APR 10, 2019 Pageview:943
In fact, the ancients were no strangers to electricity—in fact, the word “electronics” means “amber” in Greek. Because the ancient Greeks knew that rubbing amber with cloth would generate static electricity.
Benjamin Franklin sent the kite into the thundercloud, which proved that lightning is also a form of electricity, but until now, humans have not successfully tamed lightning. To study the nature of "current", scientists must try to create a continuous low-dose current.
Bioelectricity
In 1780, the Italian scientist Luigi Galvani completed the first step at the University of Bologna, proposing that the animals were driven by electricity. Galvani accidentally discovered that the frog legs on the dissecting table were twitching, and there was exactly one electrostatic generator nearby. Galvani intended to hang the frog on the copper hook to dry it. As a result, the copper hook just touched a piece of iron. At the moment of contact between the two metals, the frog's leg twitched again. So Galvani boldly guessed that the body of the frog would produce electricity, even though it had died long ago. Alessandro Volt, then professor of natural philosophy (physics) at the University of Pavia, was interested in the twitching frog legs, but he did not believe that animals would produce electricity. Volt believes that electricity is actually produced by the contact of two metals. From 1793 to 1794, Volt published several papers to explain his ideas and began the next step of research.
Different metals
Volt puts a piece of zinc and a piece of silver (such as a coin) together then gently rubs it with your tongue. At the moment of contact with the two metals, he felt a slight tingling in the tip of his tongue. In order to get a stronger effect, Volt came up with a clever idea: he made many such "metal sandwiches" and then stacked them together.
However, the combination of zinc-silver-zinc-silver does not achieve the desired effect, because the electricity generated by each group of metals is quickly offset by the next set of reversely stacked metals, so volts require non-metallic media capable of conducting electricity. Separating the pieces of metal two by two, in other words, what he needs is a non-metallic conductor. Volt chose cardboard that was soaked in salt water. Therefore, the structure of the "sandwich" becomes zinc-silver-cardboard-zinc-silver-cardboard-zinc, which is arranged in this way. He called it "volt stack", also known as "battery."
The original battery made by Volt is quite rough, and it may produce a voltage of only a few volts, but it is enough for him to feel the power of the electric shock. When the volts connect the two ends of the battery with wires, the joints of the wires also spark.
In 1799, Volt slammed out the prototype of the battery. Later, he gave a demonstration for Napoleon, and the French emperor was deeply shocked. But more importantly, on March 20, 1800, Fu had a letter to the President of the Royal Society, Sir Joseph Banks, detailing his experiments. On June 26th, Banks read aloud the English translation of this French letter at the Royal Society:
"I put dozens of small wafers together. The size of the silver piece is about 1 inch (about 2.54 cm). The size of the zinc piece is about the same as it is, and the quantity is exactly the same. I also prepared some round cardboards. They can absorb and store large amounts of brine."
Electric shock
Volt wrote in the letter that a battery can be used to connect the battery pack to a bowl of water. "Now, if you dipped one hand into a bowl and then gently touch the other side of the metal pile with a metal piece, the hand immersed in the water will feel obvious electric shock and tingling, reaching the wrist, there is The sting can even spread to the height of the elbow. "
He added: "If you attach a probe to each of the two ends of the device and then put the two probes into your ear, your hearing will be greatly affected."
Looking back now, what Volt has done is just a few times of electricity, making a little spark, which seems completely unsurprising. But the good show is just beginning. After Banks read the letter, other scientists immediately began to make batteries, and the batteries they produced a continuous current, which was the first time.
With such batteries, scientists can delve into the properties of various materials, looking for conductors and insulators. In addition, they can explore the nature of the current itself, study the potential (its unit is "volt", also known as "volt"), current (amperes), resistance (ohms) and other related knowledge.
Electricity in chemistry
Hanfrey David made a huge battery at the Royal Institute in London and used it to make some amazing chemical experiments. David speculates that a certain chemical reaction will occur after contact with different metals, thus generating electricity. So he felt that current could be used to induce a chemical reaction. According to this idea, David first separated the metal sodium and potassium.
Most of the items we use today seem to be inseparable from electricity. Volt's experiment is perhaps the most significant discovery in the history of science.
The above content is taken from the unread and explored new book "Schrodinger's Cat: 50 Experiments to Change Physics"
"Schrodinger's Cat: 50 Experiments to Change Physics":
From the perspective of the history of science, according to the time sequence, the most breakthrough major physics experiments in history are introduced. Back to the development of physics, 50 experiments are arranged in chronological order, like 50 milestones, to help readers build basic physics academic history system.
These experiments have laid the foundation for all fields of physics and are also important cornerstones for the development of human science and technology, such as: Archimedes buoyancy experiment, light velocity measurement experiment, Faraday electromagnetic experiment, Yang's double-slit experiment, searching for ether experiment, Schrodinger's cat experiment and so on.
Whether you are interested in optics, mechanics, electronics or astronomy, this book will allow you to find many interesting and inspiring answers.
The page contains the contents of the machine translation.
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