In this paper we present a method to study the frequency shift of signals sent from near Schwarzschild black hole that grows or shrinks through accretion. We construct numerical solution Einstein's equations sourced by spherical shell scalar field, with positive energy density simulate growth and negative shrink horizon. launch distribution null rays at various time slices during accretion esti...

We have measured a previously unobserved systematic frequency shift in our cesium-fountain frequency standard, NIST-F1. This shift, predicted theoretically previously, mimics the well-known end-to-end phase shift in atomic beam standards when synchronous thermal transients are present. Detuning the microwave cavity several megahertz from resonance reduces this effect to the deltaf/f = 1o(-16) l...