Lightning

The name of Australia's most celebrated thoroughbred horse, Phar Lap, derives from the shared Zhuang and Thai word for lightning. [1]. The lightning bolt shape was a symbol of male humans among the Native Americans such as the Apache (a rhombus shape being a symbol for females) in the American Old West. The wording has since been changed to reflect that it is legal for the consumer to remove the tag of a mattress that they have purchased. It is also distinguished from the "fork of lightning". The tag previously read "Do not remove under penalty of law", causing some consumers to believe that they could be arrested for cutting it off. The bolt of lightning in heraldry is distinguished from the lightning bolt and is shown as a zigzag with non-pointed ends. United States law requires all new mattresses, pillows, upholstered chairs, and similar items to be sold with a tag describing the fabric and filling.

Flash II (Barry Allen) and III (Wally West) were both granted their superspeed in accidents involving lightning. See Races from The Hitchhiker's Guide to the Galaxy. The comic book character Billy Batson changed into the superhero Captain Marvel by saying the word "Shazam!", which called down a bolt of magic lightning to make the change. None of them seem to mind and all of them are called Zem." Very few mattresses actually come back to life and attack the sleeper. Various novels and role playing games with fantasy tint involves wizardry of lightning bolt, weapon embodying the power of lightning, etc. Many of them get caught, slaughtered, dried out, shipped out, and slept on. While this is usually typical of cartoons, it has also been employed by regular TV shows and movies. large, friendly, pocket-sprung creatures which live quiet private lives in the marshes of Squornshellous Zeta.

This has often also been spoofed, with the uttering of certain words or phrases causing flashes of lightning to appear outside of windows (and often scaring or disturbing some characters). In Life, the Universe and Everything by Douglas Adams, mattresses are ".. It may herald a waking of a great evil or emergence of a crisis. Be aware that the bigger the mattress, the more expensive the sheets. and many other countries, lightning is often employed as an ominous, dramatic sign. According to experts, a mattress should be at least six inches longer than the tallest person who will be sleeping on it. In movies and comics of the contemporary U.S. Twin & Double are 75 inches long; Queen & King are 80 inches long; California Queen & California King are 84 inches long.

These two qualities make oak trees better grounded and more conductive than trees with shallow roots and closed cells. Unlike an eggcrate or other forms of padding, the mattress inner components cannot be removed and replaced when damaged. Of all common trees the most frequently struck is the oak, this is due to the deep central root that goes beneath the tree and also the hollow water filled cells that run up and down the wood of the oak's trunk. The fabric, foam or cotton eventually become concave because thick plush or pillowtop components eventually break down even if the springs do not. It is commonly thought that a tree standing alone is more frequently struck, though in some forested areas, lightning scars can be seen on almost every tree. Thick layers of padding are more likely than the springs to compress to the point of feeling like the mattress is sagging. Occasionally, a tree may explode completely, as in this Giant Sequoia struck in Geneva. Wool, silk, foam and cotton all increase the cost of the mattress.

If the damage is severe, the tree may not be able to recover, and decay sets in, eventually killing the tree. Fabric is the most expensive element of mattress construction. In following seasons trees overgrow the damaged area and may cover it completely, leaving only a vertical scar. Furthermore, there is a "Sleep number" bed that inflates and deflates inner air chambers to make it harder or softer, with separate controls and air chambers for both sides of the mattress, also to adjust to the different comfort preferences of the sleeping partners. Since sap is a poor conductor, its electrical resistance causes it to be heated explosively into steam, which blows off the bark outside the lightning's path. The brand Simmons currently produces King and Queen sized mattresses with a softer side and another firmer side, for the different tastes of the sleeping partners. Trees are frequent conductors of lightning to the ground (photo of a tree being struck by lightning). Now that we know that a majority of Americans sleep mostly on their side, further research tells us that a mattress that conforms better to the shape of the body provides better support.

Fulgurites are evidence that lightning spreads out into branching channels when it strikes the ground. Doctors used to say that when they were rather oblivious about people's sleep habits and thought that everybody slept on their back 100% of the time. These are sometimes found under the sandy surfaces of beaches and golf courses, or in desert regions. It is a common misconception that a "firm" or hard mattress provides better support. The heat of lightning which strikes loose soil or sandy regions of the ground may fuse the soil or sand into glass channels called fulgurites. The sleeping position determines which part of the body will interface with the mattress, which in turn determines the amount of stress to the body. This is about five times hotter than the surface of the sun. During a night's sleep, most people use more than one position.

