One of many amazing cognitions: Moving clocks lose time. This isn't an effect only referring to clocks, moreover the time itself in a moving system underlies the so called time dilation In our normal (Non-Geocacher day) we do mot recognize this effect since velocities are too small and therefore time differences are not measurable..

1916

Albert Einstein finished his "Theory of General Relativity":

Clocks within a gravity field lose time. A clock on the Moon will therefore measures a longer time than a clock on our Earth, since Earth's gravity is bigger..

1950+

Ivan Getting (1912-2003) significantly participated in the basic developments for the GPS. For further explanation of the GPS functionality the interested geocacher surely is aware of 1001 sources in the internet..

2000

Bill Clinton "turned off" the artificial deterioration of the satellite signal, clearing the way for the civil use of the satellite navigation for us geocachers..

What the hell is the connection between Einstein and Geocaching?

There aren't any caches on the Moon, are there? And we do not know geocachers in supersonic aircrafts searching for a cache.

Nevertheless without taking into account the above mentioned effects, which partially compensates each other, an adequate precise measuring of the position would be impossible. Neglecting the effect of the moving clock in the satellite and the stronger gravity field for the clock in the receiver on the Earth, even after only one day the position error would have summed up to nearly 12000 meters.

Even after a few minutes the search for Tupperware boxes would be a nightmare.

Thus, only due to combining the scientific efforts of Einstein and Getting - symbolized by the two parts Yin and Yang - our hobby geocaching is enabled.

Therefore: Come Together – Go for the Cache !