Many people assume that the dates scientists quote of millions of years are as reliable as our knowledge of the structure of the atom or nuclear power.And radioactive dating is so shrouded with mystery that many don’t even try to understand how the method works; they just believe it must be right.Imagery data are represented by positive digital numbers which vary from 0 to (one less than) a selected power of 2. The maximum number of brightness levels available depends on the number of bits used in representing the energy recorded.This range corresponds to the number of bits used for coding numbers in binary format. Thus, if a sensor used 8 bits to record the data, there would be 28=256 digital values available, ranging from 0 to 255.The radiometric resolution of an imaging system describes its ability to discriminate very slight differences in energy The finer the radiometric resolution of a sensor, the more sensitive it is to detecting small differences in reflected or emitted energy. The illustration on the right is the same but presented in 8 bits or 256 shades of grey, which provides more details.
I thought it would be useful to present an example where the geology is simple, and unsurprisingly, the method does work well, to show the quality of data that would have to be invalidated before a major revision of the geologic time scale could be accepted by conventional scientists.
Image data are generally displayed in a range of grey tones, with black representing a digital number of 0 and white representing the maximum value (for example, 255 in 8-bit data).