Technoquest

Questions and answers provided by Science Line's Dial-a-Scientist on 0345 600444
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The Independent Online
Questions and answers provided by Science Line's Dial-a-Scientist on 0345 600444

Q Will ice caps melted by global warming raise sea levels in the next century?

A Present forecasts put the rise at about 60cm by the end of the next century - but that is expected to be due to thermal expansion of water already in the oceans. Ice caps are not expected to melt significantly until later in the 21st century.

QAs ice is less dense than water, surely the sea level would fall if the ice caps melted?

A Melting ice in the Arctic, which floats in the ocean, would not affect the sea levels. But ice in the Antarctic is on top of a large piece of land; melting it would raise the sea level. The volume of ice in the Antarctic is 30 million cubic kilometres and accounts for more than 90 per cent of all fresh water on Earth. If this melted, sea levels would rise so much that Big Ben would be under water.

Q When a cat gets fat, do its whiskers grow longer?

A No. The length of a cat's whiskers are set genetically. If a cat grows fat, the whiskers become too short to be useful as "width guides". The cat could get stuck if it tries to squeeze through a hole that its whiskers tell it it can get through.

Q Can you use a yo-yo in zero gravity?

A Not properly. Gravity-reliant tricks such as "walking the dog" would be tricky, and "cat's cradle" would be impossible, but you could make the yo-yo leave and return to your hand by flicking your wrist. What would be bizarre would be the fact that the yo-yo could go up and down the string in any direction. It would move quite slowly, and whether it would spin is debatable. If it didn't, getting it to roll back up again would be tricky due to lack of tension in the string.

Q Do bald people get dandruff?

A Yes. Dandruff is caused by bacteria, yeast and fungi on the scalp, and these can live without hair. However, dandruff is more common in people with hair, as it helps trap heat and water, providing ideal living conditions for such bugs.

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Questions for this column can be submitted by email to chrisr@bss.org

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