21–26 Jun 2026
U. Ottawa - Learning Crossroads (CRX) Building
America/Toronto timezone
Welcome to the 2026 CAP Congress Program website! / Bienvenue au siteweb du programme du Congrès de l'ACP 2026!

Another look at the equation of time

23 Jun 2026, 18:00
1h 30m
U. Ottawa - Learning Crossroads (CRX) Building

U. Ottawa - Learning Crossroads (CRX) Building

100 Louis-Pasteur Private, Ottawa, ON K1N 9N3
Poster (Non-Student) / Affiche (Non-étudiant(e)) Atmospheric and Space Physics / Physique atmosphérique et spatiale (DASP/DPAE) DASP Poster Session | Session d'affiches DPAE

Speaker

Prof. Richard Marchand

Description

Historically the equation of time ET, giving the difference between the solar mean time and true solar time, has been useful to improve estimates of latitudes. Today with GPS accurate positioning systems, and with accurate atomic clocks, the equation of time is seldom of practical use. It is nonetheless of interest from a basic physics standpoint because of its connection with Earth orbital properties responsible for the difference between the mean solar time, and actual solar time. This presentation will explain the equation of time first using a phenomenological approach, and then, more rigorously mathematically.

Keyword-1 Equation of time
Keyword-2 Mean and actual solar time
Keyword-3 Earth orbital properties

Author

Prof. Richard Marchand

Presentation materials

There are no materials yet.