The "two-slit experiment" and its enigma

  Examined from the point-of-view of either traditional `classical'
  theory or `quantum theory' - the two-slit experiment poses severe
  problems in that they both have to say that "photons" must travel
  thru time - forwards and backwards - to achieve the results seen.

  QUOTE
  "The great physicist Richard P Feynman said that the experiment 
  with two holes encapsulates the `central mystery' of quantum
  mechanics, and that nobody understands what is going on in it."
  UNQUOTE
  - from "Companion to the Cosmos" John Gribbin ISBN 0-297-81725-6

  Feynman himself, in his lectures on quantum electrodynamics
  ["Q.E.D." Penguin Books 1990 ISBN 0-14-012505-1] says:
 
   "Nature has it all cooked up so we'll never be able to figure out
    how She does it: if we put instruments in to find out which way
    the light goes, we can find out, all right, but the wonderful
    interference effects disappear. But if we don't have instruments
    that can tell which way the light goes, the interference effects
    come back! . . . 

  ----------------------------------------------------------------

   Check http://www.perceptions.couk.com/uef/experiment.txt

   More detail and answers at 

   http://www.perceptions.couk.com/uef/radiation.html#feynman

   For the REAL answer to the two-slit enigma, see

   http://www.perceptions.couk.com/uef/radiation.html#firstly

  -----------------------------------------

              FURTHER REFERENCES

 GO - "search perceptions" - in SEARCH-ENGINE


file-ID www.perceptions.couk.com/twoslit.txt