N = N* fp ne fl fi fc fL
This is the Drake Equation. The L term at the end refers to the length of time a civilization remains able to communicate to another possible civilization.
We're running out of time.
NnBob, could you pick up some more, please, next time you're by the supermarket? Gotta keep the spices replenished.
Of course, if you mean the arbitrary period of time wherein sentient life on this planet may beyond which regress back to a point where communication with other sentients in this Galaxy is impossible...
You may be right.
Since most Obama voters are hard pressed to keep 90% of the fluid stream aimed at the urinal, operating advanced comm gear could be well past their abilities.
Looks like we can add Canadaytimes Commies to their side of the Idiot Equation.