which comes first lightning or thunder. why?
969310
They're simultaneous.  Thunder is the noise made by the lightning.  You may experience the two at different times (always thunder second) because light waves and sound waves travel at different speeds.  They actually occur at the same time, your perception of them causes the distinction.
654472
Hi, chris........both are actually the result of same thing,....\n\nwhen two clouds come together, there is electric discharge,\n\na cloud can be seen as a large capacitor.......\n\nso sound and light are produced at the same time.......\n\nsince sound travels at 330 mph, and light at 300000 mps\n\nsound reaches us later coz its very slow compared to light, so we see light immediately but it takes time for the sound to reach our ears..........\n\nwhich is better??? one doesnt happen without the other....\n\nthe power generated in a lightning is 50000 volts......\n\nscientists are trying to store the power these days, \n\nthe same they cant do with sound, and lighting is obviously more dangerous......
480333
natural LIGHTING comes from the sun,\notherwise, usually from an electric light bulb\n\nHowever, LIGHTNING, is a dual attraction between the sky and the ground, but physically speaking the negative charge in the sky is seeking out a positive charge on the ground, the LIGHTNING comes FROM THE SKY.\nHowever, you may not often see this and since there is a return of the lightning energy back up to the sky, (to balance the energy) so if you look after the sound of thunder you are seeing the return.
434074
clouds some times get charged to positive or negetive. the opposite charge is develped on the earth over which the cloud stands. if the cloud is close enough and the charge is good enough especially when water content in the air is high there will be an electric discharge fron the cloud to the earth. this is lightning and the noise of the discharge is thunder
221936
Thunder is the sound of the shockwave caused when lightning instantly heats the air around it to up to 30 000 °C (54 000 °F). That super-heated air expands rapidly, then contracts as it cools. The rapid expansion/contraction generates sound waves, making the sound that is called "thunder."\n\nSince sound and light travel at different speeds through the atmosphere, one can time the interval between them to roughly estimate how far away the bolt of lightning is. The speed of sound in air is approximately 332 m/s (742.6 mph), while the speed of light is so fast that the lightning is seen only a few microseconds after the event, so the lightning is approximately one kilometer distant for every 3 second interval (one mile for every 5 seconds).
157859
The first process in the generation of lightning is the forcible separation of positive and negative charge carriers within a cloud or air. The mechanism by which this happens is still the subject of research, but one widely accepted theory is the polarisation mechanism. This mechanism has two components: the first is that falling droplets of ice and rain become electrically polarised as they fall through the atmosphere's natural electric field, and the second is that colliding ice particles become charged by electrostatic induction. Once charged, by whatever mechanism, work is performed as the opposite charges are driven apart and energy is stored in the electric fields between them. The positively charged crystals tend to rise to the top, causing the cloud top to build up a positive charge, and the negatively charged crystals and hailstones drop to the middle and bottom layers of the cloud, building up a negative charge. Cloud-to-cloud lightning can appear at this point. Cloud-to-ground lightning is less common. Cumulonimbus clouds that do not produce enough ice crystals usually fail to produce enough charge separation to cause lightning.\n\nWhen sufficient negatives and positives gather in this way, and when the electric field becomes sufficiently strong, an electrical discharge occurs within the clouds or between the clouds and the ground, producing the bolt. It has been suggested by experimental evidence that these discharges are triggered by cosmic ray strikes which ionise atoms, releasing electrons that are accelerated by the electric fields, ionising other air molecules and making the air conductive by a runaway breakdown, then starting a lightning strike. During the strike, successive portions of air become conductive as the electrons and positive ions of air molecules are pulled away from each other and forced to flow in opposite directions (stepped channels called step leaders). The conductive filament grows in length. At the same time, electrical energy stored in the electric field flows radially inward into the conductive filament.