Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > sci.physics.relativity > #452512

Re: Units in spacetime

From Odd Bodkin <bodkinodd@gmail.com>
Newsgroups sci.physics.relativity
Subject Re: Units in spacetime
Date 2018-03-13 14:36 +0000
Organization Aioe.org NNTP Server
Message-ID <p88nm5$1ee8$1@gioia.aioe.org> (permalink)
References <fgpik3F5ps8U1@mid.individual.net> <c9da30bf-feee-4de2-8bd9-e714c0ad3a5e@googlegroups.com>

Show all headers | View raw


David (Kronos Prime) Fuller <fuller.david@hotmail.com> wrote:
> Thomas Heger
> Hi NG 
> 
> while sorting out old stuff on old harddrives, I have found this nice 
> little text, which I had written about 2010 for 'BAUT' forum. 
> 
> Hope you like that: 
> 
> ****************************************************************** 
> 
> 
> ds²= -(cdt)² + dx² + dy² + dz². 

You should be careful here. The formulation of the interval above really
only applies to spacelike intervals. For timelike intervals, the interval
is written as 
 ds²= (cdt)² - dx² - dy² - dz².

You’re going to see why just below, where you take the case dx = dy = dz =
0, which is explicitly a timelike interval. 

Now you may ask, why doesn’t one formulation of the interval work for both?
The reason is the structure of spacetime, where there are two fundamentally
different regions: inside the light cone and outside the light cone. It is
not really possible to formulate a common expression for both regions with
introducing weird stuff like imaginary distances. So one should not try.
One should just be careful to use the right expression for the right
region. 

> That is (cdt)² +ds²=dx² + dy² + dz². 
> 
> Along the lightcone we have ds=0, hence could take the square root and 
> get units of meters - as expected. 
> 
> For dx=dy=dz=0 we get ds²= -1 * c²dt² . We have to take the square root 
> of –1, what is the imaginary unit  i and get  i*cdt=ds, or ‘imaginary 
> meters’. 
> 
> For dt=0 we have a negative ds². In spacelike direction we have 
> sqrt(ds²) =sqrt(dx² + dy² + dz²), 
> 
> what has units of meters/i. 
> 
> The term ds seems to be the magnitude of a matrix, indicating the amount 
> of change in space and time, if you think in terms of four vectors a=a0 
> + a1 e1 + a2 e2 + a3 e3, then 
> det(a) = |a|2 = ao² - a1² - a2² - a3². 
> 
> The velocities in spacetime seems to be dimensionless: meter per meter. 
> 
> So we could use radians as units for velocity. 
> 
> https://photos.app.goo.gl/xrSxQ4a2rON6XiiY2
> 
> Than we have dimensions 
> of meters per meter or an ‘imaginary angle’. 
> 
> Since here I treat objects as 'self-centred' (at rest in respect to 
> itself), we could make the angle zero along the timeline and the circle 
> perpendicular  timeless, hence |a|2 = a a^-1  . 
> 
> A full circle provides a tick at some kind of clock. Since it has this 
> is an anti-symmetric behavior and the clock behaves somehow similar a 
> pendulum, swinging back and forth. 
> 
> http://cds.cern.ch/record/516564/files/0109005.pdf
> 
> On the reversal of sign of secondary Bjerknes force acting between two
> pulsating gas bubbles
> 
> 
> In spacetime perspective, that pendulum could be visualized as a 
> pointer, pointing up and down. That is like a pointer, which is
> performing a circle around a spacelike axis. 
> 
> Actually we have three spacelike axes, hence each could provide a clock 
> and we have to add the change in space along each axis to the total 
> change in time. 
> 
> Since the meter is defined with help of the second and that as some 
> counting of a clock, we have to think about spacetime having no 
> dimensions at all, other than radians and i. 
> 
> The scale has to be put in by hand, according to the scale of the system 
> observed. Even as this seems to be unsatisfactory, the world we live in, 
> behaves like having just such fractal properties. 
> 
> The plank unit h (units of angular momentum) could provide the size of a
> fundamental unit sphere, 
> since a sphere in spacetime has a volume with units of an action. 
> 
> 
> 
> 
> 
> TH
> 



-- 
Odd Bodkin -- maker of fine toys, tools, tables

Back to sci.physics.relativity | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread


Thread

Units in spacetime Thomas Heger <ttt_heg@web.de> - 2018-03-13 10:06 +0100
  Units in spacetime "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-13 07:15 -0700
    Re: Units in spacetime Odd Bodkin <bodkinodd@gmail.com> - 2018-03-13 14:36 +0000
      Re: Units in spacetime "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-13 07:51 -0700
        Re: Units in spacetime "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-13 08:34 -0700
      Re: Units in spacetime Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-13 09:20 -0700
        Re: Units in spacetime Odd Bodkin <bodkinodd@gmail.com> - 2018-03-13 16:27 +0000
          Re: Units in spacetime Odd Bodkin <bodkinodd@gmail.com> - 2018-03-13 16:28 +0000
          Re: Units in spacetime Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-13 09:45 -0700
            Re: Units in spacetime Thomas Heger <ttt_heg@web.de> - 2018-03-13 18:39 +0100
              Re: Units in spacetime Térov Balónky <iytn@yeicenlw.ik> - 2018-03-13 17:49 +0000
                Re: Units in spacetime Térov Balónky <iytn@yeicenlw.ik> - 2018-03-13 17:49 +0000
                Re: Units in spacetime Thomas Heger <ttt_heg@web.de> - 2018-03-14 13:54 +0100
                Re: Units in spacetime Térov Balónky <iytn@yeicenlw.ik> - 2018-03-14 16:02 +0000
                Re: Units in spacetime Thomas Heger <ttt_heg@web.de> - 2018-03-14 21:47 +0100
            Re: Units in spacetime Odd Bodkin <bodkinodd@gmail.com> - 2018-03-13 18:02 +0000
              Re: Units in spacetime Térov Balónky <iytn@yeicenlw.ik> - 2018-03-13 18:12 +0000
      Re: Units in spacetime "Paul B. Andersen" <relativity@paulba.no> - 2018-03-13 22:00 +0100
        Re: Units in spacetime Odd Bodkin <bodkinodd@gmail.com> - 2018-03-13 22:55 +0000
          Re: Units in spacetime Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-14 09:19 -0700
            Re: Units in spacetime "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-14 09:32 -0700
              Re: Units in spacetime "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-14 09:52 -0700
            Re: Units in spacetime Odd Bodkin <bodkinodd@gmail.com> - 2018-03-14 18:07 +0000
              Re: Units in spacetime "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-14 12:03 -0700
              Re: Units in spacetime Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-14 13:18 -0700
                Re: Units in spacetime "Paul B. Andersen" <relativity@paulba.no> - 2018-03-14 21:38 +0100
                Re: Units in spacetime Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-14 16:27 -0700
                Re: Units in spacetime Python <python@python.invalid> - 2018-03-15 01:05 +0100
                Re: Units in spacetime Odd Bodkin <bodkinodd@gmail.com> - 2018-03-15 03:52 +0000
                Re: Units in spacetime Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-14 23:10 -0700
                Re: Units in spacetime "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-15 00:16 -0700
                Re: Units in spacetime Odd Bodkin <bodkinodd@gmail.com> - 2018-03-15 11:55 +0000
                Re: Units in spacetime "Paul B. Andersen" <relativity@paulba.no> - 2018-03-15 14:40 +0100
                Re: Units in spacetime Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-03-15 16:02 +0100
                Re: Units in spacetime Odd Bodkin <bodkinodd@gmail.com> - 2018-03-15 15:20 +0000
                Re: Units in spacetime Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-15 09:49 -0700
                Re: Units in spacetime Odd Bodkin <bodkinodd@gmail.com> - 2018-03-15 19:49 +0000
                Re: Units in spacetime "Paul B. Andersen" <relativity@paulba.no> - 2018-03-15 11:26 +0100
                Re: Units in spacetime mlwozniak@wp.pl - 2018-03-15 04:03 -0700
                Re: Units in spacetime Keith Stein <keithstein111@gmail.com> - 2018-03-15 15:50 +0000
                Re: Units in spacetime "Paul B. Andersen" <relativity@paulba.no> - 2018-03-15 21:15 +0100
                Re: Units in spacetime Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-15 10:30 -0700
                Re: Units in spacetime Python <python@python.invalid> - 2018-03-15 18:32 +0100
                Re: Units in spacetime Odd Bodkin <bodkinodd@gmail.com> - 2018-03-15 19:51 +0000
                Re: Units in spacetime "Paul B. Andersen" <relativity@paulba.no> - 2018-03-15 20:56 +0100
                Re: Units in spacetime Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-15 23:20 -0700
                Re: Units in spacetime "Paul B. Andersen" <relativity@paulba.no> - 2018-03-16 10:11 +0100
