Delayed Reaction: Balancing Pressure for 277 Hours

[pallidin]

Let's say I have a container which produces a non-destructive explosion in the middle. No outside effects.
This explosion produces 2 million pounds of pressure.
Internal containment directs this force both up and down agaisnt hardened plates securely attached to the container. 1 million pounds of pressure up, 1 million pounds of pressure down.
Fine, a balanced system. The container goes nowhere.
Now, let's say that the duration of the explosion is 1 second.
So, we have 1 million pounds of pressure traveling up and down in one second.
Fine.
I devise a method whereby 1 million pounds of pressure in one second is translated into 1 pound of pressure in 1 million seconds(which is 277 hours in translation)
I incorporate this device into the reaction(down) side of the container.
Fire the explosion.
Now we have 1 million pounds of pressure up, and only 1 pound of pressure down for that first second.
Surely this would rise the container to substantial heights.
After the one second, the upward force is exhausted, but the downward force continues for 277 hours at 1 pound of downward force. This would eventually bring the container "back down to earth" but after 277 hours!
Surely I must have something wrong in this reasoning. Or do I.

 

[mathman]

"back down to earth"

Gravity would play a role and air resistance, if you're not in a vacuum. I don't know how fast it would go at the start, but you might also have relativity to consider.