Physics A-Level
Hubble constant
What Hubble constant means in Physics A-Level, as defined for OCR.
Definitions of Hubble constant
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Reference: OCR
Describes how fast the universe expands, relating recession speed to distance as v = H₀d, so it has units of s⁻¹.
H₀ links a galaxy's recession speed v to its distance d through v = H₀d, so it is the gradient of a v–d graph.
The constant H₀ in Hubble's law, with units of s⁻¹, often quoted as km s⁻¹ Mpc⁻¹.
Topics that use Hubble constant
- Cosmology (OCR A-Level)
Related terms
- Age of the universe
- Astronomical distance units
- Baseline
- Big Bang nucleosynthesis
- Big Bang theory
- Cosmic microwave background
- Cosmic microwave background radiation
- Cosmological redshift
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