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Equation 136 · Part 4 · The Bend an Elevator Cannot Fake

superscript

σy=1×10−18\sigma_y = 1\times10^{-18}
superscript

What this part means

A raised number can be a power. When it is a label or bound, it selects a case or the upper limit of a sum; the formula’s structure distinguishes these uses.

Its job in the formula

A raised mark can be a power or an index. Its position and the surrounding notation determine which.

The passage around this formula

Take each edge’s fractional-frequency comparison uncertainty to be σy\sigma_y = 1×\times10^{-18} , the stability optical clocks have already demonstrated is what centimetre-level geodesy requires [ 8 ] . The combined noise on the independent-edge difference y2y_2-y1y_1 is 2\sqrt2\,σy\sigma_y . Setting signal equal to noise, ϕ,zz\phi_{,zz}\,h2h^2 = 2\sqrt2\,σy\sigma_y , gives

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Learn the underlying idea

An exponent tells how a base is used in multiplication. In x³, x is the base and 3 is the exponent: x³ = x × x × x.

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Sources cited in the surrounding passage

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