User:Tom Allen/ta/AddendumX04P06C

... points on these geodesics come into close proximity to each other in spacetime ...

NB. ... execute (ijx) ...

NB. ... points on geodesics when the time is the same ...

   9!:11 [8

   {.@{: ((1092510+i.@(0101"_)){]) ((2^_44)qtsz]) pdDB
_0.94162166 0.74288316 0 154.26102
   {.@{: ((0914358+i.@(0078"_)){]) ((2^_44)qtsz]) pdDC
_0.94130051 0.74197949 0 154.26103
   
   {.@{: ((1092610+i.@(0045"_)){]) ((2^_44)qtsz]) pdDB
_0.94254024 0.74068578 0 154.26679
   {.@{: ((0914435+i.@(0035"_)){]) ((2^_44)qtsz]) pdDC
_0.94306282 0.73975828 0 154.2668

load 'plot'

pd 'reset'

pd (cy0"1;cy1"1) (S00yL{])"2 ((1092510+i.@(0101"_)){]) pdDB    NB. ... blue  ...
pd (cy0"1;cy1"1) (S00yL{])"2 ((1092610+i.@(0045"_)){]) pdDB    NB. ... red   ...
pd (cy0"1;cy1"1) (S00yL{])"2 ((1092654+i.@(0080"_)){]) pdDB    NB. ... green ...

pd (cy0"1;cy1"1) (S00yL{])"2 ((0914358+i.@(0078"_)){]) pdDC    NB. ... purple     ...
pd (cy0"1;cy1"1) (S00yL{])"2 ((0914435+i.@(0035"_)){]) pdDC    NB. ... pink       ...
pd (cy0"1;cy1"1) (S00yL{])"2 ((0914469+i.@(0070"_)){]) pdDC    NB. ... dark green ...

pd 'pdf'

... pdDB moves from blue -> red -> green ...
... pdDC moves from purple -> pink -> dark green ...

... geodesics ...

load 'plot'

pd 'reset'

incy0=:(2-~/\])@:(cy0"1)
incy1=:(2-~/\])@:(cy1"1)
incy2=:(2-~/\])@:(cy2"1)
incy3=:(2-~/\])@:(cy3"1)
veloc=:(((incy0^2:)+incy1^2:)^0.5"_)%incy3

pd (}:@:(cy3"1);veloc) (S00yL{])"2 ((1092510+i.@(0101"_)){]) pdDB    NB. ... blue  ...
pd (}:@:(cy3"1);veloc) (S00yL{])"2 ((1092610+i.@(0045"_)){]) pdDB    NB. ... red   ...
pd (}:@:(cy3"1);veloc) (S00yL{])"2 ((1092654+i.@(0080"_)){]) pdDB    NB. ... green ...

pd (}:@:(cy3"1);veloc) (S00yL{])"2 ((0914358+i.@(0078"_)){]) pdDC    NB. ... purple     ...
pd (}:@:(cy3"1);veloc) (S00yL{])"2 ((0914435+i.@(0035"_)){]) pdDC    NB. ... pink       ...
pd (}:@:(cy3"1);veloc) (S00yL{])"2 ((0914469+i.@(0070"_)){]) pdDC    NB. ... dark green ...

pd 'pdf'

... velocity along geodesics as a multiple of the velocity of electromagnetic waves ...