Sunday, 11 December 2011

Safe clean drinking water

VIDEO - Water
VIDEO - Water 2
VIDEO - Water scarcity

Approximately a billion people live without clean drinking water. Imagine if your taps went dry. What would we do? Would you walk to your park to get dirty water for your family as millions of mothers in Africa do every day. More than a six-hour journey to get water each day. The lack of clear and clean water, causes disease. And thousands live their days without the bare necessities. Weakened bodies sadden the heart, one billion people do without. It tears the whole world apart. We call this the water crisis. It's a crisis because every living being needs safe clean drinking water.
Because the accessibility to water affects everything in our life. As human beings need dirt-free and unpolluted drinking water.

Friday, 9 December 2011

Factors affecting density of population

Population density is the number of people per square kilometer or mile.
This may be calculated for a county, city, country, another territory, or the entire world.

Monday, 5 December 2011


Lightning has fascinated humans for a long time.

A thunderstorm, also known as a lightning storm, is a form of weather characterized by the presence of lightning and its sound effect on the Earth's atmosphere known as thunder.

The clouds at the high levels of the thunderstorm are made of ice crystals. The formation of ice in a cloud is an important element in the development of lightning. Positively charged ice crystals rise to the top of the thunderstorm and negatively charged ice particles and hailstones drop to the middle and lower parts of the storm.

If the negatively charged area at the bottom of the storm gets large enough, sends out a channel toward the ground called a step leader. It is invisible to the human eye and moves in steps toward the ground. When the step leader nears the ground, it repels all the negatively charged in the surrounding area, and attracts all the positive charge. As the positive charges collect in high enough concentration, they send out small bolts of ground to air lightning called streamers. If the streamers can make contact with the step leader, an electric current wave propagates up the channel as lightning.

Sunday, 4 December 2011

The Netherlands - a low-lying country

The Netherlands is a geographically low-lying country.
About 27% of The Netherlands and 21% of its population located below sea level, and 50% of its land lying less than one metre above sea level.