Show shortening of the day it has long been known theoretically that tho the tides act as a brake on the rotating earth and tend to lengthen the day the effect however is so slight that thai it cannot be measured in any length of time at mans disposal it may be estimated with the aid of certain assumptions and using the data available mr air W D MacA macmalan has han recently made the he necessary computation by the formulas used by en gl eldeera eln eera he ha finds for the increase of the leighty leng of the day one second in yesra |