Talk:Lightning

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Former good article nominee Lightning was a good articles nominee, but did not meet the good article criteria at the time. There are suggestions below for improving the article. Once these issues have been addressed, the article can be renominated. Editors may also seek a reassessment of the decision if they believe there was a mistake.
Article milestones
Date Process Result
October 31, 2005 Peer review Reviewed
October 16, 2006 Good article nominee Not listed
Current status: Former good article nominee
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Colors used to denote polarity in undermentioned illustration are not conventional.[edit]

https://upload.wikimedia.org/wikipedia/commons/thumb/d/dc/Leaderlightnig.gif/220px-Leaderlightnig.gif

The negative leader from the cloud is presently red, conversely the positive leader from the ground is blue. Automotive transport convention and almost universally RED signifies POSITIVE, and BLACK or BLUE signifies NEGATIVE. The negative color choice seems to be fairly flexible but the red for positive is almost set in stone (in my experience.)

I have not checked yet if there is an article on wire color coding. A short note for anyone who may start one. In 3 phase electricity one convention is to use RED, WHITE, and BLUE for live (above ground) phases and BLACK for the NEUTRAL. Considering the USA standard for 2 phase supply 115VAC - NEUTRAL - 115VAC (where the 2 115VAC lines have 230VAC potential between them) use RED for 115VAC, WHITE for NEUTRAL, and BLACK for the other 115VAC line, and considering the use RED and BLACK in DC systems, persons working on unknown systems should be aware of these possible pitfalls. Ecstatist (talk) 00:53, 10 September 2015 (UTC)

Bolt from the Blue[edit]

Currently the page both describes a 'bolt from the blue' as a name for clear-air lightning [which I believe to be correct], in the main text, and as a name for anvil-to-ground lightning in the anvil-to-ground photo-caption [which does not make sense to me]. I'm not going to make the edit unless there's actually two trends to the usage, but I think it's likely to be a joke or error of some kind. 65.95.145.103 (talk) 15:39, 23 October 2015 (UTC)

  • Actually, it is both. "A bolt from the blue", a metaphor for something coming out of nowhere, originally comes from a lightning strike from a blue sky. However, in the science community, it is also used to describe anvil-to-ground lightning. The reason for this is that anvil-to-ground lightning is a lightning bolt which develops "over" the thunderstorm cloud (in the blue), and travels generally straight down through the cloud and then strikes the ground, creating an anvil through the cloud. "Cloud to Ground" lightning isn't Anvil lightning. That strike comes from the cloud itself, not above it. You may be confusing the two. If you'd like to make an edit, you can word it so that it educates the reader that the term is "also used to describe".... I am not part of the science community, so you better check my facts, however, I remember studying this subject in college, and that's exactly how I remember it.-Pocketthis (talk) 16:43, 23 October 2015 (UTC)
  • No action was taken, so I made an edit to improve, and clarify the anvil strike caption.-thanks-Pocketthis (talk) 19:12, 23 October 2015 (UTC)

Strobe effect of GIFs may cause reactions in epileptics?[edit]

The cartoon gif, and maybe other gifs, may cause some photosensative epileptics to be affected. Yosjwuwkjd (talk) —Preceding undated comment added 23:39, 25 July 2016 (UTC)

Can the images be rearranged and separated? MOS:ANIMATION prescribes a hard limit on this: "animations must not produce more than three flashes in any one-second period. Content that flashes more than that limit is known to cause seizures.[1]" —C.Fred (talk) 23:44, 25 July 2016 (UTC)

References

  1. ^ "Guideline 2.3 Seizures: Do not design content in a way that is known to cause seizures.". Web Content Accessibility Guidelines (WCAG) 2.0. W3C. 11 December 2008. Retrieved 28 May 2015. 
I've requested assistance at Wikipedia talk:Manual of Style/Accessibility. —C.Fred (talk) 23:51, 25 July 2016 (UTC)
It seems to me that subjectively I can only detect two flashes, effectively in frames 2 and 6 (see File:Lightnings sequence 2.jpg), so it probably doesn't breach Success Criterion 2.3.1. However, if others see more flashes, then there may still be a problem, particularly as the animation loops in 1.5 seconds and the flashes that I see are only 600 ms apart.
So, I've uploaded a modified version, File:Lightnings sequence 2 animation-wcag.gif, that has some dark frames inserted to stretch out the animation. I'm pretty sure that meets SC 2.3.1, but other opinions on its usefulness would be welcome. --RexxS (talk) 16:56, 26 July 2016 (UTC)

Return Stroke DUBIOUS or even FANCIFUL[edit]

The suggestion that lightning travels "up one leg and down the other" is so rare an occurrence that it does not even rate in medical documentation. It requires proximity to a ground stroke and a huge potential between legs (e.g. one on a metal dock, the other in a body of water). By comparison, head-back-legs, head-torso-legs, and arm-torso-legs are more than 90% of injury patterns in human cases. In fact, some have suggested that allowing leg-leg flow through the groin and pelvis is preferable to lying flat on the ground. Journal of Emergency Medicine, multiple issues / Neurorehabilitation Dfoofnik (talk) 14:24, 8 October 2016 (UTC)

Why lightning?[edit]

I came here to find out why lightning occurs or in other words why is there a potential difference? Didn´t see an answer to that question. Would be nice if the answer to that common question was in the intro. Daniel.Cardenas (talk) 15:54, 5 November 2016 (UTC)

  • "Lightning is a sudden electrostatic discharge that occurs during an electrical storm. This discharge occurs between electrically charged regions of a cloud (called intra-cloud lightning or IC), between that a cloud and another cloud (CC lightning), or between a cloud and the ground (CG lightning). The charged regions in the atmosphere temporarily equalize themselves through this discharge referred to as a strike if it hits an object on the ground, and a flash, if it occurs within a cloud. Lightning causes light in the form of plasma, and sound in the form of thunder. Lightning may be seen and not heard when it occurs at a distance too great for the sound to carry as far as the light from the strike or flash".

That is the opening now, and I think it answers your question as to what lightning is. As far as "potential difference" is concerned, I found this with some research: "A typical lightning bolt bridges a potential difference (voltage) of several hundred million volts". If you'd like to incorporate that info into the opening, I don't see any reason why not, however, there are other chapters it would work in as well, such as Types or General Considerations. Pocketthis (talk) 17:01, 5 November 2016 (UTC)

Doesn't answer the question why there are charged regions or why there is a potential difference.   Thanks, Daniel.Cardenas (talk) 21:15, 5 November 2016 (UTC)
Added new section to explain this. Daniel.Cardenas (talk) 02:30, 24 November 2016 (UTC)

The poles are at a temperature where water or molecule are extremely magnetic due to the temperature Tgk11 (talk) 02:42, 23 January 2017 (UTC)