Symbol N_87
7 is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
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Why this formula appears here
where is each mineral’s measured present-day strontium-87 to strontium-86 ratio, is the shared initial ratio recovered as the line’s intercept, and / is each mineral’s measured rubidium-87 to strontium-86 ratio [ 18 ] . The initial composition is no longer an assumption fed into the calculation; it is an output the data themselves supply, and a poor fit to a straight line is itself a warning that the minerals did not, in fact, share a common origin or have remained closed systems since.
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Symbol N_86
each mineral’s measured rubidium-87 to strontium-86 ratio [ 18 ].
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Read this expression with the definitions, units, and assumptions supplied by the article.
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Published contexts (1)
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Equation 14 · Evolutionary Nuclear Physics
Radioactive Clocks: How Nuclear Physics Gave Evolution Its Time
This mathematical expression combines the displayed quantities; its precise role follows from the surrounding article text.
where is each mineral’s measured present-day strontium-87 to strontium-86 ratio, is the shared initial ratio recovered as the line’s intercept, and / is each mineral’s measured rubidium-87 to strontium-86 ratio [ 18 ] . The initial composition is no longer an assumption fed into the calculation; it is an output the data themselves supply, and a poor fit to a straight line is itself a warning that the minerals did not, in fact, share a common origin or have remained closed systems since.