October 19,
2000
The Editor
New
Scientist
Dear Sir
“Curtains
for Quantum Theory”? (October 14 cover
story, p24, by Marcus Chown) I doubt
it: quantum theory has weathered many a storm and I expect it will survive this
one. Not that I personally think it
deserves to – once you’ve adapted to its neat little ideas and populated your
mind with photons and indivisible electrons, you have to learn a considerable
amount of double-think to make this fit what Nature actually does. Especially as regards photons.
Now I don’t
know that much about electrons, but photons are another matter and the reason
for this letter is to correct Marcus on a point of fact. He mentions that “the electron fragments …
might even be ‘entangled’ … Quantum physicists have already managed to achieve
this with photons …”.
Quantum
physicists have not achieved this with photons! They have not even proved that the photon
exists, let alone that it can get entangled.
Try asking them! Those who have
actually dealt with the tests for “non-local correlations” – the experimenters,
the theoreticians, the journal editors, the referees – know perfectly well that
every single test so far has been invalid.
Every single one has had “loopholes” that allow ordinary correlations,
not quantum ones, to do the job. What is
true is that they believe to a man (they say!) that if and when a
loophole-free test is conducted it will support their theory.
Well, good
luck to them, but meantime, let us hope that they are more realistic than that
in their attempts at dealing with half-sized electrons.
(If you
would like to see some common sense ideas about what happens in the real tests
for entanglement, have a look at my web site: http://www.aber.ac.uk/~cat.)
Yours
sincerely
Caroline H
Thompson