's a discussion between a PhD and a student on whether lightning can be called DC or Unipolar. Some characterize lightning waveforms that maintain a single electric polarity (positive or negative) as "direct current." I personally prefer that "DC" refer to a voltage waveform that tries to maintain a single, steady-state voltage level for a vast majority of the time, i.e., a waveform designed to stay at a specific, non-varying voltage. Even though AC-to-DC and DC-to-DC converters have high frequency switching content and harmonic byproducts, I'd prefer to call these "DC."
- I think we can agree that what a lightning stroke waveform is not is the classic sinusoidal "alternating current" voltage waveform delivered by most electric utilities and sources. The terms AC and DC as clear differentiating nomenclature may have made more sense in the late 1800's during the Tesla versus Edison brouhaha. Even direct current VOLTAGE is a paradox. I wonder if the logical Chinese languages address this a little more clearly!
- DonL (talk) 20:18, 8 September 2010 (UTC) (..ready for IPvX, too)
- I think the best answer is... a lightning discharge is more in tune with AC... based on 3 simple facts;
- 1) All lightning protection systems utilize multi-stranded conductors, not solid wires.... reason being skin effect, AC current flows on the surface not through the core of the conductor as does DC. Woven stranded "lightning wire" maximizes surface area, not volume.
- 2) Impedance is a main concern in providing effective Surge Protection Devices, not resistance. Impedance is a factor of AC, resistance that of DC.
- 3) Charge moves in both direction through the flash channel during discharge, and most lightning events are categorized as having more than 3 return strokes, noted by the strobe light appearance of a typical lightning event.
Lightning and fires
Can't seem to find anything on fires in the main article. There must be a vast number of fires started by lightning annually just in the USA. The article below says 31,000 annually, from 2002 to 2005. And 12 deaths. The article also says nearly all lightning-started fire civilian deaths were from house fires.
http://findarticles.com/p/articles/mi_qa3737/is_200803/ai_n25140256/
DonL (talk) 20:35, 8 September 2010 (UTC)
Incidence of Strikes
The paragraph title incidence of lightning strikes fails to state or comment on the incidence of 'lightning strikes' whatsoever, instead going on about the incidence of 'fatalities or injuries from strikes'. This is not a specious distinction. Writers needed badly! 76.6.78.16 (talk) 04:55, 24 April 2011 (UTC)
History: before lightning rods?
How about a history section?
- What proportion of lightning strikes to unprotected buildings cause damage? Was lightning a factor considered in designing buildings (Material, height, location on hills, etc.), or were people entirely clueless about such risk factors?
- How did tall buildings (churches) survive before lightning rods? Yes, occasionally they were damaged, but lightning strikes on prominent structures are pretty common.
- How often were sailing ships struck? Was this a risk to the occupants or just to the ship itself? Was lightning a limiting factor in navigational routes, ship design/height, and the overall safety (personal and financial) of shipping?
I'd start it myself if I knew anything. SSSheridan (talk) 16:54, 20 April 2012 (UTC)
Corrections to References
I suggest that reference [15] is removed as it no longer relates to the subject (the pointed by it webpage has changed and carries no information related to the subject).
Plamen Grozdanov (talk) 14:25, 8 August 2012 (UTC)
Update: looks like the referenced webpage has again become relevant -- there is a small paragraph about lightnings. Thus, this reference could be kept (although I am not sure that it meets the high standards of Wikipedia). Perhaps we should remove it?
Plamen Grozdanov (talk) 22:54, 26 September 2012 (UTC)
Major revamping required, focusing on legitimate science not what we "believe" happens
I am going to start working on overhauling this article... to much common beliefs and often erroneous information, not enough documented science and verifiable proofs are used. There are so many contradictions from section to section, and even within the sections themselves.
Case in point... Trees.
- Sap, an ion rich fluid, is a great conductor in comparison to the wood, which is dry and poor in free ion concentration. The comparison needing to be made is between these two items, not some structure 100s of feet away. Damage to the tree occurs when the flash channel chooses a pathway through the sap, and during discharge the strokes superheat the sap, basically vaporizing it and causing an uncontrolled reaction aka an explosion... just like dropping cooking oil into boiling water.
