The discovery of the battery was an accident

Batteries are indispensable in our daily lives, but the discovery of batteries was actually an accident caused by an academic controversy.

In 1757, someone discovered that passing electricity through a frog's legs would cause them to contract, but there is no commonly accepted explanation for why this phenomenon occurs.

An Italian physicist named Galvani wanted to study this phenomenon systematically. He found that various external electricity could make the frog's legs contract, but he also unexpectedly discovered that the frog's legs could also contract without an external power source. For example, if a copper wire was connected to the frog's legs at one end and the other end touched the nerves of the frog's legs, the frog's legs would contract.

Since it contracts, there must be electricity. Where does the electricity come from? Galvani believed that this contraction should have the same principle as the movement of the frog when it is alive. It is the frog's legs that generate electricity and drive the movement of the muscles. He further believed that what the ancients called life vitality is this mysterious electricity. Conversely, if electricity is passed to a dead body, a phenomenon similar to resurrection can be achieved.

Galvani's theory was once quite popular and was used in various public performances. In 1803, Galvani's nephew performed a sensational demonstration in London: he electrocuted the body of a prisoner who had just been executed. The onlookers were stunned to see that the moment the current passed through the face, the corpse's jaw began to tremble, the adjacent muscles were visibly twisted, and even one eye opened. The subsequent electric shock also made the right hand open and the legs and feet move. Mary Shelley's novel "Frankenstein" is considered the world's first science fiction novel, and the plot of the corpse being stitched up and resurrected was influenced by Galvani's theory.

However, another Italian scientist, Alessandro Volta, had doubts about Galvani's theory. Volta was also interested in the experiment of making frogs move with electricity, but he found a problem when he did it himself. The movement of the frog's legs seemed to be related to the metal used to touch the legs. Specifically, when a single metal was used to touch the legs, the movement was very small, but when two metals were used together, the effect was much more obvious.

If the twitching was the organism itself generating electricity, then the type of metal used should have no effect. Volta therefore believed that this was not the electricity of the organism, but the electricity of the metal. His explanation was that when different objects came into contact, an electrical "imbalance" would be created, thus generating electricity. This imbalance could be created when organic matter came into contact with metal, and it was even more obvious when the two metals were together.

The debate between Galvani and Volta lasted for several years, but was interrupted by an accident before it could reach a conclusion. In 1797, France occupied northern Italy and established a puppet regime, requiring all university professors to swear allegiance to the new government. Galvani was deprived of all academic status and funding sources for refusing to swear allegiance, and his research was forced to terminate. He died in poverty a year later.

Volta, who was not affected by the war, continued his research. He wanted to prove that the source of electricity was the contact of metals and had nothing to do with animals. However, when two metals were placed directly together, no abnormality could be seen. This is because a new balance would be reached the moment the two metals came into contact, and only living organisms could detect this instantaneous current. Without animals, the current would exist but could not be observed.

Volta tried many methods, and finally, when he separated the metals with cardboard soaked in salt water, he observed the generation of electricity. The presence of salt water allowed the metals to continue to react chemically, so that the current could be generated stably and continuously. This is the so-called Voltaic pile, which is the world's first battery.

Although batteries had no practical use at the time, they completely changed the face of electrical research. Batteries can provide stable and controllable voltage and current anytime and anywhere, making quantitative research on electricity and research that requires long-term power supply possible. Davy and Faraday used batteries to conduct electrolysis experiments and discovered a series of new elements such as sodium, potassium, and chlorine, while Ohm used batteries to discover the relationship between voltage, current, and resistance, which is the so-called Ohm's law.

Although Galvani misjudged the source of electricity in his experiment, he guessed the mechanism of biological movement. Later experiments showed that the way living organisms transmit movement is indeed electrical signals, and it is for this reason that organisms recognize external electric current as a command to move. Today, Galvani is considered the father of modern electrophysiology, and the theoretical basis of electrocardiograms and electroencephalograms can also be traced back to him.