Of course, in real scientific research, scientists do not rely on manually drawing points on graph paper to determine a best-fit straight line or to determine the line's slope or y-intercept.
Instead, they use a statistical technique known as linear regression, which computes the least-squares best fit of a straight line through a sequence of points.
Along this line, a kickstarter-funded firm known as Consumer Physics has designed a handheld, consumer-oriented optical spectrometer, which can be used to measure the molecular constituents of an item (food items, etc.) that you shine its built-in light upon.
This cannot be used for radiometric dating, but it does suggest advanced technology such as this is rapidly advancing and soon will be available to consumers.
A related article on the age of the earth and geologic ages presented the current best known values for these dates: Ages.
The figures shown in that article are based on radiometric dating.
Note how breathtakingly close these points are to the fitted lines (thus confirming with high statistical confidence the validity of the resulting dates): The data for the first graph (upper left) is a set of measurements of basaltic achondrites (meteorites) in [Basaltic1981, pg.
Although most items are priced in the thousands of dollars, prices are dropping.
This technique, which is used in virtually all disciplines of modern social science, physical science and engineering, is entirely straightforward, and computer software is widely available to do the requisite calculations and, in fact, is built in to most spreadsheet programs.
An important fact is that linear regression, in addition to giving the best fit of the slope of the line (which then leads immediately to the date), also gives a statistical confidence interval as to the possible error in the determination of the slope.
If all we have is one data point, the formula above doesn't help much more than the original formula.
But if we have multiple data points -- multiple measurements of different samples say within a single igneous rock, then these should all lie on a straight line, whose slope m is simply related to the age of the specimen by the formula m = e; instead, this original ratio actually comes out as a result of the calculation!