> Somebody probably just ordered some highly radioactive isotopes from Advanced Space Civilization Amazon, and told them to leave it at the doorstep.

You mean United Nuclear, which brokers[1] radio isotopes to the general public? https://unitednuclear.com/index.php?main_page=index&cPath=2_... I don't see any Plutonium for sale, but that's not as interesting or useful as Cesium-137 or Polonium-210. They also sell Uranium ore, and do so directly, not brokered, so they have to be careful to vent Radon from their storage room.

[1] IIRC, the Polonium-210 I received was sent directly from Oak Ridge National Laboratory.

EDIT: The sample was actually sent by Spectrum Techniques (https://www.spectrumtechniques.com/). They must be ORNL adjacent or something.

United Nuclear hasn't changed in decades. I remember buying thermite and other fun mixtures from them for my high school chemistry class experiments 15 or so years ago. Nowadays, you can probably find some of their products much cheaper elsewhere, but they've been selling these cool things for hobbyists for so many years, I like to support them.

And by them, I mean Bob Lazar,.. United Nuclear is his operation. (UFO guy who is likely viewed in a polarized fashion here, I myself am not into the conspiracies)

Wow, that is way more affordable and easier than anything I found twenty years ago when I was looking! (Then again, back then things like this may very well have existed, but discovering them was a huge part of the problem.)

That is massively cool! I wonder if you can get depleted uranium. Would love to grab a cube of it for discussions on density.

Turns out you can! But it's $750 for a one-centimeter cube, because the US government limits commercial sales of DU to 15kg per year.

I thought they used DU as counterweight in some civilian airliners? But maybe the manufacturers have some special license to procure more DU..?

Depleted uranium has indeed been used in airplanes. Some models of 747 have a ton or so of depleted uranium, though I believe this practice was phased out in later models.

It's not just planes though. Some sailboats have been made with DU keels. Usually lead is used, but DU would presumably allow for a smaller (thinner?) keel.

You can dig it up in Iraq.

https://www.theguardian.com/world/2014/jun/19/us-depleted-ur...

Or a a nearby supernova happened to deposit plutonium and other heavy elements in a fine mist over the planet within the last 10 million years...

I'm somewhat curious if modern human civilization happened to emerge in the last ~10ky simply because all other time periods since modern humans evolved were too unstable to support civilization.

Well it was raining plutonium until now