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
Chilled beam metal pipe of water just in diameter can carry as much energy as an metal duct of air. This means that chilled beam HVAC systems require much less energy to provide the same heating and cooling effect as a traditional air HVAC system. Chilled beam cooling systems require water to be treated by heating and cooling systems. Generally, water in a passive chilled beam system is cooled to about . In active chilled beam heating systems, water temperature is usually . (Chilled beam heating systems usually cannot rely solely on convection, however, and often require a fan-driven primary air circulation