Wiki
Astrophysics
Notes, guides and references – 11 entries in 4 categories.
- Black Holes What black holes are, how they form, their structure (event horizon, photon sphere), the types from stellar to supermassive, how we observe them and what Hawking radiation is.
- Dark Matter and Dark Energy Why about 95 % of the universe is invisible: the evidence for dark matter and dark energy, what they might be, and the open questions cosmologists are working on today.
- Einstein's Theory of Relativity Special and general relativity explained simply: time dilation, length contraction, E = mc², curved spacetime, and the evidence, including why GPS has to correct for it.
- The Laws of Thermodynamics The four laws of thermodynamics explained simply, and what they mean in space: heat radiation, keeping spacecraft at the right temperature, planet temperatures, star colours and the fate of the universe.
- Types of Stars in the Universe An overview of how stars are classified by temperature and size, the main types from red dwarfs to supergiants, and the remnants they leave behind.