Is Time Relative or Absolute in Spacetime?

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What are the consequences for Background dependancy in Cosmological Horizon modelling?
 
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time is a temporal dimension of spacetime at right angles to the 3 spatial dimensions of spacetime

if you move through time, you also move through space

so you can't do one without the other


time dilation is an illusion caused by one spatial dimension being stretched
(for the observer) relative to the temporal dimension which remains unstretched
 
1) In your rest frame you are standing still, and moving through time, but not through space. Of course other intertial observers see it differently. They see you as moving through both time and space.

2) Time and space dilation through the Lorentz transformations are not illusions for two reasons: first because there is no unversal frame in which the "true" situation could be described, so all we ever have is the relative situation in which the dilations apply, and secondly because the dilations make real physics happen (e.g. the extended lifetime of the cosmic ray muon).
 
in reality there is no such thing as an unmoving mass in spacetime

the Earth and everything on it is moving at 30000 m/s around the sun

the sun and all it's planets are moving around a spiral galaxy


true time (within spacetime) is absolute and unchanging - whilst relative time is variable only between observers in relative motion
 
Last edited:
energia said:
in reality there is no such thing as an unmoving mass in spacetime
In both Einstein's and Galileo's relativity, you are allowed to define yourself as being stationary by centering a reference frame around yourself.
true time (within spacetime) is absolute and unchanging - whilst relative time is variable only between observers in relative motion
How or in what frame do you measure "true time" and doesn't this statement (about motion or lack thereof) contradict your first?
 

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