ping pong balls

[Cord Wiljes]

Don Markstein wrote:

> They'd estimated it would take about 40-50,000 ping pong 
> balls to raise their boat, but it actually floated with a 
> lot less.

With known weight and volume of a single ping pong ball they 
should surely have been able to exactly calculate this on 
beforehand down to the last ping pong ball. 

Or they could have taken a floating ship, stored it full of 
ping pong balls and then flooded it. And see if the water 
which now flows in the spaces between the ping pong balls 
is too heavy for the ship and drowns it.

The floating jar was probably an unsufficient model because
it is very important to store the ping pong balls efficiently, 
i.e. with as little space between the balls as possible. A lot
of balls will automatically take a more efficient packaging
because there are fewer walls per ball who could keep them from 
the optimal packaging. I hope they counted the balls and not 
just the total volume they filled with balls. Because packaging
can make a big difference there.

And they probably used pure water for their tests. Natural water 
(especially sea water) has a higher density so the lifting power
of a ping pong ball is greater in the real ship than "in the jar".

Raising bigger (and heavier) ships will probably not be possible
because the higher ping pong balls would be be pressed to the top
floor of the ship too hard and thus be crushed.

The most efficient way top raise a sunken ship would probably be 
to put a giant, empty ballon inside and pump it up below water.

Cord