← Back to article

Equation 8 · Physics Optimizes, Evolution Satisfices: Two Kinds of Perfection

What does this equation mean?

xix_i

Read the formula alongside the article passage below. Each part has a deeper page with its role in the equation, the supporting passage and nearby citations.

This mathematical expression combines the displayed quantities; its precise role follows from the surrounding article text. Read the equation part by part below; each part has a contextual explanation and a link to its mathematical background.

Read it piece by piece

xix_i

Symbol x_i

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

Understand this part →

subscript

subscript

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.

Understand this part →

How to interpret it

Read this expression with the definitions, units, and assumptions supplied by the article.

What the article says around this equation

a new position built only from the previous position and the local slope of fitness W at that exact point, with no access to the global shape of the landscape and no way to undo xix_i once it is fixed. In optimization-theory terms, the first rule is global by construction; the second is a greedy local rule that can only report the best it found from where it started. Physics gets to run the first kind of rule because a photon and a planet have no history to answer for. Selection is stuck running the second, forever, because every genome is a record of every place it has already been.

Read the equation in its article →

For background, read the article’s source list.

Return to Physics Optimizes, Evolution Satisfices: Two Kinds of Perfection

Browse the mathematical compendium →