elraidelsrobinsons

Sunday, April 29, 2007

Lightning

Lightning is an influential natural electrostatic release produced during a thunderstorm. Lightning's abrupt electric release is accompanied by the emission of visible light and other forms of electromagnetic radiation. The electric current passing through the release channels quickly heats and expands the air into plasma, producing acoustic shock waves in the atmosphere.

Early lightning investigate
During early investigations into electricity via Leyden jars and other instruments, a number of people planned that small scale sparks shared some similarity with lightning.

Benjamin Franklin, who also imaginary the lightning rod, endeavored to test this theory by using a spire which was being erected in Philadelphia. Whilst he was waiting for the spire completion some others conducted at Marly in France, what became to be known as the Philadelphia experiments that Franklin had optional in his book?

Franklin typically gets the credit for being the first to perform this research. The Franklin myth goes like this:

Whilst coming up for completion of the spire, he got the idea of using a flying object, such as a kite in its place. During the next shower, in June 1752, he raised a kite, accompanied by his son as an assistant. On his end of the string he emotionally involved a key and tied it to a post with a silk thread. As time passed Franklin noticed the loose fibers on the string stretching out; he then brought his hand close enough to the key and a flash jumped the gap. The rain which had fallen during the storm had covered with water the line and made it conductive.

However, in his memoirs, Franklin obviously states that he only performed this research after those made in France.

As news of the research and its specifics spread, it was met with attempts at duplication. Experiments involving lightning are always risky and commonly fatal. The most well known death during the rash of Franklin-imitators was Professor George Richman, of Saint Petersburg, Russia. He had shaped a setup similar to Franklin's, and was attending a meeting of the Academy of Sciences, when he heard thunder. He ran home with his engraver to capture the event for posterity. While the research was underway, a large ball lightning showed up, collided with Richman's head, and killed him, leaving a red spot. His shoes were blown open, parts of his clothes singed, the engraver knocked out, the doorframe of the room was split, and the door itself ragged off its hinges.

Monday, April 23, 2007

Northern Mockingbird

The Northern Mockingbird, Mimus polyglottos, is the mockingbird commonly originate in North America.Adults are grey on the head and upperparts with pale yellow eyes and a slim black bill with a slight downward curve; the underparts are light. They have a long dark tail by means of white edges and long dark legs. They have white wing bars and show white wing patches in flight.Their breeding habitat is areas with a mix of open areas and dense shrubs from southern Canada to Mexico, but is most common in the southern United States. They build a twig nest in a dense shrub or tree. This bird forcefully defends its nest against other birds and animals, including humans. When a predator is persistent mockingbirds from adjacent territories, summoned by a distinct call, may join the attack. Other birds may gather to watch as the mockingbirds harass the intruder.
They are usually permanent residents; northern birds may move south during harsh weather. However, this species has occurred in Europe as an extreme rarity.These birds forage on the ground or in vegetation; they also fly down from a perch to capture food. They mainly eat insects and berries. While foraging they will regularly spread their wings in a peculiar two-step motion to display the white patches underneath. The purpose of this behavior is disputed. Some ornithologists claim this is merely a territorial display, while others say that flashing the white patches startles hiding insects and forces them into the open. Both theories seem to have some merit.
This bird imitates the calls of other birds, animal sounds and yet machine noises. It is often found in urban areas. They often call through the night and may continue year-round apart from for the summer moulting season. Mockingbirds usually sing the loudest in the twilight of the early morning when the sun is on the horizon. While singing on a high perch they will often bolt more than a few feet into the air in a looping motion, with wings outstretched to display their white underside, then land back on the perch without breaking a note. That serves as a territorial display.Mockingbirds have a strong preference for certain trees, such as maple, sweet gum (green 5-pointed leaves and prickly porous balls), and sycamore. They normally avoid pine trees. In urban areas, mockingbirds rarely come down to the ground, unlike most birds. Also, they have a particular preference for high places, such as the topmost branches of trees and the tops of telephone poles.

