TECHNOQUEST

Q) Why does wind blow in gusts?

A) Wind is caused by air moving from an area of high pressure to an area of low pressure. The surface of the earth is not the same all over and some surfaces produce more friction than others. So wind does not flow smoothly from place to place. For example, in cities and towns - some of the roughest areas as far as friction is concerned - wind gusts the most. Higher in the atmosphere the effects of the earth's surface are minimal and the wind speed is more constant. But gusts of wind are not a definable entity - like a water wave is, for example. A gust does not travel continuously through the air, as you will notice if you watch some leaves blowing around.

Q) Who was the first scientist?

A) The word science was first coined by William Whewell in 1833. Before then, thinkers in science were known as "natural philosophers". The first of these natural philosophers that history records were Thales and his contemporaries, Anaximander and Anaximenes, who lived in Greece around 600BC. Whewell chose the terms "science" and "scientist" from the Latin scire "to know". So "science" is the pursuit of knowledge.

Q) Which star would you have to be on now to glimpse Earth when the dinosaurs were about?

A) Dinosaurs lived on the earth about 65 million years ago, so you would need to be on a star about 65 million light-years away. No stars in our galaxy are that far away, so we have to go to another galaxy. Amazingly enough, a galaxy in Virgo called M100 is almost exactly 65 million light- years away. Its distance was recently measured by a team in California using data from the Hubble Space Telescope.

Questions and answers are provided by Science Line, whose Dial-a-Scientist service is on 0345 600444.