orbitalorbital electronorbital electron captureorbital quantum numberorbital velocityorbiting astronomical observatoryorbiting geophysical observatoryorbiting solar observatoryorderorder of magnitudeordered pairordinalordinaryordinary pointordinary wave component o wave componentordinateoreferred numbersorganic semiconductororganizationorientationoriented graphoriginoriginaloriginal equipment manufacturerorthoferriteorthogonalorthogonal frequency division modulationorthogonal matrixorthogonal modeorthogonal transformationorthogonalityorthonormalososcillateoscillationoscillation detectoroscillation frequencyoscillation rangeoscillatoroscillator circuitoscillator coiloscillator harmonic interferenceoscillator radiationoscillatory circuitoscillatory surgeoscilligraphoscillographoscilloscopeoscilloscope screenoscilloscope tube
