What is Lightning: Definition and 262 Discussions

Lightning is a naturally occurring electrostatic discharge during which two electrically charged regions, both in the atmosphere or with one on the ground, temporarily equalize themselves, causing the instantaneous release of as much as one gigajoule of energy. This discharge may produce a wide range of electromagnetic radiation, from very hot plasma created by the rapid movement of electrons, to brilliant flashes of visible light in the form of black-body radiation. Lightning causes thunder, a sound from the shock wave which develops as gases in the vicinity of the discharge experience a sudden increase in pressure. Lightning occurs commonly during thunderstorms as well as other types of energetic weather systems, but volcanic lightning can also occur during volcanic eruptions.
The three main kinds of lightning are distinguished by where they occur: either inside a single thundercloud, between two different clouds, or between a cloud and the ground. Many other observational variants are recognized, including "heat lightning", which can be seen from a great distance but not heard; dry lightning, which can cause forest fires; and ball lightning, which is rarely observed scientifically.
Humans have deified lightning for millennia. Idiomatic expressions derived from lightning, such as the English expression "bolt from the blue", are common across languages.

View More On Wikipedia.org
Recent contents Top users
  1. O

    Can a Hybrid Lightning Jet Engine Outperform a Traditional Jet Engine?

    Does lightning heat air 5 times more the the suns surface? If so can a hybrid lightning jet engine work, as lightning heats up air, more then fuel can? Americas 5th gen jet fighter can travel 3* more then enemy jet's. That means it's a hybrid engine right? Compressed air heated sees the air...
  2. A

    How does lightning work? (one strike or multiple strikes?)

    I am mainly asking if it's possible for a thunder cloud to release its sorted energy in burst rather than in one strike. Like if a thundercloud had 1 billion volts would it be possible to great small sparks that allow it to shoot of 5 lighting strikes of different voltages rather than one strike...
  3. D

    What could be a load for lightning?

    if there was a way to utilize lightning what can be used as a load?
  4. A

    Current through swimmer due to lightning strike

    Homework Statement Figure 26-30 shows a swimmer at distance D=35m from a lightning strike to the water, with current I=78kA. The water has resistivity 30 Ohm*m, the width of the swimmer along a radial line from the strike is 0.7m, and his resistance across that width is 4 kOhm. Assume that the...
  5. Likith D

    What is lightning proportional to?

    Say that i were to hold an electric appliance obvious, i receive an electric shock What will 'how bad my injuries will be' depend on ? Is it potential difference, current, heating effect, ...
  6. M

    Calculating Energy Transferred in Lightning Flashes & Thunderstorms

    Homework Statement (a) It is estimated that the average electric charge carried in a lightning flash is 5C. If the p.d. between the cloud and the ground is about 800 MV, approximately how much energy is transferred in a flash? (b) In a typical thunderstorm, lightning flashes strike the ground...
  7. narasura

    Need help about lightning arrester/surge arrester

    so I'm working on a project about the usage of multiple lightning arrester by paralleling it, with 2 or 3 arresters. and my project mainly discuss about the discharge current ( current flowing through the arrester to ground) so how would be the effect exactly?? the theory says, that arester is...
  8. stevmg

    The Safest Thing to Do On an Open Field During Lightning

    As in the the title, what to do if caught in an open field during a sudden lightning storm. Have heard conflicting recommendations from laying flat to squatting in two feet. Trying to avoid being part of the return strike which would not be pleasant at all.
  9. stevmg

    Understanding the Science Behind Lightning

    This thread is to discuss the physics behind the causes/effects of lightning from a basic science point of view.
  10. dreens

    Frequency Components of a Lightning Strike

    Hi there, I recently attended a physics demonstration (Lightning show at Boston Museum of Science, my favorite exhibit obviously), where the educator argued that the reason she could safely sit in a Faraday Cage while lightning was striking said cage was the skin effect. As I understand it...
  11. J

    What Determines the Zig Zag Pattern of Lightning?

