Last lesson in a nutshell Proper time defined as Minkowski space A 4 vector is an object that conforms to LT Introduced 4 velocity 4 momentum P Piot PHYS 571 Fall 2007 More on Lorentz Transform Invariant ds 2 dx 0 2 dx1 2 dx 2 2 dx 2 2 g dx dx rotation Lorentz transformations The Lorentz transform conserve ds 2 g dx dx g dx dx dx dx g g dx dx g g Determinants 1 1 so 2 1 P Piot PHYS 571 Fall 2007 Particle dynamics in SR example 1 Consider w one incident n at rest Question Question Minimum required energy for the incoming n to enable the reaction Answer Answer At threshold the 4 final neutrons are at rest in the lab frame with we finally get the threshold energy P Piot PHYS 571 Fall 2007 Photon emission absorption Consider Then Photon 4 momentum This also applies to accelerating frames so P Piot PHYS 571 Fall 2007 Photon emission absorption example 2 In emitter s frame In absorber frame On another hand we have for photons P Piot PHYS 571 Fall 2007 Photon emission absorption example 2 Expliciting the velocity Doppler shift For f 90 deg this reduces to P Piot PHYS 571 Fall 2007 SI syst me International versus CGS cm Gram Second The prescription to convert from CGS to SI and vice versa is Example Lorentz force P Piot PHYS 571 Fall 2007 SI versus CGS cnt d Maxwell s equations in SI and CGS are The real pros also take c 1 pros because the accept the equivalence between space and time but we won t do this P Piot PHYS 571 Fall 2007
View Full Document
Unlocking...