How to Make a Warning Last 10,000 Years

Alan Wiseman's The World Without Us has a chapter titled "Hot Legacy" that explores our efforts to create warnings that will last at least 10,000 years into the future and will tell future archeologists that the interesting stuff they've found at some of our nuclear waste repositories should not be explored.

Much of the research is being done at the Waste Isolation Pilot Project is New Mexico, USA, and it's that work that SciShow details in today's video.

I remember that the Wiseman chapter also mentioned the placement of various magnets around the site as a warning that something was at least weird in this location. The video doesn't mention that, and I'm surprised because I found that one of the more interesting ideas.

Why on Earth is Depleted Uranium Used for Military Ammunition?

Depleted uranium just sounds terrifying. Sure, you can pick up some uranium ore and yellowcake from United Nuclear, but trying to buy depleted uranium is going to likely be a little dodgier.

With that being said, the US military has used depleted uranium (DU) as a source of armor penetrating ammunition over the years. I thought - wrongly from the video above - that the DU was simply used because of its high density and nature otherwise as nuclear waste. Today's video posits that there are quite a few other advantages of DU in high-caliber munitions applications.

There are also some seemingly obvious health risks involved in living in an area where spent DU shells are peppering the ground or having been in a tank where DU rounds entered and as least slightly vaporized. The video also goes through those health risks and says that they have largely been disproven, though I would be skeptical and appreciate that many military branches are "not considering depleted uranium anymore because of the environmental problems associated with it, be [they] real or perceived."

I think I'll stick to good ol' tungsten for my armor piercing needs.

Top 5 Materials Science Myths

I've heard these 'facts' before.

1. Glass is a super-cooled liquid. - amorphous vs crystalline vs liquids
2. Plastic water bottles release dioxins when frozen. - Ok, I hadn't heard this one. I'd heard about leeching at high temps.
3. Stainless steel is non-magnetic. - Some are, some aren't. Ferrite and martensite are magnetic...austenite are non-magnetic. Most (but not all) stainless steels are austenite.
4. Spider silk is stronger than steel. - interesting discussion of 'strength' and 'toughness' 
5. Radioactive metals glow green. - I knew this one...though some do glow blue

The Bizarre Market for Old Battleship Steel

Oddly, I had heard that old battleship steel - from before the development of atomic/nuclear weapons - was highly valuable for non-radioactive shielding material.

This video does a great job explaining how the Trinity explosion - and subsequent open-air, atmospheric testing of nuclear weapons - polluted any steel made after those tests via the Bessemer process for producing steel from pig iron and using atmospheric air.

I did not know, however, that the battleships scuttled at Scapa Flow had subsequently been salvaged and some of the steel used in this way. (As an aside, your friendly, neighborhood blogger has visited Scapa Flow. It's gorgeous.)

And I also didn't know that the demand for this low-background steel has mostly been superseded because of the switch from Bessemer to basic oxygen steel production.

Making Uranium Glass

I hope this goes without saying this time, but do NOT try this at home.

Today's video shows YouTuber NileRed making uranium glass. He first has to refine the uranium from uranyl nitrate into sodium diuranate (mostly a simple reaction with sodium hydroxide solution), then he has to dry the powder product, and then he has to make glass.

Making the glass is actually the most straight-forward task in that it's just melting silicon dioxide, boric acid, and soda ash together. We do that in our material science course, but we add in something to color the glass: copper (II) oxide, manganese dioxide, or chromium oxide.

NileRed adds in sodium diuranate, a uranium compound that makes a gorgeous yellow glass that fluoresces a brilliant green under UV light.

He then gets to figure out how to anneal his glass because it keeps shattering on him.

And he never tells us - as he mentions at 10:30 and a couple more times - what the heck 'special waste container' he has that makes it okay for him to dispose of uranium waste.

I feel like we might be getting into radioactive boy scout territory here, NileRed.