Thus, Einstein introduced his cosmological constant as an ad hoc factor in his equations, in order to conform with observational cosmology of the era which called for a static universe.

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The underlying factor that has been fueling constant growth for Google is innovation.

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First, each individual factor is presented with all other factors held constant at zero.

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This has been interpreted as meaning the overriding factor is the arrival of new people living close together, rather than public transport which is constant all year round.

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