[youtube]http://www.youtube.com/watch?v=UUcQSw7oO0k[/youtube]

 Total geek view of concrete

This video takes you on a journey into the atomic composition of one of the most common man made substances in the world – concrete. Second video after the jump.

[youtube]http://www.youtube.com/watch?v=4q35xHzjxB0[/youtube]

Amazing video of a plane crashing into a concrete wall