File:Heisenberg gamma ray microscope.png

Summary
Picture of the gamma-ray microscope described in Heisenberg's 1927 paper on the uncertainty principle ("Über den anschaulichen Inhalt der quantentheoretischen Kinematik und Mechanik", Zeitschrift für Physik, 43, 172-198). The blue circle is the particle, the green wave is the incoming gamma-ray and the red wave is the gamma-ray scattered up into the aperture angle θ of the microscope (depicted as solid black lines). The uncertainty in the particle position is Δx, as shown. Made by me (own work) using Xfig on 7 September 2006, and licensed under the GFDL.