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Equation 2 · Part 1 · Physics Optimizes, Evolution Satisfices: Two Kinds of Perfection

Symbol n_2

n2n_2
n2n_2

What this part means

n2n_2 is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

Its job in the formula

n2n_2 is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

The passage around this formula

A beam of light crossing from air into glass bends at the interface by exactly the angle that gets it through in the least possible time. Pierre de Fermat stated this as a principle in the 1660s, and the consequence collapses into one line of algebra: for a ray crossing between two media of refractive index n1n_1 and n2n_2 ,

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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.

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Sources cited in the article section

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