5 Ways to Visualize Our $14.5 Trillion National Debt | InvestingAnswers: "Here are our five favorite ways to put this colossal number into context.
1) A Trillion Seconds Worth of Distance Run
Can you guess how many days it takes for a trillion seconds to pass? If you said, 'Let me go get my calculator,' you're on the right track. I'll give you a hint: Each 24-hour day is worth 86,400 seconds. That's a huge number! But it's no where near a trillion.
A million seconds is 13 days.
A billion seconds is 31 years.
A trillion seconds is 31,688 years.
If you can believe it, a trillion seconds ago, modern humans were yet to exist, and Neanderthals stalked the plains of Europe."