\n\nWhen a charged step leader is near the ground, opposite charges appear on the ground and enhance the electric field. The electric field is higher on trees and tall buildings. If the electric field is strong enough, a discharge can initiate from the ground. This discharge starts as positive streamer and, if it develops as a positive leader, can eventually connect to the descending discharge from the cloud.\n\nLightning can also occur within the ash clouds from volcanic eruptions[1],[2], or can be caused by violent forest fires which generate sufficient dust to create a static charge.\n\nA bolt of lightning usually begins when an invisible negatively charged stepped leader stroke is sent out from the cloud. As it does so, a positively charged streamer is usually sent out from the positively charged ground or cloud. When the two leaders meet, the electric current greatly increases. The region of high current propagates back up the positive stepped leader into the cloud. This "return stroke" is the most luminous part of the strike, and is the part that is really visible. Most lightning strikes usually last about a quarter of a second. Sometimes several strokes will travel up and down the same leader strike, causing a flickering effect. This discharge rapidly superheats the leader channel, causing the air to expand rapidly and produce a shock wave heard as thunder.\n\nIt is possible for streamers to be sent out from several different objects simultaneously, with only one connecting with the leader and forming the discharge path. Photographs have been taken on which non-connected streamers are visible such as that shown on the right.\n\nThis type of lightning is known as negative lightning because of the discharge of negative charge from the cloud, and accounts for over 95% of all lightning.\n\nAn average bolt of negative lightning carries a current of 30 kiloamperes, transfe
49699
Look, lightning and thunder HAPPEN at the same time. Lightning causes the air to displace and when it contracts again (immediately) you get thunder, the sound of air filling a gap. You see lightning first because it is traveling @ 180,000 mps, thunder travels at the speed of sound (depends on where you live). You can generally determine how far away you are from the place of origin by counting 1 one-hundred, 2 one hundred, etc until you hear thunder and divide that number by two. That is how many miles away you are.\n\nBTW, if you see lightning and hear thunder at the same time, the event is right where you are!
514416
The correct answer is yes it can.\n\nIn a thunder or cumulonimbus cloud the warm air rises and the cold air sinks, this movement of air causes a huge difference in the electrical distribution with the top of the cloud having a positive charge and the bottom having a negative charge.  A positive charge also builds up on the earths surface.\n\nEventually these charges built to such an extent that there is an electrical discharge from the negative charge at the base of the cloud towards the positive charge at the top of the cloud and also down to the positive charge on the ground.\n\nWhat actually happens is that the first discharge travels towards earth in short but very rapid bursts of about 100 meter lengths - when you see jagged strokes of lightening this is because each burst can change direction.  As it gets closer to earth the strength of the electrical field intensifies until contact is made with the earth.\n\nThis initial discharge is only a weak stroke of lightening and is called the Leader Stroke.  As soon as contact is made there is a much more powerful stroke of lightening which travels from the earth back to the cloud and this is the lightening we see, this is called the Return Stroke.
138725
You're right--lightning is just a spark. BUT it's a spark caused by massive voltage. Voltage can be defined as a difference in electrical potential between two points, with one point having a high negative electrical charge, the other a high positive electrical charge. This difference in electrical potential can become enormous when a thunderstorm gets going full force.\n\nRain and/or hail in the storm clouds are violently rubbed together by high-velocity winds, thus building up a net negative electrical charge (abundance of electrons). On the ground below the clouds no such action takes place, thus the ground has a net positive electrical charge (deficiency of electrons).\n\nEven though air is a very good insulator, the difference in electrical potential (voltage) between the storm clouds and ground can quickly reach as high as 500,000 volts, more than enough to produce a lightning "spark."
