Planck length

E32679

The Planck length is the fundamental unit of length in quantum gravity, representing the scale at which classical concepts of space and time are expected to break down.

All labels observed (2)

Label Occurrences
Planck length canonical 16
Planck length ≈ 1.616255×10^-35 m 1

How this entity was disambiguated

Statements (47)

Predicate Object
instanceOf Planck unit
physical constant
unit of length
appearsIn black hole entropy calculations
generalized uncertainty principle formulations
theories of quantum spacetime foam
approximateValue 1.616255×10⁻³⁵ m
1.6×10⁻³⁵ metres
associatedWith Planck energy
Planck mass
Planck scale
Planck time
conceptualRole fundamental length scale of quantum gravity
scale where classical spacetime description breaks down
scale where quantum effects of gravity become significant
definedBy ℓ_P = √(ħG / c³)
dependsOnConstant gravitational constant G
reduced Planck constant
surface form: reduced Planck constant ħ

speed of light c
field cosmology
high-energy physics
quantum gravity
theoretical physics
hasDimension length
implies possible discreteness of spacetime at very small scales
introducedInContextOf Planck units
surface form: Max Planck’s natural units
isSmallestMeaningfulScaleIn many quantum gravity theories
measurability not directly measurable with current technology
namedAfter Max Planck
orderOfMagnitude 10⁻³⁵ metres
relatedConcept Planck area
Planck units
Planck volume
roleInBlackHoles sets scale for Bekenstein–Hawking entropy area term
roleInQuantumGravity candidate minimal measurable length
scaleComparison far below current experimental reach
much smaller than nuclear scale
much smaller than proton radius
SIUnit metre
status theoretical
symbol l_P
ℓ_P
usedIn black hole physics
loop quantum gravity
models of spacetime discreteness
quantum cosmology
string theory

How these facts were elicited

Referenced by (17)

Full triples — surface form annotated when it differs from this entity's canonical label.

Max Planck hasNamesake Planck length
Planck time relatedTo Planck length
Fermi (unit) largerThan Planck length
Planck temperature associatedWith Planck length
Planck units hasBaseQuantity Planck length
t_P isAssociatedWith Planck length
Planck energy relatedTo Planck length
Planck mass relatedTo Planck length
Planck mass isFundamentalScaleFor Planck length
l_P denotes Planck length
Planck scale associatedWith Planck length
Planck area relatedUnit Planck length
Planck volume definedInTermsOf Planck length
Planck volume relatedQuantity Planck length
Planck volume approximateSideLength Planck length
this entity surface form: Planck length ≈ 1.616255×10^-35 m