Learning with Kevin: Educational Resource Blog
  • Home
  • Contact Us

From Friction to Frogs’ Legs

10/14/2013

0 Comments

 
Another important step forward was made in learning about electricity. Otto von Guericke, a German announced that he had invented a machine that could create a vacuum, or the absence of air. There was a criticism all around of his idea. He paid little attention to the criticism until one day when the time had come to prove his ideas. He announced that he would now for the first time in public demonstrate his new vacuum pump. He would do it by taking the air out of a hollow globe. 

He took two hemispheres, or half globes made of copper. He showed that they could be put together to form a hollow ball. Attached to each half globe was a large metal ring. Von Guericke fitted the two halves together and took them apart several times to show how easily they could be joined or separated. Then he brought out his machine, the vacuum pump. It was an odd-looking contraption, with a handle on one side and a tube coming out the other. He once more fitted the two hemispheres together so that they formed a ball, and attached the tube. Then he turned to the people and stated that he would now remove the air from the globe with his pump.

He attached the tube to a valve in the sphere, and began to operate the handle of the pump. Up and down, up and down, he pumped as the machine hissed with each downward thrust. Soon he pumped slower and slower, just barely able to pump the handle. Finally, Von Guericke could move the handle no more, and wiping the perspiration from his brow, he announced, “I have removed the air from the globe! Inside the globe there now is – a vacuum”.

He went on and explained that there was force, or pressure, of air on the outside of the globe and since there was no air inside the ball, the pressure of air on the outside would prevent the two halves from separating. He then lifted the ball off the ground and held it up high by one of the rings so all could see. He shook it again and again. The other half did not fall away. He invited people to try to pull the two halves apart. A powerful man with all his might tried to pull but could not budge them.   

Four powerful horses were led in and hitched in pairs, one pair attached to each ring on the ball. A whip cracked. The horses pulled in opposite directions. Still the halves of the sphere remained together. Two more pairs of horses were brought on the scene and hitched to the first two horses. Now there were four horses pulled and pulled. Same result, the halves stayed together. More horses were added were added until there were eight on each side, sixteen in all, pulling and tugging with all their might. Finally a loud crack was heard. The halves separated. It had taken the strength of sixteen horses to overcome the pressure of the air. Von Guericke had proven his vacuum pump. This was the turning point in Von Guericke’s life and an important milestone in the story of electricity.

0 Comments

Your comment will be posted after it is approved.


Leave a Reply.

    Author

    Kevin is an enthusiastic writer who writes and shares interesting blogs. So stay tuned to the blog and learn with Kevin.

    Categories

    All
    About Kevin
    Education
    For Parents
    Free Resources
    Learning With Fun
    Mobile Learning
    Online Learning
    Students

    Tweets by @Learningwithkev

    Archives

    December 2021
    November 2019
    August 2019
    July 2019
    June 2019
    February 2019
    December 2018
    June 2018
    March 2018
    November 2017
    October 2017
    September 2017
    January 2017
    November 2016
    August 2016
    April 2016
    March 2016
    December 2015
    November 2015
    October 2015
    September 2015
    August 2015
    July 2015
    June 2015
    May 2015
    April 2015
    March 2015
    February 2015
    January 2015
    November 2014
    October 2014
    September 2014
    August 2014
    July 2014
    June 2014
    May 2014
    April 2014
    March 2014
    February 2014
    January 2014
    December 2013
    November 2013
    October 2013
    September 2013
    August 2013
    July 2013

    RSS Feed

Powered by Create your own unique website with customizable templates.
© Copyright 2011 learning with kevin. All Rights Reserved.