Exploding in stages

Something New Every Day – Lecture 17 – Fire and Explosion Forensics

Every explosion (except for nuclear ones) have a positive and negative phase. As the name suggests, the positive phase happens as pressure, heat and noise moves away from the site of the explosion and sometimes this is known as the ‘shock front’.

But right behind that is the negative phase which is caused when the sudden outward moving of pressure creates a vacuum behind it that sucks gasses and debris back toward the explosion.

‘Trails of Evidence: How Forensic Science Works” is a The Great Courses DVD lecture series