Who invented the second
What exactly is and how did time enter into our lives?
I have searched with Google and have not found an answer to who invented the second and why this particular length of time was used.
The second was introduced by our ancestors and was incorporated into the division of 60 minutes and 12 plus 12 hours that construct a 24 hour period to equal one rotation our or earth.
But no one tells us where did the time length of the second come from.
Why was it not based on the length of time a sparrow chirped for example.
My humble guess is that it derives from the beat of a healthy human heart, 60 beats per minute. This was the only thing that was available to listen to and that we carried around with us all of the time.
Therefore it might have been a merger of the time length of 60 seconds times 60 minutes times 24 hours to equal 86,400 beats on the human heart for one average spin of the earth.
Where are we headed with this time and gravity and how gravity effects our perception of time.