Terminology

This experiment has been done by several people, with differing levels of documentation and scientific rigor. Each study appears to use it's own terminology for describing patterns seen on CD-ROMs following microwave exposure. Following is a lexicon of terms used in this experiment.

Example Term Definition

Lightning Bolt A fractal-like branching pattern with multiple forks, similar to a tree branch or fern leaf. Typically composed of a thick trunk which forks one or more times into successively narrower lines. Referring to this pattern as a "tree pattern" with "branching" would have been equally descriptive, but seemed to be less appropriate for electrical phenomena.

Wandering Line Similar to a lightning bolt pattern, but with little or no forking. Wandering lines are often curved, as opposed to the straighter jagged appearance of a lightning bolt pattern. Often, the distinction between the two was a judgement call. Typically, wandering lines are formed by areas of foil lifting from the plastic substrate. Lightning bolts tend to completely burn off the foil and paint. Wandering lines are more often seen on CD-ROMs with thick paint on the front surface.

Concentric Arc A pattern concentric with the hub of the CD-ROM. In commercial foil CD-ROMs, these seldom burn the foil and paint during formation. However, significant amounts of foil can burn away from concentric arc patterns in CDRs, which have a continuous spiral guide groove molded into the plastic substrate. Foil pressed onto the resulting surface tends tend to heat rapidly along the grooves during irradiation, forming concentrated arcs of vaporized foil.

Mosaic A pattern of concentric arcs, criss-crossed by radial lines. This formation is unique to writable CD-ROM media with continuous spiral grooving.

Burn Mark Areas where sharp corners of foil created hot spots during irradiation. These hot spots result in areas where the plastic substrate melted. Typically, burn marks will be black or brown, irregularly shaped, and will often contain bubbles. Large numbers of burn marks indicate that the CD-ROM was probably irradiated for excessive periods. Microwaving time should be reduced in these instances.

Go back to the Microwaved CD Experiment.

Example	Term	Definition
	Lightning Bolt	A fractal-like branching pattern with multiple forks, similar to a tree branch or fern leaf. Typically composed of a thick trunk which forks one or more times into successively narrower lines. Referring to this pattern as a "tree pattern" with "branching" would have been equally descriptive, but seemed to be less appropriate for electrical phenomena.
	Wandering Line	Similar to a lightning bolt pattern, but with little or no forking. Wandering lines are often curved, as opposed to the straighter jagged appearance of a lightning bolt pattern. Often, the distinction between the two was a judgement call. Typically, wandering lines are formed by areas of foil lifting from the plastic substrate. Lightning bolts tend to completely burn off the foil and paint. Wandering lines are more often seen on CD-ROMs with thick paint on the front surface.
	Concentric Arc	A pattern concentric with the hub of the CD-ROM. In commercial foil CD-ROMs, these seldom burn the foil and paint during formation. However, significant amounts of foil can burn away from concentric arc patterns in CDRs, which have a continuous spiral guide groove molded into the plastic substrate. Foil pressed onto the resulting surface tends tend to heat rapidly along the grooves during irradiation, forming concentrated arcs of vaporized foil.
	Mosaic	A pattern of concentric arcs, criss-crossed by radial lines. This formation is unique to writable CD-ROM media with continuous spiral grooving.
	Burn Mark	Areas where sharp corners of foil created hot spots during irradiation. These hot spots result in areas where the plastic substrate melted. Typically, burn marks will be black or brown, irregularly shaped, and will often contain bubbles. Large numbers of burn marks indicate that the CD-ROM was probably irradiated for excessive periods. Microwaving time should be reduced in these instances.