A bolt of lightning can reach temperatures approaching 28,000 kelvins (50,000 degrees Fahrenheit) in a split second. There are three main sleep positions — Back, stomach and side. One such example is the destruction of the basement insulator of the 250-metre-high central mast of longwave transmitter Orlunda, which led to its collapse. There is no proven scientific way of finding the right mattress, so the best advice is to try it out. Hot lightning which lasts for more than a second can deposit immense energy, melting or carbonizing large objects. The ticking produces the look and feel of the mattress, so it is usually soft to the touch and attractive to the buyer (at least that is what manufacturers intend to create). There is sometimes spectacular and unconventional lightning damage. Most ticking is made of synthetic fibers like polyester, latex and acrylic, or of natural materials such as cotton, silk & wool.

Due to the precision timing of this type of event, it is a rare (but documented) occurrence. It is usually made to match the foundation and comes in a wide variety of colors and styles. This happens only when the heart is at its lowest electrical charge (the very lowest point that would be recorded in an EKG right before the heart recharges for its next beat) when the lightning strikes. The protective fabric cover, which encases the support and comfort layers of the mattress, is called ticking. The EMP created by a nearby lightning strike can cause cardiac arrest. The quilt can be firm or soft and plush. They are thought to be caused by the rupture of small capillaries under the skin, either from the current or from the shock wave. The quilt is a top layer of the mattress made of light foam or fibers stitched to the underside of the ticking, and provides the immediate soft texture that the user feels when lying on a mattress.

The lightning often leaves skin burns in characteristic Lichtenberg figures, sometimes called lightning flowers; they may persist for hours or days, and are a useful indicator for medical examiners when trying to determine the cause of death. It is usually made from materials that give maximum comfort — regular foam, viscoelastic foam, felt, polyester fibers, cotton fibers, egg-crate foam, non-woven fiber pads, etc. A complete physical examination by paramedics or physicians may reveal ruptured eardrums, and ocular cataracts may develop, sometimes more than a year after an otherwise uneventful recovery. The middle upholstery comprises all types of materials on top of the insulator and beneath the quilt. Amnesia and confusion of varying duration often result as well. This layer separates the mattress core from the upholstery, and it is usually made of fiber or mesh, with the intention of keeping the middle upholstery in place. Either the electrical or the mechanical force can result in loss of consciousness, which is very common immediately after a strike. Aside from the number and gauge of the coils, the upholstery layers are used to differentiate the different "qualities" of mattresses that manufacturers produce.

The intense heat generated by a lightning strike can cause lung damage, and the chest can be damaged by the mechanical force of rapidly expanding heated air. The "Comfort layer"can be divided into three sub-layers — Insulator, Middle Upholstery and Quilt. Others incur myocardial infarction and various cardiac arrhythmias, either of which can be rapidly fatal as well. Some manufacturers call the mattress core by the name "Support layer" and the cushioning materials by the name "Comfort layer". Many victims suffer immediate cardiac arrest and will not survive without prompt emergency care, which is safe to administer because the victim will not retain any electrical charge after the lightning has struck (of course, the helper could be struck by a separate bolt of lightning in the vicinity). The mattress core is covered by several soft materials, providing cushioning and comfort. The most critical injuries are to the circulatory system, the lungs, and the central nervous system. It is a combination of steel and wood.

Ground strikes, in which the bolt lands near the victim and is conducted through the victim via his or her connection to the ground (such as through the feet), can cause great damage. Since a box spring has coils, it generally increases the give in the mattress, which in turn produces a softer or bouncier feel. Splash hits occur when lightning effectively bounces off a nearby object and strikes the victim en route to ground. If the springs match the mattress it is called a coil upon coil box spring. Counterintuitively, if the victim's skin resistance is high enough, much of the current will flash around the skin or clothing to the ground, resulting in a surprisingly benign outcome. It features extra-heavy-duty springs. In a direct hit the electrical charge strikes the victim first. This type of foundation, called by the industry a zero deflection unit, increases the feeling of firmness or stability.

Lightning can incapacitate humans in 4 different ways:. It usually has seven or eight support slats, covered with cardboard or beaverboard. While sudden death is common because of the huge voltage of a lightning strike, survivors often fare better than victims of other electrical injuries caused by a more prolonged application of lesser voltage. It is usually made of pine or similar hard wood. Lightning injuries result from three factors: electrical damage, intense heat, and the mechanical energy which these generate. There are three main types of foundations:. Nearly 2000 persons per year in the world are injured by lightning strikes, and between 25 to 33 % of those struck die. Although in the past the foundation actually contained springs, increasingly today it functions primarily to elevate the mattress, although a good box spring can help prolong the life and comfort of the mattress.

Several different types of devices, including lightning rods, lightning arresters, and electrical charge dissipaters, are used to prevent or safely redirect lightning strikes. This type of coil system does tend to be the strongest, however we must remember that strength does not dictate support. It is advisable to keep appendages away from any attached metallic components once inside (keys in ignition, etc.). The idea is that with a continuous coil system, each coil is connected to the next so that it can draw strength from it. A better location would be inside a vehicle (a crude type of Faraday cage). Kingsdown also uses such a system. People have been struck in sheds, make shift shelters, etc. The brand Serta uses continuous coils in their mattresses.

