Like in a nail-biting thriller full of escapes and subterfuge, photons from far-off light sources, such as blazars, could go up against a continuous exchange of identity in their journey through the Universe. This is an operation that would allow these very tiny particles of light to escape an enemy which, if encountered, would annihilate…
Shedding Light on Galaxies’ Rotation Secrets
The dichotomy concerns the so-called angular momentum (per unit mass), that in physics is a measure of size and rotation velocity. Spiral galaxies are found to be strongly rotating, with an angular momentum higher by a factor of about 5 than ellipticals. What is the origin of such a difference? An international research team investigated…