Equation 11 · Part 10 · Radioactive Clocks: How Nuclear Physics Gave Evolution Its Time
subscript
subscript
What this part means
The lower label selects a particular version, component, or indexed member of the quantity. For example, x₀ and xₜ can be values at different positions.
Its job in the formula
A subscript distinguishes a version, component, step, or member of a quantity. It does not automatically mean multiplication.
Full expression→subscript→Article meaning
The passage around this formula
The uranium-lead and argon-argon methods both need to know, or be able to ignore, how much daughter isotope was already present when the mineral formed. The isochron method, used most often with the rubidium-strontium and samarium-neodymium systems, solves this by measuring several minerals from the same rock, each of which crystallized from the same well-mixed magma at the same time and so began with the same strontium or neodymium isotopic composition, but which incorporated different amounts of the radioactive parent isotope depending on their individual chemistry. Plotting each mineral’s present-day ratio of radiogenic daughter to stable reference isotope against its ratio of parent to…
Learn the underlying idea
A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.
Open the illustrated subscripts: which member of a family? guide →
Sources cited in the surrounding passage
These citations provide research context; check each source for the exact claim it supports.