A trick of the light?
Sir, – Margaret Moore (September 29th) asks what word will be used to describe a speed faster than the speed of light. The technical term is superluminal speed.
However, much of the media coverage of recent experiments at Gran Sasso has been very misleading. Almost all professional physicists (including the experimenters) consider the Gran Sasso result a curious anomaly almostcertainly due to some unknown error in measurement, for several reasons: 1. Light is carried by particles of zero mass and it follows that there are fundamental theoretical reasons for supposing that the speed of light in vacuum represents a natural speed limit. 2. Thousands of experiments have verified that the tiniest particles of matter can be accelerated up to speeds close to, but not equal to, this limiting speed. 3. The recent Gran Sasso experiment involves measurements of time and distance of unprecedented precision, yet it was not designed for this specific purpose; thus there are many potential sources of systematic error.
It’s true that science sometimes progresses by upsetting the status quo, but scientists are a sceptical lot and extraordinary claims require extraordinary evidence! –Yours, etc,