Path: utzoo!mnetor!uunet!lll-winken!lll-tis!ames!mailrus!tut.cis.ohio-state.edu!bloom-beacon!mit-eddie!bbn!rochester!PT.CS.CMU.EDU!andrew.cmu.edu!jk3k+ From: jk3k+@andrew.cmu.edu (Joe Keane) Newsgroups: sci.misc Subject: Re: Lightning, Up or Down? Message-ID: Date: 5 Mar 88 12:16:58 GMT References: <64600001@mic>, <1620@bgsuvax.UUCP> Organization: Carnegie Mellon University Lines: 25 In-Reply-To: <1620@bgsuvax.UUCP> In article <64600001@mic>, gary@mic.UUCP writes: > Is it correct that lightning travels from the ground up instead of the > sky down to the ground? I vaguely remember that this is the case but > do not remember where I read about it. In fact it's both. A slow, weak `leader' makes its way from the clouds to the ground. This sets up a number of return strokes, from the ground up, at intervals of about a tenth of a second. This is why you see quick flashes. In article <1620@bgsuvax.UUCP>, drich@bgsuvax.UUCP (Daniel Rich) writes: > Electricity travels from negative to > postive, therefore lightning travels upwards. Huh? > I believe that someone said that the films they had seen show it > traveling the other direction. Think about this for a second.... > electricity travels at approximately the speed of light (actually, in > air it is a little slower). At this speed, how could you ever > determine a direction from film? There's a device (can't remember its name) to photograph this on a rotating piece of film. Also, electricity may travel near the speed of light, but lightning doesn't. Gigavolts! --Joe