On 1/4/2014 7:10 PM, LizR wrote:
On 5 January 2014 16:03, meekerdb <meeke...@verizon.net <mailto:meeke...@verizon.net>> wrote:


    On 1/4/2014 6:01 PM, Jason Resch wrote:

            4. If block time corresponds to clock time, then how can there be a 
single
            block time structure that encompasses all events when clock times 
progress
            faster or slower for different observers?

        This corresponds to different objects having different velocities 
through space
        time.

    Really just different directions through spacetime.  Everything always 
moves at
    proper speed 1 (at least classically).

What exactly is "proper speed" in SR?

Dx/Dtau, where x is the coordinate vector and tau is the proper time (what a clock measures) and D is the covariant derivative. In flat space, i.e. SR, it reduces to the ordinary derivative dx/dtau. Notice that in the rest frame it's always (1,0,0,0), i.e. all the 'speed' is along the time coordinate.

Brent

--
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 everything-list+unsubscr...@googlegroups.com.
To post to this group, send email to everything-list@googlegroups.com.
Visit this group at http://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/groups/opt_out.

Reply via email to