301729
Both are correct.\n\nDuring a lightning strike, leaders travel up from the ground or object that is about to be struck. At the same time a strike comes from the clouds downward.\n\nWherever the leader is the tallest, the two will meet.\n\nThere are several types of lightning...\nCloud to ground\nGround to cloud\ncloud to cloud\n\nall are correct
757146
Lightning is one of the oldest observed natural phenomena on earth. At the same time, it also is one of the least understood. While lightning is simply a gigantic spark of static electricity (the same kind of electricity that sometimes shocks you when you touch a doorknob), scientists do not have a complete grasp on how it works, or how it interacts with solar flares impacting the upper atmosphere or the earth's electromagnetic field.\nLightning has been seen in volcanic eruptions, extremely intense forest fires, surface nuclear detonations, heavy snowstorms, and in large hurricanes. However, it is most often seen in thunderstorms.At any given moment, there can be as many as 2,000 thunderstorms occurring across the globe. This translates to more than 14.5 MILLION storms each year. NASA satellite research indicated these storms produce lightning flashes about 40 times a second worldwide.This is a change from the commonly accepted value of 100 flashes per second which was an estimate from 1925. Whether it is 40, 100, or somewhere in between, we live on an electrified planet.\n\nThe Sound of Thunder\nRegardless of whether lightning is positive or negative, thunder is produced the same way. Thunder is the acoustic shock wave resulting from the extreme heat generated by a lightning flash. Lightning can be as hot as 54,000°F (30,000°C), a temperature that is five times the surface of the sun! When lightning occurs, it heats the air surrounding its channel to that same incredible temperature in a fraction of a second.\n\nLike all gases, when air molecules are heated, they expand. The faster they are heated, the faster their rate of expansion. But when air is heated to 54,000°F in a fraction of a second, a phenomenon known as "explosive expansion" occurs. This is where air expands so rapidly that it compresses the air in front of it, forming a shock wave similar to a sonic boom. Exploding fireworks produce a similar result.\n\nWhat is the difference between a thundershower and a thunderstorm?  \nTechnically, there is none. In general, the term "thundershower" tends to denote a fairly weak storm with light to moderate rainfall and low levels of lightning activity. However, there are no defined parameters that distinguish between a thundershower and a thunderstorm. In fact, in order to avoid confusion, we in the National Weather Service do not use the term "thundershower". If a shower is strong enough to produce lightning, even just one single bolt, it's called a thunderstorm.\n\nTo Learn More about Lightning and Thunder go to \nhttp://www.srh.weather.gov/jetstream/lightning/lightning_intro.htm\n\nLIGHTNING SAFETY A MUST READ\nLightning is the MOST UNDERRATED weather hazard. On average, only floods kill more people. Lightning makes every single thunderstorm a potential killer, whether the storm produces one single bolt or ten thousand bolts.\n\nIn the United States, lightning routinely kills more people each year than tornadoes and hurricanes COMBINED. Tornadoes, hail, and wind gusts get the most attention, but only lightning can strike outside the storm itself. Lightning is the first thunderstorm hazard to arrive and the last to leave.\n\nLightning is one of the most capricious and unpredictable characteristics of a thunderstorm. Because of this, no one can guarantee an individual or group absolute protection from lightning. However, knowing and following proven lightning safety guidelines can greatly reduce the risk of injury or death. Remember, YOU are ultimately responsible for your personal safety, and should take appropriate action when threatened by lightning.\n\nWhile no place is 100% safe from lightning, some places are much safer than others.\nWhere to Go Where NOT to Go \nThe safest location during a thunderstorm is inside a large enclosed structure with plumbing and electrical wiring. These include shopping centers, schools, office buildings, and private residences.\n\nIf lightning st
174590
Sheet lightning goes from cloud to cloud.  Lightning is caused when electrical charge accumulates within clouds.  When fork lightning happens, the charge accumulated in a cloud is discharged to the ground.  When sheet lightning occurs, two different cloud masses accumulate opposite changers until they discharge.\n\nThe voltage required to discharged is directly related to the distance between objects and the dielectric constant of the medium (i.e. air).
