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Equation 105 · Part 5 · The Clock That Comes Back Wrong by Exactly Its Mass

subscript

M0c2Δτ/ℏM_0c^2\Delta\tau/\hbar
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

The shared M0M_0c2c^2Δ\Deltaτ\tau/ℏ\hbar term, common to both arms, is an overall phase and drops out of any interference signal — consistent with the rule that only relative phase between branches is ever observable. What survives is a clock-visible term set entirely by the internal-energy difference, first proposed as an observable interferometric signature of general-relativistic proper time by Zych, Costa, Pikovski, and Brukner [ 10 ] , and later reframed explicitly as a quantum analogue of the twin paradox by Loriani and collaborators [ 11 ] .

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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 surrounding passage

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