the Earth has its fields due to the motion of molten metals in the core but how does this whole universe has its fields without any discontinuity? And we can say for sure that fields are present in ...
The Heaviside-Feynman formula (see Feynman Lectures vol I Ch.28, vol II Ch. 21) gives the electric and magnetic fields measured at an observation point $P$ due to an arbitrarily moving charge $q$ $$ ...
According to a recent paper on the arXiv, they do. How credible is this result? The abstract says: The detection of magnetic fields at high redshifts, and in empty intergalactic space, support ...
Interstellar space is pretty empty but there a small number of of atoms (mostly hydrogen?) floating around. How many atoms per light year would a photon encounter while traversing interstellar space?