Editing Bottle Blaster (section)

== Why This Works ==

''Pressure'' is when a force is applied over an area. ''Air pressure'' refers to the force that the air exerts on everything around it. We can increase the pressure on something by either increasing the force applied or decreasing the area it is applied to. With this demonstration, we are increasing the pressure applied to the air and water inside the bottle. When the presenter smacks the bottle, they are forcing a small amount of air into the bottle, which increases the pressure inside the bottle. The air, when it experiences the increase in pressure, tries to balance it out by ''compressing'', or taking up less space in the bottle. The bottle is also sliding in your grip, which forces the air in the bottle to compress even more. Water, however, does not compress, so the extra space that the air leaves is taken up by the water. This creates a small ''vacuum'' in the bottom of the bottle, a literally empty space with nothing in it, just like outer space! The vacuum collapses when the air expands back, pushing the water down into it. This "water hammer" smacks down hard onto the glass, breaking it off!