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Topic: How mathematicians view physics
Replies: 8   Last Post: Nov 3, 2013 7:47 PM

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Tanu R.

Posts: 546
Registered: 12/13/04
Re: How mathematicians view physics
Posted: Nov 2, 2013 7:29 AM
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Lord Androcles wrote:

> "Tom Potter" wrote in message news:EO1du.143498$c56.58358@fx32.iad...
> ...
> Special relativity
> Space-time rotation symmetry
> ==============================================
> Bullshit.


Let me add some notes just for fun.

> Time is not a vector

Right - it is not considered to be a vector. On the other hand is
this a 'serious problem' because the Lorentz transformation, i.e.
the 'heart' of relativity - in transforms the constant time direction
of any local frame into different time direction as seen in terms
of the entire 'general spacetime' which is one of the most serious
problems the unification spacetime and quantum field physics is
presenting for quite a time now.

This can nicely be 'felt' in this gif animation:
http://upload.wikimedia.org/wikipedia/commons/e/e4/Lorentz_transform_of_world_line.gif
"The momentarily co-moving inertial frames along the world line of
a rapidly accelerating observer (center). The vertical direction
indicates time, while the horizontal indicates distance, the dashed
line is the spacetime trajectory ("world line") of the observer.
The small dots are specific events in spacetime. If one imagines
these events to be the flashing of a light, then the events that
pass the two diagonal lines in the bottom half of the image (the
past light cone of the observer in the origin) are the events
visible to the observer. The slope of the world line (deviation
from being vertical) gives the relative velocity to the observer.
Note how the momentarily co-moving inertial frame changes when the
observer accelerates." [cited from wikipedia - Lorentz transformation]

It is also this "behaviour of time" in general realativity that
is "the reason" to "promise" possible time travel to the crowd
(closed loops of time paths in general spacetime)...

See also this comparison of different models of spacetime
(which was copied from Penrose, Road to Reality:
http://4.bp.blogspot.com/_qZGouBqZeg8/SZPAYQs9woI/AAAAAAAAA60/1uI_kb1GsfQ/s1600-h/Spacetime.JPG

One problem for the unification spacetime and quantum field physics
can be "seen" here: http://www.flickr.com/photos/ethanhein/1925166760/
"Fig. 30.3 Stationarity of a spacetime is expressed as the
presence of a timelike Killing vector k. This generates a
continuous family of time-displacements preserving the metric.
If k = d/dt, where t is the ?time parameter? of a coordinate
system (t,x,y,z), then x, y, and z mustbe constant along the
integral curves of k. (See §14.7.)" [cited from Penrose, Road to Reality]

Finally, there is a "serious" proposition of a vectorial time in
relativity, called 'Vectorial Relativity' by Jorge A Franco, who even
emits a journal http://jvr.freewebpage.org/ and who explains his idea
right here http://works.bepress.com/jorge_franco/9/ (click on download)
who he considers a "vector interpretation of time"...



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