A few months ago, Allen Pan wowed the internet with a Mjölnir that only he (and, presumably, Thor) could pick up. It was a clever illusion that worked thanks to a powerful electromagnet and a fingerprint scanner keyed to Pan's thumb.
Now Pan is back with a new stunt. He built a sword out of ice. It's strong enough to chop through a watermelon, as well as decapitate helpless snowmen.
Pan made of his sword out of Pykrete, which is a composite material of water ice and sawdust. It's a tremendously tough material--so much so that during World War II, the Allies considering building warships out of it.
Pan used toilet paper instead of sawdust for the wood component. His mix was 86% water and 14% toilet paper.
He shaped the Pykrete into a sword mold. It's a blunt object without an edge, but it's still strong enough to do a lot of damage. Just imagine that watermelon is a human head and you can see what Pykrete can do.
-via Home Geekonomics