Blaylock argues that the derivation of Bell’s inequality requires a hidden assumption, counterfactual definiteness, of which Bell was unaware. A careful analysis of Bell’s argument shows that Bell presupposes only locality and the predictions of standard quantum mechanics. Counterfactual definiteness, insofar as it is required, is derived in the course of the argument rather than presumed. Bell’s theorem has no direct bearing on the many worlds interpretation not because that interpretation denies counterfactual definiteness but because it does not recover the predictions of standard quantum mechanics.

1.
G.
Blaylock
, “
The EPR paradox, Bell’s inequality, and the question of locality
,”
Am. J. Phys.
78
(
1
),
111
120
(
2009
).
2.
D.
Greenberger
,
M.
Horne
, and
A.
Zeilinger
, “
Going beyond Bell’s theorem
” in
Bell’s Theorem, Quantum Theory, and Conceptions of the Universe
, edited by
M.
Kaftos
(
Kluwer
,
Dordrecht
,
1989
), pp.
69
72
.
3.
R.
Penrose
,
Shadows of the Mind
(
Oxford U. P.
,
Oxford
,
1994
), pp.
296
300
.
4.
See, for example,
P.
Heywood
and
M. L. G.
Redhead
, “
Nonlocality and the Kochen–Specker paradox
,”
Found. Phys.
13
,
481
499
(
1983
);
A.
Stairs
, “
Quantum logic, realism and value-definiteness
,”
Philos. Sci.
50
,
578
602
(
1983
).
5.
Albert
Einstein
,
Boris
Podolsky
, and
Nathan
Rosen
, “
Can quantum mechanical description of reality be considered complete?
,”
Phys. Rev.
47
,
777
780
(
1935
).
6.
J. S.
Bell
, “
Bertlmann’s socks and the nature of reality
,”
J. Phys. Colloq.
42
,
41
61
(
1981
).
Reprinted in
J. S.
Bell
,
Speakable and Unspeakable in Quantum Mechanics
, 2nd ed. (
Cambridge U. P.
,
Cambridge
,
2004
), Chap. 16, quotation on p.
143
.
7.
J. S.
Bell
, “
On the Einstein–Podolsky–Rosen paradox
,”
Physics
1
,
195
200
(
1964
).
8.
Reference 7, pp.
195
196
, and Ref. 6.
AAPT members receive access to the American Journal of Physics and The Physics Teacher as a member benefit. To learn more about this member benefit and becoming an AAPT member, visit the Joining AAPT page.