- Pines generally have tap roots? Who came up with this? As a forester & arborist in my past life, this is far from accurate. Trees, of all types, have a shallow root system radiating outward from the trunk extending to the "drip line" (outside circumference of the branches & leaves) that is usually just as deep as the soil. Trees in rocky ground (in a mountainous environment) or rainforest with very thin soils, may develop tap roots through crevices and fractures "chasing" nutrients or water, however these are the exception, not the rule. Uprooted trees (upwards of 300ft) generally reveal a root ball of the main roots which is a small fraction of the overall height. Having cut down & ground out the roots of 100s of trees over 100 feet, rarely did I grind down more than a few feet to get the big roots.
- Pines are better conductors than broadleaf trees because of all their "sharp" needles? Again, no definitive proof, and to the contrary they may be less likely to take a strike if a similar sized broadleaf was nearby, given the needle points experience corona discharge naturally more efficiently during a thunderstorm, which may lower the localized electric field that has influence in the streamer formation and subsequent leader attachment resulting in a termination. Pine forests were used as lightning protection of DuPont weapons plants in the 30s & 40s, and is the basis of Charge Transfer Technology such as Dissipation Array Systems, and how they discourage lightning terminations to protected structures.
I'm going to tag this page, needing revision & cleanup. Can we stick with science, accurate terminology and documented evidence in our revisions please? I am also working on the lightning page, as well as many pages related to lightning. I have no qualms about revealing I do work in the lightning protection industry, however at all costs & with considerable effort, I attempt to limit any direct Conflicts of Interest, choosing documented science or industry practices as my guidelines.
ps... I don't intend to get into a edit warring match with other wikieditors involved with this page, but I can see the potential of this occurring. The "Personal Safety" section appears to be best available knowledge, but sourcing solely to the NILS raises eyebrows... given their list of referenced "papers" contain more "discredits" and legal battles against "non-traditional" lightning protection systems; and single example case studies promoting lightning rod effectiveness; national and international regulations defined by legal precedent or insurance industry findings; than it does about reporting scientific inquiry into lightning itself. Because so much is still unknown about lightning and very little of this understanding is definitive, lightning protection is much more political and about dollars and cents, than an unassociated person or someone wanting to simply convey the most unbiased understanding available, would like to admit, but it exists. Question everything goes without saying. Borealdreams (talk) 19:26, 16 March 2013 (UTC)
Major revamp needed? Yes--but for clarity and language
The article is loaded with improper grammar, confusing sentence structure, and incorrect punctuation to the point where meaning is being lost and information is lost. Case in point: "And the entire flash, lasts only a few fractions of a second, most of which is not visible to human eyes." This sentence tells us that "fractions of a second" are not "visible to human eyes," as the verb does not agree with the subject. (We have to infer that we cannot see most of the flash.) And then comes "Just like lightning, that deceives our eyes, usually looking larger or closer than it really is, the earth's atmosphere and our brain's perception of the outside world, ultimately determines whether it is "heard" or not." That disaster of a sentence is so jumbled that I cannot tell what it ultimately means to communicate.
As I am not an "expert" on the subject, I don't feel I am in a position to rewrite the many sentences needing rewritten in this article, lest I misconstrue meaning. (And given how poorly some of this article is written, it's a possibility.) But I would encourage someone who knows and understands the subject better than I do to give this article a good editing for meaning, grammar, structure, and punctuation, as much of it is a mess. Fiddlecub (talk) 05:43, 4 April 2013 (UTC)
Apollo 12
"Thirty-six-and-a-half seconds after lift-off, the Apollo 12 Mission's Saturn V rocket and its ionized exhaust plume became part of a lightning flash channel as it terminated on earth. Discharge occurred "through" vehicle, however it did not affect instrumentation or ignite the rocket's highly combustible fuel. Due to the rocket not being "grounded" as it was in the middle of the atmosphere, electrical potential does not exist, passing relatively benignly "around" the unit, just as "birds on a wire" are similarly unaffected." Yes, exactly like airplanes, which totally aren't certified to withstand the 200,000 odd amps a lightning strike puts through the airframe. (spoiler: lightning protection is the whole point of a number of FARs) We need an actual source for this one. 68.103.185.180 (talk) 23:56, 22 May 2013 (UTC)