get an object that is the exact same size and weight and thickness (in terms of the sphere's shell so to speak) as your ball that you have to test if it's closed, and that is confirmed to be sealed/closedBigBadOrc wrote:FILL WITH WATER SEE IF IT LEAKS LOLZTaQa wrote: Prove the closed ball is closed.
then weigh it
put it in water and submerge it with a tool, and time how long it takes to come up to the surface and check it's weight every time, do this about 10-15 times to accomodate for any bizarre results that would screw up the data
then figure out the average of those results, what the weight was before it was put in water and after each test etc. i'm sure you get it
then get your supposedly closed ball, and repeat test as above
if test results are strikingly similar, then the second ball that you just ran through the tests is also closed, as it would have to be to not take in water/get it's weight changed through submerging it and thus maintain the same results