283845
Clearing a few things up:\nlightning can go from cloud to ground, ground to cloud, or cloud to cloud.\nThe charge buildup that causes the lightning is focused in the cloud and on the ground.  But the lightning doesn't go from one to the other and just stop.  The difference in charge becomes large enough to cause a "jump" between the air and ground (or whatever the source/target).  This is like an arc in an electrical current... the voltage builds up to a point where the inhibition of the atmosphere (or wire covering) aren't enough to contain it, cuasing the ions to jump from the one place to the other.  As an aside, lightning is caused by opposite charges building up.  Typical lightning is negative (negative charge flowing to positive charge).  Less common is positive lightning, which is much more powerful/damaging.  The -/+ ions flow to the opposite charge.  Lightning starts wth a stepped leader of particles "reaching out" from the source AND target until a path of low enough resistance is found at which time the lightning strikes.  The path is set and large amounts of ions flow along the path until the charge difference/voltage decreases to a point at which the resistance restrains the flow again.\nThe lightning doesn't stop at the ground when coming from the cloud... it keeps spreading out until the charge difference is neutralized/the energy dissipated.  This can lead to lightning ions travelling large distances into the ground (or along underground phone lines and such).\n\nTired of me talking?  Looking for a point?\nThe point is that you can be hit in the sky!  Partciles of air aren't directly grounded either, but the lightning goes through them.  Humans are less resistant than air (that's why being the tallest object in a thunderstorm is dangerous), so in theory you are the easier path.  And just because you aren't grounded doesn't mean you don't get burned as the lightning passes through you (just as it would if you were grounded).\n\nDoubt the danger is rediculously extreme, but its a threat.
622228
The initial noise comes from the superheated air surrounding a bolt of lightning moving at high speeds, creating a fairly high pitched CRACK.  The "rolling" thunder sound is caused by that superheated air "pushing" (via air pressure in case you were wondering) the air around it.  Kinda cool to think that all we are hearing is friction of air molecules at different speeds, huh?
903257
Both at the same time!, lightning has been photgraphed heading upwards from trees, at the same time leaders head downwards as well, where they meet a lightning strike occours.\n\nThats why when you are out in the open during a storm and feel your hair standing on end - panic and get down, a leader may be leaving your head!
1088869
Lightning happens because of static electricity.  If you've ever gotten a little spark when you touched a doorknob or something metal, that's static electricity.  It happens because electrons (which make electricity) are "gathered up" in some materials when they are rubbed.  When your feet rub on a carpet, electrons from the carpet get picked up by your feet.  Then when you touch a doorknob or something metal, the electrons jump across to the doorknob, making a tiny spark.\n\nLightning is exactly the same thing, but much bigger.  The water in the clouds "rub" against the air, gathering electrons, until finally a huge spark leaps from the clouds to the ground.\n\nThunder happens right after lightning.  It happens because the lightning is so hot that it heats the air around it, making it expand.  Once the lightning is gone, the air rushes back in with a huge "bang" like giant clapping hands.\n\nThunder can be scary because it's so loud and unexpected.  But since thunder always follows lightning, here's what you can do:  When you see a flash of lightning, start counting, "one-Mississippi, two-Mississippi, three-Mississippi..." and so on until you hear the thunder.  Each "Mississippi" is about one second, and because of the speed of sound each second you count means that the lightning is about one-fifth of a mile away.  So if you can count to "five-Mississippi" before you hear the thunder, that means that the lightning is a mile away.  Knowing that it's that far away makes it not so bad.\n\nI think lightning is pretty neat to watch.  I used to live in the New Mexico desert, and when we had a thunderstorm you could see the lightning branching down from the clouds.  That's a little more interesting than just a bright flash of light.\n\nI hope that knowing more about lightning and thunder will help make it less scary for you.  Try looking up "lightning" on Google, look at some pictures and see how interesting lightning really is.
887907
Actually it is the other way around.  Since light travels faster than sound, you *see* lightning before you *hear* the accompanying thunder.\n\nLight travels at about 186,000 miles per *second*\nSound travels at about 760 miles per *hour*.  This works out to about 1/5 of a mile per second (0.2114... miles per second)\n\nSo if you count the time between when you see the lightning (almost instantaneously) and the time until you hear the lightning, then divide by 5, you can get a rough estimate of how far away to where the lightning is striking.\n\nIf the difference is 25 seconds, it is 5 miles away.  If it is 5 seconds, it is 1 mile away.  If it happens at the same time as the lightning... good luck!