Modern cosmology traces the origin and evolution of the universe from the Big Bang to the present, encompassing Hubble's law, the cosmic microwave background, dark matter, and dark energy. Key milestones include the discovery of the expanding universe, the prediction and detection of the CMB, and the evidence for cosmic acceleration.
American astronomer Vesto Slipher obtains the first measurements of radial velocities for spiral nebulae (galaxies), finding most are receding from Earth. This provides early evidence for an expanding universe. #astronomy #cosmology
Albert Einstein modifies his general relativity equations by adding a cosmological constant (Λ) to allow for a static universe, which he later calls his 'biggest blunder'. #physics #cosmology
Russian mathematician Alexander Friedmann derives solutions to Einstein's field equations that describe an expanding universe, laying the foundation for Big Bang theory. #cosmology #mathematics
Edwin Hubble identifies Cepheid variables in the Andromeda Nebula, establishing it as a separate galaxy and proving the universe is much larger than previously thought. #astronomy #cosmology
Belgian priest and astronomer Georges Lemaître formulates the theory of an expanding universe from a single 'primeval atom', later known as the Big Bang. #cosmology #physics
Edwin Hubble announces a linear relationship between galaxy distances and their recessional velocities, now known as Hubble's Law, providing strong evidence for an expanding universe. #astronomy #cosmology
Swiss astronomer Fritz Zwicky observes that galaxies in the Coma Cluster move too fast for the visible mass, suggesting unseen 'dark matter'. #astronomy #darkmatter
George Gamow, with Ralph Alpher and Robert Herman, predicts the existence of cosmic microwave background radiation as a remnant of the Big Bang. #cosmology #physics
Fred Hoyle, Hermann Bondi, and Thomas Gold propose the Steady State theory, which suggests the universe is eternal and expanding but maintains constant density via continuous matter creation. #cosmology #astronomy
Arno Penzias and Robert Wilson accidentally discover cosmic microwave background radiation, providing strong evidence for the Big Bang and earning them the 1978 Nobel Prize. #astronomy #cosmology
Robert Dicke, James Peebles, and colleagues interpret the CMB as the afterglow of the Big Bang, solidifying the Big Bang theory over Steady State. #cosmology #physics
Vera Rubin and Kent Ford measure flat rotation curves of spiral galaxies, showing they contain substantial dark matter, providing decisive evidence for its existence. #astronomy #darkmatter
Stephen Hawking predicts that black holes emit Hawking radiation due to quantum effects, connecting general relativity and quantum mechanics. #physics #cosmology
Alan Guth proposes cosmic inflation, a rapid expansion in the early universe, solving the horizon and flatness problems. #cosmology #physics )
The closest supernova observed in centuries, SN 1987A, provides insights into stellar evolution, neutrino astronomy, and the role of heavy elements in the universe. #astronomy #supernova
The Hubble Space Telescope is launched, revolutionizing astronomy with crisp images and enabling precise measurements of the universe's expansion rate and age. #astronomy #telescope
NASA's COBE satellite detects tiny temperature fluctuations in the CMB, providing the first evidence of the seeds of cosmic structure and supporting inflation. #cosmology #astronomy
Two teams, the Supernova Cosmology Project and the High-Z Supernova Search Team, find that distant Type Ia supernovae are fainter than expected, indicating the universe's expansion is accelerating due to dark energy. #cosmology #darkenergy
NASA's Wilkinson Microwave Anisotropy Probe (WMAP) begins mapping the CMB with high precision, providing detailed measurements of cosmological parameters. #cosmology #astronomy
The SDSS conducts a massive survey of galaxies, quasars, and stars, creating a detailed 3D map of the universe and contributing to dark matter and dark energy studies. #astronomy #cosmology
WMAP results show the universe is flat and composed of about 4% ordinary matter, 23% dark matter, and 73% dark energy, confirming the standard cosmological model. #cosmology #physics
ESA's Planck mission is launched to study the CMB with unprecedented sensitivity and resolution, improving measurements of cosmological parameters. #astronomy #cosmology )
Saul Perlmutter, Brian Schmidt, and Adam Riess win the Nobel Prize in Physics for the discovery of the accelerating expansion of the universe through supernova observations. #physics #cosmology
The Planck mission releases its first all-sky map of the CMB, providing the most precise values for the universe's age (13.8 billion years) and composition. #cosmology #astronomy )
The LIGO collaboration detects gravitational waves from a binary black hole merger, opening a new window on the universe and testing general relativity. #physics #astronomy
The Dark Energy Survey (DES) starts mapping galaxies and supernovae to understand the nature of dark energy, using the Blanco telescope in Chile. #cosmology #astronomy
LIGO and Virgo detect gravitational waves from a neutron star merger (GW170817), followed by electromagnetic observations, ushering in multi-messenger astronomy. #astronomy #physics
ESA's Gaia mission releases its second data release, providing precise positions and motions for over 1 billion stars, revolutionizing galactic archaeology and cosmology. #astronomy #space )
The EHT collaboration releases the first direct image of a black hole's event horizon in M87, confirming predictions of general relativity. #astronomy #physics
Roger Penrose wins for theoretical black hole study; Andrea Ghez and Reinhard Genzel for discovery of supermassive black hole at Milky Way's center. #physics #astronomy
NASA's James Webb Space Telescope, the most powerful space telescope ever, is launched to study the early universe, exoplanets, and more. #astronomy #space
DESI starts its 5-year survey to create a 3D map of galaxies and quasars, aiming to constrain dark energy and cosmic expansion. #cosmology #astronomy
ESA's Euclid space telescope is launched to study dark energy and dark matter by mapping the geometry of the universe. #cosmology #astronomy )
The North American Nanohertz Observatory for Gravitational Waves (NANOGrav) detects a low-frequency gravitational wave background likely from supermassive black hole binaries. #physics #astronomy
James Webb Space Telescope observes unexpectedly massive galaxies in the early universe, challenging existing models of galaxy formation. #astronomy #cosmology
Persistent discrepancy between local and early universe measurements of Hubble constant suggests possible new physics beyond ΛCDM. #cosmology #physics
Experiments like LZ and XENONnT set new limits on dark matter interactions, but no detection yet, driving new theoretical directions. #physics #darkmatter
NASA's Roman Telescope (formerly WFIRST) is scheduled to launch, aiming to study dark energy, exoplanets, and infrared astrophysics. #astronomy #space
The Laser Interferometer Space Antenna (LISA) pathfinder demonstrates technology for future space-based gravitational wave observatory. #physics #astronomy
