On Mon, Jan 6, 2014 at 9:03 AM, Edgar L. Owen <[email protected]> wrote:
> Jason, > > What clock measures your coordinate time? Apparently none. > Any clock in my rest frame measures my coordinate time. > It's beginning to sound just like another name for Present time. > > What's the difference? > In relativity, "present" is not globally defined, but it seems to be in your theory. Note coordinate time has no meaning either, without defining a frame of reference. Jason > > Edgar > > > > On Monday, January 6, 2014 9:47:36 AM UTC-5, Jason wrote: >> >> >> >> On Jan 6, 2014, at 6:55 AM, "Edgar L. Owen" <[email protected]> wrote: >> >> Brent, >> >> No it's not "an observation that the two twins are together at >> particular spacetime coordinates" because the spacetime t coordinates are >> different. >> >> >> Their proper times are different, but not their coordinate times. >> >> A clock time is only a representation of how much speed (and accordingly >> distance) had to be given up to travel through space. It is not an actual >> coordinate in space time, for that you use coordinate time. All things >> travel equal distances through space time in equal coordinate times, but >> not all things travel equal distances through proper time (clock time) in >> equal coordinate times. It is when the coordinate times are equal that two >> things can interact. >> >> >> >> Since the spacetime t coordinates are different WHEN are they together? >> >> >> Their coordinate times are equal. >> >> >> Certainly not in a simultaneous clock time as proved by their differing >> clocks. >> >> >> Right, their proper times are different. >> >> >> When are they together Brent? Obviously in a present moment which is a >> kind of time that clearly is not the same as clock time. >> >> >> They are together when their spatial coordinates: x,y,z and coordinate >> time t are the same. You are right this t is not the same as proper time. >> >> Your conclusion that there must be a global present for this to work is >> unneccessary. >> >> Jason >> >> >> Edgar >> >> >> >> On Monday, January 6, 2014 12:18:16 AM UTC-5, Brent wrote: >>> >>> On 1/5/2014 12:00 PM, Edgar L. Owen wrote: >>> > Brent, >>> > >>> > No, the present moment is NOT just a "label". It's an empirically >>> verifiable observation >>> > (measurement). And not only that both twins agree on that measurement, >>> namely that they >>> > have different clock times in the same shared present moment. >>> > >>> > There is simply no way around that.... >>> > >>> > Edgar >>> >>> Of course it's an observation. It's an observation that the two twins >>> are together at >>> particular spacetime coordinates. I have no problem with you calling >>> that a present >>> moment (although everyone else calls it an event). The problem is not >>> that you can't >>> define a global time at which they meet, it's that you can't define a >>> *unique* global >>> time. There are infinitely many choices of coordinate time and they >>> will all agree that >>> the twins meet at the same coordinate time - but they will not agree as >>> to which other >>> distant events in the universe are at the same time as the meeting. >>> >>> 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 [email protected]. >> To post to this group, send email to [email protected]. >> >> Visit this group at <http://groups.google.com/group/everything-list> >> http://groups.google.com/group/everything-list. >> For more options, visit <https://groups.google.com/groups/opt_out> >> https://groups.google.com/groups/opt_out. >> >> -- > 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. > -- 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.
