| | Air pressure is used by modern industry, in the form of pneumatic controls. Hydraulic controls are similar to pneumatic ones, but use fluid pressure instead of air pressure, and are more precise due to the less compressible quality of the fluids used. | | Air pressure is used by modern industry, in the form of pneumatic controls. Hydraulic controls are similar to pneumatic ones, but use fluid pressure instead of air pressure, and are more precise due to the less compressible quality of the fluids used. |
| − | A simple science experiment demonstrates the power of air pressure. Ask your parents for a few tablespoons of [[lemon]] juice or [[vinegar]], a few tablespoons of [[baking soda]], and an empty milk jug or wine bottle (preferably with the cork still in). Pour the ingredients into the jug and quickly cap it. You will see the cap start to loosen, or the cork fly out, when the chemical reaction inside the container generates enough [[carbon dioxide]] to raise the air pressure inside the bottle above the air pressure outside. This is the same principle that airlines use to pressurize the inside of an [[airplane]]'s cabin. For an extra kick, ask your parents for a chunk of [[dry ice]] to put inside the milk jug. Dry ice, being made of [[solid]] carbon dioxide, greatly increases the air pressure when it "melts" into [[gas]]. Put the ice in the milk jug, quickly screw on the cap, and place the jug in a warm location to melt the dry ice. (The inside of an oven will do just fine... but be careful not to turn on the oven!) | + | A simple science experiment demonstrates the power of air pressure. Ask your parents for a few tablespoons of [[lemon]] juice or [[vinegar]], a few tablespoons of baking soda, and an empty milk jug or wine bottle (preferably with the cork still in). Pour the ingredients into the jug and quickly cap it. You will see the cap start to loosen, or the cork fly out, when the chemical reaction inside the container generates enough [[carbon dioxide]] to raise the air pressure inside the bottle above the air pressure outside. This is the same principle that airlines use to pressurize the inside of an [[airplane]]'s cabin. For an extra kick, ask your parents for a chunk of [[dry ice]] to put inside the milk jug. Dry ice, being made of [[solid]] carbon dioxide, greatly increases the air pressure when it "melts" into [[gas]]. Put the ice in the milk jug, quickly screw on the cap, and place the jug in a warm location to melt the dry ice. (The inside of an oven will do just fine... but be careful not to turn on the oven!) |
| − | The [[Bible]] teaches us that before the [[Flood]], there was a "[[firmament]]", or [[vapor canopy]], separating the waters of the [[heaven]]s from the waters of the [[earth]]. Because all that water was pressing down on the Earth's atmosphere, the air pressure in Biblical times would have been several times greater than it is today. Some [[creation scientist]]s credit the longevity of the [[patriarch]]s to the greatly increased air pressure — much as an [[astronaut]] living in a pressurized [[space station]] ages more slowly than his twin at home. | + | The [[Bible]] teaches us that before the [[Flood]], there was a "firmament", or vapor canopy, separating the waters of the [[heaven]]s from the waters of the [[earth]]. Because all that water was pressing down on the Earth's atmosphere, the air pressure in Biblical times would have been several times greater than it is today. Some [[creation scientist]]s credit the longevity of the [[patriarch]]s to the greatly increased air pressure — much as an [[astronaut]] living in a pressurized [[space station]] ages more slowly than his twin at home. |