The laser beam's energy is concentrated into a narrow width and is very powerful. Laser light can also be focused very accurately. Over this huge distance...
This illusion has mystified thousands of the theater-going public, in fact, it has been the "piece de resistance" of many illusion acts. The ordinary method of procedure is as follows:…
"Thirty days hath September, April, June, and November," etc., and many other rhymes and devices are used to aid the memory to decide how many days are in each month…
How does a light bulb work - for kids?Have you ever looked closely at an ordinary electric light bulb? Hold it carefully while you do so. Inside, you may see…
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…
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…
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…
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…
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…
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…