Contrary to popular notion, there is no 'safe' location outdoors. They look like double wire spirals or loose ringlets, creating a network of wire running nonstop through the entire bed. Because people have been struck many kilometers away from a storm, seeking immediate and effective shelter when thunderstorms approach is an important part of lightning safety. The biggest problem with this system is called "roll together." Because the rows of coils generally run from side to side and the wire that holds them together also runs side to side, over time (not always much time at all) it will cause two people to roll towards the middle of the mattress. Thunderstorms are the primary source of lightning. For example Stearns and Foster was made with a Bonnell coil system for many years, however, when they were purchased by Bain Capitol (the same company that now owns Sealy) the coil system was changed to a Double Offset system exactly like the Sealy Posturepedic. However, recently the Cassini-Huygens mission fly-by of Venus detected no signs of lightning at all. Additionally, some brands change over the years for many reasons including, but not limited to, the change of ownership of a manufacturer.

Pioneer missions of the '70s and '80s, signals suggesting lightning may be present in the upper atmosphere were detected [10]. Brands like Sealy and Spring Air use open-end offset coils in their mattresses. During the Soviet Venera and U.S. However, loose ends increase the odds that a spring will begin to punch through the padding. Lightning on Venus is still a controversial subject after decades of study. These improvements gave offset coils an extra turn of working wire for greater spring action on each end of the coil. Lightning on Jupiter is estimated to be 100 times as powerful, but fifteen times less frequent, than that which occurs on Earth. These are called "open end offset coils".

However, lightning has been observed within the atmospheres of other planets, such as Venus and Jupiter, and electrical discharges between Jupiter and Io often occur within the gas cloud sent out by Io's volcanos. In other words, offset coils might be tied off or feature a loose end (sensory arm). Lightning requires the electrical breakdown of gas, so lightning cannot exist in the vacuum of space. An evolution of the offset coils brought the elimination of the knot that tied the end of the wire to the coil. These bolts are typically very straight. They are almost identical to the Bonnell coils, except that the top and bottom circular part of the coils have flat or straight sides, which allow for better hinging action when they are placed together in a spring unit, and which can be easily aligned. The wire unwinds as the rocket climbs, making a convenient path for the lightning to use. Bonnell coils evolved into Offset coils, which are currently popular, but happen to be the most expensive ones.

It has also been triggered by launching rockets carrying spools of wire into thunderstorms. When a sleeper is undisturbed at night they can fall into that deep sleep faster, stay in a deeper sleep longer and wake up feeling more refreshed because it allows the sleeper to get more use out of their sleep. Lightning struck the Apollo 12 soon after takeoff, and has struck soon after thermonuclear explosions. Additionally, when two people sleep on the same mattress, the individually wrapped (or individually pocketed) coil provides motion separation (when one person tosses and turns, the other doesn't feel it.) This is important because when one person tosses and turns, it may not completely wake the other person, but, it can take them out of a deep sleep which is when the body does all of its regeneration. Lightning has been triggered directly by human activity in several instances. By "pre-compressing" the coil, it becomes a firmer coil, thus making up for the steel not being tempered. Because most of these strokes occur inside a cloud, we do not see many of the individual return strokes in a thunderstorm. They "pre-compress" their pocketed coil, which means that they pack the coil into a "pocket" that is shorter (usually by a couple inches) than the coil.

This is nothing more than the return stroke, the visible part of the lightning stroke. Simmons also does some things that other brands that use pocketed coils don't. All lightning is streak lightning. The brand Simmons uses pocketed coils in their mattresses. One theory about the cause of the Space Shuttle Columbia disaster is that the craft was struck by atmospheric lightning [9]. Might not be properly tempered. Researchers have speculated that such forms of upper atmospheric lightning may play a role in the formation of the ozone layer. Also called pocketed coils, they are individually pocketed and less frequently used.

The jets lasted under a second, with shapes likened by the researchers to giant trees and carrots. They have an hour-glass shape, and the ends of the wire are knotted or wrapped around the top and bottom circular portion of the coil (round-topped and self tied). On July 22, 2002, five gigantic jets between 60 and 70 km (35 to 45 miles) in length were observed over the South China Sea from Taiwan, reported in Nature [8]. They are still prevalent in low priced mattresses. Lightning was initially observed travelling up at around 50,000 m/s in a similar way to a typical blue jet, but then divided in two and sped at 250,000 m/s to the ionosphere, where they spread out in a bright burst of light. They were adapted from buggy seat springs of the 19th century. The jet was located above a thunderstorm over the ocean, and lasted under a second. These are the oldest ones and most commonly used.

