Overview of the different types of defects in crystals.
Bulk defects and the Titanic links:
https://www.nist.gov/nist-time-capsule/nist-beneath-waves/nist-reveals-how-tiny-rivets-doomed-titanic-vessel
http://www.almostscientific.com/iron-vs-steel-rivets-why-the-titanic-sank/
