How much skin do humans shed?

Our skin is made of many layers of cells. The outer layer is flaky and the inner layers have structure giving and nourishing elements. The outer skin gets dry or damaged with time and so it gets shed. An average person sheds about 30,000 cells every minute and about 18 kilograms of skin in his or her lifetime. Most household dust is made of dead skin.

• • •

The relation between butterflies and climate change

Butterflies are delicate creatures and they are affected by climate change. A large population of butterflies indicates a healthy ecosystem and a dearth of butterflies indicates that the ecosystem is under stress. Butterflies are unable to fly if their body temperatures drop below 30 degrees Celcius.

• • •

Origin of the electric chair

Until recently, criminals in the US were executed using an electric chair. Nowadays a different form of execution by lethal injection is practised. Before the electric chair, the condemned criminals were    hanged. However, a dentist Dr Alfred P. Southwick happened to witness a drunken man getting electrocuted and dying instantly when he touched a live electric generator. He was horrified. However, it later occurred to him that this method of electrocution could be used to humanely execute condemned criminals. As a dentist he worked using chairs, so the idea of the instrument occurred in the form of a chair.

• • •

The amount of energy released by a hurricane

An average hurricane bringing in 1.5 cm per day of rain, with a circle radius of 665 km, generates a huge amount of energy (6.0 × 1014 Watts or 5.2 × 1019 Joules/ day),  which  is  equivalent of  200  times  the  electricity-generating capacity of the entire planet in a year. This is equivalent to detonating a ten megaton nuclear bomb every 20 minutes. In 10 minutes a hurricane releases more energy than all of the world’s nuclear weapons combined.

• • •

Tribute to Alexander Graham Bell

Alexander Graham Bell was a Scottish-born American inventor famous for the invention of the telephone. He died on August 2, 1922. On the day that Alexander Graham Bell was buried, millions of phones in America and Canada went dead for one minute as a mark of respect for the inventor.

• • •

Speed of a falling raindrop

A raindrop falls on the earth with varying speeds depending on its size and weight. The gravity acts on the falling raindrop and the drop picks up speed. But due to air resistance, which is generally proportional to the velocity, the raindrops attain a terminal speed. A larger raindrop would fall much faster at 9 metres per second whereas a smaller raindrop will fall at a much slower speed of 2 metres per second.

• • •