On September 14, 2001, scientists at the Arecibo Observatory photographed a huge jet double the height of those previously observed, reaching around 80 km (50 miles) into the atmosphere. One thing to remember is that while there are many different types of coils and many manufacturers, most manufacturers have their coils made by one company, Leggett & Platt. This refers to the process by which the light is generated; the excitation of nitrogen molecules due to electron collisions (the electrons having been energised by the electromagnetic pulse caused by a positive lightning bolt). However, there are only a few innerspring manufacturers and four general types. Elves is a frivolous acronym for Emissions of Light and Very Low Frequency Perturbations From Electromagnetic Pulse Sources. Construction-wise, most manufacturers claim to have the best coil-to-gauge ratio. Elves were first recorded on another shuttle mission, this time recorded off French Guiana on October 7, 1990. However, the special pockets provide the support required by the coil instead of the interconnection with other coils.

Their colour was a puzzle for some time, but is now believed to be a red hue. There are some manufacturers that make individually pocketed coils, which avoid movement on different sides of the bed because they are not interconnected. They occur in the ionosphere 100 km (60 miles) above the ground over thunderstorms. Mattresses that sag quickly usually have few interconnecting wires. Elves often appear as a dim, flattened, expanding glow around 400 km (250 miles) in diameter that lasts for, typically, just one millisecond [7]. If there are too few of these interconnecting wires a mattress can lose its shape more quickly than one that has an adequate amount. They were first recorded on October 21, 1989, on a video taken from the space shuttle as it passed over Australia. Generally, the number and quality of these interconnecting wires is not published by the manufacturers.

They are also brighter than sprites and, as implied by their name, are blue in colour. A 12.5 gauge (1.94 mm) innerspring, the thickest typically available, may feel rock hard in a double mattress even with a coil count of 400 or less. Blue jets differ from sprites in that they project from the top of the cumulonimbus above a thunderstorm, typically in a narrow cone, to the lowest levels of the ionosphere 40 to 50 km (25 to 30 miles) above the earth. With coils of 14 to 15.5 gauge (1.63 to 1.37 mm), it is important that the total coil count be high to compensate for the fact that they give so easily under pressure. Research in 2004 by scientists from Tohoku University found that very low frequency emissions occur at the same time as the sprite, indicating that a discharge within the cloud may generate the sprites [6]. The lower the number, the thicker the spring. Recent research [5] carried out at the University of Houston in 2002 indicates that some normal (negative) lightning discharges produce a sprite halo, the precursor of a sprite, and that every lightning bolt between cloud and ground attempts to produce a sprite or a sprite halo. Coils are measured in quarter increments.

Sprites were first photographed on July 6, 1989, by scientists from the University of Minnesota and named after the mischievous sprites in the plays of Shakespeare. Many premium mattresses feature 14-gauge (1.63 mm) coils. Sprites are preceded by a sprite halo that forms because of heating and ionisation less than 1 millisecond before the sprite. A low coil count and heavy gauge wire can pass as a firm mattress in the store, but it is likely that this mattress will become lumpy quickly because it does not have enough coils. Sprites usually occur in clusters of two or more simultaneous vertical discharges, typically extending from 65 to 75 km (40 to 47 miles) above the earth, with or without less intense filaments reaching above and below. Some mattress manufacturers will compensate for a higher (thinner) guage of steel by using a higher coil count. Sprites can occur up to 50 km from the location of the lightning strike, and with a time delay of up to 100 milliseconds. This couldn't be farther from the truth.

They appear as luminous reddish-orange, neon-like flashes, last longer than normal lower stratospheric discharges (typically around 17 milliseconds), and are usually spawned by discharges of positive lightning between the cloud and the ground. Most would think that obviously heavy gauge (thick) coils will offer a great deal of support while light gauge coils will give less support. Sprites are now well-documented electrical discharges that occur high above the cumulonimbus cloud of an active thunderstorm. Usually this is achieved with an individually wrapped coil system (see below.). This has sometimes been called megalightning. Most people sleep on their side, and as the side of the human body is not flat like the back, better body conformity provides better support. However, it is only in recent years that fuller investigations have been made. This was actually only true with a small percentage of people, back and stomach sleepers.

Reports by scientists of strange lightning phenomena above storms date back to at least 1886. Doctors USED to say that a harder mattress will give better support. It is not the same as ball lightning. Additionally, there are some other misconceptions as far as coil count and firmness are concerned. St Elmo's fire was correctly identified by Franklin as electrical in nature. Assuming that the overall coil count is decent, a heavy duty innerspring mattress may also increase the longevity of the mattress for large users. In fact, there are only a few pictures of it. However, some expensive and comfortable mattress only have around 400 coils, and it takes as few as 312 coils in a full mattress to provide decent support.

