From owner-freebsd-chat Fri Mar 17 22:17:38 2000 Delivered-To: freebsd-chat@freebsd.org Received: from theory1.physics.iisc.ernet.in (theory1.physics.iisc.ernet.in [144.16.71.20]) by hub.freebsd.org (Postfix) with SMTP id 3583E37B789 for ; Fri, 17 Mar 2000 22:16:55 -0800 (PST) (envelope-from rsidd@physics.iisc.ernet.in) Received: (qmail 80168 invoked from network); 18 Mar 2000 05:16:47 -0000 Received: from unknown (HELO theory8.physics.iisc.ernet.in) (144.16.71.128) by theory1.physics.iisc.ernet.in with SMTP; 18 Mar 2000 05:16:47 -0000 Date: Sat, 18 Mar 2000 10:46:49 +0530 (IST) From: Rahul Siddharthan To: Kris Kennaway Cc: Brett Taylor , Mark Ovens , Paul Richards , chat@FreeBSD.ORG Subject: Re: Useful Metric Conversions In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-chat@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > > I'll stick w/ mass - at least I'll buy the same amount on each planet or > > in an accelerating frame. :-) > > I think you meant 'inertial frame'. In an accelerating frame your inertial > mass (and gravitational mass, by the equivalence principle) will be > different. No, your mass is the same, your weight changes. You are weightless in a freely falling elevator, but certainly not massless. The definition of "inertial frame" or "accelerated frame" varies: traditionally, earth's surface is (nearly) an inertial frame with an external force (Earth's gravity) and the freely falling elevator would be an accelerated frame and the acceleration would give rise to a pseudoforce which cancels your weight due to Earth's gravity; but in general relativity the elevator is an inertial frame, not earth's surface, and your weight on earth's surface (which you attribute to "gravity") is really a pseudoforce arising from your being in an accelerated frame. > The moral of the story: buy your sugar in a freely-falling elevator car. If you only want to lose weight, of course, the freely falling elevator (or an orbiting satellite, etc) is the place to be. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-chat" in the body of the message