Constants & Units · constant
Planck length
l_P = 1.616 255(18) × 10⁻³⁵ m
- Unit
- m
- Value
- 1.616 255(18) × 10⁻³⁵
- Exact
- no
- Note
- Where quantum mechanics and gravity must merge; ~10²⁰ times smaller than a proton.
- Symbol
- l_P
- Category
- Universal
- Numeric
- 1.616255e-35
- Uncertainty
- ±1.1 × 10⁻⁵ relative
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