Hello, homemade vortex canon! Make a tightly closed box with a narrow round hole at the end, hit the sides of the box to compress the air inside, sending the air out with some force. Instant vortex ring!

From the @urnscienceshow team, via ViralViralVideos.

A firefighter and team head into a two-story home to put out a fire, all recorded with a helmet-mounted camera. Harrowing! But a great example of teamwork, using safety gear, caution and courage, training, as well as a conversation starter about fire prevention and safety tips.

via Neatorama. Thanks, @RaySadler.