Lesson 09 Tier II · Intermediate Special Relativity Time dilation, length contraction, mass-energy equivalence, and the geometry of spacetime Welcome to Tier II With the foundations in place — distance, light, gravity, stars, the solar system, telescopes — we now step into deeper waters. Tier II begins with the theory that permanently changed our understanding […]
Lesson 08 Tier I · Foundations Telescopes & Observational Methods How we actually see the universe — optical, radio, X-ray, and space-based observatories The Eye and Its Limits The naked human eye is a remarkable instrument — but it detects only the narrowest sliver of the electromagnetic spectrum, between roughly 380 and 700 nanometres. The […]
Lesson 07 Tier I · Foundations The Solar System Planets, moons, belts, the heliosphere — our cosmic neighbourhood in full Our Home in Space The Solar System formed approximately 4.6 billion years ago from a rotating cloud of gas and dust — a solar nebula. Gravity caused the centre to collapse into the Sun, while […]
Lesson 06 Tier I · Foundations Life Cycles of Stars From nebula to remnant — how stars are born, live, and die Stars Are Not Eternal A star is not a permanent fixture of the sky. It is born, it lives for a period determined almost entirely by its mass, and it dies — sometimes […]
Lesson 05 Tier I · Foundations Stellar Classification The HR diagram, spectral types, luminosity, temperature, and what the Sun’s address really means Ordering the Stars By the late nineteenth century, astronomers had accumulated spectra for thousands of stars. The challenge was to make sense of the enormous variety — stars of wildly different colours, brightnesses, […]