The first battery-like discovery occurred in 1786, when Count Luigi Galvani (an Italian anatomist, 1737-1798) found that when the muscles of a dead frog were touched by two pieces of different metals, the muscle tissue twitched.
Count Alessandro Giuseppe Antonio Anastasio Volta (Feb. 18, 1745- March 5, 1827) was an Italian physicist who realized that the twitching was caused by an electrical current that was created by chemicals. Volta invented the chemical battery (also called the voltaic pile) in 1800. His first voltaic piles were made from zinc and silver plates (separated by a cloth) put in a salt water bath. (This is similar to the unpleasant phenomenon that happens when people with metal tooth fillings bite into aluminum foil -- a small electrical current flows from one metal to the other metal, flowing through the acidic saliva and giving the biter an unpleasant sensation.) Volta soon improved the pile, using zinc and copper in a weak sulfuric acid bath. Volta's invention provided the first generator of continuous electrical current.
In 1820, the French physicist André-Marie Ampère discovered many of the laws governing the relationship between electricity and magnetism, along with how a battery works. Ampere discovered that electricity moves through conductors, and that electrical charges flow from one electrode to the other. Ampere invented the astatic needle, which detected electrical currents.
Storage batteries are batteries that can be recharged (they are also called secondary batteries or accumulators). In 1859, the French physicist Gaston Plante (1834-1889) invented a battery made from two lead plates joined by a wire and immersed in a sulfuric acid electrolyte; this was the first storage battery. It was large and hard to move because of the liquid electrolyte.
The dry cell is a an improved voltaic cell with a cylindrical zinc shell (the zinc acts as both the cathode and the container) that is lined with a porous material (not a liquid) saturated with ammonium chloride (the electrolyte). A carbon rod (the anode) is in the center of the cylinder, surrounded by graphite. This type of battery decays when not in use. The dry cell battery was developed in the 1870s by Georges Leclanche of France, who used an electrolyte in the form of a paste.
Edison batteries (also called alkaline batteries) are an improved type of storage battery developed by Thomas Edison. These batteries have an alkaline electrolyte, instead of an acid. Its electrodes are plates of iron and nickelic oxide immersed in a caustic potash electrolyte (this is a base, and not acidic).
A ballpoint marker had been invented much earlier (in 1888 by John Loud, an American leather tanner, who used the device for marking leather) but Loud's marker leaked, making it impractical for everyday use. A new type of ink had to be developed; this is what the Biro brothers did. The brothers patented their invention and then opened the first ballpoint manufacturing plant in Argentina, South America.
Isaac was born just a short time after the death of Galileo, one of the greatest scientists of all time. Galileo had proved that the planets revolve around the sun, not the earth as people thought at the time. Isaac Newton was very interested in the discoveries of Galileo and others. Isaac thought the universe worked like a machine and that a few simple laws governed it. Like Galileo, he realized that mathematics was the way to explain and prove those laws. Isaac Newton was one of the world’s great scientists because he took his ideas, and the ideas of earlier scientists, and combined them into a unified picture of how the universe works.
Isaac Newton explained the workings of the universe through mathematics. He formulated laws of motion and gravitation. These laws are math formulas that explain how objects move when a force acts on them. Isaac published his most famous book, Principia, in 1687 while he was a mathematics professor at Trinity College, Cambridge. In the Principia, Isaac explained three basic laws that govern the way objects move. He then described his idea, or theory, about gravity. Gravity is the force that causes things to fall down. If a pencil falls off a desk, it will land on the floor, not the ceiling. In his book Isaac also used his laws to show that the planets revolve around the suns in orbits that are oval, not round.
Isaac Newton used three laws to explain the way objects move. They are often call Newton’s Laws. The First Law states that an object that is not being pushed or pulled by some force will stay still, or will keep moving in a straight line at a steady speed. It is easy to understand that a bike will not move unless something pushes or pulls it. It is harder to understand that an object will continue to move without help. Think of the bike again. If someone is riding a bike and jumps off before the bike is stopped what happens? The bike continues on until it falls over. The tendency of an object to remain still, or keep moving in a straight line at a steady speed is called inertia.
The Second Law explains how a force acts on an object. An object accelerates in the direction the force is moving it. If someone gets on a bike and pushes the pedals forward the bike will begin to move. If someone gives the bike a push from behind, the bike will speed up. If the rider pushes back on the pedals the bike will slow down. If the rider turns the handlebars, the bike will change direction.
The Third Law states that if an object is pushed or pulled, it will push or pull equally in the opposite direction. If someone lifts a heavy box, they use force to push it up. The box is heavy because it is producing an equal force downward on the lifter’s arms. The weight is transferred through the lifter’s legs to the floor. The floor presses upward with an equal force. If the floor pushed back with less force, the person lifting the box would fall through the floor. If it pushed back with more force the lifter would fly into the air.
When most people think of Isaac Newton, they think of him sitting under an apple tree observing an apple fall to the ground. When he saw the apple fall, Newton began to think about a specific kind of motion—gravity. Newton understood that gravity was the force of attraction between two objects. He also understood that an object with more matter –mass- exerted the greater force, or pulled smaller object toward it. That meant that the large mass of the earth pulled objects toward it. That is why the apple fell down instead of up, and why people don’t float in the air.
Isaac Newton thought about gravity and the apple. He thought that maybe gravity was not just limited to the earth and the objects on it. What if gravity extended to the moon and beyond? Isaac calculated the force needed to keep the moon moving around the earth. Then he compared it with the force the made the apple fall downward. After allowing for the fact that the moon is much farther from the earth, and has a much greater mass, he discovered that the forces were the same. The moon in held in an orbit around earth by the pull of earth’s gravity.
Isaac Newton’s calculations changed the way people understood the universe. No one had been able to explain why the planets stayed in their orbits. What held them up? Less that 50 years before Isaac Newton was born it was thought that the planets were held in place by an invisible shield. Isaac proved that they were held in place by the sun’s gravity. He also showed that the force of gravity was affected by distance and by mass. He was not the first to understand that the orbit of a planet was not circular, but more elongated, like an oval. What he did was to explain how it worked.
Newton's Three Laws and Rockets
Details on Issac Newton's Three Laws as appiled to rocketry.
Sir Isaac Newton
Sir Isaac Newton was an English scientist (1642 - 1727) who invented the reflecting telescope in 1668.
Sir Isaac Newton
Newton always considered himself a natural philosopher, and the central strand of his scientific development consisted of his speculations on the nature of physical reality, speculations that led him away from the reigning mechanical philosophy and to a major modification of it that asserted the existence of forces acting at a distance.
Isaac Newton
Newton, Sir Isaac (1642-1727), mathematician and physicist, one of the foremost scientific intellects of all time.
On Ye Shoulders of Giants
His contribution to establishing science and the scientific method as providing the best description of the material world, and the awe in which he was held by his contemporaries, were neatly encapsulated early in the eighteenth century by the poet Alexander Pope, with his famous couplet Nature and Nature's laws lay hid in night: God said, Let Newton be! and all was light.