Wednesday, April 18, 2007

Motorcycle racing

There are a range of sports involving racing motorcycles. FIM is the international sanctioning body for many such events.As motorcycles vary very much in design, there are several different types of motorcycle racing contest, including:Road racing in its purest form is racing on public roads, such as the Isle of Man TT course, the Macau Grand Prix and some courses in Ireland. Due to the inherent dangers that these street venues often carry such as narrow lanes, curbs, and adjacent walls, most road racing is now carried out on purpose-built tracks.Circuit racing where specially designed racing bikes or modified "production" bikes race each other on particularly designed road circuits. MotoGP and Superbike are the top level racing and production classes.Classic Racing is where participants race heavily customized bikes from an earlier era - usually pre mid '70s bikes.
Motocross and its cousin supercross are held on dirt courses, characteristically featuring large jumps in which motorcycles are launched over considerable distances. Supermoto is a crossover motorcycle racing between road racing and motocross. The motorcycles are primarily motocross types with road racing tires. The racetrack is also mixed between road and dirt courses, mostly handcrafted.
Motorcycle speedway and ice speedway are held on oval circuits where riders slide their machines around turns.

Monday, April 09, 2007

Radio

Radio is the wireless transmission of signals, by modulation of electromagnetic waves with frequencies below those of light.
Radio waves.Radio waves are a form of electromagnetic radiation, formed whenever a charged object accelerates by a frequency that lies in the radio frequency (RF) portion of the electromagnetic spectrum. This is the variety from a few tens of hertz to a few hundred gigahertz.Electromagnetic radio spectrum
Other types of electromagnetic radiation, with frequencies above the RF range are infrared, visible light, ultraviolet, X-rays and gamma rays. Since the energy of an individual photon of radio frequency is too low to remove an electron from an atom, radio waves are classified as non-ionizing radiation.Radio transmission diagram and electromagnetic waves.Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space equally well, and does not need a medium of transport induces an alternating current and voltage in the conductor. This can be transformed into audio or other signals that carry information. Although the word 'radio' is used to explain this phenomenon, the transmissions which we know as television, radio, radar, and cell phone are all classed as radio frequency emissions.

Thursday, April 05, 2007

Transistor

The transistor is a solid state semiconductor device which can be used for amplification, switching, voltage stabilization, signal modulation and many other functions. It acts as a changeable valve which, based on its input current (BJT) or input voltage (FET), allows a precise amount of current to flow through it from the circuit's voltage supply.In essence, a transistor has three terminals. A current or voltage applied through/across two terminals controls a larger current through the other terminal and the common terminal. In analog circuits, transistors are used in amplifiers. Analog circuits include audio amplifiers, stabilised power supplies and radio frequency amplifiers. In digital circuits, transistors function basically as electrical switches. Digital circuits include logic gates, RAM (random access memory) and microprocessors.Transistor was also the common name in the sixties for a transistor radio, a portable radio that used transistors (rather than vacuum tubes) as its active electronic components. This is still one of the dictionary definitions of transistor.

Sunday, April 01, 2007

Sugarcane

Sugarcane or Sugar cane (Saccharum) is a type of between 6–37 species of tall grasses (family Poaceae, tribe Andropogoneae), native to warm temperate to tropical regions of the Old World. They have stout, jointed fibrous stalks 2–6 m tall and sap rich in sugar. All the species interbreed, and the major commercial cultivars are complex hybrids.
Saccharum officinarum grown in Hawaii. There are 13 million hectares (32 million acres) of sugar cane plantations worldwide, with over 100 countries growing the crop. The top twenty producing countries harvested 1200 million metric tons of sugar cane in 2002 (more than 6 times the amount of sugar beet produced). The largest producers are Brazil, India, and China.
Raw sugar has a yellow to brown color. If a white product is preferred, sulfur dioxide may be bubbled through the cane juice prior to evaporation. This bleaches many color-forming impurities into colorless ones. Sugar bleached white by this sulfitation process is called mill white, plantation white or crystal sugar. This form of sugar is the most usually consumed form of sugar in sugarcane-producing countries.