Letter: No going back

Sir: Ed Clarke's omelette (letter 30 November) will not unscramble back into eggs because of the entropy (irreversibility) created in the process of its manufacture. A better measure of the passage of time and its associated irreversibility is to ponder the claim, "Nuclear electricity will be too cheap to meter." May I have a research grant please?

Professor A PORTEOUS

Faculty of Technology

The Open University

Milton Keynes, Buckinghamshire