    In a discussion about lightning destroying electronics on sailboats the issue of controlling lightning came up. One member (Baluncore) proposed that lightning is completely predictable. I've been taught that lightning is somewhat random. To me, random implies non-linear equations with sensitive...
  12. anorlunda

    Faraday Cage For Lightning Protection

    A recent thread talked about a radio inside a metal box. That reminds me of a question I never resolved. 9 years ago my sailboat was struck by lightning. 6 people were on board, but nobody was hurt, luckily. My mast is grounded to an underwater plate via a thick copper cable inside a plastic...
  13. micromass

    Folk belief about preventing lightning damage

    In my region, there is some kind of folk belief about lightning. I personally think it is nonsense, but I'm asking to make sure it sure is nonsense. After all, I can't pretend to know much about electricity. Anyway, it is said that when there is a thunder storm near your house, then it is best...
  14. H

    Lightning vs Hydrogen Fuel for Space Travel

    In space Hydrogen fuel is burned and propels the spaceship forward in the direction it's facing. Newton's third law of motion states that for every reaction there is an equal and opposite reaction. A lightning bolt makes around Five Billion Joules of energy. I can't find specific numbers for...
  15. A

    About lightning spike generation

    Hello i am new user of in this forum... i am working on COMSOL Multiphysics for my master project i am working in the area of grounding so i have to analyze the material with lightning effect so i want to know how i can generate the lightning signal in COMSOL and how we apply to grounding rod
  16. W

    Massive Single Lightning Strike Heard From 30+ Miles Away?

    Last night there was a lightning strike, I caught the flash out of the corner of my eye through my window blinds. The thunderclap proceeded a second or two later and was incredibly loud. So loud it set off my car alarm and shook my house. There were no storms reported in the area except rain...
  17. F

    Special Relativity and lightning

    Homework Statement This is a relativity problem: [/B] A tree and a pole are 3000 m apart. Each is hit by a bolt of lightning. Mark, who is standing at rest midway between the two, sees the two lightning bolts at the same instant of time. Nancy is flying her rocket at v = 0.5c in the direction...
  18. MattRob

    Lightning Bolts / Relativity of Simultaneity

    So, I think most of the folks here are familiar with Einstein's thought experiment that illustrates the relativity of simultaneity by using two lightning bolts and how the light reaches an observer on a moving train; that an observer on the ground observers the strikes simultaneously, but an...
  19. davenn

    What caused this mysterious A-Bomb sprite over the Caribbean?

    hi guys Had to share this with you ... This is amazing, have never seen anything like this before in a lightning discharge ( nor has my mate who photo'ed it) My fellow storm chaser Michael, from NE NSW State of Australia took this photo a few days or so ago now a closeup Now tell me that...
  20. G

    Exploring the Mystery of Ball Lightning: A Physics Luddite's Journey

    Greetings from NZ...I'm a new member and a physics luddite. In 2008 I had a close encounter with what I eventually found out was Ball Lightning. I find it hard to believe that here we are 2015 and still no solution to this phenominon. Are there any researchers out there currently working on...
  21. R

    Lightning/electricity question

    Okay- first off, I know enough science to sound like an idiot, so please be gentle :-) Now, IF you had a dragon that generated an electrical charge, it wouldn't be able to direct it, lightning-style, without being able to generate an opposite charge at it's target- right? So in essence, to shot...
  22. D

    Find the temperature change of a person struck by lightning

    Homework Statement A lightning flash releases about 1010J of electrical energy. If all this energy is added to 50 kg of water (the amount of water in a 165-lb person) at 37∘C, what are the final state and temperature of the water? The specific heat of water is 4180 J/kg⋅∘C, heat of...
  23. S

    MHB Lightning Addition: Master the Art of Mental Math

    . . . . . Lightning Addition Give your volunteer a sheet of paper, a pencil and a calculator. Then give him these instructions. Number the lines 1 to10. On the first line, write any one-digit number. On the second line, write any one-digit number. On the third line, write the sum of the 1st...
  24. P

    Questions regarding the synthesization of lightning

    I'm trying to build a chamber than can recreate the process of a lightning strike. I realize that I need to charge the top and bottom (or both sides) of the chamber with extreme opposite charges, and I also realize that I need to simulate the atmospheric conditions of a lightning cloud within...
  25. D

    Lightning & Uranium: Evidence of Abundance?

