On Mon, Nov 10, 2025 at 10:27:41PM -0800, Alan Grayson wrote: > Russell; this is directed to you, primarily, since I am confident you can > answer this question with ease. If a test particle is at rest from the > perspective of some reference frame, it's claimed that this test particle is > moving at velocity c along the time axis. But what exactly does this mean? And > more important how is this possible since SR establishes that no material > particle can move at exactly velocity c? TY, AG >
Any object will experience moving though spacetime at a rate of 1 second per second. The term often used for this is "proper time". Since one second is c metres (c being just the conversion constant between metres and seconds, you could also say it is moving through spacetime at velocity c. The other thing your refer as "no material particle can move at exactly velocity c" has left out the phrase "in space". Relative to any other object's path through spacetime, the angle of the test object trajectory cannot be such that it is moving c metres through space for every second it moves through time. -- ---------------------------------------------------------------------------- Dr Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders [email protected] http://www.hpcoders.com.au ---------------------------------------------------------------------------- -- 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 view this discussion visit https://groups.google.com/d/msgid/everything-list/aRLqG8qtB6z4YEra%40zen.