Ball lightning is hardly ever seen. Depending on the size, 500 to 800 coils is considered firm. The scientist Coleman was the first to propose this theory in 1993 in Weather, a publication of the Royal Meteorological Society. Generally, but depending on the mattress size, they come with 300 to 800 coils. One theory that may account for this wider spectrum of observational evidence is the idea of combustion inside the low-velocity region of axisymmetric (spherical) vortex breakdown of a natural vortex (e.g., the 'Hill's spherical vortex'). The coil construction will determine the ammount of support the user gets. Vertically linked fireballs have been reported. This is not so true today.

Fireballs have carved trenches in the peat swamps in Ireland. Basically,it used to be said that the more coils a mattress has, the more support it will give the user. Fireballs have been seen in tornadoes, and they have also split apart into two or more separate balls and recombined. He lived in Germany and died in poverty, having never profited from his invention. The object was a glowing globular zone (the breakdown zone?) with a long, twisting, rope-like projection (the funnel?). Then, in 1871, Heinrich Westphal invented the innerspring mattress. The photograph has appeared in the scientific journal Transactions of the Royal Society. The steel coil spring was invented during the industrial revolution and was first patented for use in a chair seat in 1857.

A recent photograph by a Queensland ranger, Brett Porter, showed a fireball that was estimated to be 100 meters in diameter. Proper support is where the wire coils push back in response to weight deflection to hold the body in alignment. The typical fireball diameter is usually standardised as 20–30 cm, but ball lightning several meters in diameter has been reported (Singer). It provides support to the set. Ball lightning field properties are more extensive than realised by many scientists not working in this field. The spring mattress core is also called innerspring. Japanese research shows that ball lightning has been seen several times without any connection to stormy weather or lightning. In most modern mattresses (except for the foam-only ones), it is made up of steel coils springs, also known simply as coils.

Any complete theory of ball lightning must be able to describe the wide range of reported properties, such as those described in Singer's book "The Nature of Ball Lightning" and also more contemporary research. The core of the mattress is the most important part in the support of the body. Several theories have been advanced to describe ball lightning, with none being universally accepted. A common innerspring mattress consists of three components:. Some later experimenters have been able to briefly produce small luminous balls by igniting carbon-containing materials atop sparking Tesla Coils. Most mattresses have a thickness from 6 to 14 inches. There is some speculation that electrical breakdown and arcing of cotton and gutta-percha wire insulation used by Tesla may have been a contributing factor, since some theories of ball lightning require the involvement of carbonaceous materials. .

The engineer Nikola Tesla wrote, "I have succeeded in determining the mode of their formation and producing them artificially" (Electrical World and Engineer, 5 March 1904). With modern production methods, it takes 10 to 60 minutes to make a mattress from start to finish. Ball lightning has been described by eyewitnesses but rarely, if ever, recorded by meteorologists. The fabric used to cover the exterior of a mattress is called mattress ticking. Some have been known to pass through windows and even dissipate with a bang. Although mattresses are sold with fillings of air, water, or foam, innerspring or coil mattresses currently have over 80% of the market share in the U.S. Some make hissing or crackling noises or no noise at all. Increasingly, mattresses made with various foam materials such as latex foam, viscoelastic foam and other polyurethane-type foam, but without metal spring units, are becoming common and accepted.

They can be fast moving, slow moving or nearly stationary. Mattresses are usually used along with a foundation, which might include metal springs or torsion bars on a wooden frame, which supports the mattress. Ball lightning is described as a floating, illuminated ball that occurs during thunderstorms. A mattress is a piece of bedding typically consisting of multiple layers of foams and fibers, along with an innerspring unit used to provide support to one's back during sleep. [4]. Viscoelastic foam. As a result, the lightning discharge appears to be silent. Ventilator.

An observer may see nearby lightning, but the sound from the discharge is refracted over his head by a change in the temperature, and therefore the density, of the air around him. Upholstery Layers — This includes all the soft layers of a mattress, such as insulators, covers and quilts. Some cases of "heat lightning" can be explained by the refraction of sound by bodies of air with different densities. Tufting. In Florida, heat lightning is often seen out over the water at night, the remnants of storms that formed during the day along a seabreeze front coming in from the opposite coast. Twin Extra Long. Heat lightning can be an early warning sign that thunderstorms are approaching. Twin.

Heat lightning was named because it often occurs on hot summer nights. Topper Pad. Heat lightning (or, in the UK, "summer lightning") is nothing more than the faint flashes of lightning on the horizon from distant thunderstorms. Thermally-Bonded Cotton. Most ground-to-cloud lightning occurs from tall buildings, mountains and towers. Tempering/Stress Relief. Ground-to-cloud lightning is a lightning discharge between the ground and a cumulonimbus cloud from an upward-moving leader stroke. It works best when it provides a seamless and coordinating finish to the mattress.

