- What later discoveries about the universe followed from Hubble's proof that other galaxies exist?
Cosmology
The origin, structure, and evolution of the universe.
- Why did Einstein add a cosmological constant to his equations, and what did he later call it?
- What relationship did Hubble find between a galaxy's distance and its recession velocity?
- Why does an expanding universe imply that everything was once in the same place?
- How did the completed Hale Telescope change estimates of the size of the observable universe?
- How did the steady-state model explain an expanding universe without a beginning?
- Who independently proposed the steady-state theory in 1948, and how did their papers differ?
- What evidence eventually disproved the steady-state model?
- What did the discovery of quasars suggest about how violent the early universe was?
- What did the redshift of 3C 273 imply about its distance and energy output?
- What did Milton Friedman mean when he argued that inflation is 'always and everywhere a monetary phenomenon'?
- Why does CP violation help explain why the universe contains matter at all instead of nothing but photons?
- What scientific discoveries did Hubble go on to enable after the 1993 repair?
- Who coined the term 'dark energy,' and what fraction of the universe does it account for?
- What age for the universe did WMAP's 2003 data establish, and how precise was that estimate?
- What did the WMAP data confirm about cosmic inflation and the geometry of space?
- Why were the tiny temperature fluctuations COBE detected so significant for understanding galaxy formation?
- How did astronomers use Type Ia supernovae to measure the expansion rate of the universe?
- What is dark energy and how much of the universe's total energy does it make up?
- What did the BICEP2 team claim to have detected in the cosmic microwave background in March 2014?
- What role did the Planck satellite's joint analysis play in retracting the BICEP2 claim?
- What theoretical framework did James Peebles build to explain dark matter, dark energy, and the cosmic microwave background?
- Why did the 2019 physics prize combine a theoretical cosmologist with two observational planet-hunters in one award?
- What other concept is Jan Zalasiewicz known for in geology?