Ask Mr Brain....all will be explained

PUBLISHED : Monday, 22 February, 1999, 12:00am
UPDATED : Monday, 22 February, 1999, 12:00am

I often look at the stars and wonder - why do they shine and twinkle? CECILIA TONG Heep Yunn School Unlike the moon which only 'shines' when it is in the right position to reflect the sun's rays, acting like a large mirror, stars give off light on their own.

Stars are in fact immensely hot, huge spheres of gas. Most stars are 90 per cent hydrogen and their cores are undergoing massive nuclear reactions which result in light and other forms of radiation. Our sun is a typical medium-size star.

While some stars do vary in brightness - known with the usual scientific lack of poetry as 'variables' - most shine at a fairly constant rate and do not twinkle.

Layers of air in the Earth's atmosphere are at different temperatures and densities, and they move and swirl against each other.

This movement causes tiny deflections in the path of light from a star, resulting in the apparent twinkling.

Stars near the horizon appear to twinkle most because light from them has passed through more of the atmosphere.

According to the dictionary, the word 'agony' comes from a Greek word meaning 'to celebrate'. How did such an unlikely development come about? The ancient Greeks were fond of celebrations that included games and athletic contests. From their verb 'agein', meaning both 'to lead' and 'to celebrate', the Greeks derived the noun 'agon' to denote a public gathering for such celebrations.

The struggle to win the prize in the athletic contests then came to be called 'agonia'. This word also took on the general sense of 'any difficult struggle'.

From this sense, 'agonia' additionally came to refer to the pain, whether physical or mental, involved in such a struggle. The Romans, as was their custom, borrowed the Greek words 'agon' and 'agonia' with essentially the same meanings.

'Agonia' became 'agonie' in Middle French and in 14th-century Middle English, when Chaucer used it to mean 'mental anguish or distress'.

During the 17th century, 'agony' acquired the sense of 'intense pain of body' and then took on the additional sense of 'a violent struggle, conflict or contest', harking back to its Greek origins.

The Greek 'agon' also forms the root of such English words as 'antagonism', 'antagonise' and 'protagonist'.

Who was the first April Fool? Some people trace the tradition of April Fool's Day to Nordic mythology where Loki was known as the prankster among the gods.

Loki was said to be disruptive towards the other gods but he was also able to carry out tasks that none of the others could.

He represents the need to question and challenge authority. Loki is traditionally thought of as the patron god of April.

Why is the saying 'Hobson's choice' used to mean no choice? The saying dates back to the 16th century and was named after an Enlishman called Thomas Hobson (1544-1631) who ran a stable.

In those days people used horses for transport. If you didn't have your own horse, or your horse was tired, you could hire one from a stable. While most stables allowed you to pick your own horse, Mr Hobson refused to give his customers a choice and offered them the nearest horse or nothing.

His peculiar way of doing business was immortalised in the saying 'Hobson's choice', which means you have the choice of taking what is offered, or nothing at all.