Science: Technoquest

Q: Who invented the rubber band?

According to Harwin Chronology on Inventions, Innovations and Discoveries by Kevin Desmond (1987), it was Stephen Perry of Messrs Perry and Co, Rubber Co Manufacturers, London, from vulcanised rubber.

Q: How do you determine the sex of a tarantula?

When tarantulas are young they all look like females, but as they get older their sex becomes more obvious. Adult males have hooks on their front legs and their stomachs are smaller than females'. Also, the males' "pedipalps" (the feely bits that stick out of the head) are shaped like clubs. However, it may take 10 moults, or about seven years, for these differences to become obvious.

Q: Why is Madame Curie so famous? What did she do?

Marie Curie is often portrayed as a sort of scientific saint - the Florence Nightingale of physics. In reality, like Florence she was as tough as old boots and an able administrator. She was a left-wing atheist who at one point was involved in a terrific scandal: she was accused of breaking up another physicist's marriage, which eventually led to a duel. (Not involving her, though.)

Marya Sklodowska, as she was originally called, was the daughter of a Polish science-teacher. She went to study physics and chemistry in Paris, where she married a physics professor, Pierre Curie. In 1897 Marie decided to study radioactivity for her doctorate. She began by working through all the elements then known, and found that uranium and thorium were radioactive. She then tried minerals and discovered that uranium ore (pitchblende) was far more radioactive than it should be for the uranium that it contained.

Marie suggested that the ore contained an unknown, but highly radioactive, element in such a small concentration as to be invisible. Having little money, she and Pierre were forced to work in an old shed that had been a mortuary. It took them four years to extract a tiny quantity of radium from several tonnes of ore. They took very few precautions against the radiation, and even today Marie Curie's notebooks are still too radioactive to handle.

She received two Nobel prizes for her work on radioactivity before she died of leukaemia at the age of 67.

Continuing the family tradition, one of the couple's daughters, Irene, and her husband discovered how to make things radioactive using neutrons. They also received a Nobel prize.

Q: How many stars are there in a constellation?

The number varies a lot. They are counted by measuring the number of stars that can be seen in an area of the sky. The Southern Cross has lots of stars - 19.6 per 100 square degrees of sky. Most others have between five and six per 100 degrees.

An easier way is to count the number of bright stars.

In the northern hemisphere, Centaurus has 18 bright stars. Canis Minor has only two.

Q: How heavy is the Earth's atmosphere?

Assuming the Earth to be a perfectly flat sphere with an air pressure of 9.65 x 104 newtons per square metre (14 pounds per square inch) all over its surface, the atmosphere weighs 4.9 x 1018 newtons (a mass of about 5 million billion tonnes).

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