Cosmology & Big Bang: Expanding Space, Dark Matter & JWST
Encyclopedia/1. The Cosmos & The Natural World/3. Astronomy & Planetary Science/03. Extragalactic Astronomy & Cosmology • Curated by Admin Timeline.sg
Cosmology explores the origin, evolution, and large-scale structure of the universe. Key milestones include the discovery of cosmic expansion, the cosmic microwave background, dark matter, dark energy, and the revolutionary observations from the James Webb Space Telescope.
Chronological Storyline (45 Milestones)
Apr 26, 1920 CE
Shapley-Curtis Debate on the Scale of the Universe
Harlow Shapley and Heber Curtis debated whether spiral nebulae were within the Milky Way or separate galaxies. This debate set the stage for understanding the universe's vast scale. #cosmology #astronomy #debate
Shapley-Curtis Debate on the Scale of the Universe By Unknown author - http://siarchives.si.edu/collections/siris_arc_306337?back=%2Fcollections%2Fsearch%3Fquery%3Dshapley%26page%3D1%26perpage%3D10%26sort%3Drelevancy%26view%3Dlist, Public domain, https://commons.wikimedia.org/w/index.php?curid=19170840
1924 CE
Hubble Discovers Cepheid Variables in Andromeda
Edwin Hubble identified Cepheid variable stars in the Andromeda Nebula, proving it was a separate galaxy beyond the Milky Way. This expanded the known universe dramatically. #cosmology #galaxies #Hubble
Hubble Discovers Cepheid Variables in Andromeda By Johan Hagemeyer - http://hdl.huntington.org/cdm/ref/collection/p15150coll2/id/129, Public domain, https://commons.wikimedia.org/w/index.php?curid=53878391
1927 CE
Lemaître Proposes Expanding Universe
Georges Lemaître derived the expanding universe solution from Einstein's equations, predicting a linear relation between distance and recession velocity. This laid the foundation for the Big Bang theory. #cosmology #BigBang #expansion
Lemaître Proposes Expanding Universe By Unknown author - https://societyforthehistoryofastronomy.com/wp-content/uploads/2023/01/AA14-June-20.pdf, Public domain, https://commons.wikimedia.org/w/index.php?curid=154504242
1929 CE
Hubble's Law of Cosmic Expansion
Edwin Hubble published his observation that galaxies are receding at speeds proportional to their distance, now known as Hubble's Law. This provided strong evidence for an expanding universe. #cosmology #Hubble #expansion
Hubble's Law of Cosmic Expansion By w:en:User:ScienceApologist - This image was copied from wikipedia:en. The original description was: The raisin bread model of the universe explains how each galaxy can perceive every other galaxy in the universe as receding from it. From the WMAP website., Public domain, https://commons.wikimedia.org/w/index.php?curid=2615116
1931 CE
Lemaître Proposes the Primeval Atom
Georges Lemaître suggested the universe began as a single quantum 'primeval atom' that exploded, a precursor to the Big Bang theory. This was the first modern concept of a cosmic origin. #cosmology #BigBang #origin
1933 CE
Zwicky Discovers Dark Matter in Coma Cluster
Fritz Zwicky observed that galaxies in the Coma Cluster moved too fast for the visible mass, inferring the presence of unseen 'dark matter'. This was the first evidence for dark matter. #cosmology #darkmatter #galaxies
Zwicky Discovers Dark Matter in Coma Cluster By Comet Photo AG (Zürich) - http://doi.org/10.3932/ethz-a-000050128, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=177261830
1948 CE
Gamow, Alpher, and Herman Predict Cosmic Microwave Background
George Gamow, Ralph Alpher, and Robert Herman predicted a relic radiation from the Big Bang, now known as the cosmic microwave background (CMB). They estimated its temperature at about 5 K. #cosmology #CMB #BigBang
Gamow, Alpher, and Herman Predict Cosmic Microwave Background By ESA and the Planck Collaboration - Cosmic Microwave Background, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=130789180
