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Equation 4 · Part 1 · From Origins to Frontier: A History of Planetary Science and Exploration

Symbol eta

η\eta
η\eta

What this part means

eta 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

eta 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

…over geological time. The basic settling physics is captured by a Stokes-law sinking velocity for a dense blob of radius r and density ρm\rho_m moving through a less dense, viscous mantle of density ρs\rho_s and viscosity η\eta :

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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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