Paradox of radiation of charged particles in a gravitational field Coulomb field of the supported charge, but too small to be observable. So although the Coulomb law was discovered in a supporting frame, general relativity tells us that the field of such a charge is not precisely formula_2. The radiation from the supported charge viewed in the freefalling frame (or vice versa) is something of a curiosity: where does it go? Boulware (1980) finds that the radiation goes into a region of spacetime inaccessible to the co-accelerating, supported observer. In effect, a uniformly accelerated observer has an event horizon, and there are regions of spacetime inaccessible to this observer. C.
Direction, position, or indication sign sign category into direction signs, which are only those giving distances or directions to a given location; road identification signs (also known as "reassurance signs"), which repeat the name or number of the road, and place identification signs, which give the name of a landmark, such as a town, river or border. Unlike the other classes of sign, direction signs remain broadly undefined by the convention; the only restrictions given are that direction signs must be either a rectangle or an arrow shaped pentagon, and that they may not contain placenames in more than two languages. Additionally, direction signs on