The meter was once defined as 1 650 763.73 wavelengths of the orange light emitted by a source containing krypton-86 atoms. What is the photon energy of that light?
Thursday, September 8, 2016 7 Ideas 4th lecture Chapter 5 - Coordinates of the Sky *2 Coordinate system:- 1) Observer’s sky (local) 2) Celestial Sphere *Observer’s Sky:- 1) Azimuth (heading) tells which direction to look 1. -North 0deg 3. East 90deg 2. South 180deg 4. West 270deg 2) Altitude tells how high to look:- 1. 0deg even with ground 2. 90deg overhead Azimuth Altitude Object 200deg 30deg Jupiter 90deg 90deg Vega *3 Problems with the observer’s sky 1) Works for your location (time difference) 2) Motion of the Earth around the sun 3) Objects move *Geocentric Theory - Geo means Earth