This math image could be re-created using vector graphics as an SVG file. This has several advantages; see Commons:Media for cleanup for more information. If an SVG form of this image is available, please upload it and afterwards replace this template with {{vector version available|new image name}}.
It is recommended to name the SVG file “Minkowski diagram - photon.svg”—then the template Vector version available (or Vva) does not need the new image name parameter.
විස්තරයMinkowski diagram - photon.png
To explain Minkowski diagrams: Choosing ct instead of t on the time axis the world line of a photon becomes a straight line with a slope of 45°.