Category: Science

The atmosphere. When you hear the word explore, perhaps you think of an expedition to some distant, unknown land. Perhaps you think of explorations in Africa or at the south pole. Explorations at or near home, however, are constantly being made by scientists. Among the most important of these are explorations of the atmosphere.

Until recent times little has been known about the nature of the atmosphere or about how deep it is. Even today it has been explored for only a few miles above the ground. Before the invention of balloons and airplanes the atmosphere was studied chiefly near the earth’s surface. By climbing mountains men learned something about what the air is like a few thousand feet above sea level. They learned that when they climbed high mountains, it was hard for them to get enough air for breathing.

Matter is an important scientific term. You will use the word matter often in studying the units that follow. ‘-Matter is the general name that is given to all substances of any sort. Matter is anything that takes up space and has weight: Thus you are matter because you take up space and have weight. A dog, the things you eat, the clothes you wear, and all the things that can be seen or handled are matter.

You probably know that there is water in the soil at the bottoms of streams, lakes, and oceans. You may also know that water gets inside some rocks.

But do you know whether there is air in the soil at the bottom of the ocean of air? Do you know also whether there is air in the water of streams, lakes, and ponds? Air is both in soil and in water.