Have you ever wondered why hens don’t break their eggs when they sit on them? The secret lies in the shape of the egg. An egg is a great example of nature’s excellent skills in packing. If you squeeze the ends of an egg between the palms of your hands, it won’t break. However, if you squeeze it in the …

The green color in grass-and in most other plants-comes from chloroplast within the cells, each of which contains four different colors or pigments. These are: chlorophyll a, which is the strongest and is blue-green; chlorophyll b, which is yellow-green; xantophyll, which is yellow; and carotene, which is orange and gives carrots their bright color. Grass goes from light green in …

It is the sulphur in the air, which often comes from coal-gas used for cooking and heating, that causes silver to tarnish or blacken. Silver combines with sulphur to form the black silver sulphide sometimes found on forks and spoons which have been in contact with egg folk. Silver is a precious metal which the Greeks called shining. In spite …

Nectar is taken from a flower by the bee and carried in the honey sac back to the hive. It is transformed into honey by enzymes produced in the honey sac, which convert the natural sucrose (a complex sugar) in the nectar into fructose and glucose (simple sugar). Fructose is the sugar that makes honey sweet.

This is due to the pull of the earth’s gravity. If there were no gravity the stone would remain in the air. When the stone is thrown into the air, a force is applied to it which is greater than the pull of gravity. But as it rises higher the force becomes weaker until the stone reaches a point where …

Stainless steel resists rust because it contains a high proportion of chromium to carbon. Before the arrival of this alloy just before the First World War, knives and other household articles made of steel easily rusted unless very carefully dried. It was an English researcher named Harry Brearley who discovered that rust was encouraged by the carbon in steel and …

The pencil appears to bend owing to the refraction of light, or the change in direction of light when it passes through transparent materials. The light rays coming from the submerged part of the pencil are bent as they live the water. Light rays are reflected and absorbed by opaque materials such as glass, air, water, oil and certain plastics, …

It is the built-in skew or twist in a boomerang combined with its spinning motion that makes it return to the thrower. At first people believed that air, pressing on the lower flat surface and passing over the upper rounded face, was responsible for the return flight. But T.L. Mitchell, a Scottish explorer of Australia, gave the true explanation early …

Some animals and birds make use of tools. There are some good examples among the birds. For example, the song thrush commonly feeds on snails which it opens by flying up with the shell in its bill and dropping the snail on convenient stone. The bird often uses the same stone on a number of occasions so that it may …

The main reason we are able to float is that the density of our bodies is relatively less than the density of water. A large part of the human body is made up of air and water. Buoyancy-the ability to float depends on the individual. But with experience it is possible to improve your body balance, in other words to …