if you are choosing that ball as a frame of refference, then that would be true. The point of relativity is that there is no central frame of refference, just what you choose. its not conceit, its reality.
On Thu, Sep 25, 2008 at 11:49 AM, Harry Veeder <[EMAIL PROTECTED]> wrote: > > That is true but that is not what I mean. > > Imagine you are the ball and you are resting wrt to the table and the > earth. A cue or another ball hits you so you move at 1 m/s wrt to the > table. Would you be so self-centred as to claim you are still resting, > and that the table and the earth are now moving under you at 1 m/s? > > If such a conceit were true the pool players standing around the table > would have been flung off their feet as the earth abruptly accelerated > under them from 0 m/s to 1 m/s. > > Harry > > > > ----- Original Message ----- > From: leaking pen <[EMAIL PROTECTED]> > Date: Thursday, September 25, 2008 12:43 pm > Subject: Re: [Vo]:Chinese building "space drive" unit > >> Yes. It is more the opposite, but every step you take, you push the >> Earth, and she pushes back at you. The Earth pushes a hell of a lot >> harder, but you DO have an effect on the motion of the Earth, however >> infintesimal, with each step. >> >> On Thu, Sep 25, 2008 at 9:38 AM, Harry Veeder <[EMAIL PROTECTED]> wrote: >> > >> > >> > ----- Original Message ----- >> > From: "Stephen A. Lawrence" <[EMAIL PROTECTED]> >> > Date: Thursday, September 25, 2008 11:18 am >> > Subject: Re: [Vo]:Chinese building "space drive" unit >> > >> >> >> >> >> >> OrionWorks wrote: >> >> > I bet this device look familiar to a few vorts! >> >> > >> >> > See: >> >> > >> >> > http://blog.wired.com/defense/2008/09/chinese-buildin.html >> >> > >> >> > >> >> >> >> Uh -- not me; looks sort of like an antique picture tube, maybe, >> >> but I >> >> don't recognize it. >> >> >> >> I notice Emdrive hasn't gotten as far as running a spell checker >> over>> their front page, which doesn't automatically fill one with >> >> confidence. >> >> From the description, it appears to be a microwave oven. >> Surprising>> that they claim it will fly. >> >> >> >> I had one other comment on the website. On the theory page, >> they say: >> >> >> >> > ... Einstein's Special Law of Relativity in which separate >> frames of >> >> > reference have to be applied at velocities approaching the speed >> >> of light. >> >> >> >> This is absolutely false. SR does *not* require that you must >> apply>> "separate frames of reference" when approaching the speed >> of light. >> >> In >> >> fact any analysis which relies on total momentum or energy >> *must* be >> >> carried out entirely within a *single* reference frame or else >> you'll>> end up with nonsensical results (just as they have >> apparently done >> >> here). >> >> In the FAQs they say: >> >> > Thus the system of EM wave and waveguide can be regarded as an >> open>> > system, with the EM wave and the waveguide having separate >> frames of >> >> > reference. >> >> >> >> This is complete nonsense. The "reference frame" chosen is >> based on >> >> what makes it easiest to solve a particular problem. There's >> nothing>> magical about relativity theory here, nor is there any >> mystical>> significance to the term "reference frame"; *exactly* >> the same concept >> >> exists in ordinary Newtonian mechanics. >> >> >> >> When a pool player strikes a ball, in the frame of the table, >> the cue >> >> and the player's arm have significant momentum just before the >> ball is >> >> hit. Afterwards, the table, player, and cue have zero momentum >> in the >> >> *table's* reference frame. And yet, the ball has zero momentum >> in the >> >> *ball's* reference frame, too! So, where did the momentum go? >> >> Answer: >> >> you need to do the momentum budget using a *single* frame, not a >> >> different frame for each physical object! (But you get to pick >> which>> frame to use.) >> >> >> > >> > I have difficulty even accepting newtonian relativity. >> > Do you think by a flick of the wrist the mass of the table (and the >> > earth!) have gone from being at rest wrt to the cue ball, to >> being in >> > motion wrt to the cue ball? >> > >> > Harry >> > >> > >> >> > >
