studied solutions to general relativity including the mixmaster universe and Misner space, wrote influential text on gravitation John Moffat (1932–) proposed much faster speeds of light in the young universe, developed antisymmetric theories of gravity Lauro Moscardini (1961–) modeled galaxy clustering in the early universe N Jayant Narlikar (1938–) promoted steady state theories Isaac Newton (1642–1727) formulated the law of universal gravitation and supported the heliocentric model P György Paál (1934–1992) in the late 1950s studied the quasar and galaxy cluster distributions, in 1970 from redshift quantization came up with the idea that the Universe might have nontrivial topological structure Thanu Padmanabhan (1957–2021) studied quantum gravity and quantum cosmology Leonard Parker (1938–) established the study of quantum field theory within general relativity P. James E. Peebles (1935–) predicted cosmic background radiation, contributed to structure theory, developed models that avoid dark matter Roger Penrose (1931–) linked singularities to gravitational collapse, conjectured the nonexistence of naked singularities, and used gravitational entropy to explain homogeneity Arno Penzias (1933–) was the first to observe the cosmic background radiation Saul Perlmutter (1959–) used supernova observations to measure the expansion of the universe Mark M. Phillips (1951–) used supernova observations to discover acceleration in the expansion of the universe, calibrated the supernova distance scale Joel Primack (1945–) co-invented the theory of cold dark matter Ptolemy (90–168) wrote the only surviving ancient text on astronomy, conjectured a model of the universe as a set of nested spheres with epicycles Q Ali Qushji (1403–1474) challenged Aristotelian physics, in particular presenting empirical evidence against a stationary Earth, and may have influenced Copernicus R Lisa Randall (1962-) contributed to Randall–Sundrum models, which describe the world in terms of a warped geometry higher-dimensional universe Martin Rees (1942–) proposed that quasars are powered by black holes, disproved steady state by studying distribution of quasars Yoel Rephaeli used the distortion of the cosmic background by high-energy electrons to infer the existence of galaxy clusters Adam Riess (1969–) found evidence in supernova data that the expansion of the universe is accelerating and confirming dark energy models Wolfgang Rindler (1924–2019) coined the phrase "event horizon", Rindler Coordinates, and popularized the use of spinors (with Roger Penrose) Howard P. Robertson (1903–1961) solved the two-body problem in an approximation to general relativity, developed the standard model of general relativity Vera Rubin (1928–2016) discovered discrepancies in galactic rotation rates leading to the theory of dark matter S Rainer