← All parts of this equation

Equation 120 · Part 5 · The Bend an Elevator Cannot Fake

subscript

y1=ϕ(0)−ϕ(−h)y_1 = \phi(0)-\phi(-h)
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.

The passage around this formula

An exact analytic evaluation, not a simulation, fixes the scale this actually requires. Take three clocks stacked vertically at heights -h , 0 , and +h near Earth’s surface, giving two edges y1y_1 = ϕ(0)\phi(0)-ϕ(−h)\phi(-h) and y2y_2 = ϕ(h)\phi(h)-ϕ(0)\phi(0) . Their difference is an exact finite-difference identity up to a Taylor remainder of order h4h^4 :

Read this part in the article →

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 article section

These citations provide research context; check each source for the exact claim it supports.