On Sun, Feb 2, 2014 at 7:13 AM, <[email protected]> wrote: > > Jesse - if the assumption is a fundamental geometry akin to the surface of > a world, and if the speed of light is constant, then you could draw dots > around that world for exact intervals of the speed of light, in which case > the light arrives at each point from each other point at exactly the same > moment....isn't that saying edgar's p-time? >
I don't understand what you mean by "dots around the world for exact intervals of the speed of light"--in terms of a standard spacetime diagram from SR, what would the dots be? Different events along the path of a single light ray, or events along the paths of multiple light rays radiating from some other event, or something else? It is true that the spacetime "distance" between any two points along a light-like path is zero, if that's what you mean, but I don't see the connection between this observation and the idea that the light arrives "at exactly the same moment", I'm not sure how you're defining that phrase. "Same moment" normally suggests a judgment about simultaneity, not a judgment about the proper time along a particular path between events. Also, note that by means of a zig-zag lightlike path (like that of a light ray bouncing repeatedly between mirrors), you can connect *any* two points in spacetime that are within one another's light cones by a path of zero proper time--for example, there is a path of zero proper time between the assassination of Julius Caesar and me sitting here typing this. So if you were to define events "at exactly the same moment" in terms of the existence of a path of zero proper time connecting the events, you'd have to say that all events throughout history occurred "at exactly the same moment" which is pretty clearly not how it works with Edgar's p-time. Jesse -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
