People said this experiment was impossible, so I tried it

As promised last week, here's the first Veritasium video about thermite. 

I'm not thrilled that Dr Derek's titles seem to be getting more clickbaity and less informative. Again this week, the video's title isn't really what the video is about. It's a minor part of the video - here addressed in about six minutes in the middle of the video - and doesn't really cover the bulk of the video's content.

With that being said, seeing thermite in slow motion and through glass is pretty stunning.

Great video...bad title...

In Space, No One Can Stop You From Welding

Cold welding is frickin' weird.

Richard Feynman wrote (or said in a lecture - I'm not sure which), "when the atoms in contact are all of the same kind, there is no way for the atoms to 'know' that they are in different pieces of copper. When there are other atoms, in the oxides and greases and more complicated thin layers of contaminants in between, the atoms 'know' when they are not on the same part."

But two metallic pieces that don't have those thin layers between them - primarily because they've been in space and rubbing against each other - can spontaneously weld together to become a single piece of metal.

It's possible to get that to happen on Earth, but it's not easy because of all the pesky oxygen we have around us all the time.

Metals are way weirder at the quantum level than we think they are, man.