HP-15C The time an object takes to fall to the ground

[Vtile]

(12-21-2016 08:38 PM)Dave Shaffer Wrote:  

(12-12-2016 07:55 PM)Dieter Wrote:  Mother Nature doesn't work with more than two significant digits. The 15C program uses a rounded value of 4,9 m/s². Which should be OK for most places on earth. ;-)

Not so fast - depends on what you are doing!

Mother Nature may need 12 or 13 significant digits: in our geodesy research, we use very fancy gravimeters (look up in wikipedia) that can measure "g" (the local gravitational acceleration) to parts per trillion! With this precision, you can measure solid earth tides: the ground under your feet cycles up and down twice per day at the tens of centimeters level.

Well that is what I call a cool bit of information. Yes, mother earth do not work with two significant digits like this air floatation effect (lost in translation, Iirc it had a decent one word name) in very light, but large by volume objects.