As you are leaving from your previous ordeal, you notice that another convict is being taken to a jail cell. As you watch the guard and the convict go to the cell, they start talking.
"You do realize your rights, right?" says the guard.
The convict replies, "The judge said something strange, but I didn't understand it. What was it?"
"You are free to go anytime you like," declares the guard, "as long as you fulfill the required conditions. In your case, your door is secured with a ten-digit lock. If you can guess the right number, you are free to go."
"That's easy," says the prisoner. " I can just keep guessing numbers until I guess the right one."
"Even so," says the guard, "it would take you a hundred years to find the right number at the rate of one per second. Of course, you can always look for the hints we give you." He then points at you and proceeds to tell the new prisoner about your imprisonment.
"In addition to the normal...amenities, you have a desk and a scientific calculator. Good luck." The guard walks away.

You stand there for a few minutes before you realize that you can go. As you turn to leave, you notice that the new prisoner is walking up behind you.
"Wow, this place is great!" he says. "I only had to input one number!"

What number did he try?

If I am correct, and I probably am considering Wiki says the same, the leap ,second is not added due to the earth's rotation slowing down.  This only effects the day getting longer by 1.7 milli second per century.

The correct reason lies in the difference between a standardised day in the SI system of units and the Universal Cocordinated Time (Funny enough: UTC).  The SI day is the average of the solar day between 1750 and 1892.  Since then the Earths rotation has accumulated enough to  make it necessary to add 1 sec +/- every 18 months.   Charlie is right when he says it is not exactkly 18 months, the day where the second is added is decided in mutual agreement and probably long discussions and meetings.  In future, maybe this second will noit be added anymore, as it causes problems in IT and air traffic.  This year this problem is on the agenda.

Posted by Hugo on 2006-03-31 13:06:50