Short-term disability insurance, which is most often purchased as part of a group at work, can be paid by either the employer or the employee. Group short-term disability insurance policies are guaranteed issue, meaning you do not have to take a medical exam to buy coverage.
In 1650, Otto von Guericke invented the air pump, used to create a partial vacuum. Using hollow copper spheres and an air pump of his own construction, Guericke demonstrated that a partial vacuum could be created by pumping the air out of the sphere.
The experiment was performed in 1657 at Magdeburg, Germany by Otto von Guericke (1602-1686), the Burgomeister (mayor) of Magdeburg. The hemispheres were made of bronze and were about 1.2 feet across. Von Guericke calculated that a force of almost 2700 pounds would be needed to pull the two hemispheres apart.Directly below is a picture of the original hemispheres in the Deutches Museum in Munich.ost physicists have seen the woodcut at the right, in which eight horses on the right and eight horses on the left are trying to pull apart two evacuated hemispheres.