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Technoquest

Thursday 07 October 1999 23:00 BST
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Q. What is the average lifespan of a horse?

Q. What is the average lifespan of a horse?

According to the Science and Technology Desk Reference book, the maximum lifespan of a horse is 62 years. Obviously not all horses will live this long and an average value will be somewhat less than 62 years. The lifespan of a horse will depend on, amongst other things, the conditions in which it lives and the pressures that are put on it during its life.

Q. Why does hair go grey?

A hair is basically a tube filled with cells and pigment with spaces between. When the hair is young the spaces are filled with fluid and this keeps the pigment in place, so your hair keeps its colour. As we get older our skin doesn't produce hair quite so well and the spaces become filled with air. The pigment is lost and the hair gradually becomes white.

Q. Can you name a star?

Officially no. Except for the few dozen bright stars named by the ancients, stars are always designated by some alphanumeric system involving their placement in the sky, such as their ordering by position in a zone of declination, by brightness (or by variability of brightness) in a constellation, or simply by the digits of their co-ordinates in some system: in some instances the stars are simply given numbers in a catalogue by some astronomer or obser- vatory who collected them for some specific purpose - such as their relatively rapid motions with respect to other stars or because of particular features in their spectra. There are organisations that will try to sell you a star, but they have no official right to do so.

Q. Which will hit the ground first, a bullet fired from a gun or one dropped from the same height?

Both bullets will hit the ground at the same time. This is because the horizontal and vertical motions of objects can be treated separately. So although the first bullet has to travel further across the ground, both bullets fall the same distance and so reach the ground at the same time.

Q. Can cockroaches survive in a microwave oven?

Not at high levels. The microwave energy causes them to "pop" as the body fluids heat up. At low levels they can sometimes survive, probably due to some property of their outer skin. The oils in it may reflect the energy to prevent "popping". We strongly suggest you don't try this at home!

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