Introduction to general relativity in a setting with comparatively strong gravitational fields. This has become possible thanks to precision observations of binary pulsars. In such a star system, two highly compact neutron stars orbit each other. At least one of them is a pulsar – an astronomical object that emits a tight beam of radiowaves. These beams strike the Earth at very regular intervals, similarly to the way that the rotating beam of a lighthouse means that an observer sees the lighthouse blink, and can be observed as a highly regular series of pulses. General relativity predicts specific deviations from the regularity of these
Direct integration of a beam load having an effect on the beam is the 75 kN load applied by the pin, applied at x=0, giving Integrating the internal shear, Assuming an EI value of 1 kNformula_15mformula_15m (for simplicity, real EI values for structural members such as steel are normally greater by powers of ten) Because of the vertical supports at each end of the beam, the displacement (formula_19) at x = 0 and x = 15m is zero. Substituting (x = 0, v(0) = 0) and (x = 15m, v(15m) = 0), we can solve for constants formula_20=-1406.25 and formula_21=0, yielding For the given EI