The annihilation of electrons and positrons causes the emission of an enormous amount of high energy radiation at 511 keV (a wavelength of 0.00242 nm). Concept: The observed and emitted wavelengths ar...The annihilation of electrons and positrons causes the emission of an enormous amount of high energy radiation at 511 keV (a wavelength of 0.00242 nm). Concept: The observed and emitted wavelengths are related by: z=λobserved–λemittedλemitted or equivalently λobservedλemitted=1+z By what factor has the Universe stretched since the neutron stars merged and emitted the light that we are just seeing now?
