Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 (Tek) 9/26/83; site vice.UUCP Path: utzoo!linus!decvax!harpo!ulysses!mhuxl!ihnp4!alberta!ubc-vision!uw-beaver!tektronix!tekcad!vice!keithl From: keithl@vice.UUCP (Keith Lofstrom) Newsgroups: net.sf-lovers Subject: Re: Solar physics in "Sundiver" Message-ID: <1279@vice.UUCP> Date: Wed, 30-Nov-83 17:21:18 EST Article-I.D.: vice.1279 Posted: Wed Nov 30 17:21:18 1983 Date-Received: Wed, 15-Feb-84 04:10:44 EST Organization: Tektronix, Beaverton OR Lines: 25 I mostly agree with Lew Mammel's comments on Sundiver ( I liked Startide Rising much better ), but I couldn't let his comment on solar buffeting go without comment. If the density is 1e-6 g/cm3 (though it sounds too high), that is about 0.001 that of the Earth's atmosphere. Aerodynamic forces are proportional to the density times the relative wind velocity squared; the solar velocities would only have to be 30 times higher for an equivalent force. Hurricane velocities in the Earth's atmosphere are around 100 m/sec; an indication of the solar velocity scale is the solar wind, which comes off the sun at >300 Km/sec! For this crude analysis, the buffeting forces would be 9,000 times greater than an Earth hurricane! Of course, the real situation is dependent on the velocities in the deeper layers of the Sun, the actual turbulence, and the "wind shear". The actual buffeting could be orders of magnitude larger or smaller, but the important point is that even a "vacuum" can have a strong wind if it moves fast enough. The Sun is a powerful machine... -- Keith Lofstrom uucp: {ucbvax,decvax,chico,pur-ee,cbosg,ihnss}!teklabs!vice!keithl CSnet: keithl@tek ARPAnet:keithl.tek@rand-relay