Forensics Exam II: Ch.10 - Matter, Light, and Glass Examination

Composition of Matter

atoms

Density

an intensive glass quality, aids in identification

Refractive Index

rays bend going from one medium to another due to change in velocity, also intensive property for glass

Light as a Wave

radiation energy that can be identified through the electromagnetic spectrum

Light as a Particle

excited atoms

Flotation Method (Glass Densities)

Glass is immersed in liquid (Bromobenzene). The density of the liquid is then adjusted by adding bromoform until glass remains suspended/floats in the liquid

Glass Immersion Method (Uses Refractive Index)

Immerse glass until the refractive index of the liquid matches the refractive index of the glass. The Beckel line will be created and appear as a halo of light. It will disappear when the match point is reached.

Direction of Impact from Broken Glass

Cracks in glass are radial and concentric

• Radial cracks go outwards and appear on the opposite side of the impact

• Concentric cracks circle the initial impact spot and appear on the same side of impact

Collecting Glass

collect all relevant pieces, especially if there is a possibility that you can reconstruct the broken object