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Lightning! Lightning strikes somewhere on the surface of the earth about 100 times every second. Inside- The shocking story!

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Presentation on theme: "Lightning! Lightning strikes somewhere on the surface of the earth about 100 times every second. Inside- The shocking story!"— Presentation transcript:

1 Lightning! Lightning strikes somewhere on the surface of the earth about 100 times every second. Inside- The shocking story!

2 The Man Who Realized What Lightning Was
Benjamin Franklin In June of 1752 while in a field by himself flying a kite with a key on the end found that electrical charges in storms do exist and will strike another object with the opposite charge i.e. electricity. He also found out that it strikes buildings and causes fires He invented a lightning rod to be placed on top of the house to stop the houses from burning down in a lightning storm when the house was struck

3 How Thunderstorms and Lightning Work
Clouds have negative charged ions The earth or ground has positive charged ions When enough ions charge between both the cloud and ground lightning strikes

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5 What Happens? A lightning flash can happen in half a second. In that instant, the lightning flash superheats the surrounding air to a temperature five times hotter than that on the surface of the sun. Nearby air expands and vibrates, forming sound that we hear as thunder. Sound travels more slowly than light, so it seems that thunder occurs later. The cloud bottom carries a negative charge. Positive charges may collect on the ground, buildings, boat masts, people, flagpoles, mountaintops, or trees. A stepped leader—a negative electrical charge made of zig-zagging segments, or steps—comes partway down from the cloud. The steps are invisible; each one is about 150 feet long. When the stepped leader gets within 150 feet of a positive charge, a streamer (surge of positive electricity) rises to meet it. The leader and the streamer make a channel. An electrical current from an object on the ground surges upward through the channel. It touches off a bright display called a return stroke.

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9 Types of Lightning Normal lightning - Discussed above.
Sheet lightning - Normal lightning that is reflected in the clouds. Heat lightning - Normal lightning near the horizon that is reflected by high clouds. Ball lightning - A phenomenon where lightning forms a slow moving ball that can burn objects in its path before exploding or burning out. Red Sprite - A red burst reported to occur above storm clouds and reaching a few miles in length (towards the stratosphere). Blue Jet - A blue conical shaped burst that occurs above the center of a storm cloud and moves upward (towards the stratosphere) at a high rate of speed.

10 Cloud lightning never strikes the earth.
                   Ball lightning occurs after a ground flash. The ball is usually red, orange, or yellow. It can be as small as a grapefruit or as big as a pumpkin. After briefly hovering above the ground or darting wildly about, the lightning ball fizzles out—or ends with a startling BANG! Cloud lightning never strikes the earth. Spider Flashes of spider lightning crawl across the sky for up to 90 miles. Click a photo to see it larger.

11 Sheet Lightning

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13 Where not to be During a Storm
Do not be on a golf course holding a golf club in the air Do not be near a pool or pond Do not be in an open field Do not be in a tree Do not be under a tin or metal roof of any kind Stay indoors, and don't venture outside, unless absolutely necessary. Stay away from open doors and windows, fireplaces, radiators, stoves, metal pipes, sinks, and plug-in electrical appliances. Don't use plug-in electrical equipment like hair driers, electric toothbrushes, or electric razors during the storm. Don't use the telephone during the storm. Lightning may strike telephone lines outside. Don't take laundry off the clothesline. Don't work on fences, telephone or power lines, pipelines, or structural steel fabrication. Don't use metal objects like fishing rods and golf clubs. Golfers wearing cleated shoes are particularly good lightning rods.

14 Don’t Become a Statistic!
Don't handle flammable materials in open containers. Stop tractor work, especially when the tractor is pulling metal equipment, and dismount. Tractors and other implements in metallic contact with the ground are often struck by lightning. Get out of the water and off small boats. Stay in your automobile if you are traveling. Automobiles offer excellent lightning protection. Seek shelter in buildings. If no buildings are available, your best protection is a cave, ditch, canyon, or under head-high clumps of trees in open forest glades. When there is no shelter, avoid the highest object in the area. If only isolated trees are nearby, your best protection is to crouch in the open, keeping twice as far away from isolated trees as the trees are high. Avoid hilltops, open spaces, wire fences, metal clotheslines, exposed sheds, and any electrically conductive elevated objects. When you feel the electrical charge -- if your hair stands on end or your skin tingles -- lightning may be about to strike you. Drop to the ground immediately.

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