By their very nature, those discoveries which most change the way we perceive our physical universe are difficult to anticipate. How then, are such discoveries made, and what experimental approaches are most likely to lead to discoveries? In this article I will describe four experiments in which I have participated that have yielded unexpected new physics, and attempt to explain how they came about.

1.
David Goodstein and Judith Goodstein, “Richard Feynman and the History of Superconductivity,” in History of Original Ideas and Basic Discoveries in Particle Physics, edited by H. B. Newman and T. Ypsilantis (Plenum, New York, 1996), pp. 773–779.
2.
J.
Bardeen
,
L. N.
Cooper
, and
J. R.
Schrieffer
, “
Theory of Superconductivity
,”
Phys. Rev.
108
,
1175
1204
(
1957
).
3.
Robert W. Wilson, “The Cosmic Microwave Background Radiation,” Les Prix Nobel 1978, edited by K. Siegbahn et al. (Almqvist and Wiksell, Stockholm, 1979), pp. 113–133.
4.
G.
Gamow
, “
The Evolution of the Universe
,”
Nature (London)
162
,
680
682
(
1948
).
5.
David Wilkinson (private communication).
6.
I.
Pomeranchuk
, “
On the Theory of Liquid He3,
Zh. Eksp. Teor. Fiz.
20
,
919
926
(
1950
).
7.
Y. D.
Anufriyev
, “
Use of the Pomeranchuk Effect to Obtain Infralow Temperature
,”
JETP Lett.
1
,
155
157
(
1965
).
8.
William E. Keller, Helium-3 and Helium-4 (Plenum, New York, 1969).
9.
R. T.
Johnson
,
R. E.
Rapp
, and
J. C.
Wheatley
, “
Effect of a Magnetic Field on the Melting Curve of He3,
J. Low Temp. Phys.
6
,
445
453
(
1971
).
10.
Douglas D.
Osheroff
, “Superfluidity in He3: Discovery and Understanding,” in Les Prix Nobel 1996, edited by T. Frängsmyr and Brigitta Lundeberg (Norstedts Tryckeri AB, Stockholm, 1997), pp. 103–133.
Douglas D.
Osheroff
, Also:
Rev. Mod. Phys.
69
,
667
681
(
1997
), and available from World Scientific, Singapore on CD-ROM.
11.
D. D.
Osheroff
, “
Nuclear Magnetic Order in Solid He3,
J. Low Temp. Phys.
87
,
297
342
(
1992
).
12.
N.
Bernardes
and
H.
Primakoff
, “
Theory of Solid He3,
Phys. Rev. Lett.
2
,
290
292
(
1960
).
13.
J. R.
Sites
,
D. D.
Osheroff
,
R. C.
Richardson
, and
D. M.
Lee
, “
Nuclear Magnetic Susceptibility of Solid He3 Cooled by Compression from the Liquid Phase
,”
Phys. Rev. Lett.
23
,
836
839
(
1969
).
14.
W. P.
Halperin
,
C. N.
Archie
,
F. B.
Rasmussen
,
R. A.
Buhrman
, and
R. C.
Richardson
, “
Observation of Nuclear Magnetic Order in Solid He3,
Phys. Rev. Lett.
32
,
927
930
(
1974
).
15.
M.
Roger
,
J. M.
Delrieu
, and
A.
Landesman
, “
Nuclear Spin Ordering with Four Spin Exchange in Solid bcc He3,
Phys. Lett.
62A
,
449
452
(
1977
).
16.
D. D.
Osheroff
,
M. C.
Cross
, and
D. S.
Fisher
, “
Nuclear Antiferromagnetic Resonance in Solid He3,
Phys. Rev. Lett.
44
,
792
795
(
1980
).
17.
A.
Benoit
,
J.
Bossy
,
J.
Flouquet
, and
J.
Schweizer
, “
Magnetic Diffraction in Solid He3,
J. Phys. (France) Lett.
46
,
L923
L927
(
1985
).
18.
E. D.
Adams
,
E. A.
Schubert
,
G. E.
Haas
, and
D. M.
Bakalyar
, “
NMR in Magnetically Ordered Solid He3,
Phys. Rev. Lett.
44
,
789
792
(
1980
).
19.
David
Thouless
, “
Maximum Metallic Resistance in Thin Wires
,”
Phys. Rev. Lett.
39
,
1167
1169
(
1977
).
20.
P. W.
Anderson
,
E.
Abrahams
, and
T. V.
Ramakrishnan
, “
Possible Explanation of Nonlinear Conductivity in Thin-Film Metal Wires
,”
Phys. Rev. Lett.
43
,
717
720
(
1979
);
G. R.
Dolan
and
D. D.
Osheroff
, “
Non-Metallic Conduction in thin Metal Films at Low Temperatures
,”
Phys. Rev. Lett.
43
,
721
724
(
1979
).
21.
R. C.
Zeller
and
R. O.
Pohl
, “
Thermal Conductivity and Specific Heat of Noncrystalline Solids
,”
Phys. Rev. B
4
,
2029
2041
(
1971
).
22.
Tunneling Systems in Solids, edited by Pablo Esquinazi (Springer-Verlag, Berlin, 1998).  
This content is only available via PDF.
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.