Streeeetch Your Mind!
DO YOU KNOW WHY?
Why is it that one person yawning often makes another person yawn?
Contagious yawning has been observed – but only in humans. One hypothesis is that yawning communicates our state of wakefulness to other members in the social group. According to this theory, yawning is contagious because it is part of a mechanism which serves to synchronise our wake and sleep cycles.
Why is it that women live longer than men?
Boys are supposed to be the weaker sex at birth. Women seem to have a higher resistance to heart disease than men. Women are brought up to take better care of themselves and their health and are more likely to visit the doctor.
Why is it that we clap to show our appreciation?
Hand-clapping is not a universal sign of appreciation – some cultures hiss and some African women make a noise with their vocal chords to show their approval. It is thought that we clap because of its percussive nature. It is loud, drowns out other sounds, raises the tempo and helps to create an atmosphere.
Why does your voice sound different when you hear yourself recorded?
When we speak we hear our voices through the bones in our skull. But when we record our voice and then play it back, it sounds slightly different because we hear it through our ears.
Why do some countries put a line across the stem on a number seven?
The number seven is crossed because, when the numbers one to nine were originally written in Arabic, each figure had the same amount of angles as the number it suggested. Thus a nought was circular and had no angles, the number one had one angle and so on and the number seven with a line across the stem and a base line had seven angles.
Why do moths fly towards light?
Moths are active at night and it is believed they navigate using the moon as a reference point. However, if they mistake a bright light at night for the moon, they will fly towards it and actually fly into it. They don’t know the difference between bright lights and the moon because their navigation system evolved before the invention of artificial light.
Why does the earth revolve to the east but the weather come from the west?
The direction of the weather is controlled by the wind which is formed by the friction between the earth’s surface and the atmosphere. Imagine spinning a tennis ball in water – as it spins, the friction between the ball and the water creates waves and this is what happens between the Earth’s surface and the atmosphere to create wind. Because the poles are so cold and the equator is so hot, in the northern hemisphere the warm air flows northwards towards the cold air. This, combined with the friction of the earth’s rotation, means the wind usually blows towards the north-east dragging the weather with it.