← All parts of this equation

Equation 116 · Part 1 · The Clock That Comes Back Wrong by Exactly Its Mass

Symbol Δ E

ΔE=hΔν≈2.846×10−19 J\Delta E=h\Delta\nu\approx2.846\times10^{-19}\,\mathrm J
ΔE\Delta E

What this part means

the energy.

Its job in the formula

Δ E is part of the quantity the equation computes from the expression on the right.

Where the article explains it

A composite system with an internal excitation of energy Δ\Delta E above its ground configuration carries additional rest mass Δ\Delta E/c2c^2 , by ordinary mass–energy equivalence — no redefinition of either the relativistic or the everyday meaning of mass, simply the standard bookkeeping in which a system’s total rest energy Mc2c^2 includes whatever internal energy HintH_{\rm int} it holds: M=M0M_0+HintH_{\rm int}/c2c^2 .

The passage around this formula

To make this concrete without simulation, take the weak-field proper-time rate dτ\tau/dt≈\approx1+gz/c2c^2 for a static height z in Earth’s field, so that holding two branches at a height difference Δ\Delta z for coordinate time T gives Δ\Deltaτ\tau≈\approx g\,Δ\Delta z\,T/c2c^2 . For Δ\Delta z=1\,m\mathrm m and T=1\,s\mathrm s , Δ\Deltaτ\tau≈\approx1.090×\times10^{-16}\,s\mathrm s . Pair this with a single-photon optical clock transition near 698\,nm\mathrm{nm} , comparable to the transition used in strontium-lattice-clock proposals for this kind of experiment [ 11 , 13 ] , giving Δ\Deltaν\nu≈\approx4.295×\times10^{14}\,Hz\mathrm{Hz} and Δ\Delta E=hΔ\Deltaν\nu≈\approx2.846×\times10^{-19}\,J\mathrm J , a mass excess Δ\Delta…

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.