It’s a metal that is solid at room temperature, discovered in 1803. No one sat at a meeting and thought, “What is the densest material, and what if we cram it into this small box?” But we’re going to pretend otherwise as we speculate about the heaviest things to put in the box.

Seventy pounds is the top weight for any mailed item before you get into “overweight” mailing costs. The postal service’s weight limit is almost definitely backfilled here from a piece of commonly-used mail-sorting equipment. Let’s calculate things for the hell of it together.Īttorney Paul Sherman was quick to add a caveat to his first tweet, joking afterward that it was to prevent a “well, actually” moment from astrophysicist and noted Twitter pedant Neil deGrasse Tyson. And it’s also fun to think about, for example, a box full of steel ball bearings, or a box somehow filled to the brim with dense liquid mercury. If true, it’s pretty funny that this small flat-rate shipping box has a weight limit that is physically impossible on Earth we can muse that it says something about the severity of the U.S. If you could cram anything you wanted into a small flat-rate box from the United States Postal Service (USPS), is it possible to exceed the 70-pound domestic weight limit? A Washington, D.C.-based policy attorney said in a viral tweet last week that it was “physically impossible,” so we decided to put his theory to the test.

We could get denser if we looked to space, with “neutronium” in neutron stars.Osmium, the densest naturally occurring element, is used to make tiny, precise, durable parts.A viral tweet claims that you can’t max out the 70-pound weight limit on a small pre-paid mailing box from the United States Postal Service (USPS).

Size small flat rate box