Cloud-to-cloud or intercloud lightning is a somewhat rare type of discharge lightning between two or more completely separate cumulonimbus clouds. Tape edge or Mattress tape — It is a special fabric used to hide the seam where the pieces of ticking are sewn together. The last special type of cloud-to-ground lightning is staccato lightning, which is nothing more than a leader stroke with only one return stroke. Tack and Jump. The winds will blow each successive return stroke slightly to one side of the previous return stoke, causing a ribbon effect. Very important measure of the resistance to bottoming out under sustained downward pressure. These occur in thunderstorms where there are high cross winds and multiple return strokes. Support factor — Ratio of the deep down IFD to the surface of a mattress.

A third special type of cloud-to-ground lightning is ribbon lightning. Support. When the discharge fades it leaves behind a string of beads effect for a brief moment in the leader channel. Spring Wire. This is a regular cloud-to-ground stroke that contains a higher intensity of luminosity. Split Queen Box. Another special type of cloud-to-ground lightning is bead lightning. Smooth Top.

They are signs of an approaching storm nad are known colloquially as "bolts from the blue". Slats. These usually occur miles ahead of the main storm and will strike without warning on a sunny day. Sagging. In anvil-to-ground lightning, the leader stroke issues forth in a nearly horizontal direction till it veers toward the ground. Rotating — Turning a mattress 180 degrees so that the head of the bed becomes the foot. One special type of cloud-to-ground lightning is anvil-to-ground lightning, a form of positive lightning, since it emanates from the anvil top of a cumulonimbus cloud where the ice crystals are positively charged. Roll-Together — When a defective or worn out mattress sags in the center and causes the body of the sleeper to want to roll towards the center of the mattress.

This is the second most common type of lightning. A "bottomed out" mattress doe not easily move with the sleeper, causing aches after some time. Cloud-to-ground lightning is a great lightning discharge between a cumulonimbus cloud and the ground initiated by the downward-moving leader stroke. When sleeping, the user's body moves subtly with every breath. Discharges of electricity in anvil crawlers travel up the sides of the cumulonimbus cloud branching out at the anvil top. Ride — Reserve "springiness" and ease of vertical movement that a mattress has when a user is lying on it. Intracloud lightning is the most common type of lightning which occurs completely inside one cumulonimbus cloud, and is commonly called an anvil crawler. It is also known as bounciness or elasticity.

Some lightning strikes take on particular characteristics, and scientists and the public have given names to these various types of lightning. Resiliency — Ability of the spring, foam, fabric or fiber to spring back to its original form. Measured X-ray burst intensity also falls short, with results indicating particle energy 1/20th of the theory's value. Quilting. Cosmic rays of sufficient energy strike the atmosphere on average only once per 50 seconds per square kilometre. Queen. Another issue is the amount of energy the theory states is required to initiate the breakdown. Pressure Points.

While there seems to be a strong correlation between gamma-ray events and lightning, there are insufficient events detected to account for the amount of lightning occurring across the planet. Posturized. There are problems with the "runaway breakdown" theory, however. Pocketing. Additionally, low-frequency radio emissions detected at ground level can detect lightning bolts from upwards of 4000 km away; combining these with gamma-ray burst events detected from above show overlapping positions and timing. Pillow Top. NASA's RHESSI satellite typically reports 50 gamma-ray events per day, and many of these are strong enough to fit the theory. Platform Foundation.

The presence of these high-energy events match and support the "runaway breakdown" theory, and were discovered through the examination of rocket-triggered lightning, and from satellite monitoring of natural lightning. Offset Coil. The X-ray bursts typically have a total duration of less than 100 microseconds and have energies extending up to nearly a few hundred keV. Multi-Needle Quilt. It has been recently revealed that most lightning emits an intense burst of X-rays and/or gamma-rays which seem to be produced during the stepped-leader and dart-leader phases just before the stroke becomes visible. Migration. This was initially considered a fringe theory, but is now becoming mainstream because of the lack of other theories. Mattress Handles.

These strike other air molecules, releasing more electrons which are accelerated by the storm's electric field, forming a chain reaction of long-trajectory electrons and creating a conductive plasma many tens of meters in length. Mattress. Cosmic rays strike an air molecule and release extremely energetic electrons having enhanced mean free paths of tens of centimeters. Latex. A theory by Alex Gurevich of the Lebedev Physical Institute in 1992 proposes that cosmic rays may provide the beginnings of what he called a runaway breakdown. Lacing Wire. While there remains a possibility that researchers are failing to encounter the small high-strength regions of the large clouds, the odds of this are diminishing as further measurements continue to fall short. Knit.

