Air Presses in all Directions

When we speak about air pressure, we are often mistaken in thinking that it presses in only one direction at a time. This, of course, is not so. Air exerts its force in all directions. Only when a vacuum or an area of low pressure is created does air appear to marshal its forces and move in the direction necessary to increase the pressure in that area.

A simple experiment will prove the point.

Take an ordinary rubber balloon and hold it so that it hangs partially in an empty jar.

As you blow into the balloon and inflate it, that part of the balloon which is trapped in the jar swells out until it touches the glass sides. A few more puffs, and it becomes an easy matter to lift the jar with the aid of the balloon.

The air pressure inside the balloon exerts its force in all directions, pressing the walls of the balloon so tightly against the glass jar that it cannot easily be pulled free unless some air is released from the balloon.

Children learn best through doing

Before children can understand a thing, they need experience: seeing, touching, hearing, tasting, smelling; choosing, arranging, putting things together, taking things apart. Experimenting with real things.

Old-time school teaching used only words and the teachers thought children knew something if they could repeat it. Now we know better. To reach practical understanding we do not need to use many words with young children.

Children are clever. They learn a lot, without being taught. The greatest skill - to be able to talk, to communicate is learnt outside school. In the classroom it's the children who need to talk the most. Unfortunately it is the teacher who does most of the talking!