In fire investigations, how do glass objects function as indicators of the point of origin?

In fire investigations, glass objects can provide important insights about the fire's point of origin due to their unique physical properties when subjected to heat and fire. The presence of large checkering on glass surfaces indicates that the object was farther away from the source of the fire, leading investigators to determine the heat exposure it experienced.

When glass is heated during a fire, it can show specific patterns depending on how long and how intensely it was exposed. Large checkering patterns typically form from thermal stress and rapid cooling, which occurs when a glass object is situated at a distance from the fire’s epicenter where the heat was not as intense. This pattern can serve as a visual cue that helps to guide investigators toward identifying the direction of heat flow and ultimately pinpointing the area where the fire ignited.

Thus, understanding how glass reacts under fire conditions is crucial for determining the point of origin in fire investigations.