Part 1 - Barometers

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Author's note. This book is one of a series originally published as Who the Hell are We? but extensively revised and updated.  

Thank you for reading, voting, following and adding, 'ATOMS AND LIGHT' to your reading list or library.   Dunc MacPhun     2022 March 25.


 In chronological order, the series contains:-

https://www.wattpad.com/myworks/234080674-supernovae-and-life

https://www.wattpad.com/myworks/238813918-we-eukaryotes

https://www.wattpad.com/myworks/244084318-neolithic

https://www.wattpad.com/myworks/247058691-our-sea

https://www.wattpad.com/myworks/249120741-migration

https://www.wattpad.com/myworks/251168052-middle-era

https://www.wattpad.com/myworks/254532133-disease

https://www.wattpad.com/myworks/256201647-atoms-light

https://www.wattpad.com/myworks/257785133-steam

I will be publishing more work in this series. 


When Otto von Guericke was born in Germany, on November 30, 1602, Elizabeth I was still Queen of England and William Shakespeare was still writing new plays.

The French scientist René Descartes had designed an experiment to determine atmospheric pressure as early as 1631, (It is normally about 14.7 pound/square inch at sea level) and this idea may have inspired Von Guericke. He was intrigued by the idea of the vast, empty universe and tried to create a vacuum using a fire pump to remove water from a sealed wooden barrel but it leaked. Undeterred, in 1654, he developed a better vacuum pump using a piston in a cylinder with improved seals and check (flap) valves.

He used this to extract the air from a closed container which collapsed and then demonstrated that several men were unable to pull the airtight piston out of a sealed cylinder. He also demonstrated that a flame was extinguished from lack of air in an evacuated, sealed chamber, that water could be raised by suction and that air had weight.

He made a barometer that he used to forecast the weather. He also showed that magnetic attraction worked even in a vacuum and invented the first electrostatic generator, in the process, demonstrating electrical conduction but without realizing what it was.

His most famous experiment occurred in 1657, when he put two 20-inch diameter hemispheres together with a vacuum seal and pumped most of the air out of the enclosed space. The air pressure outside held the hemispheres together so tightly that they could not be pulled apart by two teams of horses which would have required about 4000 pounds of force.

Guericke proved that substances, like water, were not pulled by a vacuum, but were pushed by the pressure of the surrounding air. And this idea stimulated Robert Boyle in 1657 England to experiment with the relationship of air pressure and volume.

Previously, in 1630, Giovanni Battista Baliani had written a letter to Galileo asking why his attempt to siphon water, over a hill 21 metres high, failed to work. Galileo suggested an experiment and, in 1638, Raffaele Magiotti and Gasparo Berti filled a long tube, sealed at both ends, with water. They then stood the tube upright in a basin already full of water. When they removed the bottom plug some of the water poured out into the basin and, when it stopped, the level of the water inside the tube stayed at an exactly 10.3 m (34 ft) above the basin.

In 1643, one of Galileo Galilei students, Evangelista Torricelli, suggested that it was not a vacuum that kept the water in the sealed tube but the weight of the atmosphere. This was a novel idea because conventionally air did not have weight.

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