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Physics notebook Cambridge IGCSE 0625

Topic 6 of 6 · 4 modules planned

Space physics

The Earth, the Solar System, the life of stars and the evidence that the Universe is expanding.

Modules

  1. Module 1 · syllabus 6.1.1

    Earth, Sun and Moon

    Why are summer days longer than winter days?

    This module is planned. It will have readings, an experiment, practice with self-checks and a final check.

Syllabus statements for this topic · for teachers · 30 statements

Core for every pupil · Supplement also for Extended entry. Paraphrased from the Cambridge IGCSE Physics 0625 syllabus (2026–2028); check the official syllabus for exact wording.

6.1.1 The Earth

  • 6.1.1.1Earth's tilted rotation: day, night, the Sun's pathC
  • 6.1.1.2Earth's yearly orbit and the seasonsC
  • 6.1.1.3The Moon's monthly orbit and its phasesC
  • 6.1.1.4Average orbital speed v = 2πr/TS

6.1.2 The Solar System

  • 6.1.2.1Members of the Solar System; planet orderC
  • 6.1.2.2Rocky inner, gaseous outer planets; accretion modelC
  • 6.1.2.3Gravitational field with planet mass and distanceC
  • 6.1.2.4Light travel time across the Solar SystemC
  • 6.1.2.5The Sun's mass makes planets orbit itC
  • 6.1.2.6The Sun's gravity keeps objects in orbitC
  • 6.1.2.7Elliptical orbits with the Sun off-centreS
  • 6.1.2.8Analysing planetary dataS
  • 6.1.2.9Field strength and orbital speed fall with distanceS
  • 6.1.2.10Faster when closer in an elliptical orbitS

6.2.1 The Sun as a star

  • 6.2.1.1The Sun: medium hydrogen–helium star and its radiationC
  • 6.2.1.2Stars powered by hydrogen fusionS

6.2.2 Stars

  • 6.2.2.1Galaxies, the Milky Way and light-yearsC
  • 6.2.2.2One light-year is 9.5 × 10¹⁵ mS
  • 6.2.2.3Life cycle of starsS

6.2.3 The Universe

  • 6.2.3.1A Universe of galaxies; Milky Way's diameterC
  • 6.2.3.2Redshift from receding sourcesC
  • 6.2.3.3Distant galaxies appear redshiftedC
  • 6.2.3.4Redshift as evidence of expansion and the Big BangC
  • 6.2.3.5Cosmic microwave background radiationS
  • 6.2.3.6CMBR origin and its stretch to microwavesS
  • 6.2.3.7Galaxy speed from redshiftS
  • 6.2.3.8Galaxy distance from supernova brightnessS
  • 6.2.3.9Hubble constant H0 = v/dS
  • 6.2.3.10Current estimate of H0S
  • 6.2.3.111/H0 estimates the age of the UniverseS