LETTER:The Big Bang and why our universe may not be alone

Sir: I enjoyed your article "What on earth has space done for us" (4 March). However, you seem to have got the facts confused in describing how Roy Plunkett discovered Teflon in 1938.

You say "the gas had reacted with the cylinder, which was made of tetrafluoroethylene". Tetrafluoroethylene is a gas, not the sort of substance cylinders are made of. As I heard the story from Professor Eric Banks of Umist, an authority on organofluorine chemistry, Plunkett was surprised to find that a cylinder which should have contained tetrafluoroethylene was registering on the pressure gauge as being empty. He then took the brave step of cutting the cylinder open (a highly risky thing to do which would breach the safety regulations in any modern chemistry laboratory), and found that the tetrafluoroethylene had polymerised to give the greasy white solid polytetrafluoroethylene, which became known as PTFE or Teflon.

D. Roberts, FRSC

Bebington, Merseyside