Constants & Units · constant
Critical density
ρ_c = 8.5 × 10⁻²⁷ kg m⁻³
- Unit
- kg m⁻³
- Value
- 8.5 × 10⁻²⁷
- Exact
- no
- Note
- The density that makes space flat: about five hydrogen atoms per cubic metre.
- Symbol
- ρ_c
- Category
- Cosmological
- Numeric
- 8.5e-27
- Uncertainty
- ±3% (tracks H₀)
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