1950 CE
Hoyle Coins 'Big Bang' Term
Fred Hoyle, a proponent of the steady-state theory, used the term 'Big Bang' derisively during a BBC radio broadcast. The name stuck and became the popular term for the theory. #cosmology #BigBang #history
Hoyle Coins 'Big Bang' Term By AIP Emilio Segrè Visual Archives, Clayton Collection - https://repository.aip.org/hoyle-sloan-laboratory, Attribution, https://commons.wikimedia.org/w/index.php?curid=172734747
May 20, 1964 CE
Penzias and Wilson Discover Cosmic Microwave Background
Arno Penzias and Robert Wilson accidentally detected a faint microwave background noise using a horn antenna. This was identified as the CMB, providing strong evidence for the Big Bang. #cosmology #CMB #discovery
1965 CE
Dicke, Peebles, Roll, and Wilkinson Interpret CMB
Robert Dicke, Jim Peebles, and colleagues interpreted the noise found by Penzias and Wilson as the cosmic microwave background. They published the theoretical explanation, confirming the Big Bang. #cosmology #CMB #BigBang
Dicke, Peebles, Roll, and Wilkinson Interpret CMB By NASA / WMAP Science Team - http://map.gsfc.nasa.gov/media/121238/ilc_9yr_moll4096.png, Public domain, https://commons.wikimedia.org/w/index.php?curid=23285693
1970 CE
Vera Rubin Confirms Dark Matter in Galaxies
Vera Rubin and Kent Ford measured rotation curves of spiral galaxies, finding flat rotation curves that implied large amounts of unseen dark matter. This solidified dark matter as a major component. #cosmology #darkmatter #galaxies
Vera Rubin Confirms Dark Matter in Galaxies By Photograph by Mark Godfrey, courtesy of AIP Emilio Segrè Visual Archives, Gift of Vera Rubin - https://repository.aip.org/node/111858, Attribution, https://commons.wikimedia.org/w/index.php?curid=177261379
1979 CE
Inflationary Universe Proposed by Alan Guth
Alan Guth proposed the inflationary universe model, solving the horizon and flatness problems. Inflation posits a rapid exponential expansion in the early universe. #cosmology #inflation #BigBang
1980 CE
First Detection of Cosmic Neutrino Background?
The cosmic neutrino background is predicted but not yet directly detected. This milestone marks the theoretical prediction and ongoing search for relic neutrinos from the Big Bang. #cosmology #neutrinos #BigBang
1981 CE
Andrei Linde Develops Chaotic Inflation
Andrei Linde proposed chaotic inflation, a more general version of inflationary theory. This model allowed inflation to occur in a wide range of initial conditions. #cosmology #inflation #theory
Feb 23, 1987 CE
Supernova 1987A Observed
The closest supernova observed in centuries, SN 1987A in the Large Magellanic Cloud, provided crucial data on stellar evolution and neutrino emission. It also helped calibrate cosmic distances. #cosmology #supernova #astronomy
Supernova 1987A Observed By NASA Goddard Space Flight Center from Greenbelt, MD, USA - New Hubble Observations of Supernova 1987A Trace Shock Wave, Public domain, https://commons.wikimedia.org/w/index.php?curid=69021019
Apr 23, 1992 CE
COBE Satellite Detects CMB Anisotropies
NASA's COBE satellite discovered tiny temperature fluctuations in the cosmic microwave background. These anisotropies are the seeds of large-scale structure in the universe. #cosmology #CMB #COBE
COBE Satellite Detects CMB Anisotropies By NASA - https://science.nasa.gov/toolkits/spacecraft-icons (image link), Public domain, https://commons.wikimedia.org/w/index.php?curid=58072784
Jan 8, 1998 CE
Discovery of Dark Energy Accelerating Expansion
Two teams studying Type Ia supernovae found that the universe's expansion is accelerating, implying a repulsive dark energy. This discovery led to the concept of a cosmological constant. #cosmology #darkenergy #acceleration
Jun 30, 2001 CE
WMAP Satellite Launched
NASA's Wilkinson Microwave Anisotropy Probe (WMAP) was launched to study the CMB with high precision. It provided detailed measurements of cosmological parameters. #cosmology #CMB #WMAP
