Otto von Guericke (German: Otto von Guericke, November 20, 1602~May 11, 1686), German physicist and official.
Born into a noble family in Madburg, Glick studied at Leipzig University, Jena University and Leiden University.He served as an engineer in the army and was mayor of Madburg from 1646 to 1676.At that time, he was engaged in both politics and natural science research.On May 8, 1654, the Madelberg Hemisphere Experiment was carried out, showing the huge atmospheric pressure.[1]In 1650, he invented the piston vacuum pump (reciprocating vacuum pump).
In 1602, Otto von Glick was born in Madburg, Germany, with a rich family.He entered Leniz University to study law at the age of 15 and graduated at the age of 20. Besides studying law, he also has a strong interest in experiments and mathematics.After graduating from Glick University, he went to Britain and France to study. He returned to his hometown at the age of 23.At that time, Europe was involved in the whirlpool of war. After Madeborg was captured, the whole city burned down, and Glick was captured by the enemy. With the help of Swedish friends, he was able to redeem himself from prison.Later, with the help of the Swedish king, the city of Madeborg was recovered.
In 1646, Glick was elected mayor of the city.After taking office, Glick worked hard and spared no effort to build bridges and fortresses.In addition, he personally started farming to produce food that was scarce at that time.
In 1660, German physicist Otto von Grecker invented the first friction generator.Later Newton suggested changing the sulfur ball he used into a glass ball.This machine has played an important role in the electrostatic experimental research for more than 100 years.[2]
In 1686, Grick died in Hamburg at the age of 84.
Key achievements
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natural science
Grick still does not forget to study natural science and has made gratifying achievements in the study of vacuum.In the scientific circles at that time, creating vacuum was an important topic. According to the principle of the suction pump, after careful design and test, Glek finally built the piston pump.In 1663, Gerry completed the manuscript of On Vacuum, which was published in 1672.At first, Glick filled the wine barrel with water, and pumped the water into another barrel with a brass pump. The wooden barrel being pumped was sealed, with only one pumping pipe opening. Three strong assistants pulled the piston hard to slowly pump the water out of the barrel.As the water is pumped out, some sounds can be heard, and the water left in the bucket seems to be boiling violently.As the air leaks from the barrel, the sound gradually stops as the air enters the barrel.Later, copper spherical containers were used instead of wooden barrels to carry out the above experiments.At first, the piston was easy to pull. Later, as the water in the container became less and less, it became more and more difficult to pull the piston.When the piston is opened after being vacuumized, the air is squeezed into the ball rapidly, and its intensity can almost pull a person close to it into the copper ball.
Experimental exploration
Invention of air extractor
After a series of experimental explorations, Grick finally inventedAspirator。With the air extractor, he did a lot of work on vacuum andAtmospheric pressureExperiment.He found that the flame in the vacuum would go out;In the vacuum, the bird opens its mouth sadly, breathes desperately, and then dies;Fish will also die in a vacuum;Grapes can keep for six months in vacuum, etc.Glick once put the pig bladder containing air into the bell jar of the ventilator, and then pumped the air out of the bell jar. He saw that the bladder gradually expanded and burst.He also put a clock into the glass container that was making a sound. When the air in the container was pumped out, the sound would not be heard.This proves that sound cannot travel in a vacuum.Glick also connected a section of glass pipe to a pipe more than 10 meters long. The glass pipe was filled with water, and then the top was closed to make it water typebarometer, that is, water columnTorricelliAs for the mercury column in the tube, he observed that the height of the water column would change when the weather changed, so he used this instrument to make weather forecast. He made a wooden man float on the water surface of this instrument, and his fingers pointed out the air pressure at various positions.
Magdeburg hemispheres test
On May 8, 1654, Otto von Glick, the mayor of Madburg at that time, carried out a scientific experiment in the suburb of Regensburg, Germany, in order to prove the existence of atmospheric pressure. The purpose was to prove the existence of vacuum.Glick made two copper hollow hemispheres with a diameter of about 50 cm (20 inches) for experiment. There is a layer of leather soaked with oil in the middle of the hemispheres, so that the two hemispheres can be completely sealed.One hemisphere is equipped with a connecting pipe to connect the vacuum pump, and a valve can close it.When the air between the two hemispheres is pumped out, the two hemispheres will be squeezed by the surrounding atmosphere and tightly together.
Then, Glick divided the 16 horses into two groups and pulled the two hemispheres in opposite directions.When these 16 horses tried their best to pull the two hemispheres apart at last, they made a loud noise, like shooting.At that time, the people around were very surprised, and Glick took the opportunity to tell the people that it was "the power of air".If the valve on the copper hemisphere is unscrewed, air flows into the ball through the valve, and the ball is opened by pulling it with your hand.
In fact, according to theoretical calculation, the combined force of the two hemispheres can be calculated from the diameter of the hemisphere and the pressure difference inside and outside the hemisphere.In Glick's experiment, it was impossible to accurately calculate the force required to separate the two hemispheres because it was impossible to know how the vacuum pump was working.Assuming that its vacuum pump can extract all the air, it will take 20 kN of force to separate the two hemispheres, which is equivalent to the force required to lift a young African elephant.In the Madeborg hemispherical experiment, in order to vacuum the inside of the sphere, Glick designed and invented the world's first vacuum pump.
After that, Glick repeated the experiment many times in various places to entertain the curious audience.In 1656, he repeated the experiment with 8 horses from each team in Madburg, where he was mayor, and got the same result.He also tried to draw the sphere composed of two hemispheres out of the air and hang a heavy object. The two hemispheres were not separated.In 1663, he repeated this experiment in Berlin for Frederick William, the election candidate of Brandenburg, with 12 horses from each team.
Since then, the Madelberg Hemisphere Experiment has gradually become a well-known experimental method to demonstrate the principle of atmospheric pressure.Boston and other places have independently repeated the Madelberg hemispherical experiment.There are also imitations of the Madburg hemisphere for teaching purposes. Their volume is much smaller than that of the previous hemisphere. After vacuuming the space of the hemisphere, it can be pulled away without using horsepower.Deutsche Post has also issued stamps commemorating this experiment.[1]
