Equation 3 · Part 1 · Radioactive Clocks: How Nuclear Physics Gave Evolution Its Time
Symbol λ
What this part means
the decay constant characteristic of the isotope.
Its job in the formula
λ is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
Full expression→Symbol λ→Article meaning
Where the article explains it
where is the initial population, is the decay constant characteristic of the isotope, and is the half-life derived from it.
The passage around this formula
where is the initial population, is the decay constant characteristic of the isotope, and is the half-life derived from it. This is the one place in the article where the evolutionary-population analogy is exact rather than suggestive: a sample of identical atoms behaves, statistically, exactly as a population geneticist’s model of a large population with a fixed per-individual probability of an event per unit time behaves. Individual atoms are unpredictable; the population’s decline is not.
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 article section
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