How deep whales can dive

Many whales can remain submerged for long periods of time either hunting for food or simply cruising along. However, when it comes to deep diving one species of whale stands out. That is the sperm whale. Research has revealed that a sperm whale can dive to depths of 13,193m or 10,478 feet. Isn't that amazing?

How powerful lightning is

A flash of lightning which is a spark of electricity can be powerful as much as 30 million volts. Its temperature is about 30,000 degrees Celsius or 54,000 degrees Fahrenheit, which is five times as hot as the surface of the Sun!

When armoured vehicles were first used in war

Originally known as 'land ships' the name 'tank' was adopted as a deliberately misleading cover name for the early armoured vehicles. Some refer to them as "metal monsters" as they have the power to destroy anything in their path.

The first tanks to fight in a war were the British tanks,in 1916. They went into action in France during World War I.

How judo originated

Judo was devised in 1882 by Dr. Jigoro Kano in Japan. It was developed from ju-jitsu, an ancient method of self-defence without weapons. In this method, the strength and weight of the opponent are used against him.

The highest efficiency award in judo is called Shihan.

Why ice skates have such thin blades

The thin blades of ice skates help the skater to skim over the ice.

As the skate moves on the ice, the whole weight of the skater presses down on the blade.

This exerts very high pressure on the ice and as a result, the surface layer instantly melts. Friction with the ice may also serve to melt the ice.

The layer of water that is formed makes the ice slippery, enabling the skater to travel over the ice very quickly. The water freezes again as soon as the skater moves away from the area.