    We say that electrons that are freed when radioactivity of radon ionizes air molecules accelerate in the electric field E produced by thunderclouds and can thus ionize other molecules if E is greater than 3 MV/m, so that more and more free electrons are produced, which leads to lightning when...
  26. avito009

    Understanding Lightning: Causes of Ionisation and its Impact on Atmosphere

    Please explain this to me: "Electric force manifests itself in atmosphere where the atoms are ionised and that leads to lightening". why and how are atoms ionised in the above case? How does this ionisation cause lightening?
  27. R

    How does a lightning rod work?

    Greetings community An engineer came to me seeking help today. He asked me to determining the height of a lightning rod If the radius of the protection zone was given. Assuming the roof of the building is completely flat, what would the height (h = ?) have to be for a given radius of 75...
  28. C

    Science of Spellcasting: Lightning

    I hope it's not too brazen to make my first post my first thread, as well. I was tasked with developing a system of magic for a fantasy RPG I'm involved with. I wanted to step away from the traditional schools, and look at the magic in terms of what's happening. I won't elaborate, for sake of...
  29. C

    Is lightning caused by the cloud acting as a capacitor?

    So I was looking up what causes thunderstorms online and found this: "As hail moves within the cloud it picks up a negative charge by rubbing against smaller positively charged ice crystals. A negative charge forms at the base of the cloud where the hail collects, while the lighter ice crystals...
  30. S

    Exploring the Mechanics of Cloud-to-Ground Lightning Discharge

    From what I understand lightning works like a simple capacitor. The convection brings up moist air that by collision with already condensed gas molecules, causes charge separation within the cloud. The bottom part of the cloud becomes negative while the top part becomes positive. The lower...
  31. stevan

    Faraday cage as light as possible to protect from lightning

    if I build a faraday cage just to protect device from lightning or other electrostatic source (not electromagnetic pulse), and I need that as light as possible... I will build it using a mesh to make it light.. now, how large the mesh' holes is allowed ? is there any calculation for this...
  32. D

    Insulating box in a lightning storm

    This question is a variation on another question I asked recently. Suppose you were in a box made from a perfectly insulating material, and a thunderstorm was raging all around you. Would the box offer you any protection from lightning strikes? I think it would, because there would be no...
  33. D

    Car getting struck by lightning

    As we all know, if a car happens to be struck by lightning its passengers will probably be safe. The usual explanation is that the tires of the car are insulators. The actual reason, as E&M textbooks stress, is that the surface of the car, being a conductor, acts as a Faraday cage. My...
  34. Dotini

    Solar Wind Modulates Lightning - Mechanism Unknown

    http://iopscience.iop.org/1748-9326/9/5/055004/article http://www.bbc.com/news/science-environment-27406358# Activity on the Sun is sparking lightning strikes here on Earth, a study suggests. The finding was surprising, said Dr Scott, because it had been thought that an increase in the...
  35. K

    Lockheed Martin F-35 Lightning II engine power?

    https://www.youtube.com/watch?v=3PTW-9DeFs0 How can I calculate the power of the engine? Specification: Spec in Wikipedia Dry thrust: 125 kN
  36. S

    Find energy of a lightning strike

    Consider the Earth and the cloud layer 800 meters above the Earth to be the place of a parallel-plate capacitor. The cloud layer has an area of one kilometer squared. Assume this capacitor discharge that is lightning occurs, when the electric field strength between the plates reaches 3.0X10^6...
  37. M

    Lightning impulse high voltage test

    Hello, I am posting this here becase this is not a homework, it;s just something I need to know. Please tell me what these two waveforms mean? I know that they're both lightning impulse waveform but what is the difference between those two, what gives them their shapes?
  38. xthomasbhx

    Attract Lightning: Can You Use an Electro-Magnet?

