Two ways to slower aging - or just one?




twin paradox, special relativity, general relativity


In the context of teaching relativity, one encounters two situations in which two observers age at different rates. Usually, these effects are treated as if they were independent of each other. Often one is referred to as special-relativistic, the other as general-relativistic. We show that both are special cases of an effect which follows naturally from the fact that space and time form a unity. They exist in a flat space-time and therefore neither of them deserves the label general relativistic.


Wikipedia, Global positioning system, “Special and general relativity predicted that the clocks on GPS satellites, as observed by those on Earth, run 38 microseconds faster per day than those on the Earth.” (2023, April 14)

Wikipedia, Satellite navigation, “Einstein’s theory of general relativity is applied to GPS time correction, the net result is that time on a GPS satellite clock advances faster than a clock on the ground by about 38 microseconds per day.” (2023, April 14)

E. A. Desloge and R. J. Philpott, Uniformly accelerated reference frames in special relativity, Am. J. Phys. 55 (1987) 252,

S. P. Boughn, The case of the identically accelerated twins, Am. J. Phys. 57 (1989) 791,

U. Ben-Ya’acov, The “twin paradox” in relativistic rigid motion, Eur. J. Phys. 37 (2016) 055601,

A. Harpaz, The twins paradox and the principle of equivalence, Eur. J. Phys. 11 (1990) 82,

P. Davis, The New Physics (Cambridge University Press, Cambridge, 1998), p. 10

K. S. Thorne, Black holes and time warps (W. Norton Company, New York, 1994), p. Box 2.4.




How to Cite

F. Herrmann and M. Michael Pohlig, “Two ways to slower aging - or just one?”, Rev. Mex. Fis. E, vol. 21, no. 1 Jan-Jun, pp. 010202 1–, Jan. 2024.