Tuesday 01 August 1995
A If the energy output of the sun increased, there would be no reason for all wavelengths not to increase to the same extent. It is therefore unlikely that some wavelengths have increased in intensity more than others. The higher incidence of skin cancer is more likely to be caused by our changing social habits: we sunbathe more than we did and go on holiday to sunny countries. Although the protective ozone layer in the earth's atmosphere is getting thinner as a result of pollution from CFC gases, the "holes" have been found only over Antarctica (and to a lesser extent the Arctic) and there is no evidence as yet linking the thinning over temperate latitudes with the increased incidence of skin cancer.
Q Why do some cars have a static build-up and others don't?
A It is thought to have something to do with the carbon content of the car tyres. Tyres with high carbon content are more likely to dissipate static electricity.
Q Why is nitrogen used in so many explosive materials if it is so inert?
A Nitrogen gas is inert because there are three bonds holding together only two molecules. If you like, it doesn't have any hands free. In explosives, the nitrogen atoms are held to other atoms quite loosely and can therefore form other bonds readily. This makes them an unstable material.
Q Who discovered black holes?
A Pierre Laplace, the 18th-century French philosopher, first suggested the existence of a gravity field so strong that light could not escape. Albert Einstein did the mathematics and John Wheeler coined the term "black hole". As yet there is no absolute proof that a black hole exists, although there is very strong evidence suggesting it does.
Q Why isn't there a cure for the common cold?
A The common cold is caused by many different viruses. At the moment we have few medicines to treat virus infections. Those which do exist are far too strong (and have potentially unpleasant side-effects) to risk using them just to get rid of a cold. There is no vaccine for the common cold because so many different viruses cause it and it is impossible to cope with them all. A cold makes you feel a bit grotty for a few days and then you can fight it off without treatment. So a "cure" isn't really needed.
Q How do bees navigate?
A Bees navigate using the position of the sun in relation to their journey. This information is conveyed to other members of the hive through a dance that the bees do.
These questions and answers are provided by Science Line. You can use its Dial-A-Scientist service on 0345 600444
- 1 BBC told new political editor must be 'impartial' with Nick Robinson reportedly stepping down
- 2 Number of young homeless people in Britain is 'more than three times the official figures'
- 3 The map showing the most dangerous tourist destinations in Europe, according to the Foreign Office
- 4 The biggest first date turnoff has been revealed
- 5 German man found living with 300 rats in tiny apartment
BBC told new political editor must be 'impartial' with Nick Robinson reportedly stepping down
Humans of New York image of crying gay teen receives best response yet from Ellen DeGeneres
Isis propaganda video shows 25 Syrian soldiers executed by teenage militants in Palmyra
Number of young homeless people in Britain is 'more than three times the official figures'
Budget 2015: George Osborne to axe subsidies for higher income earners in social housing
More Britons believe that multiculturalism makes the country worse - not better, says poll
Nathan Collier: Montana man inspired by same-sex marriage ruling requests right to wed two wives
Greece crisis: IMF was pushed around by Angela Merkel and Nicholas Sarkozy – and now it is being humiliated
'I wish the BBC would stop calling it Islamic State' – David Cameron unleashes frustration at broadcaster
Forget little green men – aliens will look like humans, says Cambridge University evolution expert
Girl, 7, stares down hate preacher at Ohio festival with pro-LGBT rainbow flag gesture
£27000 - £35000 per annum: Recruitment Genius: A growing, successful, friendly...
£16000 - £25000 per annum: Recruitment Genius: This family owned, independent ...
£17000 - £21000 per annum: Recruitment Genius: This is a fantastic opportunity...
£17000 - £23000 per annum: Recruitment Genius: This is a fantastic opportunity...