However, measurements inside storm clouds to date have failed to locate fields this strong, with typical fields being between 100 and 400 kilovolts per metre. King. To spontaneously ionise air and conduct electricity across it, an electric field of field strength of approximately 2500 kilovolts per metre is required. Insulator. Many scientists think that positive and negative lightning in a cloud are actually bipolar lightning. Innerspring Unit. During the eighties, flight tests showed that aircraft can trigger a bipolar stepped leader when crossing charged cloud areas. Inner Tufting.

Such a polarised conductor would be able to maintain intense electric fields at its ends, supporting continued leader development in weak-background electric fields. Inner Quilt. This process provides a means for the positive leader to conduct away the net negative charge collected during development, allowing the leader system to act as an extending polarised conductor. A measure for the firmness level of foam. Heinz Kasemir first hypothesised that a lightning leader system actually develops in a bipolar fashion, with both a positive and a negative branching leader system connected at the system origin and containing a net zero charge. ILD — Initial Load Deflection. An average bolt of positive lightning carries a current of 300 kiloamperes, transfers a charge of up to 300 coulombs, has a potential difference up to 1 gigavolt (a thousand million volts), dissipates enough energy to light a 100 watt lightbulb for up to 95 years, and lasts for tens or hundreds of milliseconds. Hog Ring.

It tends to occur more frequently in winter storms and at the end of a thunderstorm. Hinged King. Positive lightning has also been shown to trigger the occurrence of upper atmospheric lightning. Helical Wire. Here is a page showing some pictures of positive lightning. Grid. At the present time, aircraft are not designed to withstand such strikes, since their existence was unknown at the time standards were set, and the dangers unappreciated until the destruction of a glider in 1999 [3]. Gauge.

As a result of their power, positive lightning strikes are considerably more dangerous. Garnetting. During a positive lightning strike, huge quantities of ELF and VLF radio waves are generated. Full Extra Long. Research carried out after the discovery of positive lightning in the 1970s showed that positive lightning bolts are typically six to ten times more powerful than negative bolts, last around ten times longer, and can strike several kilometers or miles distant from the clouds. Foundation. The overall effect is a discharge of positive charges to the ground. Foam — Padding material used in mattresses, including latex, polyurethane and viscoelastic or memory foam.

It occurs when the stepped leader forms at the positively charged cloud tops, with the consequence that a negatively charged streamer issues from the ground. Flipping/Rotating. Positive lightning makes up less than 5 % of all lightning. Flanging. An average bolt of negative lightning carries a current of 30 kiloamperes, transfers a charge of 5 coulombs, has a potential difference of about 100 megavolts and dissipates 500 megajoules (enough to light a 100 watt lightbulb for 2 months). Deep down firmness is the IFD under severe compression. This 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. It is measured by the surface Indentation Force Deflection (IFD) measurement.

Photographs have been taken on which non-connected streamers are visible such as that shown on the right. Firmness or Surface firmness — Resistance to compression near the surface of a mattress. It 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. Filler. This discharge rapidly superheats the leader channel, causing the air to expand rapidly and produce a shock wave heard as thunder. Fiber. Sometimes several strokes will travel up and down the same leader strike, causing a flickering effect. Felt.

Most lightning strikes usually last about a quarter of a second. Fatigue. This "return stroke" is the most luminous part of the strike, and is the part that is really visible. Eliocel. The region of high current propagates back up the positive stepped leader into the cloud. Double Extra Long. When the two leaders meet, the electric current greatly increases. Double Bed.

As it does so, a positively charged streamer is usually sent out from the positively charged ground or cloud. The higher the density, the longer the durability and resilience and support of the mattress. A bolt of lightning usually begins when an invisible negatively charged stepped leader stroke is sent out from the cloud. It is the most significant factor in the quality of a foam and a very significant factor in the quality of a mattress. Lightning 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. Density — It is a measure of weight and it is unrelated to firmness. This discharge starts as positive streamer and, if it develops as a positive leader, can eventually connect to the descending discharge from the cloud. Damask Cover.

If the electric field is strong enough, a discharge can initiate from the ground. Cushioning. The electric field is higher on trees and tall buildings. Crown — Convex surface that is higher in the middle than in the sides; used in some mattresses. When a charged step leader is near the ground, opposite charges appear on the ground and enhance the electric field. Cover. At the same time, electrical energy stored in the electric field flows radially inward into the conductive filament. Continuous Quilt.

The conductive filament grows in length. Continuous Coil. 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). Cone-Shaped Coil. 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. Comfort Layers. When 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. Coils.

