Two physical variables that have been linked to free-response ESP scores, geomagnetism and local sidereal time, are additionally examined. |
Over the past few sidereal days more radio signals from an as-yet-unidentified source have been detected. |
Two clocks were used, one keeping mean time i.e. 24 hours a day, the other sidereal time of 23 hours, 56 minutes and 4 seconds to the day. |
Because of the precession of the equinoxes the tropical year is shorter by about 21 minutes than the sidereal year. |
The reason that sidereal days are shorter is that while the Earth rotates on its axis, it is also moving around the Sun. |
Each year is still equivalent to the sidereal period of the Earth, one revolution around the Sun. |