Figure 5
This app represents an interactive version of figure 5.
Move the point pf defining the position of the fulcrum/momentum of the outgoing photon and see how the mass M changes
The momentum of the incoming photon pi can also be selected moving the corresponding point on the base.
Figure 6-a
This app represents an interactive version of figure 6 a).
Move the point F defining the position of the fulcrum/momentum of the outgoing photon and see how the mass M changes.
You can also move the blue point on the base to change the momentum of the incoming photon I.
This app represents an interactive version of figure 6 b).
Move the point F defining the position of the fulcrum/momentum of the outgoing photon and see how the mass M changes.
This figure is equivalent to the previous one, but without the null cone. This allows for a clearer visualization of the underlying lines.