WMAP Satellite Launched By NASA / WMAP Science Team - [1]; converted from the high-resolution TIFF version to a JPEG, Public domain, https://commons.wikimedia.org/w/index.php?curid=3944989
Feb 11, 2003 CE
WMAP First-Year Results Released
WMAP's first-year data gave precise values for the age of the universe (13.7 billion years), composition (4.6% ordinary matter, 23% dark matter, 72% dark energy), and flat geometry. #cosmology #CMB #WMAP
2005 CE
Sloan Digital Sky Survey Maps Large-Scale Structure
The SDSS created a 3D map of over a million galaxies, revealing the cosmic web of filaments and voids. This data constrained dark energy and structure formation models. #cosmology #galaxies #surveys
Sloan Digital Sky Survey Maps Large-Scale Structure By Sloan Digital Sky Survey - http://skyserver.sdss.org/dr14/SkyServerWS/ImgCutout/getjpeg?TaskName=Skyserver.Chart.Image&ra=218.928604&dec=+08.300503&scale=0.3&width=800&height=800&opt=&query=, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=75828618
Aug 21, 2006 CE
Bullet Cluster Provides Direct Evidence for Dark Matter
Observations of the Bullet Cluster showed a separation between visible matter (X-ray gas) and gravitational lensing, indicating dark matter's existence. This was strong evidence against modified gravity. #cosmology #darkmatter #evidence
Bullet Cluster Provides Direct Evidence for Dark Matter By User:Mac_Davis - http://cxc.harvard.edu/symposium_2005/proceedings/files/markevitch_maxim.pdf, Public domain, https://commons.wikimedia.org/w/index.php?curid=1080845
May 14, 2009 CE
Planck Satellite Launched
ESA's Planck satellite was launched to map the CMB with unprecedented resolution. It improved measurements of cosmological parameters and tested inflation models. #cosmology #CMB #Planck
Planck Satellite Launched By Photograph by Mike Peel (www.mikepeel.net). - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=14045307
Jul 4, 2012 CE
Higgs Boson Discovered at CERN
The discovery of the Higgs boson at the Large Hadron Collider confirmed the mechanism of mass generation. This has implications for early universe physics and particle cosmology. #cosmology #particlephysics #Higgs
Higgs Boson Discovered at CERN By CERN for the ATLAS and CMS Collaborations - https://cds.cern.ch/record/1630222, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=29737816
Mar 21, 2013 CE
Planck 2013 Results Released
Planck's data refined the age of the universe to 13.8 billion years and confirmed a flat geometry. It also found a slight tension with other measurements of the Hubble constant. #cosmology #CMB #Planck
Mar 17, 2014 CE
BICEP2 Announces Detection of Primordial Gravitational Waves
The BICEP2 experiment claimed detection of B-mode polarization in the CMB, a signal of inflation. Later analysis showed the signal was largely due to dust, but it spurred further research. #cosmology #inflation #gravitationalwaves
BICEP2 Announces Detection of Primordial Gravitational Waves By NASA/JPL-Caltech - http://photojournal.jpl.nasa.gov/jpeg/PIA17993.jpg, Attribution, https://commons.wikimedia.org/w/index.php?curid=31669336
Sep 14, 2015 CE
LIGO Detects Gravitational Waves
LIGO made the first direct detection of gravitational waves from merging black holes. This opened a new window on the universe and tested general relativity in strong fields. #cosmology #gravitationalwaves #LIGO
LIGO Detects Gravitational Waves By B. P. Abbott et al. (LIGO Scientific Collaboration and Virgo Collaboration) — full list at the end of the article - http://physics.aps.org/featured-article-pdf/10.1103/PhysRevLett.116.061102 . See also the associated Jupyter notebook., CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=46987868
Aug 24, 2016 CE
Proxima b Discovered in Habitable Zone
