Scientific Facts about the Sense Organs

Why Our Eyes Produce Tears

Our eyes produce tears all the time. When we blink, the tears are carried away through small ducts. We say that we cry when tears form so quickly that they cannot drain away fast enough.

Hearing and sound

Many animals can find the direction of a sound better than people. This is because their outer ears move and help them to locate the sound, while our outer ears do not.

Humans judge where a sound comes from by comparing how strong it is in each ear. If a sound reaches both ears at the same time and from the same distance, it is difficult to tell where it comes from.

You can make a simple experiment. Ask a friend to sit on a chair with eyes covered. Make small noises in different places and ask your friend to point to where the sounds come from. He will answer correctly when the sound is on one side, but if you make the sound directly behind his neck or under his chin, he will not know the exact direction.

How our body reacts to cold

Another interesting fact is that our hands become warm after we play with snow. At first, the cold air cools the skin, but then the blood begins to move faster and brings more warmth to our hands.

Left and right hand strength

Our right hand is usually stronger than our left because most people use it more often. For left-handed people, the left hand is stronger. People who use both hands equally have hands of about the same strength.

Record heights

The tallest man ever recorded was Robert Wadlow from the United States (1918–1940). His height was 8 feet 11 inches (272 cm), and he weighed about 491 pounds.

The smallest adult man officially known was Gul Mohammed from India (1957–1997). He was only 1 foot 10.5 inches (57 cm) tall.

Human height around the world

Human height varies greatly in different parts of the world. Some groups of people are naturally shorter, while others are taller. This depends on genetics, diet, and living conditions.