← All parts of this equation

Equation 126 · Part 1 · The Clock That Comes Back Wrong by Exactly Its Mass

Symbol m

m≈1.443×10−25 kgm\approx1.443\times10^{-25}\,\mathrm{kg}
mm

What this part means

m is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

Its job in the formula

m is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

The passage around this formula

The scale of what needs to be canceled is worth stating plainly, using the same illustrative parameters as the previous section. The laser/center-of-mass term for a single-photon transition near 698\,nm\mathrm{nm} ( keffk_{\rm eff}≈\approx9.00×\times10^6\,m−1\mathrm{m^{-1}} ) scales as keffk_{\rm eff}gT2T^2≈\approx8.8×\times10^{7}\,rad\mathrm{rad} for T=1\,s\mathrm s . The recoil term for a strontium-mass atom ( m≈\approx1.443×\times10^{-25}\,kg\mathrm{kg} ) scales as ℏ\hbar keff2k_{\rm eff}^2T/m≈\approx5.9×\times10^{4}\,rad\mathrm{rad} . The clock term computed above is ≈\approx0.29\,rad\mathrm{rad} . Both confound terms are, respectively, roughly eight and five orders of magnitude larger than the signal, which is exactly why…

Read this part in the article →

Learn the underlying idea

A variable is a named place for a value. Its letter is a local label: x can mean position in one formula and a data point in another.

Open the illustrated variables: a letter stands for a value guide →

See this notation across published equations →

Sources cited in the article section

These citations provide research context; check each source for the exact claim it supports.