An Earth-sized exoplanet was found orbiting Proxima Centauri, the nearest star to the Sun. This discovery highlights the prevalence of exoplanets and the search for life. #cosmology #exoplanets #habitability
Proxima b Discovered in Habitable Zone By ESO/M. Kornmesser - https://www.eso.org/public/images/ann16056a/, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=50869082
Oct 16, 2017 CE
LIGO and Virgo Detect Neutron Star Merger
Gravitational waves from a neutron star merger were detected, along with electromagnetic counterparts across the spectrum. This multi-messenger event provided insights into nucleosynthesis and cosmology. #cosmology #gravitationalwaves #neutronstars
LIGO and Virgo Detect Neutron Star Merger By LIGO Scientific Collaboration and Virgo Collaboration - https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.119.161101 This W3C-unspecified plot was created with Matplotlib., CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=63455773
Jul 20, 2018 CE
Dark Energy Survey Releases Year 1 Results
The Dark Energy Survey (DES) released data on hundreds of millions of galaxies, measuring dark energy and matter distribution. It provided constraints on the equation of state of dark energy. #cosmology #darkenergy #surveys
Dark Energy Survey Releases Year 1 Results By Felipe Menanteau and the Dark Energy Survey Collaboration - https://opensource.ncsa.illinois.edu/confluence/pages/viewpage.action?pageId=61604315, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=59740733
Apr 10, 2019 CE
First Image of a Black Hole (M87)
The Event Horizon Telescope captured the first direct image of a black hole's shadow in galaxy M87. This confirmed predictions of general relativity and provided a new tool for studying black holes. #cosmology #blackholes #EHT
First Image of a Black Hole (M87) By D. Marrone/UofA - Event Horizon Telescope Collaboration, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=133002860
Dec 17, 2020 CE
China's Chang'e 5 Returns Moon Samples
China's lunar mission returned the first Moon samples in 44 years. These samples help refine the lunar chronology and the history of the early solar system. #cosmology #moon #samples
China's Chang'e 5 Returns Moon Samples By China News Service - YouTube: https://www.youtube.com/watch?v=WBFJphwPDME&t=70s – View/save archived versions on archive.org, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=97338985
Dec 25, 2021 CE
James Webb Space Telescope Launched
NASA's JWST, the most powerful space telescope, was launched to observe the early universe, exoplanets, and more. Its infrared capabilities allow it to see the first galaxies and stars. #cosmology #JWST #telescope
James Webb Space Telescope Launched By NASA - https://www.jwst.nasa.gov/content/webbLaunch/whereIsWebb.html, Public domain, https://commons.wikimedia.org/w/index.php?curid=114125719
Jul 12, 2022 CE
JWST First Science Images Released
NASA released the first full-color images from JWST, including deep fields, exoplanet spectra, and nebula details. These images showcased the telescope's power and began a new era of discovery. #cosmology #JWST #images
Aug 25, 2022 CE
JWST Reveals Distant Galaxy Candidates
JWST identified galaxy candidates at redshifts beyond 10, possibly from the first 500 million years after the Big Bang. These observations challenge models of early galaxy formation. #cosmology #JWST #galaxies
Mar 14, 2023 CE
JWST Detects Carbon Dioxide on Exoplanet
JWST's spectroscopy of exoplanet WASP-39 b revealed carbon dioxide in its atmosphere, demonstrating its ability to characterize exoplanet atmospheres. This is key for habitability studies. #cosmology #exoplanets #JWST
JWST Detects Carbon Dioxide on Exoplanet By NASA, ESA, CSA, J. Olmsted (STScI) - Illustration (Artist’s Impression) of WASP-39 b and Its Star, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=125907007
Jul 12, 2023 CE
JWST's First Anniversary Image: Rho Ophiuchi