    Could you use a negatively polarized electro-magnet with a positively charged lightning storm to attract lightning to strike at your position?
  39. M

    Lightning compared to piezo electric element

    I'm building (or rather, debugging) a lightning detector that detects the electromagnetic charge emitted by a lightning bolt. I need a good way to generate a little lightning as a test signal and I'm currently using a the piezo electric part of an electric lighter which generates a small...
  40. Crazymechanic

    Ball lightning atmosphere interaction

    There are numerous threads here about ball lightning but I am not exactly sure have any of those addressed this issue? Now a ball lightning even though haven't been duplicated in the lab is most likely a some sort of sphere or form of a plasma or ionized gas that has to do with charges and...
  41. larrybud

    Lightning strike blew out odd pieces in my house

    Last Wednesday we had a thunderstorm in this mid April in Michigan. While I was in my bedroom, a lightning bolt hit QUITE close to my house. Had to be < 100 feet. Subsequently, I discovered a number of odd pieces of my electronics had gone bad: 1) HDMI port in my Comcast DVR, yet the...
  42. Greg Bernhardt

    Flyers exposed to dark lightning

    Flyers exposed to "dark lightning" As a frequent air traveler I find this interesting and perhaps alarming...
  43. B

    Train gets struck by lightning

    Homework Statement A train with proper length of 200m is traveling at the speed of 120km/hr. An observer on the ground sees two lightning striking the two ends of the train at exactly the same time. What the time interval of the lightning strikes observed by the observer on the train? The...
  44. P

    Lightning Protection Systems: Direct vs Indirect Strokes & EMPs

    About two weeks ago, I wanted to find out more about the design of lightning protection systems. In particular, I wanted to figure out what gage of wire would be necessary for linking a lightning rod to earth-ground. What I had learned is that the gage of the wire would have to be extremely...
  45. P

    Doubt regarding direction of current during lightning

    In which direction do current flow during lightning? If it is from cloud to earth, which charge gets accumulated in below part of the cloud?
  46. J

    Lightning Questions: Answers to Elusive Mysteries

    I've been reading about how lightning occurs, but I have some questions that are never answered. 1. What exactly is the stepped leader? What in it gives off light before the connection is made and current starts flowing? Are there already some electrons flowing into this newly connected point...
  47. K

    How big does a Li-Po battery has to be to absorb a lightning bolt?

    What I'm asking is not strike and dissipate, I'm asking really capturing and storing the energy for later use. I mean are we talking more than cubic kilometers? I know a thunderbolt is just regular, really high power DC but if 220V@10,000W can be bottled in a less-than-half-a m³ UPS, why is...
  48. G

    Anyone want Paul Kolac's ball lightning generator?

    Anyone want Paul Kolac's ball lightning generator? NOTE: The existence of "ball lightning" is well accepted by some scientific communities, notably submarine engineers (because it has been seen near batteries inside submarines, though reproduction outside submarines has been problematic), and...
  49. H

    Can a Grounded Target Evade a Direct Lightning Strike with Sufficient Speed?

    I'm not sure if this question belongs here or in the classical physics section. So please forgive me if it is in the wrong place. My question is can a lightning strike, that originates from the sky directly above and unto a grounded target, be evaded with speeds less than the speed of the...
  50. N

    Harnessing the power of lightning

    I was thinking to create a feasible method to effectively harness power of lightning. Even though lightning does not have enough power to meet global energy requirement, i was intending to do it for knowledge's sake. I realized, in order to tap into the vast electric charges of clouds, it was...
Back
Top