I was in the post office yesterday, and I noticed they have these flat-rate shipping boxes, advertised with the slogan “If it fits, it ships.” So you pay $13.95 to ship anything that will fit inside a 12″ x 12″ x 5 1/2″ box, for example. Wouldn’t it be funny to fill up one of these boxes with the densest element on the periodic table, then go to the post office and ship it?
Of course the element I speak of is osmium, which weighs in at a hefty 22.6 g/cm3. If my math is correct here, that 12″x12″x5.5″ box translates into 792 cubic inches, or 12.98 liters. Fill it up with a huge block of osmium and it would weigh 293 kilograms, or 646 pounds.
So you’d probably actually need like 6 people to lift the box. And the fact that osmium costs ~$30/gram, this little prank would cost $8.8 million to pull off. Depleted uranium might be a little more economical. It’s only 19.1g/cm3, so fill up that same box with DU and it would only weigh 546 pounds. Still pretty funny.