Crime Scene Forensics - Analyzing Properties of Glass Found at a Crime Scene

What is glass?
Heating a combine of silicon dioxide (a element in sand), calcium carbonate (a component in stone), and sodium carbonate (a component in soda) produces a replacement chemical product referred to as glass. Throughout the heating method, there are further alternative chemicals added to change the qualities of the glass, and these various impurities become incorporated into the final glass product. It's up to the criminalist to determine the chemical composition of those additives and impurities. Knowing these facts can aid in either matching an unknown sample to a known supply or weeding it out.
Scientifically studying the physical, optical, and chemical makeup of glass will purpose to a specific manufacturer to help in an exceedingly criminal investigation. A chunk of glass from a truck windshield or flip signal lamp would possibly indicate the build, model, and typically the year of a vehicle concerned in a very hit-skip incident, employed in a criminal offense, or involved in an exceedingly motorized vehicle accident.
Measuring glass density: So as to live glass density, a cylindrical-formed container filled with liquids of known varied densities is used.
The most common liquids utilised within the cylinder are bromoform and bromobenzene. Every liquids are mixed along, and then the glass sample is added. Then another one or the other of the liquids is added until the glass sample is suspended in the mixture; i.e. the sample is neither floating at the top nor sinking at the underside of the container. Once the glass sample is suspended, it will be concluded that the glass and liquid mixture have the identical density. Since every the liquids have known densities, the crime scene technician can calculate the density of the mixture and of the glass with very little problems. Scientifically speaking, when a known piece of glass is suspended (control), and an unknown piece is dropped into the container (experimental), if the unknown is suspended too, the criminal scientist can conclude that the 2 things of glass have the identical densities. On the other hand, if the unknown piece of glass either sinks or floats, the two items of glass don't share consistent density and thus do not come from the identical source.
Analyzing light-weight transmission, reflection, and refraction: Completely different glass product can transmit, replicate, and refract lightweight in many ways. Lightweight transmission refers to light-weight-weight passing through glass much like daylight through a windshield. Light-weight reflection refers to light-weight bouncing off glass. Light-weight refraction refers to lightweight passing through glass but its pathway is bent. An example of refracted light-weight-weight is once you stick a straight stick into water and note that the stick is "bent." It's the medium, water (like glass), that changes slightly the direction of sunshine supplying you with the appearance that the stick is bent. Fully completely different kinds of glass vary in a very variety of of these optical properties. Experimentally, a criminal offense scene laboratory technician can show that a pair of items of glass are similar, if they have the identical optical properties.
For example, you'll check the refractive index by submerging a chunk of glass in liquid with a refractive index that changes when the temperature of that liquid changes. Silicon oil could be a smart liquid to use. As heat is added and raises the temperature of the oil, the temperature at that the glass piece appearance prefer it goes to disappear indicates that the refractive indices of both the glass and therefore the oil are the same. Since the refractive index of silicon oil is assumed throughout any temperature, measuring the temperature of the liquid at its heated state shows the refractive index of the unknown piece of glass.
Analyzing chemical properties: A forensic laboratory technician will check for any additional chemicals or impurities in glass with an inclination toward matching the chemical composition of the known and unknown samples. Any variations found by the criminal scientist permit him to rule out the known provide because the source of the unknown piece of glass.
Knowing the density, optical properties, and chemical composition of glass found at the scene of a criminal offense will bring crime scene investigators one step nearer to solving a crime.
The next time you watch your favorite CSI or Forensic Files TV show, you will have a better understanding of how glass is studied in a terribly crime lab so on bring a perpetrator to justice.

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Link : Robin Perez has been writing articles online for nearly 2 years now. Not only does this author specialize in Crime, you can also check out his latest website about: Antique Sewing Machines Which reviews and lists the best Antique Toy Sewing Machines

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