wrote a popular encyclopedia of cosmology, geography, and world history Hanns Hörbiger (1860–1931) formulated a pseudoscientific theory of ice as the basic substance of all cosmic processes Fred Hoyle (1915–2001) promoted the steady state theory, used the anthropic principle to explain the energy levels of carbon nuclei Edwin P. Hubble (1889–1953) demonstrated the existence of other galaxies and confirmed the relation between redshift and distance John P. Huchra (1948–2010) discovered the Great Wall, a superstructure-scale filament of galaxies I Mustapha Ishak Boushaki (1967–) physicist researcher on Cosmology Jamal Nazrul Islam (1939–2013) published seven books on Cosmology K Ronald Kantowski (1939–) discovered spatially homogeneous but anisotropic solutions to general relativity Johannes Kepler (1571–1630) pioneered heliocentrism, discovered elliptical planetary motion, attempted to explain heavenly motions through physical causes Isaak Markovich Khalatnikov (1919–2021) conjectured an oscillatory model with an essential singularity for the evolution of the universe Tom W. B. Kibble (1932–2016) introduced the concept of cosmic strings Robert Kirshner (1949–) discovered the Boötes void, a large region sparsely populated with galaxies, and wrote a popular book on cosmology Edward Kolb (1951–) studied big bang cosmology including the emergence of baryons and dark matter, and wrote a popular textbook on cosmology Lawrence M. Krauss (1954–) author of popular science books on cosmology including A Universe from Nothing L Ofer Lahav (1959–) studied dark matter and dark energy Tod R. Lauer (1957–) catalogued massive black holes at galaxy centers and correlated their mass with other properties of the galaxies' structures Georges Henri Lemaître (1894–1966) proposed the big bang theory and the distance-redshift relation Janna Levin (1967–) seeks evidence for a bounded universe of nontrivial topology Andrew R. Liddle (1965–) studied inflationary models, wrote two books on inflation and primordial inhomogeneities Evgeny M. Lifshitz (1915–1985) conjectured an oscillatory model with an essential singularity for the evolution of the universe Andrei Linde (1948–) pioneered inflationary models and proposed eternal chaotic inflation of universes from the false vacuum Abraham Loeb (1962–) researched primordial stars, primordial black holes, quasars, reionization, gravitational lensing, and gamma-ray bursts Jean-Pierre Luminet (1951–) studied black holes and the topology of the Universe David H. Lyth (1940–) studied particle cosmology, wrote two books on inflation and primordial inhomogeneities M João Magueijo (1967–) proposed much faster speeds of light in the young universe as an alternative explanation to inflation for its homogeneity Richard Massey (1977–) mapped dark matter in the universe Charles W. Misner (1932–)