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Equation 1 · Part 2 · The Valley of Stability Is a Fitness Landscape

Symbol R

δR=1×10−11\delta R = 1\times10^{-11}
RR

What this part means

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

Its job in the formula

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

The passage around this formula

…accuracy. A 2020 result from the PENTATRAP collaboration, comparing cyclotron frequencies of a highly charged rhenium ion in two internal states, reports a fractional precision of one part in one hundred billion — δ\delta R = 1×\times10^{-11} — in a single-ion Penning-trap measurement [ 9 ] . The same family of instrument, applied across an isobaric chain rather than within one ion’s internal structure, is how the mass differences that fix nuclear binding energies are actually obtained; Klaus Blaum’s 2006 review of…

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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.

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Sources cited in the surrounding passage

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