This analysis shows that a special relativity interpretation matches observed type 1a supernova redshifts. Davis & Lineweaver reported in 2003 that a special relativity match to supernova redshift observations can be ruled out at more than 23σ, but MacLeod’s 2004 conclusion that this finding was incorrect and due to a mathematical error is confirmed. MacLeod’s plot of special relativity against observation has been further improved by using celerity (aka proper velocity) instead of peculiar velocity. A Hubble plot of type 1a supernova celerity against retarded distance has a straight line of 70 km s-1 Mpc-1 for as far back in time as we can observe, indicating that, with a special relativity interpretation of cosmological redshift, expansion of the universe is neither accelerating nor decelerating, and it is not necessary to invoke the existence of dark energy.
The words used to describe time don’t clearly distinguish when time is a dimension, used for locating objects and events in spacetime, and when it is a property of objects that can age at different rates. It is proposed to revise the terminology of time to distinguish between ‘tick-time’ (a dimensional property) and ‘tock-time’ (a property of objects related to energy).