Physics Ontology

One map of physics, three ways in. Drill down on any quantity to see its units, the equations it lives in, and how its values span the universe.

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TT
Base SI

Temperature

Average thermal energy per degree of freedom; an SI base quantity.

SI unit

kelvin (K)

Dimension: [ Θ ][\,\Theta\,]

Other units

  • kelvin (K)

Order of magnitude

How values of temperature span the physical world (in K, log scale).

Lab record (cold)
10-10 K
Deep space (CMB)
2.70 × 100 K
Room temperature
2.93 × 102 K
Sun's core
1.50 × 107 K
Planck temperature
1.40 × 1032 K
Lower limit10-9 KUpper limit1032 K

Appears in 8 equations

Ideal Gas Law
pV=nRTp V = n R T
Entropy Change
ΔS=QT\Delta S = \dfrac{Q}{T}
Heat Transfer
Q=C ΔTQ = C \, \Delta T
Ideal Gas Law (Boltzmann form)
pV=NkBTpV = Nk_BT
Molecular Kinetic Energy
12m⟨c2⟩=32kBT\tfrac{1}{2}m\langle c^2\rangle = \tfrac{3}{2}k_BT
Specific Heat Capacity
ΔE=mc Δθ\Delta E = mc\,\Delta\theta
Stefan–Boltzmann Law
L=σAT4L = \sigma A T^4
Wien's Displacement Law
λmax⁡T=b\lambda_{\max} T = b

Associated scientists

Sadi CarnotJames Prescott JouleLudwig BoltzmannAmedeo AvogadroJosef StefanWilhelm Wien