Introduction to general relativity this energy loss would be too small to be detectable, but this energy loss was observed in 1974 in a binary pulsar called PSR1913+16. In such a system, one of the orbiting stars is a pulsar. This has two consequences: a pulsar is an extremely dense object known as a neutron star, for which gravitational wave emission is much stronger than for ordinary stars. Also, a pulsar emits a narrow beam of electromagnetic radiation from its magnetic poles. As the pulsar rotates, its beam sweeps over the Earth, where it is seen as a regular series of radio pulses, just
Electron-beam machining to about 200,000 km/s. Magnetic lenses are used to focus the electron beam to the surface of the work-piece. By means of electromagnetic deflection system the beam is positioned as needed, usually by means of a computer. Vacuums must be used to reduce contamination, and minimize electron collisions with air molecules. Because work must be done in a vacuum, EBM is best suited for small parts. The interaction of the electron beam with the work piece produces hazardous x-rays, and only highly trained personnel should use EBM equipment. Electron-beam machining Electron-beam machining (EBM) is a process where high-velocity electrons concentrated