Through the long‐range force of gravity, mass controls the evolution of the universe. Studies of the internal motion of large, gravitationally bound systems such as galaxies and clusters of galaxies have already shown us, rather convincingly, that the mass in these systems is dominated by some form of matter that is not luminous at any wavelength from radio to x ray. (See the article by Scott Tremaine in PHYSICS TODAY, February, page 28.)

1.
R. G.
Kron
,
Vistas Astron.
26
,
37
(
1982
).
J. F.
Jarvis
,
J. A.
Tyson
,
Astron. J.
86
,
476
(
1981
).
2.
J. A. Tyson, in CCDs in Astronomy, G. Jacoby, ed., Astron. Soc. Pacific, San Francisco (1990), p. 1.
3.
J. A.
Tyson
,
Astron. J.
96
,
1
(
1988
).
4.
P.
Guhathakurta
,
J. A.
Tyson
,
S.
Majewski
,
Astrophys. J.
357
,
L19
(
1990
).
5.
F.
Zwicky
,
Phys. Rev. Lett.
51
,
290
(
1937
).
6.
E. L.
Turner
,
J. P.
Ostriker
,
J. R.
Gott
,
Astrophys. J.
284
,
1
(
1984
).
7.
G.
Hinshaw
,
L. M.
Krauss
,
Astrophys. J.
320
,
468
(
1987
).
8.
W.
Press
,
J. E.
Gunn
,
Astrophys. J.
185
,
397
(
1973
).
See also
J. E.
Gunn
,
Astrophys. J.
147
,
61
(
1967
);
J. E.
Gunn
,
150
,
737
(
1967
).
9.
D.
Walsh
,
R. F.
Carswell
,
R. J.
Weymann
,
Nature
279
,
381
(
1979
).
10.
C.
Kochanek
,
Astrophys. J.
375
,
492
(
1991
).
11.
J. A.
Tyson
,
F.
Valdes
,
J. F.
Jarvis
,
A. P.
Mills
,
Astrophys. J.
281
,
L59
(
1984
).
12.
A.
Hoag
,
Bull. Am. Astron. Soc.
13
,
799
(
1981
).
13.
R.
Lynds
,
V.
Petrosian
,
Bull. Am. Astron. Soc.
18
,
1014
(
1986
);
R.
Lynds
,
V.
Petrosian
,
Astrophys. J.
336
,
1
(
1989
).
G.
Soucail
,
Y.
Mellier
,
B.
Fort
,
F.
Hammer
,
G.
Mathez
,
Astron. Astrophys.
184
,
L9
(
1987
).
G.
Soucail
,
Y.
Mellier
,
B.
Fort
,
G.
Mathez
,
M.
Cailloux
,
Astron. Astrophys.
191
,
L19
(
1988
).
14.
T.
Noonan
,
Astron. J.
76
,
765
(
1971
).
R. D.
Blandford
,
R.
Narayan
,
Astrophys. J.
310
,
568
(
1986
).
R. D.
Blandford
,
E. S.
Phinney
,
R.
Narayan
,
Astrophys. J.
313
,
28
(
1987
).
B. P.
Paczynski
,
Nature
325
,
572
(
1987
).
S. A.
Grossman
,
R.
Narayan
,
Astrophys. J.
324
,
L37
(
1988
).
15.
B.
Fort
,
J.
Prieur
,
G.
Mathez
,
Y.
Mellier
,
G.
Soucail
,
Astron. Astrophys.
200
,
L17
(
1988
).
Y.
Mellier
,
G.
Soucail
,
B.
Fort
,
G.
Mathez
,
Astron. Astrophys.
199
,
13
(
1988
).
16.
J. A.
Tyson
,
F.
Valdes
,
R. A.
Wenk
,
Astrophys. J.
349
,
L1
(
1990
).
J. A. Tyson, in After the First Three Minutes, AIP Conf. Proc. 222, S. Holt, C. Bennett, V. Trimble, eds., AIP, New York (1991), p. 437.
17.
S.
Tremaine
,
J. E.
Gunn
,
Phys. Rev. Lett.
42
,
407
(
1979
).
18.
F.
Valdes
,
J. A.
Tyson
,
J. F.
Jarvis
,
Astrophys. J.
271
,
431
(
1983
).
J.
Miralda‐Escude
,
Astrophys. J.
380
,
1
(
1991
).
R. D.
Blandford
,
A. B.
Saust
,
T.
Brainerd
,
J. V.
Villumsen
,
Mon. Not. R. Astron. Soc.
2451
,
600
(
1991
).
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