Cumulonimbus clouds that do not produce enough ice crystals usually fail to produce enough charge separation to cause lightning. Coil Count — Number of coils in the mattress or box spring. Cloud-to-ground lightning is less common. Clipped Border Rod. Cloud-to-cloud lightning can appear at this point. Channel Quilt. 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. Center Rail.

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. Cambrick. 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. California King. The mechanism by which this happens is still the subject of research, but one widely accepted theory is the polarisation mechanism. Bunkie Board. The first process in the generation of lightning is the forcible separation of positive and negative charge carriers within a cloud or air. Bunkie.

Positive lightning does not generally fit the above pattern. Box Spring. This rapid restrike effect was probably known in antiquity, and the "strobe light" effect is often quite noticeable. Border Rod. In addition, lightning often contains a number of restrikes, separated by a much larger amount of time, 30 milliseconds being a typical value. Bonnell Coil. It may persist for longer periods with lower current. Body Impressions.

The main stroke travels at about 0.1 c (100 million feet per second) and has high current for 100 microseconds or so. Bed Rails. Once the ground discharge meets the stepped leader, the circuit is closed, and the main stroke follows with much higher current. Bed Frame or Bed Base/Frame. When the downward leader is quite close, a small discharge comes up from a grounded (usually tall) object because of the intensified electric field. Air Bed. This initial phase involves a small electric current and is almost invisible compared to the later effects. It is not good to habitually sit on the same spot of the mattress edge.

An initial discharge, (or path of ionised air), called a "stepped leader", starts from the thundercloud and proceeds generally downward in a number of quick jumps, typical length 50 meters, but taking a relatively long time (200 milliseconds) to reach the ground. The mattress should not be folded or bent. The following picture emerged:. The mattress should not be lifted or carried using the handles, which are only for positioning it. Although causes were debated (and are today to some extent), research produced a wealth of new information about lightning phenomena, especially amounts of current and energy involved. Do not soak a mattress or foundation. The impetus for new research was from the field of power engineering: power transmission lines came into use, and engineers needed to know much more about lightning. If stained, use mild soap with cold water and rub lightly.

Although experiments from the time of Franklin showed that lightning was a discharge of static electricity, there was little improvement in theory for more than 150 years. Use a good quality washable mattress pad to keep the mattress free from stains. His shoes were blown open, parts of his clothes singed, the engraver knocked out, the doorframe of the room split, and the door itself torn off its hinges. Vacuuming is the only recommended way to clean a mattress. While the experiment was underway, a large ball lightning showed up, collided with Richmann's head, and killed him, leaving a red spot. Use a vacuum cleaner for regular cleaning. He ran home with his engraver to capture the event for posterity. An impermeable mattress protector can be used to keep it clean.

He had created a set-up similar to Franklin's, and was attending a meeting of the Academy of Sciences when he heard thunder. Do not wet a mattress. The most well-known death during the spate of Franklin imitators was that of Professor Georg Richmann, of Saint Petersburg, Russia. It must be noted that since around 2000, several manufacturers started producing one-sided models that cannot be flipped and in some cases should not be turned either. However, experiments involving lightning are always risky and frequently fatal. All mattresses need to be rotated to reduce wear patterns that develop over time. As news of the experiment and its particulars spread, the experiment was met with attempts at replication. The foundation should also be turned every 12 months.

However, in his autobiography (written 1771-1788, first published 1790), Franklin clearly states that he performed this experiment after those in France, which occurred weeks before his own experiment, without his prior knowledge as of 1752. Some manufacturers recommend to alternately turn and flip the mattress once every two weeks for the first three months and then twice per year after that. The rain which had fallen during the storm had soaked the line and made it conductive.. Most manufacturers recommend to rotate the mattress (180 degrees, so the head of the bed becomes the foot) every three months and to turn the mattress at least twice a year. As time passed, Franklin noticed the loose fibers on the string stretching out; he then brought his hand close to the key and a spark jumped the gap. Otherwise, even the most expensive mattress will fail. On his end of the string he attached a key and tied it to a post with a silk thread. Most manufacturers of box spring mattresses suggest that the consumer should regularly rotate and flip the mattress and box spring.

During the next thunderstorm, which was in June 1752, he raised a kite, accompanied by his son as an assistant. A new mattress should be put on a firm base, never on a saggy base. Whilst waiting for completion of the spire, he got the idea of using a flying object, such as a kite, instead. Back sleepers need a mattress that offers enough support to fill in the gaps in the contour of the back, while at the same time providing enough comfort, according to the user's preference. The Franklin experiment is as follows:. A study of sleep quality and bed firmness showed that four of nine male subjects slept significantly better on softer mattresses and two on the harder mattresses. Franklin usually gets the credit, as he was the first to suggest this experiment. A side sleeper will probably want a softer mattress, to minimize pressure points, especially if they have a very curved or rounded figure.