Question for Prof Gift

THE EDITOR: As one whose electrical engineering education stopped at HNC level and that over fifty years ago, it is with profound respect and diffidence that I would like some clarification on Professor Gifts’ letter regarding the speed of light. I have read much of Einstein’s Theory of Relativity and understand nothing about it. But I do have a logical mind and Professor Gifts’ explanation of the speed of light leaves me puzzled.

It is generally accepted that the speed of light is constant and to my mind the Professor’s analogy with the traffic light does not make sense. If, as he says, a light is flashed towards a person standing still the speed of light will be measured as A. Assuming for the moment that the speed of light is 60 mph then that is A as measured by the person receiving the flash. If, however, the man moves towards the light at 10 mph (B) then the apparent speed of light will be 70 mph. A plus B. However this does not alter the fact that the actual speed of light has not changed but only apparently so to the man. Perhaps someone will point out the error in my logic, I am always ready to learn!

HUGH PUTT