Bremsstrahlung vs Gravity swing-by

Question

It seems too me there’s an analogy between the two, but I understand we have a loss of kinetic energy in the former and we can have a gain in the latter. What am I missing?

In: 3

Answer 1

accelerating charged particles emit photons. gravity is too weak so that only happens with merging black holes. gravity assists are more similar to neutrons getting slowed down by water or just elastic collisions.