The are arranged by difficulty and topic, each with a complete, self-contained solution that explains not only the mathematics but also the physical reasoning. No steps are skipped.
(b) In the lab frame, boost the photon four-momenta. For a photon emitted at angle ( \theta'=0 ) in the rest frame, the lab energy is ( E = \gamma E' (1+\beta) ). The second photon (emitted at ( \theta'=\pi ) in rest frame) has lab energy ( E = \gamma E' (1-\beta) ). Their directions are not opposite in the lab frame. Using the aberration formula, the lab angle between the two photons is found to be ( 2 \arctan\left(\frac{1}{\gamma\beta}\right) ) (for ( \beta = v/c )). Full derivation shows that for ( v\to c ), the angle approaches ( 0 ) (both photons forward), consistent with beaming. The are arranged by difficulty and topic, each
(a) By conservation of four-momentum: ( (m,0,0,0) = (E_\gamma, E_\gamma,0,0) + (E_\gamma, -E_\gamma,0,0) ) in natural units ( c=1 ). This gives ( 2E_\gamma = m ), so ( E_\gamma = m/2 ). Restoring ( c ): ( E_\gamma = \frac{m c^2}{2} ). For a photon emitted at angle ( \theta'=0
(The complete solution spans half a page with all intermediate algebra and a spacetime diagram.) “Relativity is often taught as a collection of astonishing results — time slows down, space contracts, black holes trap light. Yet without solving problems, these insights remain abstract. This book bridges the gap between conceptual understanding and technical mastery. Using the aberration formula, the lab angle between
Special relativity (150 problems) builds fluency with Lorentz transformations, four-vectors, and relativistic dynamics. General relativity (150 problems) starts from the equivalence principle and walks through curved spacetime, geodesics, Einstein’s equations, and key applications.
The are arranged by difficulty and topic, each with a complete, self-contained solution that explains not only the mathematics but also the physical reasoning. No steps are skipped.
(b) In the lab frame, boost the photon four-momenta. For a photon emitted at angle ( \theta'=0 ) in the rest frame, the lab energy is ( E = \gamma E' (1+\beta) ). The second photon (emitted at ( \theta'=\pi ) in rest frame) has lab energy ( E = \gamma E' (1-\beta) ). Their directions are not opposite in the lab frame. Using the aberration formula, the lab angle between the two photons is found to be ( 2 \arctan\left(\frac{1}{\gamma\beta}\right) ) (for ( \beta = v/c )). Full derivation shows that for ( v\to c ), the angle approaches ( 0 ) (both photons forward), consistent with beaming.
(a) By conservation of four-momentum: ( (m,0,0,0) = (E_\gamma, E_\gamma,0,0) + (E_\gamma, -E_\gamma,0,0) ) in natural units ( c=1 ). This gives ( 2E_\gamma = m ), so ( E_\gamma = m/2 ). Restoring ( c ): ( E_\gamma = \frac{m c^2}{2} ).
(The complete solution spans half a page with all intermediate algebra and a spacetime diagram.) “Relativity is often taught as a collection of astonishing results — time slows down, space contracts, black holes trap light. Yet without solving problems, these insights remain abstract. This book bridges the gap between conceptual understanding and technical mastery.
Special relativity (150 problems) builds fluency with Lorentz transformations, four-vectors, and relativistic dynamics. General relativity (150 problems) starts from the equivalence principle and walks through curved spacetime, geodesics, Einstein’s equations, and key applications.
