Can you imagine a time when people did not use numbers?The first people on earth lived by hunting wild animals and collecting wild fruit and nuts.They had no need to count.Numbers did not matter to them.But then, about 11,000 years…
Acupuncture is an ancient Chinese method of relieving pain and treating disease. The procedure involves the insertion of needles into various parts of the body. Acupuncture has been used to treat conditions such as: asthma, deafness, migraines, ulcers, eye diseases,…
The polygraph – device for detecting a lie is one of the tools in a criminal investigation and is used by the police in many countries. However, the data obtained using this device is not accepted everywhere as direct evidence…
Dead animals and plants rot and decay. In swampy areas, for example, dead plants fall into the water. As they decay, they give off gas. Scientists call this biogas. Biogas comes from garbage, sewage, and manure, too. Biogas is a…
The Geothermal energy is renewable, clean and sustainable energy generated from the Earth’s heat, which is constantly replenished. At the center of the earth, it is very, very hot. The temperature is thought to be about 13,000 °F (7000 °C),…
Do you know what it is like at the center of the earth? It is very, very hot. The temperature is thought to be about 13,000 °F (7000 °C), which is hot enough to melt rock. The heat spreads to…
Have you ever watched the sea during a storm? The waves crash down with enormous energy. Sometimes they are strong enough to damage seaside walls and buildings, or even make cliffs crumble. Do you know how we can make use…
The wind has been a source of energy for thousands of years. Before the development of the steam engine, most ships relied on wind power to fill their sails and push them along. Windmills were used to turn grindstones and…
More energy reaches earth from the sun than could be converted by millions of power stations. The sun’s energy costs nothing, but how can we use it?We can use the sun’s energy to heat the water in our homes. One…
Did you know that a power station can produce electricity without burning coal or oil, and without using nuclear fuel? How? A power station can turn the potential energy of water into kinetic energy and then convert this energy into…