Topic explanation

Standard explanation

Dark matter is the name given to non-luminous matter inferred mainly from its gravitational effects on visible matter, radiation and cosmic structure.

Key points

• v²r = GM(r)/r²
• M(r)=v²rG
• Galaxy Rotation: Evidence for dark matter includes observations such as: galaxy rotation; motions of galaxies in
• Gravitational Lensing: Mass bends the paths of light. The amount of lensing can reveal total gravitational mass, including
• Dark matter is inferred because observed gravity exceeds what visible matter alone can explain.

Labelled diagram