1. Vanderbilt Student Volunteers for Science
VACUUMS
Vanderbilt Student Volunteers for Science

2. What is a Vacuum? A space in which there is no matter
OR essentially a space where all gases are removed so there is no air pressure
In the REAL world, the closest thing to a perfect vacuum is OUTER SPACE

3. More About Vacuums…..
Earth is NOT a vacuum because GRAVITY prevents gases from ESCAPING
Earth therefore has ATMOSPHERIC PRESSURE

4. What is AIR PRESSURE? Weight of the atmosphere pressing down on EARTH
Measured by a BAROMETER
Air pressure at SEA LEVEL is 14.7 psi
Air pressure changes with ALTITUDE

5. Experiment Questions:
What happened to the balloon in the jar?
Now what happens to the balloon when you loosen the connection between the hose and the base?
Now what happens when we do the experiment with a marshmallow?

6. Magdeburg Hemispheres
Magdeburg Hemispheres are a pair of large copper hemispheres with mating rims
Used to demonstrate the POWER of ATMOSPHERIC PRESSURE
When the rims were sealed with grease and the air was pumped out, the spheres could not be pulled apart BY A TEAM OF HORSES!!!!!!