                Re: Units in spacetime Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-18 22:25 -0700
                Re: Units in spacetime "Paul B. Andersen" <relativity@paulba.no> - 2018-03-19 09:17 +0100
                Re: Units in spacetime Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-19 10:36 -0700
                Re: Units in spacetime Odd Bodkin <bodkinodd@gmail.com> - 2018-03-19 17:57 +0000
                Re: Units in spacetime Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-19 11:16 -0700
                Re: Units in spacetime Odd Bodkin <bodkinodd@gmail.com> - 2018-03-19 18:43 +0000
                Re: Units in spacetime Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-19 13:02 -0700
                Re: Units in spacetime "Paul B. Andersen" <relativity@paulba.no> - 2018-03-19 21:24 +0100
                Re: Units in spacetime Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-20 09:32 -0700
                Re: Units in spacetime Python <python@python.invalid> - 2018-03-20 17:40 +0100
                Re: Units in spacetime Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-20 09:55 -0700
                Re: Units in spacetime Dirk Van de moortel <dirkvandemoortel@notmail.com> - 2018-03-20 18:25 +0100
                Re: Units in spacetime Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-20 14:21 -0700
                Re: Units in spacetime Dirk Van de moortel <dirkvandemoortel@notmail.com> - 2018-03-20 22:57 +0100
                Re: Units in spacetime Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-20 16:00 -0700
                Re: Units in spacetime Darryl Fletcher <lu@ewiwwe.tt> - 2018-03-20 23:38 +0000
                Re: Units in spacetime "Paul B. Andersen" <relativity@paulba.no> - 2018-03-22 14:01 +0100
                Re: Units in spacetime Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-22 13:45 -0700
                Re: Units in spacetime "Paul B. Andersen" <relativity@paulba.no> - 2018-03-27 20:18 +0200
                Re: Units in spacetime xip1415926@gmail.com - 2018-03-27 14:40 -0700
                Re: Units in spacetime xip1415926@gmail.com - 2018-03-26 07:38 -0700
                Re: Units in spacetime "Paul B. Andersen" <relativity@paulba.no> - 2018-03-27 19:53 +0200
                Re: Units in spacetime xip1415926@gmail.com - 2018-03-27 12:21 -0700
                Re: Units in spacetime Tom Roberts <tjroberts137@sbcglobal.net> - 2018-03-27 16:47 -0400
                Re: Units in spacetime "Paul B. Andersen" <relativity@paulba.no> - 2018-03-28 09:34 +0200
                Re: Units in spacetime Thomas Heger <ttt_heg@web.de> - 2018-03-20 21:12 +0100
                Re: Units in spacetime Thomas Heger <ttt_heg@web.de> - 2018-03-16 10:32 +0100
                Re: Units in spacetime "Paul B. Andersen" <relativity@paulba.no> - 2018-03-16 12:33 +0100
                Re: Units in spacetime Thomas Heger <ttt_heg@web.de> - 2018-03-17 21:29 +0100
                Re: Units in spacetime Odd Bodkin <bodkinodd@gmail.com> - 2018-03-14 20:51 +0000
                Re: Units in spacetime "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-20 15:41 -0700
            Re: Units in spacetime Thomas Heger <ttt_heg@web.de> - 2018-03-15 14:04 +0100
              Re: Units in spacetime Thomas Heger <ttt_heg@web.de> - 2018-03-15 20:10 +0100
      Re: Units in spacetime Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-03-22 05:57 +0100
        Re: Units in spacetime Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-03-27 19:57 +0200
  Re: Units in spacetime numbernumber1964@gmail.com - 2018-03-20 13:49 -0700
    Re: Units in spacetime Keith Stein <keithstein111@gmail.com> - 2018-03-21 07:26 +0000
  Re: Units in spacetime numbernumber1964@gmail.com - 2018-03-22 15:28 -0700
    Re: Units in spacetime Thomas Heger <ttt_heg@web.de> - 2018-03-23 09:57 +0100
      Re: Units in spacetime xip1415926@gmail.com - 2018-03-25 18:54 -0700
  Re: Units in spacetime numbernumber1964@gmail.com - 2018-03-23 10:48 -0700
    Re: Units in spacetime Thomas Heger <ttt_heg@web.de> - 2018-03-25 19:03 +0200
      Re: Units in spacetime xip1415926@gmail.com - 2018-03-26 06:39 -0700
        Re: Units in spacetime Thomas Heger <ttt_heg@web.de> - 2018-03-26 21:43 +0200
  Re: Units in spacetime Keith Stein <keithstein111@gmail.com> - 2018-03-30 11:00 +0100
    Re: Units in spacetime Will Bos <sllu@wsws.sb> - 2018-03-30 10:52 +0000
      Re: Units in spacetime Will Bos <sllu@wsws.sb> - 2018-03-30 11:02 +0000
    Re: Units in spacetime Thomas Heger <ttt_heg@web.de> - 2018-04-03 06:45 +0200

csiph-web