Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site pur-phy.UUCP Path: utzoo!watmath!clyde!cbosgd!ihnp4!inuxc!pur-ee!CS-Mordred!Pucc-H:pur-phy!act From: act@pur-phy.UUCP (Alex C. Tselis) Newsgroups: net.astro,net.physics Subject: Equivalence Principle and Electric Charge Message-ID: <1534@pur-phy.UUCP> Date: Sat, 1-Dec-84 19:00:35 EST Article-I.D.: pur-phy.1534 Posted: Sat Dec 1 19:00:35 1984 Date-Received: Tue, 4-Dec-84 05:01:00 EST Distribution: net Organization: Purdue Univ. Physics Dept., IN Lines: 16 I have a question concerning the apparent paradox between electromagnetic theory and the equivalence principle. I hope those who know about these sorts of things can resolve this paradox in an easy way. The question concerns the behavior of electric charges in a gravitational field. Suppose that I were to take an electrical charge (a point charge or a distributed one; it makes no difference), put a force on it and accelerated it. It would then radiate electromagnetic waves. Now suppose that I were to place this charge on a table in my office. The charge is in a gravitational field (due to the earth). But according to the equivalence principle, a gravitational field is equivalent to an acceleration (at least locally; I can always make the distribution of charge so that it is confined to a small enough spatial region so that the earth's gravitational field can be taken to be uniform over it.). However, this charge does not radiate, even though it is in a situation which is equivalent to an acceleration. How is this resolved?