JWST released a stunning image of the Rho Ophiuchi cloud complex, revealing star formation in unprecedented detail. This highlights the telescope's ability to study stellar nurseries. #cosmology #JWST #starformation
JWST's First Anniversary Image: Rho Ophiuchi By NASA, ESA, CSA, STScI, K. Pontoppidan (STScI), A. Pagan (STScI) - Rho Ophiuchi cloud complex, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=134309239
Sep 12, 2023 CE
JWST Finds Most Distant Supermassive Black Hole
JWST discovered a supermassive black hole in a galaxy at redshift 10.6, existing just 450 million years after the Big Bang. This challenges theories of black hole formation. #cosmology #blackholes #JWST
Jan 8, 2024 CE
Euclid Mission Launches to Study Dark Energy
ESA's Euclid mission was launched to map the geometry of the dark universe. It will measure dark energy and dark matter through weak lensing and galaxy clustering. #cosmology #darkenergy #Euclid
Euclid Mission Launches to Study Dark Energy By European Space Agency - Euclid looking into the Universe, CC BY-SA 3.0 igo, https://commons.wikimedia.org/w/index.php?curid=128347141
Mar 21, 2024 CE
DESI Releases First Year Data
The Dark Energy Spectroscopic Instrument (DESI) released its first year of data, measuring the expansion history of the universe with unprecedented precision. It aims to constrain dark energy. #cosmology #darkenergy #DESI
DESI Releases First Year Data By Lawrence Berkeley National Lab/KPNO/NOIRLab/NSF/AURA - DESI crossfade 4, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=134717399
Jun 1, 2024 CE
JWST Confirms Hubble Tension
JWST observations of Cepheid variables in nearby galaxies confirmed the Hubble constant measured by Hubble, deepening the discrepancy with CMB-based predictions. This suggests new physics. #cosmology #HubbleTension #JWST
Oct 15, 2024 CE
Nancy Grace Roman Space Telescope Launch
NASA's Roman Space Telescope, formerly WFIRST, launched to study dark energy, exoplanets, and infrared astrophysics. It will conduct wide-field surveys to complement JWST. #cosmology #darkenergy #Roman
Nancy Grace Roman Space Telescope Launch By NASA - https://roman.gsfc.nasa.gov/gallery-spacecraftillustrations.html, Public domain, https://commons.wikimedia.org/w/index.php?curid=136706293
Feb 10, 2025 CE
LISA Pathfinder Demonstrates Technology for Gravitational Wave Observatory
ESA's LISA Pathfinder mission successfully tested technology for a space-based gravitational wave observatory. This paves the way for LISA, which will detect low-frequency waves from cosmic sources. #cosmology #gravitationalwaves #LISA
LISA Pathfinder Demonstrates Technology for Gravitational Wave Observatory By DLR German Aerospace Center - LISA Pathfinder, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=32945545
Jul 1, 2025 CE
CMB-S4 Project Begins Construction
The CMB-S4 project, a next-generation ground-based CMB experiment, started construction. It will map the CMB with unprecedented sensitivity to search for primordial gravitational waves. #cosmology #CMB #inflation
Mar 20, 2026 CE
JWST Discovers Population III Star Candidates
JWST identified candidate Population III stars, the first generation of stars made from primordial gas. This discovery would confirm theories of early chemical enrichment. #cosmology #stars #JWST
JWST Discovers Population III Star Candidates By NASA/JPL-Caltech/ESO/R. Hurt - http://www.eso.org/public/images/eso1339e/, Public domain, https://commons.wikimedia.org/w/index.php?curid=28274906
May 15, 2027 CE
LISA Mission Launch
ESA's Laser Interferometer Space Antenna (LISA) launched to detect gravitational waves from supermassive black hole mergers and other cosmic sources. It will open a new low-frequency window. #cosmology #gravitationalwaves #LISA
LISA Mission Launch By NASA, Public domain, https://commons.wikimedia.org/w/index.php?curid=10372273
